| Summary: | 碩士 === 國立嘉義大學 === 食品科學系研究所 === 104 === This study intended to investigate the effects of roasting condition functional properties and sensory of black soybean tea bag. Whole black soybean, as the material were pretreated by crushed and sieved, roasted by heat (temperature: 80/120/150oC; time: 50/100/150 min), and packaged into tea bag, for detected its normal properties, such as water content and water activity. Nine samples and one control of black soybean tea bags were soaked into 100 oC hot water for 5 mins (black soybean: water= 1: 20) and filtered for exteaction. The extects were subjected to the analysis of antioxidant capacity (DPPH and ABTS˙+ radicals scavenging activity, and reducing power), antioxidant substances (total phenols, flavonoids, and total anthocyanin content), normal quilty properties (degree of color, pH, and turbidity), microorganism content (E. coli and coliform), and sensory evaluation. The results showed that the higher anthocyanin content were 113.66±9.89, and 100.86±2.37 mg/g at the group of low temperature-long time (80oC/ 150 min), and mid temperature-long time (120 oC/ 50 min), respectively. The highest content of total phenols, and flavonoids were showed at the group of mid temperature-mid time (120 oC/ 100 min; 10.29±0.17 mg gallic acid/g) and low temperature-mid time (80 oC/100 min; 37.62±0.48 mg quercetin/ g), respectively. The trend of antioxidant capacity (DPPH and ABTS˙+ radicals scavenging activity, and reducing power) was the same as that of content of total phenols at each group. All samples exhibited negative coliforms and E. coli, and observed decrease of pH, water content and water activity. Hunter L and a value of all samples decreased and increased, respectively; whereas b value of those showed the non-consistent trend. The lowest value of clarity was at the group of low temperature-long time. The result of sensory evaluation was showed that three groups of high temperature were most preferred by consumers, due to the producing of acceptable aroma and flavor by high temperature roasting. Black soybean tea bag, retained the significant antioxidant properties after thermal processing of roasting was the potential to develop into the functional health food.
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