The Effect Of Wheat Gluten Hydrolysates On Physiological Function Of Mice In Heat-stress

This study consists of two parts of research: First, the hydrolysis of wheat gluten by protease and the analysis of the hydrolysates. Second, a functional analysis of wheat gluten hydrolysates was carried on the mice in heat-stress.PartⅠHydrolysis of wheat gluten: In this study, 77 % crude protein wheat gluten was selected. The enzymatic method was according to Zhang Ya-fei's, optimal Protamex conditions were referenced to, at the conditions of [S] 4.0 % (w/w), 40℃, E/S 10 % (w/w), pH 6.5, after the reaction of 2 hours then termination of hydrosis in boiling water.The component analysis of wheat gluten hydrolyzate: gel filtration chromatography was used in the analysis of the distribution of molecular weight of peptides in wheat gluten hydrolyzate. Gradient elution and external standard method of RP-HPLC was used to quantitative determination of 17 kinds of amino acids. At the same time the indirect determination of glutamine in peptides, BTI was used to protect glutamine in peptides except for N-glutamine.The results showed that: the degree of hydrolysis of the hydrolysates was 15.62 %. Molecular weight less than 1400 Da of small peptides were reaching 76.27 %. 300-700 Da of small peptides accounted for 60.68 % ( about two to five peptides). Total amino acid in hydrolysates accounted for 31.82 mg/mL and glutamic acid contented of 12.59 mg/mL. There was 39.57 % of glutamic acid in total amino acid. The effective glutamine in peptides contented 2.54 mg/mL and took for 7.99 % of total amino acids.PartⅡSingle factor experimental design was used. Seventy-two female KM mice during 25-28 days old were choused, which were randomly divided into 4 treatments, each treatment was divided into 3 groups, and each group (cage) had 6 mice. TreatmentⅠwas control group, which was added 1.0 % of wheat gluten in the basic diet. TreatmentⅠ, treatmentⅡ, treatmentⅢ, treatmentⅣwere test groups, which were separately added 0.2 %, 1.0 %, 1.8 % of wheat gluten hydrolysates in the basic respectively. Test under the conditions of heat-stress with room temperature over 30℃, humidity around 70 % keeping 28 d. Test at 14 d and 28 d, each group randomly selected three mice, each treatment was nine mice, to do the determination of the relevant target in order to study the effect of wheat gluten hydrolysates on growth performance, immune function, intestinal function, antioxidant capacity of intestinal of the trial mice in heat-stress.The experimental results showed as follows:1. The effect of wheat gluten hydrolysates on growth performance of trial mice in heat-stressThe differences of wheat gluten hydrolysates on various stages of average day feed intake, average day gain and average day feed intake / average day gain were no significant(P>0.05). However, on the entire period, different levels of wheat gluten hydrolysates had different extent of improvement on average day feed intake, average day gain of the trial mice, and average day feed intake / average day gain had different extent of descent. Group 0.2 %WGH was significantly higher than the control group on average day feed intake(P<0.01) and on average day gain(P<0.05). The value of average day feed intake / average day gain of Group 1.8 %WGH was the lowest, and 25.23 % lower than the control group.2. The effect of wheat gluten hydrolysates on immunity of trial mice in heat-stress Addition of wheat gluten hydrolysates could improve the spleen index (SI) and the liver index (LI), and significantly enhance the content of IL-2 and SIgA in intestinal tissue of trial mice. SI of WGH treatments did not significantly improve (P>0.05), and different volume of wheat gluten hydrolysates had different effects in different period. In the prophase of the experiment (1-14 d), LI of Group 1.8 %WGH had 7.54 % higher than the control group (P<0.05). And in the anaphase of the experiment(15-28 d), LI of Group 1.0 %WGH and Group 1.8 %WGH improved 9.69 % (P<0.05) and 8.51 % (P<0.05) than the control group. Except for Group 0.2 %WGH which had significant difference with the control group (P<0.05), the content of IL-2 and SIgA in the rest of treatments all had very significant difference with the control group(P<0.01).3. The effect of wheat gluten hydrolysates on intestinal function of trial mice in heat-stressIn the prophase of the experiment(1-14d), intestinal length of Group 1.8 %WGH had 7.27 % longer than the control group(P<0.05), Group 0.2 %WGH had 5.47 % shorter in the anaphase of the experiment(15-28 d), and others had no significant differences(P>0.05). Intestinal muscular layer thickness, villus height and villous height/crypt depth of Group 1.0 %WGH and Group 1.8 %WGH were significant higher than the control group(P<0.05). Crypt depth of WGH treatments had no significant differences with the control group in the prophase of the experiment (1-14 d), but there was a downward trend. And crypt depth of Group 0.2 %WGH and Group 1.0 %WGH were 28.35 % (P<0.05) and 35.82 % (P<0.01) than the control group. The absorbability of D-xylose of Group 1.0 %WGH and Group 1.8 %WGH were higher than the control group (P<0.01). Under the experimental conditions, addition of 1.0 %WGH had the best effect on the improvement of small intestinal mucosa morphology and the increase of intestinal absorptive capacity.4. The effect of wheat gluten hydrolysates on intestinal antioxidant capacity of trial mice in heat-stressWGH had significant effect on the intestinal antioxidant capacity of trial mice in heat-stress. Compared with the control group, Group1.0 %WGH and Group1.8 %WGH had very significantly improve in mice intestinal tissue levels of GSH and CAT (P<0.01), and had very significantly descent in mice intestinal tissue levels of MDA (P<0.01). SOD in mice intestinal tissue levels of Group1.0 %WGH was significantly improve than the control group (P<0.05). In the prophase of the experiment (1-14 d), SOD of Group 1.8 %WGH had a improvement by 32.96 % than the control group (P<0.01).