Abstract
Defatted peanut meal is a low value agro-industrial residue from peanut oil production with potential use as a value addition food ingredient. In this study, peanuts were roasted at 100°C for 5 min, de-skinned and milled into whole peanut flour (WPF) from which the defatted meal (DPM) was prepared by acetone extraction and the peanut protein concentrate (PPC) obtained from the DPM using isoelectric pH precipitation. The protein content, amino acid profile, total phenolic content (TPC), total flavonoid content (TFC) and in vitro antioxidant properties of the peanut samples were then determined. Results showed that DPM had a TPC of 0.12 ± 0.02 mg gallic acid equivalent (GAE)/g, which was significantly (p < 0.05) higher than and twice the levels in WPF and PPC (0.06 ± 0.03 mg GAE/g). However, WPF had TFC of 0.21 ± 0.01 μg quercetin equivalent (QE)/g, which was significantly (p < 0.05) higher than DPM (0.16 ± 0.03 μg QE/g) and PPC (0.11 ± 0.05 μg QE/g). However, PPC had superior amino acid profile in addition to stronger radical scavenging and metal chelation activities than WPF and DPM. The results suggest that PPC is a protein rich product that could be utilized as an ingredient in food product fortification to enhance nutritional quality and in the formulation of functional foods with antioxidant benefits.
Highlights
Peanuts (Arachis hypogaea), known as groundnuts are protein-rich edible oilseed legumes grown in the tropical and subtropical regions
The total phenolic content (TPC) value of defatted peanut protein meal (DPM) (0.12 mg gallic acid equivalent (GAE)/g dry wt) was twice the values observed for whole peanut flour (WPF) and peanut protein concentrate (PPC) (0.06 mg GAE/g dry wt), which may have been caused by lipid removal coupled with the adopted processing method
Plant proteins generally exhibit low solubility and the presence of lipids in a flour could alter the solubility by sequestering hydrophobic polyphenols, which could have contributed to the higher TPC of WPF compared to the DPM and PPC in which lipids were removed
Summary
Peanuts (Arachis hypogaea), known as groundnuts are protein-rich edible oilseed legumes grown in the tropical and subtropical regions. Peanuts could be a good replacement for tree nuts especially for low-income communities and underdeveloped economies since both have similar morphology and nutritional profile. The entirety of the peanut plant is a rich conglomerate of phenolic compounds and the kernel, testa, hull and by-products are used in various food formulations (Arya et al, 2016; Toomer, 2020). Recent studies have suggested that peanuts could be used in composite flour for the production of flatbread (Salve et al, 2020), animal feeds (Duodu et al, 2018), food packaging (Riveros et al, 2018), and probiotics supplements (Klu et al, 2014). The interest in phenolic compounds derived from vegetables and their biological roles in nutrition and disease reduction is increasing (Giada, 2013; Gutiérrez-Grijalva, 2016)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
