Emerging Green Techniques for the Extraction of Antioxidants from Agri-Food By-Products as Promising Ingredients for the Food Industry

Abstract

Nowadays, the food industry is heavily involved in searching for green sources of valuable compounds, to be employed as potential food ingredients, to cater to the evolving consumers’ requirements for health-beneficial food ingredients. In this frame, agri-food by-products represent a low-cost source of natural bioactive compounds, including antioxidants. However, to effectively recover these intracellular compounds, it is necessary to reduce the mass transfer resistances represented by the cellular envelope, within which they are localized, to enhance their extractability. To this purpose, emerging extraction technologies, have been proposed, including Supercritical Fluid Extraction, Microwave-Assisted Extraction, Ultrasound-Assisted Extraction, High-Pressure Homogenization, Pulsed Electric Fields, High Voltage Electrical Discharges. These technologies demonstrated to be a sustainable alternative to conventional extraction, showing the potential to increase the extraction yield, decrease the extraction time and solvent consumption. Additionally, in green extraction processes, also the contribution of solvent selection, as well as environmental and economic aspects, represent a key factor. Therefore, this review focused on critically analyzing the main findings on the synergistic effect of low environmental impact technologies and green solvents towards the green extraction of antioxidants from food by-products, by discussing the main associated advantages and drawbacks, and the criteria of selection for process sustainability.

Improved Oxidative Stability and Sensory Quality of Beef Hamburgers Enriched with a Phenolic Extract from Olive Vegetation Water

“…To control lipid oxidation in fresh ground meat preparations and extend their shelf-life, food additives with antioxidant properties are usually employed. In a clean label perspective of meat product formulation, synthetic food antioxidants could be replaced by natural extracts obtained from agri-food by-products and waste, which are rich in bioactive compounds (such as carotenoids, phenolic compounds, essential oils, or β-glucans) [ 9 , 10 ] that display different health properties, and antioxidant and antimicrobial activities. In this regard, one of the most interesting food by-products is olive mill wastewater (OMWW), which is generated during olive processing for the production of olive oils and is characterized by a high content of organic compounds (sugars, tannins, pectins, and phenolic substances) and mineral salts [ 11 ].…”

Pulsed Electric Field-Assisted Extraction of Aroma and Bioactive Compounds From Aromatic Plants and Food By-Products

“…Nowadays, the food, pharmaceutical, and cosmetic industries are continuously striving to meet the evolving consumer demands for clean labels and natural compounds with functional and health beneficial properties (flavorings, colorants, antioxidants) (1,2). In this line, the plant extracts market is increasingly catching on, and the preferences for natural products are expected to drive its growth during the coming years (3).…”

“…On the other hand, conventional extraction methods are typically time and energy consuming, and require excessive usage of organic solvents, which are mostly toxic and harmful (13). In light of these drawbacks, recently more sustainable, efficient, rapid, and environmentally friendly extraction techniques based on the use of green solvents coupled with emerging technologies, such as microwave, ultrasound, and pulsed electric field (PEF), were proposed to reduce the mass transfer resistances of target solutes and solvents through the cell envelop (membrane, wall) (1).…”

Pressurized Liquid Extraction of Polyphenols and Anthocyanins from Saffron Processing Waste with Aqueous Organic Acid Solutions: Comparison with Stirred-Tank and Ultrasound-Assisted Techniques

“…Plant processing by-products consist mainly of peels, seeds, stems, flowers, and disfigured and undersized or damaged tissues. These residues are rich in a spectrum of bioactive compounds including polyphenols, carotenoids, oils, pectins, etc., and their promotion as cheap and abundant bioresources is state-of-the-art for the commercialization of commodities in the food, pharmaceutical, and cosmetics industry [4]. Thus, proper management of these byproducts should target their re-introduction to the production line as raw materials for the obtaining of novel products with health-related properties and added value through sustainable technologies of extraction [3].…”