Open access peer-reviewed chapter - ONLINE FIRST

# Valorization Options of Strawberry Extrudate Agro-Waste. A Review

By Juan Cubero-Cardoso, Antonio Serrano, Ángeles Trujillo-Reyes, Denys K. Villa-Gómez, Rafael Borja and Fernando G. Fermoso

Submitted: July 16th 2020Reviewed: September 11th 2020Published: October 12th 2020

DOI: 10.5772/intechopen.93997

## Abstract

This review summarizes and critically analyzes the different types of potential valorization options for strawberry extrudate in order to have a broader overview of the potential management of this waste. Animal feed is commonly used as a management option for the strawberry extrudate; however, most of the strawberry extrudate is disposed in landfills. Strawberry extrudate contains different bioactive compounds that encourage the use of an alternative management approach than landfilled. The present review offers a complete comparative, including the advantages and drawbacks of each reviewed technique, to facilitate the selection of the most suitable technology for the different valorization scenarios. This review has been structured in three sections: 1. Composition of the strawberry extrudate and strawberry especially focused on their content in bioactive compounds. 2. The different techniques of extraction and purification of bioactive compounds. 3. The handling and management of the resulting biomass after the extraction process of bioactive compounds.

### Keywords

• strawberry extrudate
• bioactive compounds
• bioproducts
• extraction techniques
• purification

## 1. Introduction

### 4.3 Bioethanol production

Bioethanol is one of the most produced alcohols from the fermentation of sugars found in fruits and vegetables [7, 91, 92, 93]. Theoretically, any organic product with a high content of sugars and starch, such as strawberry extrudate, may be susceptible to obtaining bioethanol [91]. Inedible sources from the strawberry extrudate such as lignocellulosic biomass, which mainly comprises cellulose, hemicellulose, and lignin, can be hydrolysed to produce a mixture of pentoses and hexoses that can be transformed into bioethanol [94]. Bioethanol from agro-waste, such as strawberry extrudate, could be a promising technology that involves four processes, pre-treatment, enzymatic hydrolysis, fermentation and distillation, this final step is crucial for the process to be economically viable on a commercial scale due to high energy consumption in the form of steam to increase the yield of bioethanol production when lignocellulose materials are used as raw material [93]. These processes have several challenges and limitations, such as the efficient pre-treatment process to eliminate lignin from the lignocellulosic agro-residues. The proper pre-treatment process can increase the concentrations of fermentable sugars after enzymatic hydrolysis, thus improving the efficiency of the entire process [92].

### 4.4 Bioplastics production

Fossil fuel depletion, global warming, and problems of pollution of the environment that provoke plastics in its life cycle are encouraging the development of biodegradable plastics [95, 96]. Agri-food waste are usually rich in many useful substances such as lipids, polysaccharides, and aromatics, which could be used for the manufacture of biodegradable polymeric materials. Bioplastics already play an important role in the sectors of packaging, agriculture, consumer electronics and motoring, but still have a very low share in the total production of plastics. Currently, about 1% of the annual tons of plastic are bioplastics [97]. Examples of such bioplastics are exopolysaccharides, polycaprolactone, polybutylene succinate, polybutylene adipate terephthalate, polyhydroxyalkanoates or polyhydroxybutyrates [97, 98]. For obtaining bioplastics from agri-food waste, the waste must be treated to extract or isolate specific macromolecules, such as cellulose, lignin, suberin, starch, or monomers, such as vegetable oils, tannins and terpenes [96, 99]. A study conducted on the production of bioplastics from Murta fruit extract, that is a native Chilean berry, showed the feasibility of using berries for bioplastic production [8].

### 4.5 Biochar production

Biochar is the solid carbonaceous residue produced through organic waste and used as a soil improver [100, 101]. Biochar is produced through several types of methods such as pyrolysis, torrefaction or hydrothermal carbonization [100, 101].

There are no studies reported in the literature dealing with the production of biochar from strawberry extrudates. However, the above-mentioned techniques (pyrolysis, torrefaction and hydrothermal carbonization) could be potentially applied for this substrate. Several studies have been carried out on the hydrothermal carbonization of other agri-food waste, such as olive cuttings and olive pulp [102]; grape marc [103]; olive mill waste, canned artichoke and orange waste [104].

## 5. Conclusions

This chapter has reviewed up-to-date literature on the bioactive compounds contained in strawberries, which have an important health and market value. Different extraction and purification techniques to obtain valuable compounds from strawberry extrudate have been reviewed and analyzed. The reviewed techniques present different advantages and drawbacks that were analyzed to facilitate the selection of the most suitable process for each valorisation scenario. Finally, different stabilization options for the biomass remaining after extraction have also been reviewed. Stabilization is required to avoid severe environmental impacts, and additionally could be an economically beneficial aid for balancing the cost of the extraction of high value-added compounds. As usually for any waste management option, selection of the best extraction, purification and stabilization technique for the strawberry extruded is a tailor-made solution for each situation.

## Acknowledgments

This research was funded by the Spanish Ministry of Economy and Competitiveness by Project CTM2017-83870R. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).

## Conflict of interest

The authors declare no conflict of interest.

## How to cite and reference

### Cite this chapter Copy to clipboard

Juan Cubero-Cardoso, Antonio Serrano, Ángeles Trujillo-Reyes, Denys K. Villa-Gómez, Rafael Borja and Fernando G. Fermoso (October 12th 2020). Valorization Options of Strawberry Extrudate Agro-Waste. A Review [Online First], IntechOpen, DOI: 10.5772/intechopen.93997. Available from: