Contributions abut host-guest complex formation between CDs and CDs derivatives and essential oils.
The essential oils normally had low physicochemical stability and low solubility in water. These facts limit their industrial applications in general and in food formulations particularly. This chapter characterizes the physicochemical properties and the antioxidant and antimicrobial activities of three encapsulated essential oils – guava leaf, yarrow and black pepper essential oils – in hydroxypropyl-β-cyclodextrin (HPβCD).
- essential oils
- food technology applications
- pharmacological applications
- antioxidant activity
- antimicrobial activity
1. CDs in food science and food technology
There is much interest in manipulating the complex-forming ability of cyclodextrins (CDs) with a view to developing applications [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]. In the last years, several reviews describing the use of CDs in food and flavor applications have been published [5, 6, 11, 12, 13, 14, 15, 16]). CDs have been recommended for applications in food processing and as food additives with a variety of aims: (i) to protect lipophilic food components that are sensitive to oxygen and light- or heat-induced degradation; (ii) to solubilize food colorings and vitamins; (iii) to stabilize fragrances, flavors, vitamins, and essential oils against unwanted changes; (iv) to suppress unpleasant odors or tastes and (v) to achieve a controlled release of certain food constituents.
Indeed, CDs form inclusion complexes with a variety of molecules including fats, flavors and colors. For instance, they are used for the removal and masking of undesirable components and controlled release of desired food constituents . Moreover, CDs are used in food formulations for flavor protection or flavor delivery . Most natural and artificial flavors are volatile oils or liquids, and complexation with CDs provides a promising alternative to the conventional encapsulation technologies for flavor protection. CDs act as molecular encapsulants, protecting the flavor throughout many rigorous food-processing methods such as freezing, thawing and microwaving. β-CD as a molecular encapsulant allows the flavor quality and quantity to be preserved to a greater extent and longer period compared to other encapsulants and provides longevity to the food item . In Japan, CDs have been approved as “modified starch” for food applications for more than two decades, serving to mask odors in fresh food and to stabilize fish oils. One or two European countries—for example, Hungary—have approved γ-CD for use in certain applications because of its low toxicity. It was proved that CDs may alter the sensory profile of a food and the flavor release depends of the CD type , the temperature  and may depend the solvent nature that is, water, water/alcohol mixtures, etc. . Their beneficial effects essentially derive from the ability to form stable inclusion complexes with sensitive lipophilic nutrients and constituents of flavor and taste, making easy to prepare powdered flavor materials [23, 24, 25] and even to release such flavors during cooking . Toxicological data are examined and an assessment of CDs from the standpoint of safety for human consumption is made . Regulations are covered, showing a general trend toward a wider acceptance of CDs as food additives. The growing health consciousness of consumers and expanding market for functional foods and nutraceutical products are opening up to CDs a promising future in food industry .
The complexation of CDs with sweetening agents such as aspartame stabilizes and improves the taste. It also eliminates the bitter aftertaste of other sweeteners such as stevioside, glycyrrhizin and rubusoside. CD itself is a promising new sweetener. Enhancement of flavor by CDs has been also claimed for alcoholic beverages such as whisky and beer . The bitterness of citrus fruit juices is a major problem in the industry caused by the presence of limonoids (mainly limonin) and flavonoids (mainly naringin). Cross-linked CD polymers are useful to remove these bitter components by inclusion complexation . CDs are also used to control bitterness in tannins, plant and fungal extracts; skim milk hydrolyses and overcooked tea and coffee . They can also be used to keep the profile of oil volatiles in paste samples that were vacuum- or spray-dried [31, 32], due to their high encapsulation efficiency. The most prevalent use of CD in process aids is the removal of cholesterol from animal products such as eggs or dairy products, like cheese . CD-treated material shows 80% removal of cholesterol. Free fatty acids can also be removed from fats using CDs, thus improving the frying property of fat (e.g., reduced smoke formation, less foaming, less browning and deposition of oil residues on surfaces) . Fruits and vegetable juices are also treated with CD to remove phenolic compounds, which cause enzymatic browning. In juices, polyphenol oxidase converts the colorless polyphenols to colored compounds and addition of CDs removes polyphenoloxidase from juices by complexation. Sojo et al.  studied the effect of CDs on the oxidation of
Other studies describes the development of a gas chromatography-mass spectrometry (GC-MS) library to identify optically active compounds in the flavor and fragrance field using enantioselective GC with CD derivatives (CDs) as chiral selectors in combination with MS [36, 37], but also olfactometry can be used for detection to have extra information about flavors . The ability to separate and quantitate enantiomers at low levels should be useful for detecting adulterated products, for evaluating fermentation processes and for the accurate characterization of enantiomeric flavor components, growth regulators, pesticides, and herbicides as well as their chiral environmental degradation products and metabolites .
Flavonoids and terpenoids are good for human health because of their antioxidative and antimicrobial properties but they cannot be utilized as foodstuff owing to their very low aqueous solubility and bitter taste. Sumiyoshi  discussed the improvement of the properties of these plant components (flavonoids and terpenoids) with CD complexation. CDs are used in preparation of foodstuffs in different ways. For example, highly branched CDs are used in flour-based items like noodles, pie dough, pizza sheets and rice cakes to impart elasticity and flexibility to dough . They are also used in the preparation of antimicrobial food preservatives containing trans-2-hexanalin in apple juice preparation  and in the processing of medicinal mushrooms for the preparation of crude drugs and health foods. CDs are used in the preparation of controlled release powdered flavors and confectionery items and are also used in chewing gum to retain its flavor for longer duration, a property highly valued by customers . CDs are also used in the detection of aflatoxin in food samples .
A large variety of commercial encapsulation practices are currently followed, however, those involving the formation of flavor/CD molecular-inclusion complexes offer great potential for protection of volatile and labile flavoring materials present in a multicomponent food system throughout many rigorous food-processing methods (cooking, pasteurization, etc.) [14, 45, 46, 47]. In the same way, CDs can eliminate some taste. In fact, a bitter taste is the main reason for the rejection of various food products although exceptions to this rule are rooted in many cultures: in some foods and beverages, such as coffee, beer, and wine, a certain degree of bitterness is expected [2, 48, 49, 50, 51]. Bitterness, however, has proved a major limitation in the acceptance of commercial citrus juices. A commercial process is needed that removes bitter components without adding anything to the juice, while still maintaining the expected flavor and nutritional value of the product. CDs can be used for the removal or masking of undesirable components. Some foods have a peculiar smell, but, when CDs are added in their manufacture, these components form CD-inclusion complexes deodorizing the result product. For instance, this process is used for deodorizing soybean milk and soy protein, and also for removing the peculiar fish odors, seafood and meat products [52, 53, 54]. On the other hand, the formation of inclusion complexes with CDs can protect some lipophilic food components that are sensitive to oxygen and heat- or light-induced degradation . In addition, CDs protected phenolic compounds from enzymatic oxidation by forming inclusion complexes [56, 57, 58, 59].
2. Essential oils
As example, in the present chapter we have selected some essential oils to characterize their inclusion complex in (hydroxypropyl-β-CD) (Figure 2). They were black pepper essential oil, guava essential oil and yarrow essential oil.
Black pepper (
3. CDs and essential oils
The use of CDs for the essential oils encapsulation can protect the active compounds of essential oils from environmental conditions [13, 14] and improve the aqueous solubility of essential oils for increasing their capacity to functionalize the products in which it is used as additive . As quote above, CDs are cyclic oligosaccharides consisting of glucopyranosyl units linked by α-(1,4) bonds . The widely used natural CDs are α-, β- and γ-CD consisting of 6, 7 and 8 glucopyranose units, respectively [90, 91]. These molecules have a unique structure with a hydrophobic cavity and a hydrophilic surface, which can form inclusion complex with a wide variety of guests. They can be used to enhance the solubility of insoluble compounds, stabilize labile guests against oxidation, control volatility and sublimation, modify taste by masking off flavors, entrap odors and control the releasing of drugs and flavors . Among those CDs, β-CD is the most widely applicable kind because of its suitable cavity size for common guests with molecular weights between 200 and 800 g/mol and its availability and reasonable price . Although β-CD can be used with many guests, its solubility in water is low (1.8 g in 100 mL water at 25°C). In some cases, there is a need to enhance water solubility of β-CD by adding the hydroxyl-alkyl groups on the β-CD surface. A hydroxyl-alkylated or hydroxypropyl-β-CD derivative (HPβCD) is relatively high aqueous solubility (above 60 g in 100 mL water at 25°C) with low toxicity and satisfactory inclusion ability .
On the other hand, encapsulation of essential oils or their chemical components with CDs or CD derivatives for improvement of biological properties have been observed [5, 95, 96, 97, 98] or their antimicrobial activity .
Indeed, a large amount of contributions about technologic applications of CD-inclusion complex of essential oils and their main components has been published in the last 10 years, some of them are included in Table 1.
3.1. Encapsulation efficiency
As quoted above, we present the encapsulation efficiency of three essential oils (guava oil, yarrow oil and black pepper oil) in hydroxypropyl-β-CD (HPβCD).
In the case of yarrow oil and carvacrol (yarrow oil major component), there efficiency were 45.05 and 86.59%, respectively  see Table 2. Black pepper  exhibit similar behavior with efficiency of 50.55 and 85.30, respectively, for essential oil and its main component (β-caryophyllene). Finally, guava leaf oil encapsulation efficiency was 52.5%, while it reached 91.8% for limonene, the major pure compound of guava leaf oil .
|Essential oil||Guest||References||Essential oil component||Guest||References|
|Black pepper essential oil||Hydroxypropyl-β-CD||||Allyl isothiocyanate|
|Cinnamon essential oil||β-CD||[99, 102, 103]||β-CD||[101, 104]|
|Clove bod oil||β-CD||[99, 107]||Carvacrol|
|Coriander essential oil||β-CD||||Hydroxypropyl-β-CD|||
|Garlic oil||β-CD||[102, 111]||Cinnamaldehyde||β-CD||[99, 103]|
|Guava leaf oil||Hydroxypropyl-β-CD||||Citronellal||β-CD|||
|Olive leaf oil||β-CD||||Eugenol||β-CD||[99, 115, 116, 117, 118]|
|Oregano essential oil||β-CD||[107, 119]||Limonene||β-CD|||
|Thyme essential oil||β-CD||[121, 122]||2-Nonanone||β-CD|||
|Sweet basil essential oils||β-CD||||Thymol||β-CD||[103, 109, 121]|
|Yarrow essential oil||Hydroxypropyl-β-CD||||Vanillin||β-CD||[126, 127]|
|Compound||Encapsulation efficiency (%)||Compound||Encapsulation efficiency (%)|
|Black pepper oil||50.55||β-caryophyllene||85.30|
|Guava leaf oil||52.50||Limonene||91.80|
This difference in encapsulation efficiency of the pure compound and the essential oil results from the presence of other minority components. In the case of yarrow oil and carvacrol , the other components like 1,8 cineole, thymol, camphor and linalool have also high affinities for CD [6, 121, 128, 129, 130, 131, 132] that compete for inclusion complex formations. Kamimura et al.  reported that the encapsulation efficiency values of pure carvacrol in HPβCD prepared by kneading and freeze-drying methods were around 78 and 84%, respectively.
Similar explanation would justify the diferences in encapsulation efficiency of the pure compound and the black pepper oil  because the presence of other components in the black pepper oil such as limonene, δ-3-carene and pinene  that also have high affinities for HPβCD. In the case of guava leaf oil , the large values found are due to minority components, such as β-caryophyllene, 1,8-cineole and α-pinene, exhibit low affinity for the β-CD that are not easily encapsulated and the competition between the other host for the guest in not so important.
Similar observation has been reported for other authors in the literature  showing that encapsulation efficiencies of cinnamon oil and clove oil were 41.72 and 77.74%, respectively. The encapsulation efficiencies of major components including trans-cinnamaldehyde in cinnamol oil and eugenol in clove oil were also examined and showed higher encapsulation efficiency of 84.70 and 90.15%, respectively. In addition, comparable values of encapsulation efficiency were found in other carriers such as alginate-chitosan system. In this case, the yarrow oil components exhibited 82.4% efficiency of polyphenol encapsulation [133, 134].
3.2. Characterization of host-guest complex
3.2.1. Morphological examinations
It is well known that the inclusion complex formation would change the morphology of CDs . Figure 6 presents the morphology of the encapsulated oils studied by SEM.
The particle shape and morphology of the encapsulated oil were similar to those of free HPβCD in the cases evaluated – guava, yarrow and black pepper – see Figure 7. It indicates the hydrogen bonding of the free HPβCD molecules interact with each other in solution producing the cluster of HPβCD [136, 137]. This case not occurs in inclusion complex because inclusion complex formation also induces the conformation change of CD and obstructs the agglomeration among them. Similar observations have been previously reported that the distribution of inclusion complex of carvacrol and β-CD, and the gathering of free β-CD were also found .
By contrast, the free HPβCD particle sizes are much larger than those of the encapsulated products. These results are in agreement with Guimaraes et al. , who analyze carvacrol encapsulation with β-CD. Considering that HPβCD form clusters in solution through intermolecular hydrogen bonds [136, 137], it seems that the incorporation of different essential oils interferes in these interactions and reduces particle size.
3.2.2. Fourier-transform infrared spectroscopy (FT-IR)
FT-IR technique can be used to investigate the variation of shape, intensity and position of peaks .
FT-IR spectrum of black pepper oil consisted of the prominent absorption bands at 2954, 2923 and 2865 cm−1 for C─H stretching vibration of methylene group, 1638 cm−1 for H─O─H bending, 1447 cm−1 for C─H scissoring vibration, 1369 cm−1 for symmetrical deformation vibration of CH3, 886 cm−1 for C─H deformation vibration and 789 cm−1 for S─C absorption. However, FT-IR spectrum of the encapsulated black pepper oil showed that no character similar to the free black pepper oil. All bands of black pepper oil spectrum were totally obscured by HPβCD bands it was possible that black pepper oil entered the cavity of HPβCD and inclusion complex was formed.
In the case of yarrow oil, its FT-IR spectrum of yarrow oil shows prominent absorption bands at 2956 cm−1 for ═CH2 symmetrical stretching vibration, 2926 cm−1 for C─H stretching vibration of methylene group, 2869 cm−1 for ─CH stretching, 1652 cm−1 for H─O─H bending, 1626 cm−1 for C═C stretching vibration of the allyl group, 1446 cm−1 for C─H scissoring vibration, 1380 cm−1 for symmetrical deformation vibration of ─CH3, 1366 cm−1 for symmetrical deformation vibration of ─CH3, 1240 cm−1 and 1103 cm−1 for P─O and P═O, 1022 cm−1 for C─O─C stretching vibration, 916 cm−1 for C─S─C stretching vibration, 875 cm−1 and 865 cm−1 for C─H bending of aromatic ring. The spectrum of HPβCD shows prominent absorption bands at 3406 cm−1 for O─H stretching vibration, 2970 cm−1 for ═CH2 symmetrical stretching vibration, 2930 cm−1 for C─H stretching vibration, 1646 cm−1 for H─O─H bending vibration, 1157 cm−1 for C─O─C asymmetrical stretching vibration, 1083 cm−1 and 1033 cm−1 for symmetric C─O─C stretching vibration . FT-IR spectrum of inclusion complex was identical to HPβCD and no feature similar to yarrow oil. The results indicated that HPβCD covered all the absorption bands of yarrow oil in the spectrum of inclusion complex indicating the entering to the cavity of HPβCD and the formation of inclusion complex.
Finally, FT-IR spectrum of guava leaf oil showed prominent absorption bands at 2921 cm−1 for C─H stretching vibration of methylene group, 1642 cm−1 for H─O─H bending, 1447 cm−1 for C─H scissoring vibration, 1376 cm−1 for symmetrical deformation vibration of CH3, 886 cm−1 for C─H deformation vibration and 789 cm−1 for S─C absorption. FT-IR spectrum of encapsulated guava leaf oil shows no feature similar to the free guava oil. The bands of guava leaf oil spectrum were almost completely concealed by very intense and broad bands of HPβCD. However, the absorption band at 608 cm−1 of HPβCD disappeared in encapsulated guava leaf oil. This change may be related to the interaction between guava leaf oil and HPβCD in the inclusion complex.
The inclusion complex formation of β-CD was also investigated by Liu et al.  using FT-IR analysis. The absorption bands of β-caryophyllene were not detected in the spectrum of inclusion complex. The changes were related to the inclusion complex formation of β-CD and the guests which whole of guest could be contained in the CD cavity. Wang et al.  have reported similar results. In their study, the inclusion complex formation of soybean lecithin and β-CD was determined by FT-IR. All the absorption bands of soybean lecithin encapsulated in β-CD were obscured by β-CD spectrum showing that inclusion complex of β-CD and soybean lecithin was formed. However, Gomes et al.  reported that the absorption band at 1738 cm−1 of the red bell pepper pigments was observed after encapsulation in β-CD indicating that some region of the encapsulated molecules was not contained in the cavity of β-CD.
3.2.3. Ultraviolet-visible spectrophotometry (UV-Vis)
Essential oils contain various bioactive chemicals, which adsorb ultraviolet (UV) or visible light (Vis) at different wavelengths. CD host-guest complex formation would alter UV-Vis absorption spectra . Otherwise, the spectra of the guests appear in line of CD . Therefore, UV-Vis spectrophotometry, evaluated the inclusion complex formation of HPβCD and the three essential oils. The UV absorption spectra of guava leaf oil, limonene and their inclusion complexes were compared. Indeed, maximum absorption value of guava leaf oil was at 214.5 nm, which was mainly attributed to limonene. The absorption peak at 205 nm corresponds to β-caryophyllene and/or pinene. The peak at 275 nm of guava leaf oil was ascribed to 1,8-cineole.
The spectra of the physical mixture of HPβCD with guava leaf oil and with limonene before complexation were consistent with that of guava leaf oil or pure compound. The absorption spectra of the physical mixture of HPβCD with guava leaf oil and with limonene were in accordance to with the spectra of guava leaf oil and pure limonene, respectively. When the active compounds in essential oil or the pure compound were encapsulated into the cavity of HPβCD, the absorption peaks of each compound disappeared in the spectra of the inclusion complexes. To recover active compounds encapsulated in the HPβCD cavity, the active compounds were extracted from HPβCD by dissolving the inclusion complexes in 95% acetonitrile. The encapsulated compounds were released from the cavity of HPβCD and HPβCD was separated from guava leaf essential oil or limonene in solution by centrifugation. The solution was diluted 100 times with acetonitrile and the absorbance was measured by UV spectrophotometer.
After extraction from the inclusion complexes, the absorption peaks of encapsulated compounds in guava leaf oil could be observed. In this line, besides limonene, the absorption peaks at 205 and 275 nm suggested the presence of β-caryophyllene and 1,8-cineole, respectively. The results indicated that the active compounds in guava leaf oil had formed inclusion complex with HPβCD. Therefore, the chemical components of guava leaf oil were successfully encapsulated in the HPβCD.
UV spectrum of yarrow oil shows peaks at 270–275 nm indicated the presence of carvacrol, 1,8-cineole, thymol and camphor. A minor peak at 243 nm attributed to linalool. The spectra of the physical mixture of HPβCD with yarrow oil and with pure compound (carvacrol) conformed to UV spectra of yarrow oil and pure carvacrol, respectively. When the active compounds in yarrow oil or carvacrol were entrapped with HPβCD, the absorption peaks of each compound also disappeared in the spectrum of the inclusion complexes.
After extraction from the inclusion complex, the absorption peaks of entrapped compounds in yarrow oil appeared at 270–275 nm implying carvacrol and also are 1,8-cineole, thymol, camphor and linalool. In this study, the chemical components of yarrow oil were successfully entrapped in the HPβCD, as in the previous case. However, the encapsulation efficiency of yarrow oil was much lower than those of its pure compound. This was likely because the competition of major active compound among other components in essential oil has occurred during inclusion complex formation.
Finally, the absorption spectrum of black pepper oil was recorded with absorption peaks at 200, 205 and 214.5 nm for δ-3-carene, β-caryophyllene and limonene, respectively . The maximum absorption peak at 205 nm was ascribed to β-caryophyllene. The spectra of the physical mixture of HPβCD with black pepper oil and with β-caryophyllene accorded with UV spectra of black pepper oil and pure β-caryophyllene, respectively. When the active compounds in black pepper oil or the pure compound (β-caryophyllene) were entrapped into the cavity of HPβCD, the absorption peaks of the compounds also disappeared in the spectrum of the inclusion complex.
After extraction from the complex, the observable peaks of entrapped compounds in black pepper oil could be seen. The spectrum of encapsulated compounds from black pepper oil show absorption peaks at 205 and 214.5 nm indicating β-caryophyllene and limonene, respectively. The UV spectrum indicated that the chemical components of black pepper oil were successfully entrapped in the HPβCD. As in the previous cases, the encapsulation efficiency of active compounds of black pepper oil was much lower than those of its pure compound. This was likely because the competition of major active compound among other components in black pepper oil has occurred during inclusion complex formation.
3.2.4. Phase solubility
Phase solubility study is generally performed to evaluate the stability and to classify the inclusion complex when they are in the solution. The phase solubility profiles can be obtained from the interaction between the guests (encapsulated compounds) and the hosts (CDs or derivatives) in the solution. In solution, a fundamental parameter such as stability constant (Ks) of inclusion complex formation can be used to evaluate the stability of the inclusion complex  – see Table 3.
|Inclusion complex||T/°C||Ks/M−1||Inclusion complex||T/°C||Ks/M−1|
|Black pepper oil-HPβCD||25||104.5||β-caryophyllene-HPβCD||25||132.8|
|Black pepper oil-HPβCD||35||100.0||β-caryophyllene-HPβCD||35||114.0|
|Guava leaf oil-HPβCD||25||25.0||Limonene-HPβCD||25||628.0|
|Guava leaf oil-HPβCD||35||33.8||Limonene-HPβCD||35||605.9|
In the case of black pepper, A linear relationship between the amount of dissolved essential oil or β-caryophyllene and the concentrations of HPβCD in this study with slope ˂1 was classified as a typical AL-type (type A reveals an inclusion complex formation where the amount of encapsulated compounds increase as the HPβCD concentration increases, subscript L indicates a 1:1 molecular ratio formation of soluble complexes) . As the majority of encapsulated compounds are mono- and sesquiterpenoids and phenylpropane derivatives of an average molecular weight of 120–160 g/mol, a 1:1 complex formation is observed . The molar ratio of host to guest molecules is usually 1:1 for inclusion complexes formed in solution, except for complexes with long-chain or bifunctional guest molecules (e.g. guest molecules having two aromatic rings on opposite sides of a small central molecule segment). In aqueous system, black pepper oil and β-caryophyllene show difference in stability of complex form with the Ks of 104.5 and 132.8 L/mol at 25°C, respectively. This might be because of the other components in black pepper oil might compete to HPβCD form complex with β-caryophyllene. The decreases in Ks values with increasing temperatures were expected for exothermic processes .
Equivalent results were observed for yarrow oil host-guest complex, as we can observe in Table 3. In agreement with the results reported in Table 3 – for black pepper essential oil and yarrow essential oil – similar Hill et al.  and Kamimura et al.  have reported observations. The water solubility of trans-cinnamaldehyde, eugenol, cinnamon bark extracts and clove bud extract samples increased with increasing temperatures while the Ks value of the samples decreased with increasing temperature . Kamimura et al.  reported that water solubility of the pure carvacrol increased and the Ks value decreased with increasing temperatures.
Regarding to guava leaf essential oil – see Table 3, low Ks value were obtained for guava leaf oil than for limonene. They were in the order of those for β-CD complexes according to Connors . This might be due to the competence of the other components in guava leaf oil with limonene to form HPβCD complexes. In addition, the decrease in Ks values with increasing temperature reflects that complex formation is an exothermic process . However, these results reflect that the aqueous solubility of guava leaf oil can be increased with increasing HPβCD concentration. Considering that very labile complexes (Ks < 100 L/mol) result in premature release of the guests because of the weak interaction between hosts and guests , the very labile encapsulated guava leaf oil could be useful for fast release systems such as pharmaceutical applications.
3.3. Evaluation of antioxidant activity of host-guest complex
Antioxidant activity was evaluated in terms of DPPH scavenging capacity (%) of free and encapsulated guava leaf oil compared to a synthetic chemical antioxidant (BHT) at concentrations ranged from 5 to 50 μg/mL.
It was established that the components responsible for the antioxidant activity of guava leaf oil are limonene, α-pinene and β-caryophyllene . While limonene has a moderate antioxidant activity , β-caryophyllene and α-pinene show weak and moderate DPPH scavenging activity, respectively [146, 147]. Unfortunately, the encapsulated guava leaf oil gave slightly lower DPPH scavenging activity than that of the free guava leaf oil. This could be because HPβCD blocks the functional groups of the active compounds that react with DPPH radicals .
In the case of yarrow oil carvacrol as a major component shows strong antioxidant activity (72% DPPH scavenging at 50 μg/mL). The most effective antioxidants usually contain aromatic or phenolic rings, which interrupt the free radical chain reaction by donating H• to the free radicals . The encapsulated yarrow oil gave slightly lower antioxidant activity than the activity of the free yarrow oil. It was a result of the HPβCD was blocking the functional groups of active compounds during reacting with DPPH radicals . However, the encapsulation has been reported to increase the stability of the essential oils [13, 14].
Black pepper oil shows antioxidant activity with 54% DPPH scavenging (50 μg/mL black pepper oil) (Figure 5). It was established that the components responsible for the antioxidant activity are β-caryophyllene, limonene and α-pinene . β-caryophyllene, a major component of black pepper oil, was found to give a weak DPPH scavenging activity . Limonene, a minor composition, has been reported to give a moderate antioxidant activity and another component, α-pinene, also possesses a moderate antioxidant property . It should be noted that free HPβCD did not show antioxidant activity.
However, the inclusion complexes have been reported to increase the stability of the essential oils [13, 14]. After exposure to sunlight, the DPPH scavenging of free guava leaf oil drastically decreased around 43–54% at all tested concentrations (5–50 μg/mL), which was likely due to limonene and pinene sensitive to sunlight . Then, the inclusion complexation of guava leaf oil with HPβCD could protect the active components against the effect of light. In effect, after sunlight exposure, the DPPH radical scavenging capacity of the encapsulated guava leaf oil was more stable than the free guava leaf oil by 26–38%.
Similar results were found for yarrow essential oil, where DPPH radical scavenging (with concentration range from 5 to 35 μg/mL of essential oil) decreased around 41–51% after exposure to sunlight for 12 h. The yarrow oil with higher concentration range (40–50 μg/mL) exhibited lower loss of DPPH radical scavenging (36–37%). Obviously, as in the previous case, the encapsulation of yarrow oil in HPβCD could protect the active components against the effect of sunlight. The complexation with HPβCD improved the stability of yarrow oil by 27–30% in a similar range that guava leaf oil (26–38% -
The DPPH radical scavenging capacity of black pepper oil drastically decreased after 12 h exposure to sunlight (Figure 4). At the sample concentration range of 5–25 μg/mL, the DPPH scavenging capacity decreased around 42–48%, while the decreasing of 30–39% was found at higher concentration range (30–50 μg/mL). The stability of encapsulated black pepper oil was improved from the free black pepper oil by 18–24%. This effect is lower that observed for guava and yarrow essential oils (26–38 and 27–30%, respectively).
3.4. Evaluation of antibacterial activity of host-guest complex
Table 4 shows minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of essential oil for
Guava leaf oil displayed antibacterial activity against both bacteria with MIC value of 500 μg/mL, that could be attributed to guava leaf oil monoterpenes (such as limonene) which have been found to play efficient role in antimicrobial activity via membrane structures increasing membrane fluidity and permeability . Pure limonene was reported to give antimicrobial activity against
The antibacterial activity of guava leaf oil was improved after encapsulation in HPβCD by 4 and 2 times against
Yarrow oil exhibited antibacterial activity against
The antibacterial efficacy of yarrow oil was much improved after encapsulated in HPβCD by 4 and 8 times against
Microencapsulation of essential oils in HPβCD was achieved proving that the host-guest complex formation implies different physicochemical characteristics from free essential oil. As advantage, the DPPH radical scavenging capacity of the encapsulated oil was more stable than for the free oil indicating that the inclusion complex with HPβCD could protect the active components of oil against the effect of sunlight. As well, encapsulation also increased the antibacterial activity of essential oils against both
The Graduate School of Prince of Songkla University and Thai Government under Grant No.AGR560387S financially supported this work.
Szejtli J, Osa T. Comprehensive Supramolecular Chemistry. Vol. 3. Cyclodextrins. New York: Pergamont; 1996
Singh M, Sharma R, Banerjee UC. Biotechnological applications of cyclodextrins. Biotechnology Advances. 2002; 20:341-359
Arias-Estevez M, García-Río L, Mejuto JC, Rodríguez-Dafonte P, Simal-Gandara J. Influence of micelles on the basic degradation of carbofuran. Journal of Agricultural and Food Chemistry. 2005; 53(18):7172-7178
Arias-Estevez M, García-Falcón MS, García-Río L, Mejuto JC, Rial-Otero R, Simal-Gandara J. Binding constants of oxytetracycline to animal feed divalent cations. Journal of Food Engineering. 2007; 78(1):69-73
Astray G, Gonzalez-Barreiro C, Mejuto JC, Rial-Otero R, Simal-Gandara J. A review on the use of cyclodextrins in foods. Food Hydrocolloids. 2009; 3:1931-1640. DOI: 10.1016/j.foodhyd.2009.01.001
Astray G, Mejuto JC, Morales J, Rial-Otero R, Simal-Gandara J. Factors controlling flavors binding constants to cyclodextrins and their applications in foods. Food Research International. 2010; 43(4):1212-1218
Gonzalez-Barreiro C, Rial-Otero R, Simal-Gandara J, Astray G, Cid A, Mejuto JC, Manso JA, Morales J. Chapter 8: In starch-based polymeric materials and nanocomposites. Chemistry, processing, and applications. In: Starch-Derived Cyclodextrins and Their Future in the Food Biopolymer Industry. Boca Ratón: CRC Press; 2012. pp. 167-182. ISBN: 978-1-4398-5117-3
Cid A, Mejuto JC, Orellana PG, López-Fernández O, Rial-Otero R, Simal-Gandara J. Effects of ascorbic acid on the microstructure and properties of SDS micellar aggregates for potential food applications. Food Research International. 2013; 50(1):143-148
Cid A, Morales J, Mejuto JC, Briz-Cid N, Rial-Otero R, Simal-Gandara J. Thermodynamics of sodium dodecyl sulphate-salicylic acid based micellar systems and their potential use in fruits postharvest. Food Chemistry. 2014; 151:358-363
Cid A, Morales J, Dieguez-Perez M, Rial-Otero R, Mejuto JC, Simal-Gandara J. Chapter X: In cyclodextrines: propriétés, chimie et applications: Application des cyclodextrines comme catalyseurs dans les médias micro-hétérogènes. Besançon: Presses Universitaires de Franche-Comté; 2014. ISBN: 978-2-84867-520-6
Cravotto G, Binello A, Baranelli E, Carraro P, Trotta F. Cyclodextrins as food additives and in food processing. Current Nutrition Food Science. 2006; 2(4):343-350
Hedges AR, McBride CU. Of b-cyclodextrin in food. Cereal Foods World. 1999; 44(10):700-704
Hedges AR, Shieh WJ, Sikorski CT. Use of cyclodextrins for encapsulation in the use and treatment of food products. In: Risch SJ, Reineccius GA, editors. Encapsulation and Controlled Release of Food Ingredients. Vol. 590. ACS Symposium Series. Washington DC: ACS; 1995. pp. 60-71
Qi ZH, Hedges AR. Use of cyclodextrins for flavours. In: Ho CT, Tan CT, Tong CH, editors. Flavour Technology: Physical Chemistry, Modification and Process. Vol. 610. ACS Symposium Series. Washington DC: ACS; 1995. pp. 231-243
Samant SK, Pai JSC. New versatile food additive. Indian Food Packer. 1991; 45(3):55-65
Szente L, Szejtli J. Cyclodextrins as food ingredients. Trends in Food Science and Technology. 2004; 15:137-142
Prasad N, Strauss D, Reichart G. Cyclodextrins inclusion for food, cosmetics and pharmaceuticals. European Patent 1084625. 1999
Kant A, Linforth RST, Hort J, Taylor AJ. Effect of β-cyclodextrin on aroma release and flavor perception. Journal of Agricultural and Food Chemistry. 2004; 52:2028-2035
Muñoz-Botella S, del Castillo B, Martín MA. Cyclodextrin properties and applications of inclusion complex formation. Ars Pharmaceutica. 1995; 36:187-198
Reineccius TA, Reineccius GA, Peppard TL. Encapsulation of flavors using cyclodextrins: Comparison of flavor retention in alpha, beta, and gamma types. Journal of Food Science. 2002; 67(9):3271-3279
Reineccius TA, Reineccius GA, Peppard TL. Flavor release from cyclodextrin complexes: Comparison of alpha, beta, and gamma types. Journal of Food Science. 2003; 68(4):1234-1239
Reineccius TA, Reineccius GA, Peppard TL. The effect of solvent interactions on α-, β-, and γ-cyclodextrin/flavor molecular inclusion complexes. Journal of Agricultural and Food Chemistry. 2005; 53:388-392
Liu X-D, Furuta T, Yoshii H, Linko P, Coumans WJ. Cyclodextrin encapsulation to prevent the loss of l-menthol and its retention during drying. Bioscience, Biotechnology, and Biochemistry. 2000; 64(8):1608-1613
Tobitsuka K, Miura M, Kobayashi S. Interaction of cyclodextrins with aliphatic acetate esters and aroma components of La France pear. Journal of Agricultural and Food Chemistry. 2005; 53:5402-5406
Tobitsuka K, Miura M, Kobayashi S. Retention of a European pear aroma model mixture using different types of saccharides. Journal of Agricultural and Food Chemistry. 2006; 54:5069-5076
Shiga H, Yoshii H, Taguchi R, Nishiyama T, Furuta T, Linko P. Release characteristics of flavor from spray-dried powder in boiling water and during rice cooking. Bioscience, Biotechnology, and Biochemistry. 2003; 67(2):426-428
Munro IC, Newberne PM, Young VR, Bär A. Safety assessment of γ-cyclodextrin. Regulatory Toxicology and Pharmacology. 2004; 39:S3-S13
Parrish MA. Cyclodextrins – A Review. Newcastle-Upon-Tyne, England: Sterling Organics; 1988
Szejtli J, Szente L. Elimination of bitter, disgusting tastes of drugs and foods by cyclodextrins. European Journal of Pharmaceutics and Biopharmaceutics. 2005; 1:115-125
Hedges AR. Industrial applications of cyclodextrins. Chemical Reviews. 1998; 98:2035-2044
Bhandari BR, D’Arcy BR, Padukka I. Encapsulation of lemon oil by paste method using β-cyclodextrin: Encapsulation efficiency and profile of oil volatiles. Journal of Agricultural and Food Chemistry. 1999; 47:5194-5197
Shiga H, Yoshii H, Ohe H, Yasuda M, Furuta T, Kuwahara H, Ohkawara M, Linko P. Encapsulation of shiitake (Lenthinus edodes) flavors by spray drying. Bioscience, Biotechnology, and Biochemistry. 2004; 68(1):66-71
Kwak HS, Jung CS, Shim SY, Ahn J. Removal of cholesterol from cheddar cheese by β-cyclodextrin. Journal of Agricultural and Food Chemistry. 2002; 50:7293-7298
Sojo MM, Nuñez-Delicado E, Garcia-Carmona F, Sanchez-Ferrer A. Cyclodextrins as activator and inhibitor of latent banana pulp polyphenol oxidase. Journal of Agricultural and Food Chemistry. 1999; 47:518-523
Sung H. Composition for ginger preservation. Repub Korea KR 9707148. 1997
Bicchi C, Liberto E, Cagliero C, Cordero C, Sgorbini B, Rubiolo P. Conventional and narrow bore short capillary columns with cyclodextrin derivatives as chiral selectors to speed-up enantioselective gas chromatography and enantioselective gas chromatography-mass spectrometry analyses. Journal of Chromatography A. 2008; 1212:114-123
Liberto E, Cagliero C, Sgorbini B, Bicchi C, Sciarrone D, D’Acampora-Zellner B, Mondello L, Rubiolo P. Enantiomer identification in the flavour and fragrance fields by “interactive” combination of linear retention indices from enantioselective gas chromatography and mass spectrometry. Journal of Chromatography A. 2008; 1195:117-126
Wüst M, Mosandl A. Important chiral monoterpenoid ethers in flavours and essential oils -enantioselective analysis and biogenesis. European Food Research and Technology. 1999; 209:3-11
Armstrong DW, Chang C-D, Li WY. Relevance of enantiomeric separations in food and beverage analyses. Journal of Agricultural and Food Chemistry. 1990; 38:1674-1677
Sumiyoshi H. Utilisation of inclusion complexes with plant components for foods. Nippon Shokuhin Shinsozai Kenkyukaishi. 1999; 2:109-114
Fujishima N, Kusaka K, Umino T, Urushinata T, Terumi K. Flour based foods containing highly branched cyclodextrins. Japanese Patent JP 136898. 2001
Takeshita K, Urata T. Antimicrobial food preservatives containing cyclodextrin inclusion complexes. Japanese Patent JP 29054. 2001
Mabuchi N, Ngoa M. Controlled release powdered flavour preparations and confectioneries containing preparations. Japanese Patent JP 128638. 2001
Chiavaro E, Dallasta C, Galaverna G, Biancardi A, Gambarelli E, Dossena A, et al. New reversed-phase liquid chromatographic method to detect aflatoxins in food and feed with cyclodextrins as fluorescence enhancers added to the eluent. Journal of Chromatography. A. 2001; 937:31-40
Jouquand C, Ducruet V, Giampaoli P. Partition coefficients of aroma compounds in polysaccharide solutions by the phase ratio variation method. Food Chemistry. 2004; 85:467-474
Pagington JS. Beta-cyclodextrin – The success of molecular inclusion. Chemistry in Britain. 1987; 23:455-458
Bhandari B, D’Arcy B, Young G. Flavour retention during high temperature short time extrusion cooking process: A review. International Journal of Food Science and Technology. 2001; 36:453-461
Suzuki J. Japan Kokai, JP 7569100. 1975
Shaw PE, Tatum JH, Wilson CW Improved flavor of navel orange and grapefruit juices by removal of bitter components with β-cyclodextrin polymer. Journal of Agricultural and Food Chemistry. 1984; 32:832-836
Binello A, Cravotto G, Nano GM, Spagliardi P. Synthesis of chitosan-cyclodextrin adducts and evaluation of their bitter-masking properties. Flavour and Fragrance Journal. 2004; 19(5):394-400
Binello A, Robaldo B, Barge A, Cavalli R, Cravotto G. Synthesis of cyclodextrin-based polymers and their use as debittering agents. Journal Applied Polymer Science. 2008; 107:2549-2557
Sakakibara S, Sugisawa K, Matsui F, Sengoku K. Japan Patent JP 851248075. 1985
Takeda Chem. Ind. Ltd. Japan Kokai JP 81127058. 1981
Kuwabara N, Takaku H, Oku S, Kopure Y. Japan Kokai JP 88267246. 1988
Del Valle EMM. Cyclodextrins and their uses. Process Biochemistry. 2004; 39:1033-1046
López-Nicolas JM, Nuñez-Delicado E, Sánchez-Ferrer A, García-Carmona F. Kinetic model of apple juice enzymatic browning in the presence of cyclodextrins: The use of maltosyl-beta-cyclodextrin as secondary antioxidant. Food Chemistry. 2007; 101:1164-1171
López-Nicolas JM, Pérez-López AJ, Carbonell-Barrachina A, García-Carmona F. Use of natural and modified cyclodextrins as inhibiting agents of peach juice enzymatic browning. Journal of Agricultural and Food Chemistry. 2007; 55:5312-5319
López-Nicolas JM, Pérez-López AJ, Carbonell-Barrachina A, García-Carmona F. Kinetic study of the activation of banana juice enzymatic browning by the addition of maltosyl-beta-cyclodextrin. Journal of Agricultural and Food Chemistry. 2007; 55:9655-9662
López-Nicolas JM, García-Carmona F. Use of cyclodextrins as secondary antioxidants to improve the color of fresh pear juice. Journal of Agricultural and Food Chemistry. 2007; 55:6330-6338
Burt S. Essential oils: Their antibacterial properties and potential applications in foods – A review. International Journal of Food Microbiology. 2004; 94:223-253
Valero M, Salmerón M. Antibacterial activity of 11 essential oils against Bacillus cereusin tyndallized carrot broth. International Journal of Food Microbiology. 2003; 85:73-81
Dorman HJD, Surain P, Deans SG. Vitro antioxidant activity of a number of plant essential oils and phytoconstituents. Journal of Essential Oil Research. 2000; 12:241-248
Helander IM, Alakomi HL, Latva-Kala K, Mattila-Sandholm T, Pol I, Smid EJ. Characterization of the action of essential oil components on Gram-negative bacteria. Journal of Agricultural and Food Chemistry. 1998; 46:3590-3595
Calo JR, Crandall PG, O’Brian CA, Ricke SC. Essential oils as antimicrobials in food systems – A review. Food Control. 2015; 54:111-119
Srinivasan K. Black pepper and its pungent principle-piperine. A review of diverse physiological effects. Critical Reviews in Food Science and Nutrition. 2007; 47:735-748
Awen BZ, Ganapati S, Chandu BR. Influence of sapindus mukorossi on the permeability of ethyl cellulose free film for transedermal use. Research Journal of Pharmaceutical, Biological and Chemical Sciences. 2010; 1:35-38
Hussain A, Naz S, Nazir H, Shinwari ZK. Tissue culture of black pepper ( Piper nigrumL.) in Pakistan. Pakistan Journal of Botany. 2011; 43:1069-1078
Singh G, Marimuthu P, Catalan C, de Lampasona MP. Chemical, antioxidant and antifungal activities of volatile oil of black pepper and its acetone extract. Journal of the Science of Food and Agriculture. 2004; 84:1878-1884
Dorman HJD, Deans SG. Antimicrobial agents from plants: Antibacterial activity of plant volatile oils. Journal of Applied Microbiology. 2000; 88:308-316
Menon AN, Padmakumari KP, Jayalekshmy A. Essential oil composition of four major cultivars of black pepper ( Piper nigrumL.) III. Journal of Essential Oil Research. 2003; 15:155-157
Dima C, Cotarlet M, Tiberius B, Bahrim G, Alexe P, Dima S. Encapsulation of coriander essential oil in beta-cyclodextrin: Antioxidant and antimicrobial properties evaluation. Romanian Biotechnological Letters. 2014; 19:9128-9140
Kalemba D, Kunicka A. Antibacterial and antifungal properties of essential oils. Current Medical Chemistry. 2003; 10:813-829
Jaiarj P, Khoohaswan P, Wongkrajang Y. Anticough and antimicrobial activities of Psidium guajavaLinn. leaf extract. Journal of Ethnopharmacology. 1999; 67:203-212
Lozoya X, Reyes-Morales H, Chávez-Soto MA, Martínez-García MC, Soto-González Y, Doubova SV. Intestinal anti-spasmodic effect of a phytodrug of Psidium guajavafolia in the treatment of acute diarrheic disease. Journal of Ethnopharmacology. 2002; 83:19-24
Oh WK, Lee CH, Lee MS, Bae EY, Sohn CB, Oh H. Antidiabetic effects of extracts from Psidium guajava. Journal of Ethnopharmacology. 2005; 96:411-415
Sacchetti G, Maietti S, Muzzoli MV, Scaglianti M, Manfredini S, Radice M, Bruni R. Comparative evaluation of 11 essential oils of different originas functional antioxidants, antiradicals and antimicrobials in foods. Food Chemistry. 2005; 91:621-632
Manosroi J, Dhumtanom P, Manosroi A. Anti-proliferative activity of essential oil extracted from Thai medicinal plants on KB and P388 cell lines. Cancer Letters. 2006; 235:114-120
Hsin-Chun C, Ming-Jen S, Li-Yun L, Chung-May W. Chemical composition of the leaf essential oil of Psidium guajavaL. from Taiwan. Journal of Essential Oil Research. 2007; 19:345-347
Ogunwande IA, Olawore NO, Adeleke KA, Ekundayo O, Koenig WA. Chemical composition of the leaf volatile oil of Psidium guajavaL. growing in Nigeria. Flavour and Fragrance Journal. 2003; 18:136-138
Wichtl, M. Teedrogen und phytopharmaka. Stuttgart: Wissenschaftl Verlagsges. mbH; 1997. pp. 395-399
Cavalcanti AM, Baggio CH, Freitas CS, Rieck L, Sousa RS, Santos JES. Safety and antiulcer efficacy studies of Achillea millefoliumL. after chronic treatment in Wistar rats. Journal of Ethnopharmacology. 2006; 107:277-284. DOI: 10.1016/j.jep.2006.03.011
Jonsdottir G, Omarsdottird S, Vikingssona A, Hardardottirc I, Freysdottir J. Aqueous extracts from Menyanthes trifoliateand Achillea millefoliumaffect maturation of human dendritic cells and their activation of allogeneic CD4+ T cells in vitro. Journal of Ethnopharmacology. 2011; 136:88-93
Baretta IP, Felizardo RA, Bimbato VF, Santos MGJ, Kassuya CAL, Junior AG. Anxiolytic-like effects of acute and chronic treatment with Achillea millefoliumL. extract. Journal of Ethnopharmacology. 2012; 140:46-54. DOI: 10.1016/j.jep.2011.11.047
Candan F, Unlu M, Tepe B, Daferera D, Polissiou M, Sokmenc A, Akpulat HAA. Antimicrobial activity of the essential oil and methanol extracts of Achillea millefoliumssp. millefolium Afan (Asteraceae). Journal of Ethnopharmacology. 2003; 87:215-220. DOI: 10.1016/S0378-8741(03)00149-1
Potrich FB, Allemand A, Silva LM, Santos AC, Baggio CH, Freitas CS, Mendes DAGB, Andre E, Werner MFP, Marques MCA. Antiulcerogenic activity of hydroalcoholic extract of Achillea millefoliumL.: Involvement of the antioxidant system. Journal of Ethnopharmacology. 2010; 130:85-92. DOI: 10.1016/j.jep.2010.04.014
Trumbeckaite S, Benetis R, Bumblauskiene L, Burdulis D, Janulis V, Toleikis A. Achillea millefoliumL. s. l. herb extract: Antioxidant activity and effect on the rat heart mitochondrial functions. Food Chemistry. 2011; 127:1540-1548
Alfatemi SMH, Rad JS, Rad MS, Mohsenzadeh S, da Silva JAT. Chemical composition, antioxidant activity and in vitro antibacterial activity of Achilleab wilhelmsiiC. Koch essential oil on methicillin-susceptible and methicillin-resistant Staphylococcus aureusspp. 3. Biotechnology. 2014; 5:39-44. DOI: 10.1007/s13205-014-0197-x
Helena M, Cabral M. A review on cyclodextrin encapsulation of essential oils and volatiles. Flavour and Fragrance Journal. 2010; 25:313-326
Schmann HJ, Schollmeyer E. Applications of cyclodextrins in cosmetic products: A review. Journal of Cosmetic Science. 2002; 53:185-191
Bender ML, Komiyama M. Cyclodextrin Chemistry. Berlin: Springer; 1978
Saenger W. Cyclodextrin inclusion compounds in research and industry. Angewandte Chemie. 1980; 19:344-362
Marques HMC. A review on cyclodextrin encapsulation of essential oils and volatiles. Flavour and Fragrance Journal. 2010; 25:313-326
Waleczek KJ, Marques HMC, Hempel B, Schmidt PC. Phase solubility studies of pure (−)-alpha-bisabolol and camomile essential oil with beta-cyclodextrin. European Journal of Pharmaceutics and Biopharmaceutics. 2003; 55:247-251
Garnero C, Zoppi A, Genovese D, Longhi M. Studies on trimethoprim: Hydroxypropyl-β-cyclodextrin: Aggregate and complex formation. Carbohydrate Research. 2010; 345:2550-2556
Chandler RF, Hooper SN, Harvey NJ. Ethnobotany and phytochemistry of yarrow Achillea millefoliumcompositae. Economic Botany. 1982; 36:203-215. DOI: 10.1007/BF02858720
Benedek B, Geisz N, Jager W, Thalhammer T, Kopp B. Choleretic effects of yarrow ( Achillea millefoliumL.) in the isolated perfused rat liver. Phytomedicine. 2006; 13:702-706. DOI: 10.1016/j.phymed.2005.10.005
Keser S, Celik S, Turkoglu S, Yilmaz O, Turkoglu I. Determination of antioxidant properties of ethanol and water extracts of Achillea millefoliumL. (Yarrow). Asian Journal of Chemistry. 2011; 23:3172-3176
Keser S, Celik S, Turkoglu S, Yilmaz O, Turkoglu I. Antioxidant activity, total phenolic and flavonoid content of water and ethanol extracts from Achillea millefoliumL. Turkish Journal of Pharmaceutical Sciences. 2013; 10:385-392
Hill LE, Gomes C, Taylor TM. Characterization of beta-cyclodextrin inclusion complexes containing essential oils (trans-cinnamaldehyde, eugenol, cinnamon bark, and clove bud extracts) for antimicrobial delivery applications. LWT – Food Science and Technology. 2013; 51:86-93
Rakmai J, Cheirsilp B, Torrado-Agrasar A, Mejuto JC, Simal-Gandara J. Physico-chemical characterization and evaluation of bio-efficacies of black pepper essential oil encapsulated in hydroxypropyl-beta-cyclodextrin. Food Hydrocolloids. 2017; 65:157-164
Li X, Jin Z, Wang J. Complexation of allyl isothiocyanate by α- and β-cyclodextrin and its controlled release characteristics. Food Chemistry. 2007; 103:461-466
Ayala-Zavala JF, Soto-Valdez H, Gonzalez-Leon A, Alvarez-Parrilla E, Martin-Belloso O, Gonzalez-Agular GA. Microencapsulation of cinnamon leaf ( Cinnamonum zeylanicum) and garlic ( Allium sativum) oils in β-cyclodextrin. Journal of Inclusion Phenomena and Macrocyclic Chemistry. 2008; 60:359-368
Ponce-Cevallos PA, Buera MP, Elizalde BE. Encapsulation of cinnamon and thyme essential oils components (cinnamaldehyde and thymol) in β-cyclodextrin: Effect of interactions with water on complex stability. Journal of Food Engineering. 2010; 99:70-75
Piercey MJ, Mazzanti G, Budge SM, Delaquis PJ, Paulson AT, Hansen LT. Antimicrobial activity of cyclodextrin entrapped allyl isothiocyanate in a model system and packaged fresh-cut onions. Food Microbiology. 2012; 30:213-218
Songkro S, Hayook N, Jaisawang J, Maneenuan D, Chuchome T, Kaewnoppart N. Investigation of inclusion complexes of citronella oil, citronellal and citronellol with β-cyclodextrin for mosquito repellent. Journal of Inclusion Phenomena and Macrocyclic Chemistry. 2012; 72:339-355
Qiu N, Cheng X, Wang G, Wang W, Wen J, Zhang Y, Chen L. Inclusion complex of barbigerone with hydroxypropyl-cyclodextrin: Preparation and in vitro evaluation. Carbohydrate Polymers. 2014; 101:623-630
Anaya-Castro MA, Ayala-Zavala JF, Muñoz-Castellanos L, Hernández-Ochoa L, Peydecastaing J, Durrieu V. β-Cyclodextrin inclusion complexes containing clove ( Eugenia caryophyllata) and Mexican oregano ( Lippia berlandieri) essential oils: Preparation, physicochemical and antimicrobial characterization. Food Packaging and Shelf Life. 2017; 14:96-101. DOI: 10.1016/j.fpsl.2017.09.002
Santos EH, Kamimura JA, Hill LE, Gomes CL. Characterization of carvacrol beta-cyclodextrin inclusion complexes as delivery systems for antibacterial and antioxidant applications. LWT Food Science and Technology. 2015; 60:583-592
Miguel MG, Dandlen SA, Figueiredo AC, Pedro LG, Barroso JG, Marques MH. Comparative evaluation of the antioxidant activities of thymol and carvacrol and the corresponding beta cylodextrin complexes. Acta Horticulturae. 2009; 853:363-368
Kamimura JA, Santos EH, Hill LE, Gomes CL. Antimicrobial and antioxidant activities of carvacrol microencapsulated in hydroxypropyl-beta-cyclodextrin. LWT – Food Science and Technology. 2014; 57:701-709
Wang J, Cao Y, Sun B, Wang C. Physicochemical and release characterisation of garlic oil-β-cyclodextrin inclusion complex. Food Chemistry. 2011; 127:1680-1685
Rakmai J, Cheirsilp B, Mejuto JC, Simal-Gandara J, Torrado-Agrasar A. Antioxidant and antimicrobial properties of encapsulated guava leaf oil in hydroxypropyl-beta-cyclodextrin. Industrial Crops and Products. 2018; 111:219-225
Bhandari BR, D’Arcy BR, Bich LLT. Lemon oil to β-cyclodextrin ratio effect on the inclusion efficiency of β-cyclodextrin and the retention of oil volatiles in the complex. Journal of Agricultural and Food Chemistry. 1998; 46:1494-1499
Mourtzinos I, Salta F, Yannakopoulou K, Chiou A, Karathaos VT. Encapsulation of olive leaf extract in beta cyclodextrin. Journal of Agricultural and Food Chemistry. 2007; 55:8088-8094
Gong L, Li T, Chen F, Duan X, Yuan Y, Zhang D, Jiang Y. An inclusion complex of eugenol into β-cyclodextrin: Preparation, and physicochemical and antifungal characterization. Food Chemistry. 2016; 196:324-330
Chun JY, You SK, Lee MY, Choi MJ, Min SG. Characterization of β-cyclodextrin self-aggregates for eugenol encapsulation. International Journal of Food Engineering. 2012; 8:1-19
Wang T, Li B, Si H, Chen L. Release characteristics and antibacterial activity of solid-state eugenol/β-cyclodextrin inclusion complex. Journal of Inclusion Phenomena and Macrocyclic Chemistry. 2011; 71:207-213
Seo JE, Min SG, Choi MJ. Release characteristics of freeze-dried eugenol encapsulated with β-cyclodextrin by molecular inclusion method. Journal of Microencapsulation. 2010; 27:496-505
Kotronia M, Kavetsou E, Loupassaki S, Kikionis S, Vouyiouka S, Detsi A. Encapsulation of oregano ( Origanum onitesL.) essential oil in β-cyclodextrin (β-CD): Synthesis and characterization of the inclusion complexes. Bioengineering. 2017; 4:74-89
Fang Z, Comino P, Bandari B. Effect of encapsulation of d-limonene on the moisture adsorption property of β-cyclodextrin. LWT – Food Science and Technology. 2013; 51:164-169
Tao F, Hill LE, Peng Y, Gomes CL. Synthesis and characterization of β-cyclodextrin inclusion complexes of thymol and thyme oil for antimicrobial delivery applications. LWT – Food Science and Technology. 2014; 59:247-255. DOI: 10.1016/j.lwt.2014.05.037
Del Toro-Sanchez CL, Ayala-Zavala JF, Machi L, Santacruz H, Villegas-Ochoa MA, Alvarez-Parrilla E, Aguilar G. Controlled release of antifungal volatiles of thyme essential oil from β-cyclodextrin capsules. Journal of Inclusion Phenomena and Macrocyclic Chemistry. 2010; 67:431-441
Albarca R, Rodríguez FJ, Guarda A, Galotto MJ, Burna JE. Characterization of beta-cyclodextrin inclusion complexes containing and essential oil component. Food Chemistry. 2016; 196:968-975
Lawtrakul L, Inthajak K, Toochinda P. Molecular calculations on β-cyclodextrin inclusion complexes with five essential oil compounds from Ocimun basilicum(sweet basil). Science Asia. 2014; 40:145-151
Rakmai J, Cheirsilp B, Torrado-Agrasar A, Simal-Gandara J, Mejuto JC. Encapsulation of yarrow essential oil in hydroxypropyl-beta-cyclodextrin: Physiochemical characterization and evaluation of bio-efficacies. CyTA Journal of Food. 2004; 15:409-417
Zeng Z, Fang Y, Ji H. Side chain influencing the interaction between β-cyclodextrin and vanillin. Flavour and Fragrance Journal. 2012; 27:378-385
Karathanos VT, Mourtzinos I, Yannakopoulou K, Andrikopoulos NK. Study of the solubility, antioxidant activity, and structure of inclusion complex of vanillin with beta-cyclodextrin. Food Chemistry. 2007; 101:652-658
Numanoǧlu U, Şen T, Tarimci N, Kartal M, Koo OMY, Önyüksel H. Use of cyclodextrins as a cosmetic delivery system for fragance materials: Linalool and benzyl acetate. AAPS PharmSciTech. 2007; 8:34-42
Haiyee ZA, Saim N, Said M, Illias RM, Mustapha WAW, Hassan O. Characterization of cyclodextrin complexes with turmeric oleoresin. Food Chemistry. 2009; 114:459-465. DOI: 10.1016/j.foodchem.2008.09.072
Kfoury M, Landy D, Ruellan S, Auezova L, Greige-Gerges H, Fourmentin S. Determination of formation constants and structural characterization of cyclodextrin inclusion complexes with two phenolic isomers: Carvacrol and thymol. Beilstein Journal of Organic Chemistry. 2016; 12:29-42. DOI: 10.3762/bjoc.12.5
Kfoury M, Auezova L, Fourmentin S, Greige-Gerges H. Investigation of monoterpenes complexation with hydrosypropyl-β-cyclodextrin. Journal of Inclusion Phenomena and Macrocyclic Chemistry. 2014; 80:51-60. DOI: 10.1007/s10847-014-0385-7
Jiang ZT, Tan J, Tan J, Li R. Chemical components and molecular microcapsules of folium Artemisia essential oil with β-cyclodextrin derivatives. Journal of Essential Oil-Bearing Plants. 2016; 19:1155-1169. DOI: 10.1080/0972060X.2016.1185973
Belscak-Cvitanovic A, Stojanovic R, Manojlovic V, Komes D, Cindric IJ, Nedovic V, Bugarski B. Encapsulation of polyphenolic antioxidants from medicinal plant extracts in alginate-chitosan system enhanced with ascorbic acid by electrostatic extrusion. Food Research International. 2011; 44:1094-1101
Dordevic V, Balanc B, Belscak-Cvitanovic A, Levic S, Trifkovic K, Kalusevic A, Kostic I, Komes D, Bugarski B, Nedovic V. Trends in encapsulation technologies for delivery of food bioactive compounds. Food Engineering Reviews. 2015; 7:452-490. DOI: 10.1007/s12393-014-9106-7
Guimaraes AG, Oliveira MA, Alves RS, Menezes PP, Serafini MR, Araujo AAS, Bezerra DP, Junior LJQ. Encapsulation of carvacrol, a monoterpene present in the essential oil of oregano, with β-cyclodextrin, improves the pharmacological response on cancer pain experimental. Chemico-Biological Interactions. 2015; 227:69-76
Le Bas D, Rysanek N. Structural aspect of cyclodextrins. In: Duchene D, editor. Cyclodextrins and their Industrial Uses. Vol. 105-211. Paris: Editions de Sante; 1987. pp. 351-393
Batzdorf T, Muller-Goymann CC. Release of ketoprofen from aqueous systems in the presence of hydrophilic β-cyclodextrin derivatives. Indian Journal of Pharmaceutical Sciences. 1993; 55:857-860
Szente L. Analytical methods for cyclodextrins, cyclodextrin derivatives and cyclodextrin complexes. Supramolecular Chemistry. 1996; 3:78-253
Wang X, Luo Z, Xiao Z. Preparation, characterization, and thermal stability of β-cyclodextrin/soybean lecithin inclusion complex. Carbohydrate Polymer. 2014; 101:1027-1032
Liu H, Yang G, Tang Y, Cao D, Qi T, Qi Y, Fan G. Physicochemical characterization and pharmacokinetics evaluation of β-caryophyllene/β-cyclodextrin inclusion complex. International Journal of Pharmaceutics. 2013; 450:304-310. DOI: 10.1016/j.ijpharm.2013.04.013
Gomes LMM, Petito N, Costa VG, Falcao DQ, Araujo KGL. Inclusion complexes of red bell pepper pigments with β-cyclodextrin: Preparation, characterisation and application as natural colorant in yogurt. Food Chemistry. 2014; 148:428-436
Szejtli J. Cyclodextrins and their Inclusion Complexes. Budapest: Akademiai Kiado; 1982. pp. 115-122
Yuan C, Jin Z, Li X. Evaluation of complex forming ability of hydroxypropyl-beta-cyclodextrins. Food Chemistry. 2008; 106:50-55
Higuchi T, Connors KA. Phase solubility techniques. Advances in Analytical Chemistry and Instrumentation. 1965; 4:117-122
Connors KA. The stability of cyclodextrin complexes in solution. Chemical Reviews. 1997; 5:1325-1357
Zengin H, Baysal AH. Antibacterial and antioxidant activity of essential oil terpenes against pathogenic and spoilage-forming bacteria and cell structure-activity relationships evaluated by SEM microscopy. Molecules. 2014; 19:17773-17798
Dai J, Zhu L, Yang L, Qiu J. Chemical composition, antioxidant and antimicrobial activities of essential oil from Wedelia prostrata. EXCLI Journal. 2013; 12:479-490
Nawar WF. Lipids. In: Fennema O, editors. Food Chemistry. New York: Marcel Dekker, Inc.; 1996. pp. 225-320
Misharina TA, Polshkov AN, Ruchkina EL, Medvedeva IB. Changes in the composition of the essential oil of marjoram during storage. Applied Biochemistry and Microbiology. 2003; 39:311-316
Trombetta D, Castelli F, Sarpietro MG, Venuti V, Cristani M, Daniele C, Saija A, Mazzanti G, Bisignano G. Mechanisms of antibacterial action of three monoterpenes. Antimicrobial Agents and Chemotherapy. 2005; 49:2474-2478
Soković M, Glamočlija J, Marin PD, Brkić D, Van Griensven LJLD. Antibacterial effects of the essential oils of commonly consumed medicinal herbs using an in vitro model. Molecules. 2010; 15:7532-7546
Lambert RJW, Skandamis PN, Coote PJ, Nychas GJE. A study of the minimum inhibitory concentration and mode of action of oregano essential oil, thymol and carvacrol. Journal of Applied Microbiology. 2001; 91:453-462. DOI: 10.1046/j.1365-2672.2001.01428.x
Soković M, Tzakou O, Pitarokili D, Couladis M. Antifungal activities of selected aromatic plants growing wild in Greece. Nahrung. 2002; 46:317-320
Couladis M, Tzakou O, Kujundzić S, Soković M, Mimica-Dukić N. Chemical analysis and antifungal activity of Thymus striatus. Phytotherapy Research. 2004; 18:40-42. DOI: 10.1002/ptr.1353
Soković M, Grubišić D, Ristić M. Chemical composition and antifungal activity of the essential oils from leaves, calyx and corolla of Salvia brachyodon Vandas. Journal of Essential Oil Research. 2005; 17:227-229. DOI: 10.1080/10412905.2005.9698884
Šiler B, Živković S, Banjanac T, Cvetković J, Živković JN, Ćirić A, Soković M, Mišić D. Centauries as underestimated food additives: Antioxidant and antimicrobial potential. Food Chemistry. 2014; 147:367-376. DOI: 10.1016/j.foodchem.2013.10.007
Soković M, van Griensven LJLD. Antimicrobial activity of essential oils and their components against the three major pathogens of the cultivated button mushroom, Agaricus bisporus. European Journal of Plant Pathology. 2006; 116:211-224. DOI: 10.1007/s10658-006-9053-0