In Vitro Digestibility Of Chemically Modified Starches And Two Resistant Starches’ Effects Of Antioxidant Capacity In Rats Fed A High Fat Diet

Six different native starch was chemically modified by acetylation, esterification,hydroxypropylation, and cross-linking,and the effects of these modifications on the nutritionally important starch fractions, namely rapidly digestible starch (RDS),slowly digestible starch (SDS), and resistant starch (RS), were studied in cooked starches. Some physicochemical properties of the native and modified starches were also studied. Effects of antioxidant capacity in rats fed a high fat diet.The results are as follows:At first,six different native starch was chemically modified by acetylation, esterification, hydroxypropylation, and cross-linking, and the physical and chemical properties of these modified starches were studied. Acetylation, esterification and hydroxypropylation can increased the starch peak viscosity, decrease the pasting temperature. Some starch has the largest peak viscosity after OSA esterifying, but some are hydroxypropylated starch. Not pasting under the high temperature, the high cross-linking starches had no viscosity.Acetylation, esterification and hydroxypropy-lation can increased the transparency of the starchs, OSA esterifying has the biggest influence on the waxy starch, acetylatying has the biggest influence on the potato starch, others are hydroxypropylation. Cross-linking decreased the transparency of all the starchs; Acetylation, esterification and hydroxypropylation can decreased retrogradation,all the starch modified by OSA esterifying has the best retrogradation; The freeze-thaw stability was substantially improved by acetylation, esterification and hydroxypropylation, the modification method bring different results,and hydroxypropylation were more effective.Then in vitro digestibility of chemically modified starches were studied. The chemical modifications can affect the starch digestibility:the chemical modifications contribute in raising the amount of RS and SDS, and decreesing RDS content in gelatinized starch. Hydroxypropylation appeared more effective in hindering enzymatic digestion than other modification methods and showed the highest RS content, the OSA starch showed the highest SDS content. Several starch showd slightly different.At last,in order to investigate the effect of HP-CL and CL-OS A on antioxidant defense system in C57BL/6J rats fed high fat diet. The rats were grouped as control group (CL), high-fat group (HF), high fat+SPS group (HF-SPS),high fat+CL-OSA group(HF-CLOSA-SPS),high fat+HP-CL(HF-HPCL-SPS) with12rats each and fed corresponding diets for12weeks. Slaughtered measuremen of serum and liver in rats T-SOD, MDA, CAT, T-AOC, GSH-PX content.The results were shown as follows:.compared to the group of HF, the serum T-AOC and GSH-Px activity of HF-HPCL-SPS were significantly increased(P<0.05), the serum SOD and CAT activity of had a trend to increase, MDA had a trend to decrease; the liver T-AOC and SOD activity were significantly increased(P<0.05), the liver GSH-Px and CAT activity had a trend to increase,the level of MDA was significantly decreased (P<0.05).Compared to the group of HF, the serum T-AOC activity of HF-CLOSA-SPS had a trend to increase,MDA had a trend to decrease;the liver T-AOC was significantly increased(P<0.05), the liver SOD activity had a trend to increase,the level of MDA had a trend to decrease. By comprehension consideration, HP-CL and CL-OS A can improve the antioxidant defense system in rats fed high fat diet, HP-CL is better than CL-OSA.