Research On Ferments Of Rice-grain Sprout And Its Resistance To Free Radicals

As the staple food,rice has already had the old history in human society.Rice mainly contains 65%-70% starch,8%-11% proteins and polyphenol compounds.The rice-grain sprout has the more abundant nutritional ingredients than rice before germination.In the study,the indica rice produced in Guangzhou was used as the main material.After 48 h of germination,it was de-shelled and grinded to be hydrolyzed by amylase and hydrolyzed by protease with the 1:10 of feed liquid.The enzymatic hydrolysate was conducted two-section fermentation through yeast and lactobacillus to make ferment.The main contants of this study are as follow.1)The changing situations of total phenols contents,glutathione contents and SOD enzyme activity in the fermentation process of ferment through rice-grain sprout(for short rice-grain sprout).2)The scavenging activity of DPPH free radical,hydroxyl radical and superoxide anion free radical of rice-grain sprout ferment' finished products after vacuum freeze drying.3)The difference of antioxidant contents and scavenging free radical ability of ferment of the rice-grain sprout and untreated rice(for short the rice)of the same kind under the equal fermentation conditions was compared.Research results were shown as follows: After 12 h of growth,reproduction of yeast reached the highest value,for lactobacillus,the reproduction reached the highest value after 33 h.After enzymolysis of protease,the polypeptide contents in enzymatic hydrolysate of the rice-grain sprout and the rice was 4.707mg/m L and 4.365mg/m L,respectively.After fermentation of yeast,it was reduced to 3mg/m L and 3mg/mL,respectively.Before starting fermentation,enzymatic hydrolysate in two ferments has already had the higher total phenols contents,including 216?g/m L in fermentation of rice-grain sprout and 199?g/mL in fermentation of the rice.After 45 h of fermentation,total polyphenol contents were increased to 238?g/m L and 208?g/mL.After germination,rice contains a little glutathione and SOD enzyme,while untreated rice doesn't have it.In the fermentation process,glutathione contents and SOD enzyme activity can be greatly increased,indicating 1.962mg/m L and 322.6U/m L of ferment in rice-grain sprout and 1.323mg/mL and 221.6U/mL of ferment in the rice.The rice-grain sprout may have the greater amplitude of increase.Fermentation of yeast is better for improving glutathione contents.The SOD enzyme activity promotion of yeast and lactobacillus is almost the same.Meanwhile,by crushing yeast and lactobacillus in ferment of the rice-grain sprout through ultrasound,SOD enzyme activity was improved by 5.1% and reached 338.0U/m L,while glutathione contents were improved by 6.4% and reached 2.085mg/m L.By using IC50 to express the scavenging activity of ferment for free radical,the scavenging rate of rice-grain sprout ferment and rice ferment for DPPH was 0.767mg/mL and 0.803mg/mL.Their scavenging activity for hydroxyl radical was 0.729mg/mL and 0.765mg/m L,respectively and their scavenging activity for superoxide radical was 0.459mg/mL and 0.497mg/mL,respectively.The results showed that rice-grain sprout ferment had the higher scavenging activity for various free radicals,especially for superoxide radical.In the water retention test of silica gel,5% of mycose was used as the reference.After 24 h of water retention test,it found that water-retention rate of rice-grain sprout ferment reached 50.47%,which was extremely close to 56.61% in 5% of mycose.The study showed that the rice-grain sprout may contain antioxidant substance polyphenol compounds,SOD enzyme,and glutathione peptides and have the stronger scavenging activity for DPPH radical,hydroxyl radical and superoxide radical.It also has the good water retention,thus it can be used as the functional food and basic materials of daily chemical products.