The Legumes of Neltuma spp. (ex Prosopis spp.) and Their Properties for Human and Animal Food

Abstract

The objective of this chapter is to present the advances in the use of Neltuma (ex Prosopis) pods for human and animal consumption, taking into account their distribution in Argentina. Images of the distribution of principal species used in forest cultivation, types of pods, nutritional tables and possible uses are included. Fruit threshing machine to obtain seeds and flour from the National Germplasm Bank of Prosopis of the Faculty of Agricultural Sciences of the National University of Córdoba, and some regional recipes are described.

1. Introduction

The word “algarrobo” refers to several species of the genus Fabaceae, a word deriving from the Spanish Arabic dialect (“al jarruba”) [1] which means “the tree.” This was the name given to the specimens of the species Ceratonia siliqua L., which were spontaneously distributed along the coasts of the Mediterranean Sea and Middle East [2]. When Spanish people arrived in America, they assigned the name “algarrobo” to specimens of Neltuma (ex Prosopis) and coincidentally the native communities called it “taku” which also means “the tree.” These species coincide in being legumes with similar aspects in their shape and use, mainly food for animals and humans [3]. All of these species present pods as fruit. An example of the component of the typical pods is shown in Figure 1. The vulgar name for these pods is “algarroba.”

Figure 1.

Components of a typical Neltuma pods (algarroba).

The genus Neltuma (ex Prosopis) has a wide diffusion in various phytogeographical regions of the country, extending from Prepuna to Patagonia, mainly in the Provinces of Monte, Chaco and Espinal [4, 5]. Hughes et al. [6], divide the genus Prosopis sensu Burkart [7] into three genera: Anonychium, Neltuma and Strombocarpa, two of which are present in Argentina with 39 recognised taxa amongst species, varieties and subspecies (Table 1).

Scientific name		Vulgar name
N. x vinalillo	(Stuck.) C.E. Hughes & G.P. Lewis
N. affinis	(Spreng.) C.E. Hughes & G.P. Lewis	ñandubay, espinillo
N. alba	(Griseb.) C.E. Hughes & G.P. Lewis	árbol, algarrobo blanco, ibopé-pará
N. alba var. panta	(Spreng.) C.E. Hughes & G.P. Lewis	algarrobo panta
N. alpataco	(Phil.) C.E. Hughes & G.P. Lewis	alpataco
N. alpataco var. lamaro	(Phil.) C.E. Hughes & G.P. Lewis	alpataco
N. alpataco f. rubra	(Phil.) C.E. Hughes & G.P. Lewis	alpataco
N. argentina	(Burkart) C.E. Hughes & G.P. Lewis	algarrobilla, algarrobo de guanaco
N. caldenia	(Burkart) C.E. Hughes & G.P. Lewis	caldén, huichru
N. calingastana	(Burkart) C.E. Hughes & G.P. Lewis	cusqui
N. campestris	(Griseb.) C.E. Hughes & G.P. Lewis
N. castellanosii	(Burkart) C.E. Hughes & G.P. Lewis
N. chilensis	(Molina) C.E. Hughes & G.P. Lewis	algarrobo de chile, algarrobo blanco
N. chilensis var. catamarcana	(Molina) C.E. Hughes & G.P. Lewis
N. chilensis var. riojana	(Molina) C.E. Hughes & G.P. Lewis
N. denudans	(Benth.) C.E. Hughes & G.P. Lewis	algarrobo patagónico
N. denudans var. patagonica	(Benth.) C.E. Hughes & G.P. Lewis
N. denudans var. stenocarpa	Benth.) C.E. Hughes & G.P. Lewis
N. elata	(Burkart) C.E. Hughes & G.P. Lewis	algarrobillo, huschillo
N. fiebrigii	(Harms) C.E. Hughes G.P. Lewis
N. flexuosa	(DC.) C.E. Hughes & G.P. Lewis
N. flexuosa var. depressa	(DC.) C.E. Hughes & G.P. Lewis
N. flexuosa var. fruticosa
N. flexuosa f. subinermis	(Burkart) C.E. Hughes & G.P. Lewis	algarrobo, algarrobo negro
N. hassleri	(Harms) C.E. Hughes G.P. Lewis	algarrobo paraguayo
N. hassleri var. nigroides	(Harms) C.E. Hughes G.P. Lewis
N. humilis	(Gillies ex Hook.) C.E. Hughes & G.P. Lewis	algarrobilla, barba de tigre
N. kuntzei	(Harms ex Kuntze) C.E. Hughes & G.P. Lewis	itín, palo mataco
N. nigra	(Griseb.) C.E. Hughes & G.P. Lewis	algarrobo negro, ibopé-hú
N. nigra var. longispina	(Griseb.) C.E. Hughes & G.P. Lewis
N. nigra var. ragonesei	(Griseb.) C.E. Hughes & G.P. Lewis
N. pugionata	(Burkart) C.E. Hughes & G.P. Lewis	algarrobo de las salinas, algarrobo
N. ruizlealii	(Burkart) C.E. Hughes & G.P. Lewis
N. ruscifolia	(Griseb.) C.E. Hughes & G.P. Lewis	vinal, ibopémorotí
N. sericantha	(Gillies ex Hook.) C.E. Hughes & G.P. Lewis
Strombocarpa abbreviata	(Benth.) Hutch.
S. ferox	(Griseb.) C.E. Hughes & G.P. Lewis	churqui, churqui jujeño
S. reptans	(Benth.) A. Grey	mastuerzo, retortuño
S. torquata	(Cav. ex Lag.) Hutch.	tintitaco, tusca

Table 1.

Taxa present in Argentina of the genus Neltuma and Strombocarpa (ex Prosopis).

Tree and shrub carobs are multiple-use species [8]. The aboriginal populations and the conquerors knew about these attributes [4, 9]. Species in this genus provide not only wood forest products (WFP), but also non-wood forest products (N-WFP). The tree species of this genus offer a wood that is highly appreciated for its hardness, stability and preservation. It is used in carpentry and for furniture. It is also used for poles, rods and in the manufacture of charcoal (calorific value: 4200 kcal/kg) [10].

Amongst the N-WFP of plant origin, the genus Neltuma (ex Prosopis) provides leaves, fruits and seeds that are an important source of food for animals. The fruits and their derivatives can also be used as human food. The leaves have high protein value. They contain 22% crude protein, 15% digestible protein and 55% dry matter digestibility [10].

There are numerous uses of the N-WFP of vegetable origin offered by the species of the genus Neltuma, amongst of them are: resin, gum, bark and fruits. For example, tannin is extracted from the bark, which is used in the tanning of leather and also in dyes [11]. The fruits, seeds, bark and flowers also have a medical use [11]. Ethyl alcohol can be obtained from the fermentation of the fruits [10, 12]. Neltuma species can act as biocontrol agents. Proof of this is the stem extracts of N. chilensis that are effective in the control of a Homoptera [13].

Other N-WFP that are obtained in Neltuma forests are animals and animal products, such as cattle, goats, sheep [14] from which products like meat, leather, milk, cheese and wool are obtained. The species of this genus are good producers of nectar and pollen, so beekeeping becomes important and favoured, generating other resources of animal origin, such as honey, wax, propolis and pollen [10, 15].

Neltuma is also important because it provides services to the forest. It acts as a protective source by providing nitrogen to the soil through the symbiotic association with fixing bacteria and also shade for cattle. Some indirect benefits are: the pasture under its canopies is of better quality, and it supplies abundant organic matter to the soil for present semi-persistent foliage, etc. [10].

In North America, soils under Neltuma canopy have more than 1000 kg/ha of nitrogen and more than 8000 kg/ha of carbon than soils outside tree canopies [16]. The contributions of organic matter, nitrogen and phosphorus of N. flexuosa forest are significant in the phytogeographical regions of Central Monte of Argentina, constituting true islands of fertility [17]. This species has not only to create edaphic heterogeneity in the region, but also contributed to create climatic heterogeneity, modifying the microclimate, water regime and light conditions under its canopy. This environmental heterogeneity allows a different spatial distribution of species and increases diversity at a regional scale [18]. In India, Neltuma has been used to improve high pH (10.4) soils. On the other hand, Neltuma species can grow in saline concentrations equal to ocean water [16].

The rural inhabitants of the southern sector of the Calchaquí Valley, province of Catamarca, recognise the use of pods of three species that they call “white,” “black” and “panta,” identified from the morphology of its fruit and depending on its flavour. As regards the possible production, a total of 9 products obtained from the pod were mentioned (flour, coffee, fodder, liquor, “añapa,” “aloja,” “arrope,” “aguardiente” and seedlings), being used by families as a source of fodder, food, drink and medicine [19].

“Patay” is defined as a kind of dry bread, floury and sweet paste that is obtained by drying, grinding and sifting the fruits, compressing the flour obtained and then proceeding to cook it. It is marketed locally. The “chuningo” is similar to the previous one, but the ground dough is soaked and eaten without baking. The drinks are: the “aloja,” a native alcoholic fermented drink obtained by fermenting the pods of “algarrobo” which is made by grinding the fruits with water; the “añapa,” which is a non-fermented, sweet and refreshing drink, is prepared simply by crushing the fruits in a mortar with water. The sweet product is the “arrope,” which is a type of honey obtained by cooking, grinding and sifting. (4). Amongst the flours are: whole fruit flour (FF), mesocarp flour (MF), seedless fruit flour (SFF), seed flour (SF), cotyledon flour (CF) and meso- endocarp residue (R). When the flour is toasted, it can be used to prepare substitutes for chocolate and coffee [20].

2. National Germplasm Bank of Prosopis of the Faculty of Agricultural Sciences of the National University of Córdoba (BNGP)

The BNGP’s main objective is the conservation and commercialization of seeds of quality and known origin. It currently has 1650 accessions in the Passive Bank corresponding to 1106 trees of 9 Neltuma (ex Prosopis) tree species from different regions of Argentina [21]. In the last 8 years, it has managed to register 24 Seed-Producing Areas (10 for N. alba, 5 for N. chilensis, 3 for N. flexuosa, 2 for N. nigra, 3 of N. chilensis x N. flexuosa, 1 of N. alba x N. sp.), and 2 Seed Stands (N. alba and N. flexuosa), from which it obtains seeds to respond to the needs of afforestation and restoration. Figure 2 shows some of the locations of the species present in the BNGP.

Figure 2.

a) Phytogeographic Regions of Argentina. Distribution of the main Neltuma species in Argentina: b) N. alba, c) N. chilensis, d) N. flexuosa, e) N. nigra and f) N. caldenia.

3. Characterisation of Neltuma species

The collected species are morphologically characterised in the laboratory. A measurement of leaf and fruit characters is carried out to confirm the taxon of belonging following the specifications proposed by Verga [22] and Joseau et al. [21, 23].

INASE [24] establishes marketing categories according to the degree of improvement. For a seed-producing area (APS) a morphological characterisation is necessary, whilst for a higher category (seeds from seed stands) a morphological and genetic analysis are required.

Figure 3 presents some examples of leaves and fruits according to taxon, where the existing variability is observed.

Figure 3.

View of leaves and fruits of a) N. chilensis, b) N. alba, c) N. nigra, d) N. caldenia and e) N. flexuosa.

4. Neltuma (“algarrobo”) flour

Algarrobo flour is a traditional food product made by the communities that inhabit the Chaco Semiarid and Monte ecoregion [25]. However, “algarrobo” trees are also distributed in other phytogeographic regions [4, 5].

Articles 680, 681, 681 bis, 681 tris of Chapter IX of the Argentine Food Code provide specifications for the commercialization of flour from the species of the genus Neltuma (ex Prosopis) and define “algarrobo” flour as “the product of the grinding of the clean, healthy and dry seeds” of N alba and/or N. nigra and/or N. chilensis and/or N. flexuosa (Art.681) and of N ruscifolia (Art. 680). It also defines “algarrobo” “fruit flour” (complete pod with its seeds) as “the product of grinding the complete fruits” of N. alba and/or N. nigra and/or N. chilensis and/or N. flexuosa (Art. 681 tris). Likewise, the concept of “Patay” is incorporated in the same code as “made by kneading ‘algarrobo’ flour, in any of its types: seed or fruit, with water; shaping dough into loaves before taking it to the oven to bake it” [26].

In general, the whole fruit is used to obtain flour. The types the flours obtained after drying the pods are used as substitutes for cocoa and coffee because they do not contain stimulating substances such as caffeine and theobromine. In addition, it constitutes a suitable ingredient in the preparation of sweet products such as cakes, muffins and cookies due to its high sugar content and good aroma and flavour [27]. The roasted white “algarrobo” seeds can also be used as a coffee substitute [15].

The fruits of the genus Neltuma (ex Prosopis) are legumes with a high content of proteins, carbohydrates, fibres and minerals. The legumes which vary in size, colour and chemical characteristics depending on the species [3]. Correa et al. [28] found differences between clones of N. alba in terms of protein and fibre content, on the one hand, and phenolic component content, on the other hand, in the SF of this species. Hence, when producing on a large scale it is necessary to know the genetic materials to be established in implanted forests.

Flour is gaining great importance in the diet for celiacs, as it is free of gliadins and gluteins. It is considered a building food as it contains protein and energy due to its sugars; in addition to providing mineral salts and vitamins [4, 29].

González-Montemayora et al. [20] carried out a review to incorporate legumes such as pods of some Neltuma species in the food industry. Some of them produce functional bread-making, protein-fortifying wheat flour with these legumes and enhancing the bioactive content of bread. These authors state that one of the main challenges of adding any legume to a bakery product is the rheological changes in the dough and the final product. Pereira de Gusmão et al. [30, 31], quoting González-Montemayora et al. [20], concluded that the use of flour from Neltuma fruits with a size between 500 and 100 μm is suitable for products such as bread, cakes and cookies. The rheology, tenacity and extensibility of the dough decreases as the concentration of “algarrobo” flour increases and the more quantity is added, the weaker the remaining dough. Escobar et al. [32] produce CF from N. chilensis added a percentage of 10% to wheat flour to make cookies and fried flakes, increasing the contribution of available lysine, its protein and dietary fibre content, improving the soluble/insoluble fibre ratio, without affecting its physical characteristics or sensory acceptability. “Algarrobo” flour does not have the binding characteristic of wheat flour. It has sweetening properties, natural flavouring and mineral and protein content, making it interesting for the food industry [20].

There are many other Neltuma which beans are used for flour. They have some differential characteristics: for example, N. chilensis flour contains fewer carbohydrates than N. alba flour, and together with N. flexuosa they have higher amounts of fibre and protein than N. alba flour (Table 2). Table 2 also shows that the flours of N. ruscifolia and N. alpataco stand out for the high amount of carbohydrates, whilst that of N. nigra stands out in the amount of fats.

Variables	MF; %	SF; %	R; %	FF; %	FF; %	FF; %	FF; %	FF; %	FF; %
	N. ruscifolia	N. ruscifolia	N. ruscifolia	N. ruscifolia	N. alba	N. nigra	N. alpataco	N. chilensis	N. flexuosa
Ashes	6.07	3.40	4.40	4.45	3.2	3.2	3.33	3.4	3.9
Protein	10,5	33.81	8.34	12.70	7.8	7.8	10.2 (protein); 2.6 (mucilage)	11.48–13.2	13.1
Fats	5.59	5.94	3.73	4.32	0.68	6.59	3.23	2.4–3.02	1.7
Carbohydrates	77.84	56.80	83.58	78.52	53.0; saccharose; 2.5; fructose	53.0; saccharose; 2.e; fructose	62.0	39	46
Crude fibre	6.50	5.80	22.56	17.82	20.0	23.0	25.5	27.20–35.3	29.9
Calcium	0.153	0,078			0.1860	0.1610
Phosphorus	0.472	0.187
Potassium	0.589	0.905			0.9030	1.0600
Magnesium	0.044	0.040			0.0560	0.0690
Iron	4.570	25.420			0.0049	0.0026
Zinc	3.890	1.480
Manganese	15.30	0.840			0.0047	0.0077
Copper	21.70	1.620
Polyphenols					0.6210	1.0810		0.29–0.31	0.35–0.37
Antioxidant capacity					0.5450	0.9350
References:	[33]				[34]		[35]	[36, 37]

Table 2.

Composition of grinding fractions of N. ruscifolia fruit and whole fruit (dry basis) of N. ruscifolia, N. alba, N. nigra, N. alpataco, N. chilensis and N. flexuosa.

MF: Mesocarp flour, SF: Seed flour, R: Meso-endocarp residue, FF: Fruits flour

5. Methods of elaboration of Neltuma flours

These vary from precarious systems with some degree of technology to industrial-scale projects.

The traditional production process involves the collection of the pods, drying by direct exposure to solar radiation (Figure 4a) and finally their manual grinding in mortar [25].

Figure 4.

Components of the “algarrobo” threshing machine (Cosiansi, 1991): a) pods hopper, b) shredder, c) threshing cylinder I, d) sieves, e) flour tray, f) knuckles tray, g) seed tray, h) hopper for knuckles, i) threshing cylinder II.

5.1 Fruit collection

When the fruits are ripe, they are collected by placing them in plastic burlap bags that allow aeration. Collection seasons are generally: December–January for N. flexuosa and N. chilensis; December to February for N. alba, late January to February for N. nigra and May–April for N. caldenia. If the collection is possible, it is done from the tree manually or by placing a mesh to catch the fruits at the time of shaking for phytosanitary reasons.

The collected bags should be stored in a dry environment with air circulation to avoid deterioration and proliferation of insects. The collected fruits are selected, separating the healthy fruits from others in poor condition, foreign matter and insects.

The fruits are generally attacked by insects belonging to the Bruchidae family [38]. One method to eliminate bruchids is to place the bags kept in dried conditions in the freezer at a temperature of −18°C for 10 days (Figure 4b) [21].

Silva et al. [39] conclude that the chemical and physical quality of fruits stored for animal feed is maintained with the use of closed bins with a capacity of 40 kg with the addition of dry insect repellent plants (Capparis atamisquea Kuntze and Ocimum basilicum L.) placed at the base, in the middle and at the top.

5.2 Fruit washing

The fruits are washed with 5% sodium hypochlorite to eliminate adhering substances and microorganisms with subsequent rinsing, draining and air-drying on meshes placed for this purpose.

5.3 The grinding of fruits

This varies according to the region. The Institute of Popular Culture [40] processes dry and healthy fruits with a 3000 rpm hammer mill with a 6 HP TEKNE 400 brand gasoline engine [41], which processes 40 to 50 kg of fruits per hour. The granulometry of the grinding obtained goes through a 12 mm diameter sieve. If it absorbs moisture, it is necessary to dry it in a solar dryer. INCUPO [40] performs a second grinding by varying the sieve with a 2 mm diameter mesh. It is necessary to dry it again in the solar dryer, to then mechanically sieve with a 1 mm metal mesh. The product obtained is stored in plastic drums with hermetic closure of 220 litres (80 kg). In these drums the product lasts 1 year if it is kept hermetically closed with low moisture content in storage. The TEKNE 400 hammer mill is also proposed by Cornejo Becker et al. [42] who made a proposal to bring flour production to an industrial level, using rotary washers, vibrating sieve, tray dryer, conveyor belt and ground product packaging.

In the Monte region, the company “El Resurgir del Algarrobal S.A.” collect N. flexuosa directly from trees devoid of shrubs and grasses below. When collecting impurities are also collected. Inclined planes and fans are used to clean light remains of fruits. To separate heavy remains they perform immersion in water, so the pods come out clean. The pods are sun-dried and hand-selected. To obtain “algarrobo” flour, they use a hammer mill with interchangeable sieves and obtain the desired granulometry by reducing the step. The flour is collected in hermetic jars after sifting and packaging. The destination is human consumption [43].

The community of Santa María de Catamarca presented the use of an individual solar dryer and a medium-scale solar dryer as an improvement in the traditional process of drying Neltuma fruits to obtain flour [25].

Mom et al. [44], studying two species of Neltuma, argue that the milling process to obtain flour by dry milling demands the use of previously dried fruits. One of the critical factors is the high sugar content (40%), which requires drying to very low moisture (<6%) to avoid stickiness. In N. alba a reduction of 80% was observed in the drying time at 60 and 70°C. A grinding more homogeneous and with very fine granulometry of all the components (soluble in water and insoluble in ethanol) is observed in N. alba, whilst that the highest granulometry of N. flexuosa is found in the flour and not in the water-insoluble fraction.

Freyre et al. [33] for the separation of different fractions of the (N. ruscifolia) used a concentric disc mill that retains the endocarp, and allows the exo-mesocarp mixture to pass through. The endocarps enter in a disc mill with radial grooves that open the endocarp and release the seeds. The separation will be implemented using a pneumatic separator, sieves and manually. In this process three different products were obtained: fraction H or pulp meal (MF), fraction S of pure seeds (SF) and the residual fraction (R), made of the residues obtained in each step. The particle size of each of these fractions was reduced and homogenised using a Cyclotec mill. The proximal composition of these fractions is observed in Table 2.

Escobar et al. [32] obtained cotyledon meal from pods of N. chilensis harvested in April in Chile. To obtain them, the pods were dried in a tunnel with forced air at 60°C until a residual humidity of 8–10%. They extracted the cotyledons from the pods manually and peeled them with a 0.75% w/v solution of sodium hydroxide according to the method of Escobar et al. [45]. The cotyledons obtained are thermally treated with moist heat (cotyledon: water ratio of 1:3) at overpressure (1.57 atm) for 9 minutes for the inactivation of heat-sensitive antinutritional compounds. The cotyledons were dried at 35°C until a residual humidity of 8% and they were ground in two stages, a pre-milling until a granulometry of 250 μm (Mill Arthur H. Thomas. C.O.) and a milling.

Peru has established technical standards for the production of products originating from the pods of the “algarrobos” and guidelines for the implementation of standards to establish quality and aptitude requirements for the product, process and service, contemplating various aspects of production in a manner to provide sustainable economic development [46].

The BNGP in the threshing process uses the machine designed by Ing. Agr. (M Sc.) Jorge Cosiansi [47], which allows to obtain flour as well as seeds. The machine has a power of 6 HP, a weight of 380 kg, a hopper capacity of 40 kg of pods and a threshing capacity of 20 min for that amount of fruit (Figure 4).

5.4 Threshing process

The pods collected in plastic burlap bags by the BNGP go through a cleaning and drying process before the threshing (Figure 4c). Cleaning is done by emptying the bag on a table, where with the help of a fan the pods are separated from other elements (grass, branches and insects and other materials). Once clean, the pods are placed in ovens for 48 hours at a temperature of 40°C with forced air circulation for drying until the moisture content drops to approximately 9%. Before being threshed, the fruits are broken into pieces of about 2–3 cm manually using a bucket and a stick as a pylon.

The dried and split pods are incorporated into the pod hopper of the thresher for indehiscent fruits (Figure 4a). In the lower part of the hopper there is a shredder (Figure 4b), which continues the process of breaking the material and allows the passage of the crushed pods to the threshing cylinder I (Figure 4c). The threshing cylinder I is in charge of opening the material and releasing the seeds. All the material falls to a set of sieves (Figure 4d), which classifies and transports to three output compartments: one for “algarrobo” flour (Figure 4e), another for the knuckles (Figure 4f) and a third compartment for the seeds with other impurities (flour and grains, Figure 4g). In the case of materials that have smaller knuckles and seeds, the hopper for knuckles (Figure 4h) and the threshing cylinder II (Figure 4i) can be used, which has the opening elements (tines) closer together.

To obtain a purity of seed of 80% (according to INASE Res. 374/14 standard), the seed obtained must go through a final cleaning process that is carried out with a fan and an inclined plane, where impurities are blown away and escape through the upper part of the inclined plane and the clean seeds are collected at the base of it (Figure 4c).

5.5 Performance

An adult of N. chilensis tree can produce up to 100 kg of pods. However, pod production does not occur uniformly every year, due to different factors, therefore it can be said that the average is 20 to 60 kg of pods per tree, whilst N. nigra varies from 20 to 50 kg per tree [48]. The production of N. alba begins around 5 years of the tree’s life, and produces 5 to 40 kilogrammes of pods per tree each year [49] (Figure 5).

Figure 5.

a) Previous drying in full sun of the plastic bags with pods b) Cold treatment to eliminate bruchids (−18°C) to bagged and dried fruits, c) P. flexuosa pods prepared for threshing d) seeds of P. alba from Campo Duran Seed.

3040 kg of pods yields 1400 kilogrammes of flour and the rest is made up of bran, which is the residue used to make balanced feed for animals (poultry, pigs and cattle) [40]. Cornejo Becker et al. [42] diagrammed a “algarrobo” flour plant and mention a yield of 42% in Salta.

One hundred kilos of ripe and dry “algarroba” (fruit) contain 30 kg of sugar, 20 kg of starch, 8 kg of protein and 2 kg of lipids, nutritive substances and more than 60 kg of cellulose [11].

In summary, it is concluded that the fibre content of “algarrobo” flour is higher than that of whole wheat flour, it has less fat with a very good composition of essential fatty acids (linoleic and oleic) and a notable amount of mineral salts (amongst others) Ca; Fe and P. The iron in the white “algarrobo” tree reaches values established for the liver of cattle. The nutritional characteristics and the behaviour of the product define it as a quality flour that can be used in bakery products [50].

6. Animal feeding

“Algarrobas” are collected to feed livestock, whole or processed, alone or as part of a ration, fresh or after storage. Researchers have conducted studies on ground carob in cattle feed rations, especially in Brazil and India. “Algarrobas” are ground to ensure maximum nutritional value, since most of the seeds are made up of proteins which are not indigestible when passing through the digestive tract of cattle [13].

In the Argentine Chaco Region, “algarroba” flour production is in summer, coinciding with the season of greatest pasture production in the area. Its use can be deferred for times of forage scarcity (late autumn and winter). The high energy values of “algarroba” flour can significantly improve daily weight gains in cattle [3].

Prokopiuk et al. [51] say that pods of N. alba have nutritional values (95.3% dry matter, 6.8% crude protein, 35.7% neutral detergent fibre, 33.1% acid detergent fibre, in vitro digestibility of dry matter 66.6%, non-structural carbonates 52.3%, ethereal extract 2.2%) indicating that they are located within the main group of feed for ruminants, that of bulky ones, those that have a low weight: volume, with fibre content greater than 18%. Comparatively within this group, they could replace conserved maize and grain sorghum forages.

Prokopiuk et al. [3] used coarse fractions of ground “algarroba” from N. alba as a winter supplement (1 kg/animal/day, 0.5% live weight) for 4 months for 200 kg live weight steers of the Braford breed in the province of Chaco, Argentina, in front of a witness without supplement. All remained on implanted pasture, with an average stocking rate of 0.5 animal/ha, in a continuous grazing system where the predominant species was Gatton panic (Panicum maximum). The ground “algarroba” supplied a concentration of metabolizable energy of approximately 2.4 Mcal/kg DM. The supplemented steers had significant increases in haematocrit, erythrocytes, haemoglobin and iron and there were no adverse clinical side effects, improving the blood levels of some nutritional indicators, and slightly increasing the weight of the growing animals. No animal registered signs of disease.

Gonzalez- Montemayora et al. [20] studied the whole meal of dried pods of N. alba, N. chilensis and N. nigra from Bolivia obtained with a knife mill, and found that N. nigra and N. alba stood out for their protein, fibre and protein content. Low levels of antinutrients (saponins, lectins, trypsin, polyphenols, nitrates, phytate) and that the antinutritional substances studied do not represent a risk for the population. They also highlighted that the contribution of dietary fibre was higher 45.93% (N. nigra), 46.28% (N. chilensis) and 48.15% (N. alba).

Gonzalez- Montemayora et al. [20] found a high protein digestibility in vitro for the whole meal of pods of N. nigra (60.97%) and N. alba (55.37%), the same as Galera [52], although for N. chilensis it had the lowest protein digestibility. (45.57%). In this species Silva et al. [39] recorded 71.18% and state that it decreases with unprotected storage time, reaching a digestibility of 30%.

Chagra Dib et al. [53] cite that milk production at the beginning of lactation increased when Creole goats that were on natural pasture are supplemented in winter with alfalfa hay, commercial balanced and “algarrobo” pods. It also improved butterfat and crude milk protein. Weight loss was lower when they received alfalfa hay plus “algarrobo” pods.

7. Conclusions

Numerous publications support the need to improve technological production processes to obtain quality “algarrobo” flour in order to have a food product of good nutritional quality, high added value, of natural origin both for local residents and those who want to engage in industrial activity. It is recommended to use proven genetic material when forest plantations of the Neltuma genus are carried out for industrial purposes. Algarrobo flour is a quality food with building properties because it contains proteins and energy due to its sugars, as well as salts, minerals and vitamins that serve as an excellent food for both human and animal consumption. There is a wide variability depending on the taxon and origin of the fruits. Hence, the need to increase research that characterises the physical, chemical and nutritional properties in order to provide consumers with “algarrobo” flour. The establishment of technical standards and guides for their implementation similar to those of Peru would be a very useful tool for “algarrobo” flour producers since it will allow to homogenise the production and quality of the product obtained to improve competitiveness and commercialization in the national and international market.

8. Supplementary material: “Algarrobo” flour recipes

8.1 Benefits and recipes

“Algarrobo” flour is obtained by grinding the pods and seeds. It helps regulate digestive and intestinal processes, due to its pectic acid and fibre content. It has low fat content. It has vitamins A, B, D, as well as a significant amount of minerals (magnesium, calcium, potassium, iron and phosphorus). Also, it is suitable for celiacs. Its versatility as a food is a real stimulus to create desserts and infusions. The recipes shown below are an example of this:

8.2 Own recipes

“Algarrobo” Cake

Ingredients: 1 cup of sugar, 1 cup of “algarrobo” flour, 3 large eggs, 1 teaspoon of vanilla essence, 2 cups of self-rising flour.

Preparation: Beat the eggs, add the sugar and “algarrobo” flour. Continue beating until obtaining a cream. Add vanilla essence, add the 2 cups of self-rising flour. Mix well. Finally add 1 cup of liquid yogurt of the flavour you prefer, mix well. Leave 10 minutes for the yogurt bacteria to act.

If it lacks liquid, add a little more yogurt, or lemon juice, or a few drops of cognac, or port. The sugar can be replaced by honey, but the “algarrobo” flour tastes like mount honey. Flour a cake pan and place the preparation. Place it in the oven. Cooking can take between 1/2 hour or an hour depending on the depth of the source to be used (Figure 6a).

Figure 6.

“Algarrobo” flour recipes: a) Fruit pudding, b) “algarrobo” bonbons and c) “algarrobo” cake.

“Algarrobo” Bonbons

Ingredients: 50 g of “algarrobo” flour, 50 g of rolled oats, 50 g of grated coconut, ½ cup of pastry dulce de leche, liquid yogurt if it is necessary.

Preparation: Mix the “algarrobo” flour with the rolled oats, the pastry dulce de leche to form a paste. Add grated coconut and liquid yogurt if it is necessary. Make balls and pass them through grated coconut to cover them (Figure 6c).

8.3 “Paciencia del Monte” recipes

Moulded Sweet Potato

Ingredients: 1 kg of sweet potato; 250 g pumpkin squash (*), 500 cc of water, 1 tablespoon of natural vanilla, agar-agar, 1 or 2 tablespoons of “algarrobo” flour, 3 or 4 tablespoons of honey [54].

Preparation: Peel the sweet potatoes and cut them into cubes under running water so that they do not turn black. Also, peel and cut pumpkin squash into cubes. Place the sweet potatoes together with the pumpkin squash in a container with water. Cook over moderate heat until everything is tender. Remove the preparation and let it warm slightly. Blend until it forms a cream and pour into a saucepan, perfume with vanilla. Bring it back to a low heat, over a diffuser, so that it heats up slowly and does not stick. Add agar-agar, dissolved in a little cold water and continue cooking, stirring with a wooden spoon for 5 more minutes. Remove from heat and add honey and mix. Pour into a mould, moistened with water or brushed with oil. When it begins to take consistency, dissolve the “algarrobo” flour with water to form a cream. Pour over the moulding. Mix with a spoon to give a marbled effect. Let it cool and cut it into portions.

(*) It is used to give better colour. If omitted, reduce a little amount of water.

Charlotte

Ingredients: 1/2 cup of “algarrobo” flour, 1/2 cup of water, 3 tablespoons of honey, natural vanilla, to taste.

Preparation: Mix the flour with the water trying not to form lumps. Bring the mixture to a low heat, cooking for 3 or 4 minutes, whilst stirring with a wooden spoon. Remove the preparation, sweeten it with honey and perfume it with vanilla. Use hot.

Creams

Ingredients: 1/2 kg pumpkins, ½ litre of water, 3 tablespoons of “algarrobo” flour, 1 tablespoon of corn starch, half walnuts to decorate.

Preparation: Peel the pumpkin and cut into cubes and cook them with water. Remove from the heat and blend the preparation. Bring back to the fire, over the diffuser. Separately, mix the “algarrobo” flour with the corn starch and dissolve everything with 3 tablespoons of cold water. Add to the previous preparation, stirring with a wooden spoon, until thick. Remove it, flavour it with vanilla, and sweeten it with honey. Pour it into little bowls, when it solidifies decorate each portion with a nuts and take it to the fridge until serving.

Fancy Cookies

Ingredients: 4 cups fine wholemeal flour, 1 cup “algarrobo” flour, 1 teaspoon baking soda, 1 tablespoon lemon zest; 3 tablespoons of honey, 1 egg, 3 tablespoons of oil, milk or water, the necessary amount.

Preparation: Arrange in a bowl the flours, the baking soda and the lemon zest. Separately, beat the honey with the egg, oil and vanilla. Mix both preparations as the milk or water is incorporated in sufficient quantity to form a consistent dough. Let it rest for 30 minutes. Stretch it with the help of a rolling pin until it is 1 cm thick. Cut squares 5 cm on each side or other shapes to taste, place the dough on oiled and floured plates. Bake them at a moderate temperature for 10 to 15 minutes. Remove them and let cool on a wire rack. Decorate them with natural jams.

Algarrobo Cream

Ingredients: ½ cup of “algarrobo” flour, 1 egg, 3 table spoons of honey, 3 tablespoons of ricotta, 1 teaspoon of natural vanilla.

Preparation: Place the “algarrobo” flour, egg, honey, ricotta and vanilla in the blender glass. Blend everything, adding a minimum of liquid (water or cooking liquid from some fruit) used to dip cakes or for decorations.

Lemon Pie

Ingredients: “Algarrobo” base for cakes: 1 tablespoon of fresh brewer’s yeast, required amount of warm water and 2 tablespoons of oil, 2 tablespoons of honey, 1 teaspoon of natural vanilla, 2 cups superfine wholemeal flour, 3 tablespoons of “algarrobo” flour.

Filling: Lemon yolk cream; 2 tablespoons of oil, 2 tablespoons of honey, lemon zest and juice, 2 egg yolks, 2 tablespoons of corn starch, 1 cup of water.

Meringue, according to the recipe.

Preparation: Dissolve the yeast in ½ cup of warm water. Add the oil, honey and vanilla. Separately, combine the flours and arrange them in the shape of a crown. Pour the previous preparation in the centre. Take the dough as water is incorporated: a medium consistency should be obtained. Place the bun in a warm place and let it rest for 30 minutes. Stretch it out.

Filling: Place in the blender glass: the oil, the honey, the zest with the lemon juice, the yolk and the starch. Blend as the water is incorporated. Pour the preparation into a container and take it to a water bath for 30 minutes, stirring with a wooden spoon. Remove the cream and pour it over the cake.

Arrange the meringue on top forming peaks. Gratinate at maximum temperature. Remove, cool and serve.

Fruit Pudding (Figure 6a).

Ingredients: 2 green apples, ½ cup of seedless raisins, 2 tablespoons of honey, 1 teaspoon of natural vanilla, a small bowl of oil, 2 tablespoons of fresh brewer’s yeast, required amount of warm water, 4 cups of fine wholemeal flour, 1 cup of “algarrobo” flour, 100 g of dried fruit (chopped walnuts and almonds, plums and figs in pieces, etc.).

Preparation: Arrange in the blender glass: cubed apples, raisins, honey, vanilla, oil and yeast, dissolved in 1/2 litre of water. Blend perfectly. Pour the smoothie over the previously mixed flours and combine the ingredients, adding more water, if necessary. It should be a more consistent paste than the sponge cake. Add the dried fruit, and let it rest for 30 minutes in a warm place. Pour into oiled and floured moulds. Let rise for 30 minutes in a preheated and turned off oven. Bake at a moderate temperature for 45 to 60 minutes (depending on the depth and diameter of the moulds used). Remove them, let them warm and unmould on a wire rack.

Cocadas

Ingredients: 3 cups of wholemeal flour, half a cup of “algarrobo” flour, 1 cup of grated coconut, ½ teaspoon of baking soda, 3 apples, 3 tablespoons of honey, 1 teaspoon of natural vanilla, the necessary amount of milk.

Preparation: Combine the flours with the coconut and the baking soda. Arrange them in the shape of a crown, placing the grated apples, honey and vanilla in the centre. Take the dough, incorporating the necessary milk to obtain a consistent paste. Let it rest for 30 minutes, place it in a sleeve with a wide curly nozzle. Make crests on oiled and floured plates. Cook the cocadas in the oven at maximum temperature for approximately 10 minutes. Remove them, let them warm and detach them with a spatula. Let them cool on a rack.

Brown Cake

Ingredients: 1 tablespoon of fresh brewer’s yeast, 1/2 cup of warm milk, 100 g of defatted ricotta, 2 tablespoons of oil, 4 tablespoons of honey, 1 teaspoon of natural vanilla, 3 cups of superfine wholemeal flour, ½ cup of “algarrobo” flour, 1 cup of corn starch, 1 apple, 50 g of seedless raisins. To decorate: 400 g Chantilly, ricotta (or natural jams).

Preparation: Dissolve yeast in warm milk. Beat it and let it rest. Place in the blender glass: the ricotta, the oil, the honey and the vanilla. Blend and reserve. Mix the flours and starch in a large bowl. Make a hole in the centre and pour the yeast and the liquid inside. Work the dough, incorporating the flours on the sides until you achieve a consistency similar to that of a sponge cake. If it is necessary add more warm milk. Add the diced apple, raisins and walnuts, mixing to distribute well. Let the mixture rest in a warm place for 30 minutes, pour it into a 30 cm diameter and 12 cm high pan (or 2 smaller moulds) oiled and floured. Bake at moderate temperature for approximately 40 minutes. The cake is ready when the surface is consistent and detaches from both sides of the mould. Remove it, let it warm and unmould it on a wire rack.

“Algarrobo” Jelly

Ingredients: ½ litre of water, 1 tablespoon of agar-agar, 2 tablespoons of “algarrobo” flour, 1 tablespoon of lemon zest, 3 or 4 tablespoons of honey.

Preparation: Place the water over low heat. Separately, mix the agar-agar with the carob and add 5 tablespoons of cold water. Add the boiling water, stirring continuously with a wooden spoon. Continue cooking for approximately 10 minutes without stopping stirring, and add the zest. Remove the preparation and add the honey. Mix very well and pour into individual moulds. When the preparation is warm, take them to the fridge and reserve them until dessert time, unmould and decorate with fresh fruit.

Añapa (Refreshing Drink)

Preparation: Mix “algarrobo” flour with very cool water, let stand for about an hour and then strain. This drink is more nutritious and natural than all commercial sodas made with industrial flavourings and colourings.

Acknowledgments

The authors of this chapter are grateful for the contributions to writing in English made by by Analia Piacenza, Victoria Ubino and Susi Garcia.