Yen Yu-Fen, Chen Su-Der
Department of Food Science, National Ilan University, Number 1, Section 1, Shen-Lung Road, Yilan City 26041, Taiwan.
Foods. 2022 Jun 15;11(12):1766. doi: 10.3390/foods11121766.
Rice bran and soybean residue are high in nutrients and active ingredients. They are used as media in the solid-state fermentation of . They not only reduce raw material costs, but also raise the economic value and applications of soybean residues and rice bran. After 30 days of fermentation, the moisture content (w.b.) of the product was approximately 40%, requiring it to be pasteurized and dried later. The objective of this research is to use radio frequency (RF) rapid heating technology to pasteurize and dry the solid-state fermented product. A 500 g bag of solid-state fermented product took only 30 and 200 s at the RF electrode gap of 15 cm to pasteurize and reduce the moisture content (w.b.) below 15%, respectively; therefore, the methods can be used instead of the traditional 60 min autoclave sterilization and 100 min hot air drying at 45 °C. After RF treatment, the fermented product was white, indicating that browning was prevented; the product contained 5.03% mycelium, 9.83% crude polysaccharide, 4.43% crude triterpene, 3.54 mg gallic acid equivalent/g dry weight (DW) of total polyphenols, and 0.38 mg quercetin equivalent/g DW of flavonoid contents and showed a good antioxidant capacity.
米糠和豆渣富含营养成分和活性成分。它们被用作固态发酵的培养基。它们不仅降低了原材料成本，还提高了豆渣和米糠的经济价值及应用。发酵30天后，产品的水分含量（湿基）约为40%，后续需要进行巴氏杀菌和干燥处理。本研究的目的是利用射频（RF）快速加热技术对固态发酵产品进行巴氏杀菌和干燥。一袋500克的固态发酵产品在射频电极间距为15厘米时，分别仅需30秒和200秒就能完成巴氏杀菌并将水分含量（湿基）降至15%以下；因此，该方法可替代传统的60分钟高压灭菌和45℃下100分钟的热风干燥。经过射频处理后，发酵产品呈白色，表明防止了褐变；该产品含有5.03%的菌丝体、9.83%的粗多糖、4.43%的粗三萜、3.54毫克没食子酸当量/克干重（DW）的总多酚以及0.38毫克槲皮素当量/克DW的黄酮含量，并表现出良好的抗氧化能力。
