engleski

Influence of Electrotechnologies on the Recovery of Polyphenols from Blueberry By-product

There has been a growing interest to reuse food waste and by-products as a prime source for the recovery of polyphenolic compounds. Furthermore, extraction of these compounds is considered as the best approach for the valorization of such byproducts. In many cases, conventional extraction techniques, maceration, digestion, infusion, Soxhlet extraction etc. are considered as non- green since they tend to be, time consuming, involve large amounts of solvents, cause degradation of some of the desired compounds. For that reason, new pre-treatment technologies that can replace conventional methods partially or completely, thus reducing the solvent consumption, temperature and/or the extraction time, can be a useful tool to get more efficient and sustainable processes. The use of electrotechnologies, especially pulsed electric fields and high voltage electrical discharges, may be a promising tool to achieve the above mentioned purposes ; thus improving extraction processes in the upgrading of by-products. The objective of this study was to compare the efficiency of pulsed electric field and high voltage electrical discharge on the blueberry pomace extract characteristics. All extractions were performed with methanol and ethanol based solvents (50%, v/v). Significant effect between studied extraction methods (p<0.005) on the yield of total polyphenols was obtained. The results showed that the highest extraction yield (10.51 mg GAE/L) of polyphenols was obtained by pulsed electric field in ethanol based extraction solvent with 100 pulses at 20 kV/cm. Under the same conditions, the highest antioxidant activity of extract was achieved (0.83 mmol Trolox/L).

pulsed electric fields and high voltage electrical discharges ; polyphenols ; antioxidants ; blueberry pomace

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