Optimization of biomimetic fermentation technique for enhanced and eco-friendly extraction of phenolics from pomegranate peel

Abstract

In this research, we mimicked pomegranate orchard conditions for Aspergillus growth on powdered pomegranate fruit waste (PFW) to extract and purify phenolic compounds. Pomegranate's high ellagitannin content makes it attractive to Aspergillus sp., whose spores are abundant in these environments. Four experiments were conducted with varying PFW:water ratios (1:2.5, 1:5, 1:7, and 1:10), aeration, agitation, and incubation times. The 1:10 ratio achieved the highest antioxidant activity (256.34 mg GAE/g DM) and total phenolic content (300.3 mg GAE/g DM) after 48 h of fermentation, comparable to advanced chemical methods. PCR analysis identified Aspergillus tubingensis, and mycotoxin measurements showed no detectable aflatoxins or ochratoxin A, confirming extract safety and purity. This study introduced a pioneering, natural method for phenolic extraction. Additionally, the very higher protein content of fermented extract (1.18 %) compared to the non-fermented extract (0.03 %), suggests its potential as an attractive topic for future investigations as source of food industrial enzymes.