Peptide Fractions Obtained from Rice By-Products by Means of an Environment-Friendly Process Show In Vitro Health-Related Bioactivities

Abstract

Recently, the isolation of new health-related bioactive molecules derived from agro-food industrial by-products by means of environment-friendly extraction processes has become of particular interest. In the present study, a protein by-product from the rice starch industry was hydrolysed with five commercial proteolytic enzymes, avoiding the use of solvents or chemicals. The digestion processes were optimised, and the digestates were separated in fractions with four different molecular weight ranges by using a cross-flow membrane filtration technique. Total hydrolysates and fractions were tested in vitro for a wide range of biological activities. For the first time rice-derived peptides were assayed for anti-tyrosinase, anti-inflammatory, cytotoxicity and irritation capacities. Antioxidant and anti-hypertensive activities were also evaluated. Protamex, Alcalase and Neutrase treatments produced peptide fractions with valuable bioactivities without resulting cytotoxic or irritant. Highest levels of bioactivity were detected in Protamex-derived samples, followed by samples treated with Alcalase. Based on the present results, a future direct exploitation of isolated peptide fractions in the nutraceutical, functional food and cosmetic industrial fields may be foreseen.

Food-Derived Bioactive Peptides in Human Health: Challenges and Opportunities

“…Furthermore, the choice of protease used and the time of enzymatic hydrolysis could be important in deciding the type of peptides generated. For example, rice proteins hydrolyzed with bacillolysin showed a stronger anti-inflammatory and anti-tyrosinase activities compared with those hydrolyzed by subtilisin [ 18 ]. On the other hand, samples hydrolyzed with leucyl and papain aminopeptidase and cysteine endopeptidase showed the least activity [ 18 ].…”

“…For example, rice proteins hydrolyzed with bacillolysin showed a stronger anti-inflammatory and anti-tyrosinase activities compared with those hydrolyzed by subtilisin [ 18 ]. On the other hand, samples hydrolyzed with leucyl and papain aminopeptidase and cysteine endopeptidase showed the least activity [ 18 ]. Similarly, different enzymes generated bioactive peptide-rich hydrolysates from bovine muscle and porcine plasma with divergent taste profiles, as observed in a recent study [ 19 ].…”

Bioactive Peptides

“…The peptides may be recovered by freeze-drying, desalting [19], cross-flow membrane filtration [35], and membrane ultrafiltration or column chromatography. Gel filtration can be used to quickly desalt low molecular weight peptides and separate them based on their sizes.…”

Introductory Chapter: From Waste to New Resources

“…Tea waste Microwave-assisted extraction/solvent extraction [28] Oils Rice bran Supercritical carbon dioxide extraction and compressed liquefied petroleum gas/solid-liquid extraction [36,37] Essential oils Citrus peel Solvent extraction/hydrodistillation [38] Steam explosion at high temperature and pressure [39] Microwave-assisted hydro-diffusion [40] Proteins Brewers' spent grain Sequential extraction of proteins and arabinoxylans; enzymatic-assisted extraction [15,41] Rice by-products Enzymatic hydrolysis and membrane filtration technique [42] Hazelnut meal Solvent extraction (water, acetone) [43] Rapeseed by-products Ultrasound-assisted aqueous extraction [44] Carotenoids Tomato pomace and skin Enzymatic-assisted extraction [45] Supercritical fluid extraction/solvent extraction [46] Supercritical fluid extraction [47] Citrus peel Ultrasound-assisted extraction [48] Sea buckthorn seeds Supercritical carbon dioxide fluid extraction [49] Proteins and bioactive peptides Whey wastewater Membrane separation/ultrafiltration/microfiltration/nanofiltration/reverse osmoses [50] Mild enzymatic hydrolysis [51] Cheese whey Ultrafiltration/nanofiltration [52] Fish and chicken Isoelectric solubilization and precipitation [53] Sardine solid waste Enzymatic hydrolysis and ultrafiltration [54] Shellfish Enzymatic hydrolysis and micro-, ultra-, and nanofiltration/ion exchange chromatography [55] Sugars Whey wastewater Membrane separation and spray drying [50] Cheese whey Ultrafiltration/nanofiltration [52] satisfy the current demands of economic preservation and consumer satisfaction in safety, nutritional and sensory aspects. Also, as the preservation of foods is often a multicomponent issue, the "hurdle" concept was introduced, highlighting the complex interaction between the factors that are significant for food safety and stability [56][57][58].…”