Effects of Microwave-Assisted Steam Drying and Freeze-Drying Techniques in the Raw Wheat Germ for the Antioxidant Activity and Microbiological Quality
Öz
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 TEAC 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.
Anahtar Kelimeler
Freeze drying, Microwave-assisted steam drying, Wheat germ, Stabilization
Destekleyen Kurum
Van Yüzüncü Yıl Üniversitesi Bilimsel Araştırma Projeleri Koordinasyonu
Proje Numarası
FDK-2017-5582
Kaynakça
- Ali, S., Usman, S., Nasreen, Z., Zahra, N., Nazir, S., Yasmeen, A., & Yaseen, T. (2013). Nutritional evaluation and stabilization studies of wheat germ. Pakistan. Journal of Food Science, 23(3), 148-152.
- Bae, S. H., & Suh, H. J. (2007). Antioxidant activities of five different mulberry cultivars in Korea. LWT - Food Science and Technology, 40, 955-962. https://doi.org/10.1016/j.lwt.2006.06.007
- Bakkalbaşi, E., Yilmaz, Ö. M., Javidipour, I., & Artik, N. (2012). Effects of packaging materials, storage conditions and variety on oxidative stability of shelled walnuts. LWT - Food Science and Technology, 46, 203-209. https://doi.org/10.1016/j.lwt.2011.10.006
- Bilgiçli, N., Elgün, A., Herken, E. N., SelmanTürker, Ertaş, N., & Ibanoǧlu, Ş. (2006). Effect of wheat germ/bran addition on the chemical, nutritional and sensory quality of tarhana, a fermented wheat flour-yoghurt product. Journal of Food Engineering, 77 (3), 680-686. https://doi.org/10.1016/j.jfoodeng.2005.07.030
- Brand-Williams, W., Cuvelier, M. E., & Berset, C. (1995). Use of a free radical method to evaluate antioxidant activity. LWT - Food Science and Technology, 28(1), 25-30. https://doi.org/10.1016/S0023-6438(95)80008-5
- Brandolini, A., & Hidalgo, A. (2012). Wheat germ: Not only a by-product. International Journal of Food Sciences and Nutrition, 63 (S1), 71–74. https://doi.org/10.3109/09637486.2011.633898
- Çakmakçı, M.L., Karahan, A.G., & Çakır, İ. (2008). Microbiology. Food Technology Society, Ankara, Turkey.
- De Vasconcelos, M. C. B. M., Bennett, R., Castro, C., Cardoso, P., Saavedra, M. J., & Rosa, E. A. (2013). Study of composition, stabilization and processing of wheat germ and maize industrial by-products. Industrial Crops and Products, 42, 292-298. https://doi.org/10.1016/j.indcrop.2012.06.007
- Dudonné, S., Vitrac, X., Coutiére, P., Woillez, M., & Mérillon, J. M. (2009). Comparative study of antioxidant properties and total phenolic content of 30 plant extracts of industrial interest using DPPH, ABTS, FRAP, SOD, and ORAC assays. Journal of Agricultural and Food Chemistry, 57(5), 1768-1774. https://doi.org/10.1021/jf803011r
- Erim Kose, Y. (2021). Kinetic modeling of oxidation parameters and activities of lipase-lipoxygenase in wheat germ oil. Article e423 Grasas y Aceites, 72(3). https://doi.org/ 10.3989/gya.0554201.