Yield, physicochemical, and antioxidant properties of Atlantic salmon visceral hydrolysate: Comparison of lactic acid bacterial fermentation with Flavourzyme proteolysis and formic acid treatment

Abstract

This study compares a cost‐effective microbial method, involving lactic acid (LA) fermentation, with the conventional formic acid (FA) treatment and Flavourzyme (FL) enzymatic hydrolysis for valorizing Atlantic salmon processing waste (Viscera). LA and FA processing approaches relied on production (LA) or addition (FA) of organic acids to lower the pH and activate the inherent proteases in these tissues, whereas FL processing was carried out at the optimum conditions for Flavourzyme (37 °C, pH 7.0). Highest protein hydrolysate fraction recovery (∼57%) was seen in LA fermentation, while FA processing resulted in the highest protein levels (∼87%) in the recovered hydrolysate fraction and lowest residual fraction (∼4%). In general, FL processing demonstrated higher Fe(II) chelation (73%) and ferric reducing capacity (27 mM glutathione equivalent) whereas LA‐hydrolysates showed enhanced sacrificial antioxidant properties. Findings from this study would have implications on the application and production of salmon‐based protein hydrolysates, especially, from the perspective of their functionality. Practical applications Peptides derived from natural sources such as fish products have been extensively reported to exert antioxidant activity that mitigates oxidative stress and providing beneficial effects to human health as well as food storage. Several sources of proteins are being explored for the production of biologically active peptides. Utilizing by‐product streams such as fish processing waste is especially attractive as these are cheaper and rich sources of protein. Therefore, utilizing marine bioprocessing waste for the production food‐grade protein hydrolysates is promising, especially in Atlantic Canada.

Functional and Bioactive Properties of Peptides Derived from Marine Side Streams

“…As mentioned before, bacterial enzymes can also release peptides through their own natural metabolism. With respect to this, protein hydrolysates with reported functional and bioactive properties have been prepared from Atlantic salmon side streams by a lactic acid bacteria inoculum [28].…”

Production and processing of antioxidant bioactive peptides: A driving force for the functional food market

“…Production of antioxidant peptides from various protein sources using the fermentation process involves inoculation of microbial strains into the reactor containing homogeneous mixtures of concentrated protein, water and microbial foods, mostly simple sugars, which can be used by the strains for growth and development (Najafian and Salam, 2018). The protein is mostly broken by microbes activity and peptidases secreted by the action of microbes during fermentation (Rajendran et al, 2018). Therefore, the choice of microbial strains is highly important to generate sufficient and effective peptides with high antioxidant activity (Ozyurt et al, 2017).…”

“…Lactic acid bacteria are frequently used to produce antioxidant peptides from different protein sources. Several studies reported the production of antioxidant protein hydrolysates and peptides from the protein of different plant, animal and marine sources, and their industrial by-products fermented by Bacillus subtilis A26, Bacillus amyloliquefaciens An6, Streptococcus spp., Lactobacillus brevis, Lactobacillus plantarum, Pediococcus acidilactici and Enterococcus gallinarum (Godinho et al, 2015;Jemil et al, 2016;Najafian and Babji, 2018;Ozyurt et al, 2017;Rajendran et al, 2018). Najafian and Salam (2018) identified two new antioxidant peptides, Ala-Ile-Pro-Pro-His-Pro-Tyr-Pro and Ile-Ala-Glu-Val-Phe-Leu-Ile-Tre-Asp-Pro-Lys, from Loma fish protein hydrolysate fermented by Lactobacillus plantarum IFRPD P15.…”

Production of Bioactive Peptides from Lactic Acid Bacteria: A Sustainable Approach for Healthier Foods

“…The production of bioactive peptides by LAB proteolysis of fish‐based residues have not been demonstrated yet. Rajendran, Mohan, Khiari, Undenigwe, and Mason () compared three different treatments to obtain protein hydrolysates with antioxidant properties including LAB fermentation, which showed enhanced glutathione protection against oxidation when compared with enzymatic or intentional acidification. However, they attributed the generation of this antioxidant peptides by the action of inherent proteases in the tissues of the fish residue, which are activated by pH reduction instead of the proteolytic action of LAB proteases.…”