The Mechanism Study On Digestibility And Anti-obesity Effects Of Rice Starch-catechin Complex Constructed By Hot-extrusion 3D Printing

With the rapid economic growth and the continuous evolution of disease spectrum,obesity caused by excessive energy intake and consumption imbalance is increasing with each passing day,which has become a global public health problem that cannot be ignored and threatens human health and social development.The design of personalized health food based on the concept of dietary intervention to achieve the defense and treatment of obesity has become the forefront and hot research in the field of food nutrition science.In this study,the current status of nutrition intervention research on obesity at home and abroad,as well as the characteristics and development trend of personalized nutritional food customization by hot-extrusion 3D printing technology were firstly investigated.Furthermore,it was proposed that the digestibility and nutritional functions of rice starch,the main nutritional components of rice,could be regulated by hot-extrusion 3D printing and the interaction of catechin molecules.Based on these,an in-depth systematic study was conducted on the anti-enzymatic mechanism and antiobesity mechanism of the rice starch-catechin complex(3DP-REC),with a view to designing starchy food such as healthy staple food from a new visual perspective.This is a leading edge subject which are of important scientific significance,and can play a positive role in promoting the application of hot extrusion 3D printing technology to the personalized customization of healthy starch food and dietary intervention to prevent obesity.The relationship between the structural evolution and anti-digestion property of 3DP-REC and the mechanism of its resistance to enzymatic hydrolysis were studied by using modern structural characterization techniques and molecular dynamics simulation.The results showed that hot-extrusion 3D printing could increase the single helix structure content,double helix structure content,relative crystallinity,nano-aggregate ordered structure and surface shortrange ordered structure of gelatinized rice starch,and reduce its amorphous structure content and thus improve the ordered degree of the overall structural.The addition of catechin molecules,on the one hand,could form a single helix structure and V-type crystalline structure with starch molecules by the hydrophobic forces,and form short-range ordered structure such as new double helix structure,nano-aggregate ordered structure and partly compact structure with starch molecules by hydrogen bonding interaction at the same time,and thus further increased the ordered structure content of gelatinized rice starch.The improvement of structural ordering,i.e.the denser molecular chain arrangement,could effectively hinder the migration and binding of pancreatic ?--amylase in starch molecules and thus increase the SDS and RS content.On the other hand,catechin molecules and starch molecules which existed in the amorphous region of 3DP-REC could form a complex by relatively weak ?-? dominated and hydrogen bonding assisted interaction.This complex was easy to dissociate in the digestive environment,at which time the free catechin bound to the Trp59 site of pancreatic-amylase,thus shielding the positive active site of starch's specific binding to pancreatic-amylase and acting as an enzyme inhibitor.Therefore,it could be seen that the anti-enzymatic hydrolysis mechanism of 3DP-REC was the formation of long-range ordered structure and short-range ordered structure and catechin dissociation enzyme inhibitor through evolution.The synergistic effect effectively blocked its degradation by pancreatic ?-amylase,thus reducing the content of RDS and increasing the content of SDS and RS.The anti-obesity mechanism of 3DP-REC with different catechin addition levels(2.5%,5% and 7.5%)on high-fat diet obese rats was revealed by combining serum lipidomics and hepatic transcriptomics.The results showed that 3DP-REC intervention could regulated the expression of key genes in liver glucolipid metabolic pathways and then effectively promoted the generation of liver glycogen and insulin secretion,promoted the ?-oxidation of fatty acid,liver bile acid synthesis,inhibited fatty acid synthesis and cholesterol synthesis to significantly reduce the blood glucose level,at the same time improved lipid levels by lowering the content of serum phosphatidyl choline,phosphatidyl ethanolamine,triglycerides,ceramide and phosphatidyl glycerol,eventually inhibited lipid deposition,thus against obesity induced by high fat diet.In addition,3DP-REC intervention could also down-regulated key proinflammatory genes to improve liver function metabolism disorder,inflammatory state,oxidative stress and tissue damage caused by inflammation.In addition to blood glucose,the above effects were enhanced with the increase of catechin content in 3DP-REC,and the intervention effect of 3DP-7.5%REC was the best,reaching the level of the normal group.Bioinformatics methods such as 16 S r RNA high-throughput sequencing were used to further explore the effects of 3DP-REC intervention on intestinal microecology and its relationship with anti-obesity in rats with high-fat diet obesity.The results showed that 3DPREC intervention significantly improved colonic tissue injury caused by high-fat diet,effectively reduced energy intake and inhibited lipid deposition by promoting the expression of gastrointestinal hormones and reducing the level of total bile acid in the intestine,and the intervention effect was dependent on catechin content in 3DP-REC.3DP-REC intervention could also promote the abundance of beneficial bacteria in the intestinal tract,such as Lactobacillus and Bifidobacterium,and improved the structure of intestinal flora.In particular,it significantly increased the contents of propionic acid and butyric acid in the intestinal tract by promoting the growth and reproduction of short-chain fatty acid producing bacteria.Among them,3DP-2.5%REC intervention significantly increased the content of butyric acid and 3DP-5%REC intervention significantly increased the content of propionic acid.KEGG function prediction results showed that 3DP-REC intervention could prevent lipid deposition by activating thermogenic function and regulating protein metabolic pathways.Based on the correlation analysis between the changes of microbiota and physiological index after 3DP-REC intervention,it could be seen that 3DP-REC could effectively inhibit the growth and metabolism of harmful bacteria such as Romboutsia,promote the reproduction of propionic and butyric acid-producing bacteria such as Veillonella,Butyricicoccus,Ruminococcaceae,and Bifidobacterium,so as to improve the lipid disorder,abnormal liver function metabolism and oxidative stress injury caused by high-fat diet.Based on the above results,the interaction relationship between "dietary intervention of REC-intestinal microbiota structure-metabolic and biochemical index related to obesity" was preliminarily established.By integrating TSE energy metabolism monitoring and molecular biology methods,the effects of 3DP-REC on the thermogenic function of brown adipose tissue and the mechanism of regulating energy metabolism and anti-obesity were clarified.Our study showed that 3DPREC intervention could significantly promote the expressions of lipolysis-related key proteins in brown adipose tissue and beige adipose tissue and accelerated the rate of lipid decomposition and provided energy for the mitochondria which significantly improved UCP1 protein expression and activated the thermogenesis function of brown fat.The above metabolic pathways improved the energy consumption,increased the resting state of basal metabolism,and then effectively resisted fatty deposits of insulin resistance and reduce the body weight and body fat content caused by high fat diet,eventually achieved the anti-obesity effect.Among them,the effect of promoting the heat production at room temperature was more obvious with the increase of catechin content in 3DP-REC.The study showed that the synergic effects of hot-extrusion 3D printing and addition of catechins could effectively regulate the anti-digestion properties of rice starch,and the constructed 3DP-REC had very good anti-obesity effect and nutritional function.We believe the obtained results and mechanisms have great academic value,which are expected to provides new design ideas and theoretical guidance for achieving personalized nutritional and healthy starch-based food.