Preparation Of Chickpea Resistant Starch And Its Functional Properties And Applications

Chickpea(Cicer arietinum Linn)is a high amylose legume with a high amylose content of 40%-60%in its seeds,with a high percentage of resistant starch(RS)and thus a low GI index.RS has various physiological functions and plays an important role in reducing risk factors for metabolic diseases such as diabetes and obesity.In this paper,we investigated the preparation process of chickpea starch(RCS)with high RS content as raw material;analyzed the changes of physicochemical properties and structural characteristics before and after modification;investigated the effects of chickpea starch and its resistant starch on glucolipid metabolism and intestinal flora of type 2 diabetic(T2DM)mice through animal experiments;and finally applied the prepared chickpea RS to cookie making in order to reduce the GI value of cookies.The results were as follows:1.Single-factor experiments were conducted by the pressure-heat method,enzymatic debranching method,citric acid esterification method and lauric acid complex method,respectively.The results showed that the RS content of chickpea was in the following order:citric acid esterification method>enzymatic debranching method>lauric acid compound method>pressurized heat method.The results of orthogonal optimization of the enzymatic debranching method showed that the reaction time and aging time had a significant effect on the RS content(P<0.05).The optimum preparation conditions were:prulanase addition of 4u/g,reaction time of 6 h and aging time of 24 h.The RS content was 40.12%under these conditions.The results of response surface optimization for the citric acid esterification method showed that there were significant interactions between citric acid addition and reaction time,reaction temperature and reaction time(P<0.05),and citric acid addition,reaction time and reaction temperature had significant effects on RS content(P<0.01).The optimal preparation conditions were:citric acid addition of 30%,reaction time of 3 h,and reaction temperature of 120°C.The RS content was 75.58%under these conditions,which was increased by about 9 times.2.The physicochemical properties and structural characteristics of chickpea starch before and after modification were determined and analyzed.The results of electron scanning microscopy(SEM)and polarized light microscopy showed that the citrate esterified starch(CCS)granules could still maintain their original morphology and the polarized light cross was weakened.The enzymatically debranched starch(EDS)granules were completely destroyed and showed irregular lamellar structure,and the polarized crosses disappeared.The results of rapid viscometer(RVA)showed that the viscosity of CCS and EDS decreased significantly(P<0.05),approximately in a straight line.x-ray diffraction(XRD)and Fourier infrared spectroscopy(FT-IR)showed that there was the generation of ester bonds in CCS,and the crystalline shape was consistent with the original starch as C-type,while the EDS crystalline shape changed to B-type,and the process only involved the change of the internal structure of starch.the relative crystallinity of both CCS.Differential calorimetry scanner(DSC)results showed that the initial pasting temperature(T_o),peak pasting temperature(T_p),termination temperature(T_c),and thermal han(ΔH)were significantly lower(P<0.05)for both CCS and EDS obtained from the two modification treatments,but T_c-T_o was significantly higher(P<0.05)for EDS than for RCS.Compared with RCS,the solubility,transparency,water holding capacity,and oil holding capacity of CCS and EDS were significantly(P<0.05)increased,and the swelling force and freeze-thaw stability were significantly(P<0.05)decreased.And the solubility,swelling power,transparency and freeze-thaw stability of EDS were significantly higher than those of CCS.3.8-week-old C57BL/6J mice were used and randomly divided into normal control group(CN),diabetic control group(DCN),and intervention groups:RCS group,CCS group,and EDS group.They were fed at 20-26°C for 5 weeks.The T2DM model was established by high-fat and high-sugar diet in concert with STZ induction to investigate the effects of RCS,CCS and EDS interventions on growth,glucolipid metabolism and intestinal flora of mice.The results showed that the intervention with RCS,CCS and EDS significantly(P<0.05)increased the body weight of T2DM mice.And after 5 weeks of intervention,the glucose,total cholesterol(TC)and renal and liver indices in the RCS,CCS and EDS groups were significantly(P<0.05)lower than those in the DCN group.Among them,CCS intervention significantly reduced low-density lipoprotein cholesterol(LDL-C)levels.Compared with the DCN group,CCS intervention significantly(P<0.05)reduced interleukin-6(IL-6),interleukin-10(IL-10),and anti-tumor factor(TNF-α)levels and was not significantly different from the CN group,while EDS intervention significantly(P<0.05)reduced IL-6 and IL-10 levels and had no significant effect on TNF-αlevels.The results of liver sections showed that after the intervention,the damaged liver tissue structure was restored in the RCS,CCS and EDS groups,and the fat vacuolation phenomenon appeared to be significantly improved,and the overall results observed in the CCS and EDS groups tended to be in the general group.In terms of the overall effect of regulating glucolipid metabolism and resisting inflammation,CCS>EDS>RCS.Bioinformatic analysis of mouse fecal samples based on 16S r RNA V4-V5 high-throughput sequencing technology showed that the number of OTUs specific to the EDS group was significantly higher than that of the DCN group,and Alpha Diversity analysis showed that the intervention with RCS,CCS,and EDS improved intestinal flora diversity compared with the DCN group.UPGMA clustering tree analysis showed that compared with CCS compared to RCS,EDS intervention had a greater effect on the structural aspects of species composition.lef Se analysis and species abundance plots showed that the DCN group and the RCS,CCS,EDS intervention groups had different differential species.At the phylum level,the differential species in the RCS group were Firmicutes,the differential species in the CCS group were Bacteroidota,and the differential species in the EDS group were Verrucomicrobiota and Proteobacteria.Among them,the use of RCS,CCS,and EDS interventions significantly reduced the ratio of the phylum Firmicutes/Bacteroidota.At the genus level,the differential species in the DCN group were Dubosiella and Akkermansiaceae,the differential species in the CCS group were Bacteroides and Parasutterella,and the differential species in the EDS group were Akkermansia.Among them,CCS intervention significantly increased the abundance of Bacteroidota,and EDS intervention significantly(P<0.05)increased the abundance of Lactobacillus,Muribaculaceae and Parasutterella.4.The effect of different RS(CCS)substitution amounts on the quality of dough and cookies was investigated.The qualitative results showed a significant(P<0.05)increase in dough firmness and adhesiveness at 10-20%RS substitution,and a significant(P<0.05)decrease in dough elasticity,chewiness,and cohesiveness at 25%RS substitution.The addition of RS significantly(P<0.05)increased the brightness and specific volume of the cookies and decreased the redness and yellowness of the cookies.The qualitative results showed that the hardness,crispness and cohesiveness of the cookies were significantly(P<0.05)reduced at RS substitution of 5-25%,the elasticity of the cookies was significantly(P<0.05)reduced at RS substitution of 15-25%,and the adhesiveness and chewiness of the cookies were significantly(P<0.05)reduced at RS substitution of 10-25%compared to the control ratio.At 15%RS substitution,cookies had the highest sensory score and a significantly lower GI value(61.59)than the control cookies.