ผลของสภาวะการสกัดด้วยคลื่นเสียงความถี่สูงและวิธีการทำแห้งต่อปริมาณโพรไซยานิดินส์และกิจกรรมการต้านออกซิเดชันของสารสกัดจากถั่วแระญี่ปุ่น (Glycine max L.)

Abstract

Green soybean (Glycine max L.) seeds (GSS) are rich in various antioxidants and phytonutrients with procyanidin being a notable phytochemical that could treat and prevent many diseases including anti-inflammatory, and antioxidants. Green soybean is a fast-growing crop, so it is popular for cultivating and exporting frozen green soybean to Japan. Low-quality green soybean is the waste from frozen green soybean processing which also contains various nutrients. The low-quality green soybean extraction by ultrasound-assisted extraction (UAE) in the power of 125 watts for 15 min at temperature level of 40, 50, and 60˚C and solid-to-liquid ratio of 1:15, 1:20, and 1:25 for 9 were investigated. Higher extraction temperatures were found to degrade antioxidants, while increased solvent volume enhanced antioxidant content in the solution. Thus, the optimal conditions for GSS extraction were determined as 40˚C and a solid-to-liquid ratio of 1:25 that contained total phenolic compound (76.8 ± 0.46 mg GAE/ g) flavonoid (30.9 ± 0.58 mg CAE / g) procyanidin (21.4 ± 0.05 mg CAE/ g) antioxidant activity of DPPH (192 ± 0.09 μmol Trolox eq/ g) and FRAP (318 ± 0.71 μmol Trolox eq/ g) respectively. The GSS extract was dried by hot air drying (50, 60, and 70˚C), spray drying (130 and 160˚C at feed rates 2 and 3 ml/min), and freezing drying. The spray dried GSS extract at 160˚C, feed rate of 3 ml/min was the appropriate method to preserve antioxidant and antioxidant activity which contained total phenolic compound (245.23 ± 6.10 mg GAE / 100 g DW) flavonoid (15.55 ± 0.07 mg CAE / 100 g DW) procyanidin (14.05 ± 0.24 mg CAE / g DW) antioxidant activity of DPPH (8.33 ± 0.21 μmol Trolox eq/ 100 g DW) and FRAP (13.53 ± 0.53 μmol Trolox eq/ 100 g DW) respectively. The spray dried GSS extract was analyzed to water activity, moisture content, and color was 0.26, 5.03 ± 0.1%, L* (95.5 ± 0.06) a* (-2.49 ± 0.11) b* (6.3 ± 0.35) respectively. Although, freeze drying retained the highest antioxidant content and antioxidant activity freeze drying had a slower evaporation rate (0.35 ± 0.01 mg CAE/ 100 g h.) and higher drying energy (183 kWh), and specific energy consumption (12.48 ± 0.2 kWh per mg CAE/ 100 g h.) compared to spray drying. Spray drying at 160˚C, feed rate 3 ml/min has 0.66% procyanidin retention that second rang from freeze drying and high evaporation rate (3.3 ± 1.1 mg CAE / 100 g h.), energy consumption (7.03 kWh.), and specific energy consumption (0.50 ± 0.02 kWh per mg CAE/ 100 g h.). The present study also assessed the effects of storage temperature at 25, 35, and 45˚C for 3 months on antioxidant and antioxidant activity in GSS dried powder. Total phenolic content and antioxidant activity of FRAP were found to increase trend but flavonoid, procyanidin, and antioxidant activity of DPPH were found to decrease trend during storage. The dried GSS extract stored for 3 months demonstrated an increase in water activity and moisture content and the color of L* was brighter, while greenness and yellowness faded. The activity energy (Ea) of the GSS extract dried was 69.43 kJ/mol and Q10 was 0.4. To ensure the preservation of bioactive compounds and antioxidants activity, the GSS extract powder was packed in an aluminum foil bag and stored at 45°C, which maintained its quality for 53.7 weeks with a procyanidin retention rate of over 83%. In conclusion, the optimal ultrasound-assisted extraction conditions were 40˚C and green soybean seed-to-water ratio of 1:25. The spray drying at 160˚C, feed rate of 3 ml/min was suitable for GSS extraction drying that can be preserved at 45˚C for 53.7 weeks. Extract procyanidin 4.92 mg CAE per green soybean seed 1 g. This study provides valuable insights into the preparation of procyanidin extract powder from GSS, which could find applications in functional food products.