| In this study, red vinasse was used as raw materials to determine the nutritious and, functional component, additionally, its physicochemical and processing properties as well as its antioxidant properties (in-vitro antioxidant methods) and antibacterial activity had been studied systematically. Based on the tests, the protein in red vinasse was degraded to amino acid by enzymatic hydrolysis to develop the red vinasse's flavoring powder. Taking the amino acid nitrogen content in enzymatic liquid as evaluation index, the orthogonal experimental design of L9(34) was adopted to optimize the critical hydrolysis parameters. Meanwhile, the drying technology and grinding degree were discussed and confirmed. The red vinasse's flavoring powder had good flavor, rich nutrition and special health value. The main results were showed as follows:(1) Research on the main nutritious and functional component and physicochemical and processing properties of red vinasseThe nutritious and functional component in the red vinasse were determined, meanwhile, the effects of different processing methods, pH, illumination, and additive on the total phenol content and color of red vinasse were also studied. The results showed that the total solids content of red vinasse was 28.59±0.28%, the main nutrjents which contenting were crude protein 12.19±0.32%, crude fat 1.78±0.28%, starch 5.13±0.39%, dietary fiber 6.83 ± 0.21%and total sugar2.43 ± 0.16%, and the main functional components were total phenol 359.36 ± 1.56 ug/g, polysaccharides 105.0+1.3 ug/g, lovastatin including Mona K Brooklyn 239.3 ± 2.1 ug/g. Baking, cooking and high pressure heat treatment could result in decline significantly of the total phenol content and brightness value L, value b of red vinasse (p?0.01), while lead to a very significant increase in value a (p<0.01). It indicated that after different processing methods, the color of red vinasse tended to be more red. In slightly acid neutral condition (pH=6.0-7.0), the phenolics compounds of red vinasse were relatively stable, while in acid or alkaline condition, it tended to decline very significantly (p?0.01). With the increaseing of pH, the brightness value L of red vinasse decreased gradually, but when its acidic or alkalinity enhanced, its value a decreased significantly (p?0.05) and value b increased significantly (p?0.05), it indicated that the color of red vinasse tended to be red light. The full illumination could make the strongest damage on the phenolics compounds and color of red vinasse, which mainly resulted in very significant decreasing of total phenolic content and value a of red vinasse (p?0.01), significant increasing of its value b (p?0.05), followed by UV irradiation, and the weakest was incandescent light. Different additives had no significant effects on the brightness value L of the samples, but its value a increased significantly and value b decreased significantly (p?0.05). The protection of 0.05% ascorbic acid solution on the phenolics of red vinasse was significantly higher than other additive.(2) Research on the antioxidant in-vitro and antibacterial activity of red vinasseWith VC solution as positive control, scavenging abilities on DPPH ·, ·OH and O2- · and reducing ability on potassium ferricyanide of red vinasse's supernatant were determined and contrasted by in-vitro antioxidant methods. Additionally, its inhibitory activity for bacteria such as E. coli, salmonella, staphylococcus aureus and bacillus subtilis were researched. The results indicated that in the certain range of concentration, red vinasse had strong oxidation resistance activities, and has distinct dose-effect relationship of scavenging free radicals. The biggest clearance rate of red vinasse's supernatant on DPPH ·, ·H and O2- · was 99.36%,67.33% and 95.21%, respectively, the average scavenging ability on DPPH · of red vinasse per gram was equivalent to 0.1049 mg VC;the average scavenging ability on·OH of red vinasse per gram was equivalent to 0.17368 mg VC; the average scavenging ability on O2-·of redvinasse per gram was equivalent to 0.2945 mg VC. When the tested concentration was in the 40%, there was no significant difference between red vinasse's supernatant and 0.1 mg/mL VC solution on the reducing power for potassium ferricyanide (p?0.05), but on the contrary, the former was very significantly smaller than the latter on the reducing power (p?0.01). The inhibition effects of red vinasse's supernatant (1 g/mL) on the two kinds of Gram-positive bacteria was fine, the inhibition ability on bacillus subtilis was highest, in which diameter of antibacterial circle was 15.2±0.1 mm and the inhibition rate was 84.00%; on staphylococcus aureus, the diameter of antibacterial circle was 14.6±0.2 mm and the inhibition rate was 75.58%. While on salmonella and E.coli, the inhibition ability of red vinasse's supernatant (1 g/mL) was obviously weak, the diameters of antibacterial circle on the two kinds of bacteria were 10.6±0.2 mm and 9.2±0.1 mm respectively, and the inhibition rates were 37.42% and 24.06%, respectively. The test results showed that red vinasse had strong antioxidant ability and certain antibacterial activity.(3) Research on the critical processing technology of red vinasse's flavoring powderOn the basis of determining suitable protease for hydrolyzing protein of red vinasse, the amino acid nitrogen content in enzymatic liquid was taken as the evaluation index, effects of enzymatic hydrolysis conditions on hydrolyzing red vinasse protein were studied by single-factor experiments, further, the orthogonal experimental design of L9(34) was adopted to optimize the critical hydrolysis parameters. Meanwhile, the suitable drying technology and grinding degree of red vinasse's flavoring powder were discussed and confirmed. The results showed that the suitable protease for hydrolyzing red vinasse protein was neutral protease. Under the condition that solid-liquid ratio of enzymatic liquid was 1:3, and the temperature, time, pH and the amount of neutral protease in the resolution of enzyme got 50?, 2.75 h,7.0,400 u/g, respectively, the amino acid nitrogen contenting in the solution reached 5.683%, which was 2.61 times higher than in fresh red vinasse. The oxidationdegree of red vinasse's flavoring powder by heat pump drying was lower than that by hot air drying. Meanwhile, total phenol content losing of the former was significantly lower than that of the latter and the difference was 16 mg/g. After rehabilitating the samples in the water, the color was more red. The dispersion stability of red vinasse's flavoring powder by 200 grinding degree was better than that by 100's grinding and its aqueous solution system had good stability with dense, uniform dispersion, without obvious precipitation at the bottom. |
PDF Full Text Request