High-Pressure Technologies for the Recovery of Bioactive Molecules from Agro-Industrial Waste

Abstract

Large amounts of food waste are produced each year. These residues require appropriate management to reduce their environmental impact and, at the same time, economic loss. However, this waste is still rich in compounds (e.g., colorants, antioxidants, polyphenols, fatty acids, vitamins, and proteins) that can find potential applications in food, pharmaceutical, and cosmetic industries. Conventional extraction techniques suffer some drawbacks when applied to the exploitation of food residues, including large amounts of polluting solvents, increased time of extraction, possible degradation of the active molecules during extraction, low yields, and reduced extraction selectivity. For these reasons, advanced extraction techniques have emerged in order to obtain efficient residue exploitation using more sustainable processes. In particular, performing extraction under high-pressure conditions, such as supercritical fluids and pressurized liquid extraction, offers several advantages for the extraction of bioactive molecules. These include the reduced use of toxic solvents, reduced extraction time, high selectivity, and the possibility of being applied in combination in a cascade of progressive extractions. In this review, an overview of high-pressure extraction techniques related to the recovery of high added value compounds from waste generated in food industries is presented and a critical discussion of the advantages and disadvantages of each process is reported. Furthermore, the possibility of combined multi-stage extractions, as well as economic and environmental aspects, are discussed in order to provide a complete overview of the topic.

Phytochemicals Determination, and Antioxidant, Antimicrobial, Anti-Inflammatory and Anticancer Activities of Blackberry Fruits

“…The process of extraction is not a selective method for the obtention of bioactive compounds. Thus, during the process, sugars, fibers, proteins, fats and other compounds with low or any antioxidant activity may be extracted [ 58 ]. Even so, the antioxidant activity exerted by blackberry extract by FRAP assay was comparable to 108 mg/g d.w. of quercetin and a 73.8 mg/g d.w. of ascorbic acid.…”

Juçara Fruit (Euterpe Edulis Martius) Valorization Combining Emergent Extraction Technologies and Aqueous Solutions of Alkanediols

“…A pressure of 10 MPa was chosen to perform the high-pressure extractions since it has been reported in the literature that a pressure higher than 10 MPa has a negligible effect on the solubilization and recovery of the target compounds [ 16 , 57 ]. One of the explanations for this is attributed to the change in density with pressure, which is generally insignificant due to the non-compressibility of the liquid [ 58 ]. In addition, the use of higher pressure conditions is directly associated with higher energy requirements.…”

Passion fruit (Passiflora edulis Sims) by-products as a source of bioactive compounds for non-communicable disease prevention: extraction methods and mechanisms of action: a systematic review

“…Viganó ( 110 ) investigated the use of pressurized liquids assisted by ultrasound on defatted passion fruit bagasse and identified the presence of polyphenols. It focused on agro-industrial waste and utilized high-pressure technologies to extract antioxidants, and it can be possible to extract piceatannol and sirtuin B from bagasse using sequential high-pressure extractions ( 110 , 117 ).…”