Inhibition of Angiotensin I Converting Enzyme and Lipoxygenase, and Its Antihypertensive Effect of Whey from Lactic acid Bacteria Fermented Soymilk

• Main Authors: Yin-Shen Lin, 林寅申
• Other Authors: Jenn-Shou Tsai
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/93731490161485664602

碩士 === 國立海洋大學 === 食品科學系 === 91 === The soymilk was used as a material, and fermented with mixed five lactic acid bacteria (Lactobacillus casei、Lactobacillus acidophilus、Streptococcus thermophilus、 Lactobacillus bulgaricus、 Bifidobacterium longum) for 0 to 30 hours at 42℃. The experiment was divided into two parts. Experiment I, soymilk was fermented with lactic acid bacteria only. In experiment Ⅱ, soymilk was fermented with lactic acid bacteria, and protease of prozyme 6 was added after fermentation for 5 hours. The effect of whey powder on inhibitory activity against angiotensin I-converting enzyme (ACE) and lipoxygenase (LOX) and antihypertensive effect of fermented soymilk was investigated. Experiment I: The pH of soymilk decreased from 6.56 to 4.07, the soluble protein content of whey increased from 47 to 71 mg/g, the free amino acid content increased from 91.27 to 128.49 mg/g, γ-aminobutyric acid were increased from 93.9 to 198.4 mg/100g, daidzein and genistein and were increased to 218.0 and 101.6μg/g, the peptide content increased from 39.6 to 44.4 mg/g, the IC50 value of ACE inhibitory decreased from 0.367 to 0.128 mg/ml, and the IC50 value of LOX inhibitory decreased from 0.435 to 0.127 mg/ml as the fermentation time from 0 to 30 hours, respectively. Experiment Ⅱ: The pH decreased from 6.56 to 4.12, the soluble protein content of whey increased from 47 to 390 mg/g, the free amino acid content increased from 91.27 to 214.4 mg/g, γ-aminobutyric acid were increased from 93.9 to 361.6 mg/100g, daidzein and genistein and were increased to 90.8 and 116.4 μg/g, the peptide content increased from 39.6 to 463.3 mg/g and the IC50 value of ACE inhibitory decreased from 0.367 to 0.332 mg/ml, and the IC50 value of LOX inhibitory decreased from 0.435 to 0.152 mg/ml as the fermentation time from 0 to 30 hours, respectively. The molecular weight distribution of whey was between 1300~500 Da by gel permeation chromatography with G-15, as the whey was produced from soymilk with fermentation for 30 hours. And, the fractionated product (M.W.=900-800) showed the highest inhibitory efficiency ratio (IER) when the soymilk was fermented 30 hours, and IER were 795 %/mg/ml. The whey was used as drinks, and administrated to the spontaneously hypertensive rat (SHR) for 7 weeks. The systolic blood pressure of SHR was reduced 19.0 mmHg after 7 weeks oral administration of whey with fermentation for 30 hours.