Effects Of Thermal Processing On Functional Components,Texture Of Tartary Buckwheat Products And Simulated Digestion In Vitro

Tartary buckwheat flour(whole、core、bran)are chosen to be investigated in this study.The steaming,boiling and roasting are to be as processing methods.In order to study the effect of thermal processing on functional components,texture of Tartary buckwheat products and simulated digestion in vitro.Firstly,the basic components of three Tartary buckwheat products are determined after steaming,boiling and roasting.The results show that thermal processing has a significant decrease in protein,starch and fat.When steamed for 15 min,cooked for 4 min,and roasted at 180 °C for 30 min,the basic component loss of the Tartary buckwheat product was small.Steaming is superior to boiling and roasting in reducing the loss of basic components.Secondly,three Tartary buckwheat products after the thermal processing,that can cause the color change,decreased on L,value decreased on a,enhancement on b,and ΔE was significantly different.The effect of roasting on color changed is higher than that of steaming and boiling,which means that the degree of heat treatment is different.The texture properties of Tartary buckwheat products are changed,the hardness increased,the chewiness decreased,the elasticity decreased,and the sample deformation did not differ significantly.In general,the effect of roasting on the texture and color of Tartary buckwheat products is better than boiling.Thirdly,thermal processes can cause the functional components and antioxidant capacity of Tartary buckwheat products change significantly.The reduction of total phenol by steaming is lower than that of boiling and roasting.The loss rate of free flavonoids and combined flavonoids by roasting is higher than that of steaming.The loss rate of free flavonoids by boiling is higher than that of steaming and roasting.Steamed products have better antioxidant capacity than boiled and roasted products.Steaming have better preserve the functional components and antioxidant capacity of Tartary buckwheat products than boiling and roasting.Then,the correlation analysis showed that total phenol,free flavonoids,combined flavonoids and rutin were significantly correlated with DPPH free radical scavenging rate,ABTS free radical scavenging ability,OH radical scavenging rate,superoxide anion scavenging rate and reducing ability.It indicates that total phenol,free flavonoids,combined flavonoids and rutin are mainly antioxidant substance.Steaming can retain and improve the antioxidant capacity.Finally,through simulated digestion in vitro,the release of flavonoids from Tartary buckwheat products increased significantly.Especially,combined flavonoid content is increased.Steaming has a higher increase in the amount of flavonoids released from boiling and roasting,and has stronger antioxidant capacity after simulated digestion in vitro.