The effect of different pH sodium hydrogen carbonate solutions soaking pretreatment on antioxidant activities of germinating sesame

• Main Authors: He, Sing-Shan, 何幸珊
• Other Authors: Chiu, E-Mean
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/11383741150043731143

碩士 === 國立宜蘭大學 === 食品科學系碩士班 === 99 === esame （Sesamun indicum L） belongs to the Pedaliaceae family and is an annual, selfpollinated oilseed crop. It has been preferentially consumed in oriental food because of its distinctive flavor and the stabilizing antioxidant properties of sesame lignans. Sesame exhibits many beneficial physiological effects, which are mostly various kinds of natural anti-oxidant materials, such as sesamin, seasamolin, tocopherol, ect. Its chemical stability can be used in anti-oxidant, reducing the cholesterol and removing the internal free radicals. After soaking with different pH(5.7.9)sodium hydrogen carbonate solutions and deionized water for 9 hours, sesame was placed in incubator at 25℃ for 1-6 days germination. Sesame seedlings were sampled each date in the period of germination, then freeze dried for the following studies. Methanol extracts of sesame seedlings and sesame oil were then used for antioxidants analysis and antioxidation activity evaluation in this study. In order to trace the changes of proximate composition in sesame during germination, the ingredients of sesame seedling was analyzed. There was no significant difference on the content of ash 4.846.06% and crude protein 17.72-23.23 %, nevertheless the amount of carbohydrate 9.12-38.91% increased while crude fat 66.40-33.15% decreased proportionally in the period of germination. Regard to the fatty acid composition in sesame oil, there was no significant difference in percentage of fatty acid constituents during germination of sesame. The changes of antioxidants in sesame seedlings and sesame oils showed that the content of total polyphenols, compound A and compound B increased significantly during germination, and the total polyphenols in sesame seedling and oils distributed within 16-80 mg / g MeOH extract and 6-30 mg / g MeOH extract respectly. The content of total polyphenols in sesame seedlings higher than sesame oils. The amount of total polyphenols in sesame seedlings raised fastest in all of the soaking pretreatments when pretreated with DIW, and that was in the sesame oils when pretreated with pH9-CBS. On the contrary, the quanty of sesamin, sesamolin and γ-tocopherol contained in sesame were decreased in the period of germination, their levels were within 194.66-60.10 mg /100 g oil, 209.64-92.50 mg / 100 g oil and 51.27-40.42 mg / 100 g oil respectly. For evaluating the antioxidation capacity of sesame during germination, the reducing power, DPPH free radical scavenging ability and ORAC capacity were estimated. In the period of germination, the reducing power, scavenging DPPH free radical and ORAC activity of sesame seedlings and sesame oil were accelerated. However, The chelating ability of ferrous raised at the early period of germination, and then declined at a later period. In generally, regardless the methods used for estimating the antioxidative activity. It was the antioxidative activity of sesame seedlings in DIW > CBS soaking pretreatment, if compared of different pH sodium hydrogen carbonate solutions soaking pretreatment on antioxidant activities, pH showed little effect on antioxidant activity. It was the antioxidative activity of sesame oils in CBS > DIW soaking pretreatment, if compared of different pH sodium hydrogen carbonate solutions soaking pretreatment on antioxidant activities, show for thepH5-CBS > pH7-CBS > pH9-CBS.