Study On The Processing Quality And Application Of Ginkgo Starch Treated In Thermal,Ultrasonic Or High Pressure Field

Starch is the most abundant natural polysaccharide in plants and plant starches in current studies are mostly focused on cereals and beans.As the most abundant carbohydrate in ginkgo biloba,the properties of starch from ginkgo have not been extensively studied.On the one hand,the purpose of this research is to analyze the chemical properties,structure and processing quality of starch from four ginkgo cultivars,and changes of physicochemical properties of starch from ginkgo after ultrahigh pressure and ultrasonic treatment.On the other hand,the twin-screw extruder is used to process the ginkgo powder,which is compounded with coffee to make a coffee-ginkgo composite granule.And the results can provide support for theoretical predictions for production and processing of ginkgo biloba and further development.Four ginkgo cultivars that Yuanling No.9,Tancheng NO.1,Dongting NO.2 and Yuzhui No.5 were used as research materials to analyze the relationship between the chemical properties,structure and processing quality of starches from different ginkgo cultivars.Studies have shown that Yuanling NO.9(30.93%),Yuzhui NO.5(29.03%)have higher amylose content,while Dongting NO.2(28.13%),Tancheng NO.1(28.51%)has the lowest content.Also,Yuzhui NO.5 has the highest breakdown viscosity(BV)(63.50±5.57)and consistence viscosity(CSV)(311.00±0.91),so it has poor thermal stability and weak anti-retrogradation.Dongting NO.2 has the highest water absorption index(1.09±0.02)and oil absorption index(1.05±0.01).Yuanling NO.9 showed the highest To(75.35±0.54?),Tp(79.46±0.03?)and Tc(85.12±0.56?)values,while Yuzhui NO.5 showed the lowest To(72.63±0.18?),Tp(76.51±0.14?)and Tc(82.17±0.28?)values.And ginkgo starch paste is a pseudoplastic fluid,and the K(4.101±0.11)of Yuzhui No.5 is higher than that of Tancheng No.1(2.564±0.12%).Yuzhui NO.5 starch has the highest rapidly digest starch(75.38±0.02%)and is the most digestible also.Yuanling NO.9 starch was selected as research material,which was subjected to ultrahigh pressure treatment(200 MPa,400 MPa,500 MPa,and 600 MPa)and different times(5 min,10 min,15 min,and 20 min)Sonication.Studies have shown that ginkgo starches after ultrahigh pressure treatment has better freeze-thaw stability,ginkgo starch after 200 Mpa treatment is not easy to dehydrate,and has good water retention performance,you can try to apply it to frozen food.The ultrahigh pressure treatment significantly increased the storage modulus(G')and loss modulus(G'')of ginkgo starch pastes,and increased the viscosity and elasticity also.And the values of SDS,RS and SDS+RS are the highest at 500 Mpa.While increasing the flavor and taste of food,it can reduce the risk of obesity and diabetes compared to the original starch.Ginkgo starch had the highest transparency(5.67±0.05)at 20 minutes of ultrasonic treatment,and had the lowest water release rate after 15 minutes of treatment,and had good freeze-thaw stability.Thus it can be applied in frozen foods.As the experimental results indicated that 20 min's ultrasonic treatment of ginkgo starch had the highest water absorption index(1.20±0.01)and the hightest oil absorption index(1.20±0.01).The pseudoplasticity of ginkgo starch paste decreased after ultrasonic treatment.And the longer the ultrasonication time,the greater decrease in apparent viscosity.The SDS,RS and SDS+RS values of ginkgo starches after ultrasonic treatment were higher than the original starch,and the SDS,RS and SDS+RS content of ginkgo starch had the highest value(17.07±0.02%,12.43±0.01%,29.50±0.00%).The ginkgo powder was extruded and processed to study the influence of the extrusion process parameters on the product index,and the optimal extrusion process was determined as follows: screw speed is 25 Hz,feeding speed is 10-14 Hz,the die temperature is 200-205 °C and the material moisture is 14%.And ginkgo flavored coffee powder formulations were developed as follows: ginkgo cooked powder 20 g(water content 14%),coffee powder 30 g,citric acid 0.25 g,tea polyphenols 0.5 g,and ammonium bicarbonate 0.5 g.In the end,extruding ginkgo has positive significance In in solving ginkgo storage and transportation problems,improving ginkgo resource utilization,enriching powder food types,etc..