Effects of Microwave-Assisted Steam Drying and Freeze-Drying Techniques in the Raw Wheat Germ for the Antioxidant Activity and Microbiological Quality


Erim Köse Y., Meral R., Cavidoğlu İ.

an Yuzuncu Yıl University Journal of the Institute of Natural & Applied Sciences, vol.26, no.3, pp.163-171, 2021 (Peer-Reviewed Journal)

  • Publication Type: Article / Article
  • Volume: 26 Issue: 3
  • Publication Date: 2021
  • Doi Number: 10.53433/yyufbed.1017973
  • Journal Name: an Yuzuncu Yıl University Journal of the Institute of Natural & Applied Sciences
  • Page Numbers: pp.163-171

Abstract

The purpose of this research was to study the effects of stabilization and storage conditions on the antioxidant activity and microbiological quality of raw wheat germ (R). For this reason, the raw germ samples were stabilized by microwave-assisted steam drying (MWS) and freeze-drying (FD) methods, and they were stored at different storage temperatures (-18, + 4 and 25°C) with polyethylene bags for 90 days. The total phenolics contents (TPC), antioxidant activities (DPPH and ABTS assay methods), and the counts of total mesophilic aerobic bacteria (TMAB), and the total yeast-mold count (YMC) of the germ samples were investigated. Methanol extracts of FD samples showed higher TPC and antioxidant activity than MWS samples significantly (p<0.05). Although MWS samples had remarkably lower microbial counts (TMAB and YMC), their antioxidant properties were adversely affected by heat treatment. According to obtained data samples stored at -18 °C showed the most reliable results in terms of tested parameters.