Pomegranate Peel Based Novel Food Product

Abstract

Pomegranate peel (PoP) is a valuable waste of juice processing industry and is a rich source of biomolecules of immense health significance. Plentiful research based evidences on ethnopharmacological and nutraceutical properties of PoP calls for the attention of food scientists in designing food products with innate ability to improve quality of life. This study focuses on exploring nutritional and nutraceutical properties of PoP, hydro-alcoholic extracts and the bagasse as ingredient of choice in developing novel food product. An indigenous cultivar of pomegranate “Alipuri” was procured from the local farm of Southern Punjab and pomegranate peel hydro-alcoholic extracts (PoPx) were derived from the peel fraction of the fruit. Nutritional and biological properties of PoP revealed the waste as a potential source of compounds bearing significant antimicrobial, antioxidant and antiulcer activities. Hydro-alcoholic extracts of PoP revealed significantly (p<0.05) higher concentration of phenolics i.e. 427.19 mgGAE/g and radicals scavenging activities as measured by DPPH and FRAP assays. Hydro-alcoholic extracts of PoP inhibited urease activity by 97.9% and IC50 for different extracts was recorded ~44.4 μM. PoP extracts presented significant inhibitory properties against gram positive and negative microorganisms including Pseudomonas aeruginosa, Escherichia coli, Salmonella typhimurium, Bacillus subtilis, Staphylococcus aureus and Aspergillus niger. Minimum inhibitory concentration (MIC) of PoPx was recorded between 0.25–0.89 mg/mL. With reference to its features to be utilized as a food ingredient, PoP and the peel bagasse (PM) were incorporated in baked good for the development of nutritionally enriched and biologically stable cookies. The study revealed PoP supplementation to impart significant (p<0.05) improvement in dietary fibers (0.32–1.96 g/100 g), total phenols (90.7–161.9mg GAE/100 g) and inorganic residues (0.53–0.76 g/100 g) of cookies. Cookies carrying highest levels of PoP (7.5%), PoPx (1.0%) and PM (7.5%) were recorded with more than 50% radical scavenging activity whereas, products phenolics pool significantly inhibited oxidative and microbiological deterioration of the finished good during three months storage period. Cookies supplemented with PoP were recorded to present organoleptically acceptable quality at 6.0% supplementation while least difference in sensorial profile was noticed among control and cookies developed with 1.0% PoPx. Toxicity assessment of PoPx at higher doses i.e. 1000ppm presented non-lethal response in brine shrimps larvae. Safety assessment of PoP, PoPx and PM revealed non-significant (p>0.05) 8 effect of supplementation on various blood indices among normal healthy rats model. Lipid modulatory role of PoP and its extracts was witnessed convincingly indicating PoP and the extracts as viable ingredient in improving high density lipoprotein and lowering low density lipoprotein concentration. The study delineates no abnormal rise or fall in hematological parameters thereby suggesting a nontoxic response of PoP and its various fractions. The findings of this research propose PoP as a valuable waste of food processing industry that could further be exploited in designing nourishing recipes bearing disease preventive and ameliorative features.