Techno functional properties of bioactive proteins from indigenous apricot cultivar. Habi and Shai oil cake by alkaline solution and isoelectric precipitation
Highlights
- •Transformation of low-value agro-industrial residue into a high-protein ingredient contributes to waste reduction and supports the development of environmentally friendly food solutions.
- •The extracted protein isolates showed notable improvements in functional and health-promoting properties.
- •The isolated demonstrated good digestibility when treated with pepsin and pancreatin and showed antimicrobial activity against pathogens like Escherichia coli and Pseudomonas fluorescens.
- •These findings provide a scientific basis for incorporating apricot seed proteins into various food systems as novel and functional alternatives.
Abstract
The valorization of agro-industrial by-products as sustainable plant protein sources has gained increasing attention due to the growing demand for alternative proteins and the need to reduce food processing waste. However, information on the extraction and bio-functional properties of proteins from indigenous apricot (Prunus armeniaca L.) kernel oil cakes remains limited. This study investigated the extraction of protein isolates from apricot cultivars Habi and Shai using ultrasound-assisted alkaline extraction followed by isoelectric precipitation and evaluated their physicochemical, functional, bioactive, and in vitro digestibility properties. Ultrasound-assisted extraction enhanced protein recovery, increasing it to 71.3% (Habi) and 77.8% (Shai). The isolates exhibited desirable functional characteristics, including water-holding capacity (0.53 and 0.40 g/g), oil-holding capacity (0.79 and 0.55 g/g), mean emulsion droplet size (2.8 and 2.65 μm), foaming capacity (38.9 and 48.3%), and foaming stability (39.0 and 37.6%) for Habi and Shai, respectively. Maximum protein stability was observed at pH 9.0. Both isolates showed concentrated-dependent α-glucosidase inhibitory activity, reaching 45% and 37.6% inhibition at 2500 mg/mL for Habi and Shai, respectively. Simulated gastrointestinal digestion significantly increased the degree of hydrolysis, antioxidant activity as determined by DPPH (38.7 and 44.4%)and ABTS (51.2 and 54.5%) assays and reducing power. Enzymatic hydrolysates generated using pepsin and pancreatin also exhibited enhanced antimicrobial activity against Escherichia coli (12 and 14 mm for Habi and Shai, respectively) and Pseudomonas fluoroscens (9.6 and 12.8 mm for Habi and Shai, respectively). This study demonstrates, for the first time, that protein isolates obtained from indigenous Pakistani apricot kernel oil cakes possess excellent techno-functional and bioactive properties, highlighting their potential as sustainable functional food ingredients, natural antioxidants, and nutraceutical protein sources in value-added food systems.
