Purification of the apple pomace polyphenol extract using adsorbent resin

Polyphenols from agro-industrial waste particularly of fruit origin are a reliable source of antioxidants and antimicrobials that can be used as natural food additives. Organic solvents play an important role in extracting the polyphenols, however, inefficiency in exerting bioactivity and interference with the organoleptic properties are among the reasons that hinder their use as food additives. These problems can be alleviated by purification. In this study, the effect of resin types and elution solvent for purification of the apple pomace extracts on total phenolic content (TPC) and antioxidants were investigated. Crude ethanolic extracts were purified using amberlite resins (XAD7HP and FPX66) in a glass column (25 × 310 mm). The sorption flow rate was 2 Bed volume (BV) per hour, rinse 2 BV per hour, and desorption was 2 BV per hour. Final wash and regeneration were each done by 2 BV per hour. Polyphenol content and antioxidant capacity were quantified spectrophotometrically using Folin-Ciocalteu and Ferric reducing ability of plasma (FRAP) assays respectively. Polyphenol recovery was 50% in XAD7HP (Lowest) using ethanol and 69% in FPX66 (Highest) using acetone. For the case of FRAP recovery, 76% (Lowest) was observed in FPX66 using ethanol while 93% (Highest) was observed in XAD7HP using acetone. Conclusively, FPX66 is the ideal resin for the purification of apple pomace extracts for enhancing antioxidant activity compared to XAD7HP. Further, acetone seems to be a good desorption solvent compared to ethanol

Changes in colour parameters and anthocyanin content of aseptically filled sour cherry juice during storage

To overcome the problems of seasonality and geographical location in fruit production and processing, the production of aseptic semi-finished juice is an excellent solution. Even without refrigeration, aseptic pressing has a shelf life of more than a year, making it possible to produce finished products all year round. The production technology involves the addition of ascorbic acid to the pulp to fix or preserve colour. There is an increasing customer demand for ascorbic acid substitutes on the international market. In Hungary, one of the most important exports is aseptic sour cherry juice. In our work, ascorbic acid used for colour fixation was replaced by acerola concentrate. The anthocyanin content and colour coordinate values (Lp, ap, bp, H, C) of aseptically filled sour cherry juice were determined and compared with the control sample during the 12 months of storage