Background:Yam(Dioscorea opposita Thunb.)has been consumed as a food and used in traditional Chinese medicine for thousands of years.Resistant starch(RS)3 is of particular interest because it is heat-resistant,safe an...Background:Yam(Dioscorea opposita Thunb.)has been consumed as a food and used in traditional Chinese medicine for thousands of years.Resistant starch(RS)3 is of particular interest because it is heat-resistant,safe and non-toxic,and retains good nutritional benefits;it is therefore used in a wide range of traditional and emerging foods as a heat-stable prebiotic ingredient.In our previous study,we found that yam RS includes strong lipid-lowering and anti-constipation activities.Methods:Yam RS3 was prepared by autoclaving-retrogradation and pullulanase debranching to yield autoclaving-retrogradation yam RS and pullulanase debranching yam RS,respectively.First,the physicochemical properties of both RS3s were analyzed.Second,the structures of the RS3s were characterized by scanning electron microscopy,X-ray powder diffraction,and Fourier transform infrared spectroscopy.Finally,the regulatory effects of the RS3s on the gut microbiota were evaluated using an in vitro fecal fermentation model.Results:The RS content of the RS3s decreased after processing,but was higher in pullulanase debranching yam RS(35.67%)than in autoclaving-retrogradation yam RS(28.71%).Compared with native yam starch,RS3s lost their original granular shapes and instead exhibited irregularly shapes with continuous phases.The crystalline structure of the RS3s was completely altered,with pullulanase debranching yam RS exhibiting B-type patterns.Both RS3s,and especially pullulanase debranching yam RS,promoted a significant increase in short chain fatty acid content after in vitro fermentation(all P<0.05).Moreover,pullulanase debranching yam RS significantly increased the abundance of beneficial bacteria and decreased the abundance of harmful bacteria such as Escherichia and Shigella(all P<0.05).Conclusion:Our findings show that yam RS3s can regulate the composition of the gut microbiota and promote the production of short chain fatty acid,especially butyric acid.Pullulanase debranching was a more effective method for producing functional yam RS3.展开更多
Processed green banana starch with high resistant starch content is commonly used as a prebiotic in the food industry.Physical treatment of starch including moist heat treatment and annealing brings significant effici...Processed green banana starch with high resistant starch content is commonly used as a prebiotic in the food industry.Physical treatment of starch including moist heat treatment and annealing brings significant efficiency and safety to the product.This study was carried out to understand better the effects of moist heat treatment(HMT)and annealing on the changes in green banana starch.Moist heat treatment gradually increased the resistant starch content to a peak of 55 wt% at 25% moisture.Meanwhile,annealing rapidly increased resistant starch to the peak of 45 wt% with negligible water usage(3 mL).The starch granules were disrupted by the annealing process which involved vigorous hydrolysis of the starch chains by the annealing process.Both treatments also changed the crystallinity(type B to type C).The swelling and water solubility of starch treated with HMT gradually decreased from 72 to 65 kJ/mol.K with increasing moisture from 0% to 30%.These properties had an insignificant difference with starches treated by annealing with~65 kJ/mol.K.The trends of oil/water absorption and freeze-thaw stability of the samples were similar to the changes in resistant starch content.Overall,moist heat treatment-maintained granule structure during the treatment of starch.Annealing allowed rapid changes in resistant starch content and significant effects on starch’s physical properties.展开更多
基金the key project at central government level(No.2060302)Key R&D Project of Hebei Province(V1584581541757)+1 种基金the Science and Technology Project of Qinghai Province(No.2021-SF-150)the National Key R&D Program of China(No.2019YFC1710603,No.2019YFC1710604).
文摘Background:Yam(Dioscorea opposita Thunb.)has been consumed as a food and used in traditional Chinese medicine for thousands of years.Resistant starch(RS)3 is of particular interest because it is heat-resistant,safe and non-toxic,and retains good nutritional benefits;it is therefore used in a wide range of traditional and emerging foods as a heat-stable prebiotic ingredient.In our previous study,we found that yam RS includes strong lipid-lowering and anti-constipation activities.Methods:Yam RS3 was prepared by autoclaving-retrogradation and pullulanase debranching to yield autoclaving-retrogradation yam RS and pullulanase debranching yam RS,respectively.First,the physicochemical properties of both RS3s were analyzed.Second,the structures of the RS3s were characterized by scanning electron microscopy,X-ray powder diffraction,and Fourier transform infrared spectroscopy.Finally,the regulatory effects of the RS3s on the gut microbiota were evaluated using an in vitro fecal fermentation model.Results:The RS content of the RS3s decreased after processing,but was higher in pullulanase debranching yam RS(35.67%)than in autoclaving-retrogradation yam RS(28.71%).Compared with native yam starch,RS3s lost their original granular shapes and instead exhibited irregularly shapes with continuous phases.The crystalline structure of the RS3s was completely altered,with pullulanase debranching yam RS exhibiting B-type patterns.Both RS3s,and especially pullulanase debranching yam RS,promoted a significant increase in short chain fatty acid content after in vitro fermentation(all P<0.05).Moreover,pullulanase debranching yam RS significantly increased the abundance of beneficial bacteria and decreased the abundance of harmful bacteria such as Escherichia and Shigella(all P<0.05).Conclusion:Our findings show that yam RS3s can regulate the composition of the gut microbiota and promote the production of short chain fatty acid,especially butyric acid.Pullulanase debranching was a more effective method for producing functional yam RS3.
文摘Processed green banana starch with high resistant starch content is commonly used as a prebiotic in the food industry.Physical treatment of starch including moist heat treatment and annealing brings significant efficiency and safety to the product.This study was carried out to understand better the effects of moist heat treatment(HMT)and annealing on the changes in green banana starch.Moist heat treatment gradually increased the resistant starch content to a peak of 55 wt% at 25% moisture.Meanwhile,annealing rapidly increased resistant starch to the peak of 45 wt% with negligible water usage(3 mL).The starch granules were disrupted by the annealing process which involved vigorous hydrolysis of the starch chains by the annealing process.Both treatments also changed the crystallinity(type B to type C).The swelling and water solubility of starch treated with HMT gradually decreased from 72 to 65 kJ/mol.K with increasing moisture from 0% to 30%.These properties had an insignificant difference with starches treated by annealing with~65 kJ/mol.K.The trends of oil/water absorption and freeze-thaw stability of the samples were similar to the changes in resistant starch content.Overall,moist heat treatment-maintained granule structure during the treatment of starch.Annealing allowed rapid changes in resistant starch content and significant effects on starch’s physical properties.
