Advances on the Antioxidant Peptides from Nuts: A Narrow Review

Abstract

Antioxidant peptides extracted from natural foods have been studied for their potential use in the development of additives, nutraceuticals, and therapeutic agents. Nut proteins are considered an excellent source of plant-derived proteins for the human diet, due to their high protein content and digestibility of up to 86.22%. Furthermore, compared with grain and soybean proteins, nut proteins have a special amino acid composition, which makes their protein structure different, and promotes their disparate functional characteristics and great bioactivity potential. This review presents the most remarkable studies on antioxidant peptides from nuts, to gain insights into feasible production methods, different evaluation indexes within in vivo or in vitro systems, high bioavailability, and the complex structure-activity relationship resulting from the particularity of their protein structure and amino acid composition. Previously published studies mainly focused on the effects of the production methods/processes of nut-derived peptides on antioxidant activity, and proved that nut-extracted antioxidant peptides can resist the degradation of acid, alkali, and gastrointestinal enzymes, have high antioxidant activity in vitro and in vivo, and also have the potential to cross small intestinal epithelial cells in a stable and integral manner. However, the structure-activity relationship of antioxidant peptides from nuts has not been fully established, and the structure information of antioxidant peptides obtained from various nut protein sources is still unclear. The findings presented in this review can be used to provide the theoretical basis for the design and production of nut-derived antioxidant peptides.

Antioxidant Properties of Protein-Rich Plant Foods in Gastrointestinal Digestion—Peanuts as Our Antioxidant Friend or Foe in Allergies

“…Hwang et al, 2008, found that roasted and defatted peanut esterase hydrolysate could moderate linoleic acid autoxidation, scavenge DPPH free radicals and inhibit human LDL oxidation in vitro [138], attributing these effects to Maillard reaction products from the lipid-carbohydrate-protein system in roasted peanuts. Zhao et al, 2022 reviewed all antioxidant peptides from nuts generated by various enzymatic hydrolyses since 2010, and among 33 references compiled, 10 were dedicated to peanut preparations [140]. Only one study employed pepsin as the representative of GIT proteases, showing that peanut peptides obtained by pepsin possess one-third lower antioxidant activity by DPPH scavenging radical test than the hydrolysates obtained by alcalase and that this activity does not change concerning the varying degree of hydrolysis [141].…”

“…Data regarding the antioxidant peptides derived from the nuts are emerging [ 135 , 137 , 138 , 139 , 140 ]. The type and position of amino acids, grand average of hydropathicity index and its mass are smartly used to select six candidate peptides (upon analysis of BIOPEP database): FSEY, QIESW, SEGFEW, IDLGTTY, GEGFFEM and NLNQCQRYM from hazelnut protein hydrolysates with higher antioxidant capacity than glutathione against linoleic acid oxidation [ 135 ].…”

Insights into the Hippocampus Proteomics Reveal Epigenetic Properties of Walnut-Derived Peptides in a Low-Grade Neuroinflammation Model

“…Chronic neuroinflammation and oxidative stress are crucial contributors to the emergence of neurological diseases . Increasing findings imply that food-derived peptides can improve the onset of several neurodegenerative diseases by lowering the secretion of inflammatory cytokines and preventing the oxidative damage . Ni et al found that protein hydrolysate from chicken meat improved the performance of short- and long-term memory during the novel object recognition trial by alleviating hippocampal neuroinflammation and oxidative stress in middle-aged mice .…”

“…5 Increasing findings imply that food-derived peptides can improve the onset of several neurodegenerative diseases by lowering the secretion of inflammatory cytokines and preventing the oxidative damage. 6 Ni et al found that protein hydrolysate from chicken meat improved the performance of short-and long-term memory during the novel object recognition trial by alleviating hippocampal neuroinflammation and oxidative stress in middle-aged mice. 7 Wang et al demonstrated that walnut protein hydrolysate (WPH) enormously promoted the frequency of crossing the platform, increasing the frequency and distance of crossing the target quadrant, decreasing the escape latency and distance in the Morris water maze test compared with the lipopolysaccharide (LPS)-induced cognitive impairment mice.…”

Prediction of ACE‐inhibitory and antioxidant peptides from storage proteins of edible seeds and nuts using in silico approaches

“…Seeds of sunflower, sesame, mustard, and soyabean known to have high contents of proteins are excellent source of bioactive peptides with health‐promoting properties (Samtiya et al, 2021). Bioactive peptides and proteins derived from almond, cashewnut, peanut, walnut and hazelnut have demonstrated remarkable biological properties which may be used as ingredients to formulate therapeutic functional foods and nutraceuticals (Arya et al, 2016; Çağlar et al, 2021; Chen et al, 2021; Huang et al, 2022; Li et al, 2020; Zhao et al, 2022). Even though edible seeds and nuts are known as promising source for bioactive peptides with health benefits, there is inadequate information on the biological characterization of bioactive peptides derived from these sources.…”