Study On The Properties,Preparation And Effect Of Rice Starch-fatty Acid Complex

Starch can form a kind of complex with lipid substances,which can change the thermal properties,solubility,retrogradation and textural indexes of starch.And the complexs by adding into it will change the quality of the food.In this experiment,five kinds of rice were used as raw materials.The method of alkali was used to make the rice starch.Take 10g rice starch dissolved in 100mL distilled water.Fatty acids(stearic acid and oleic acid)were added in starch at a ratio of 2%(w/w)should be dissolved in ethanol first.The mixture was stirred with a stirrer,heated and stirred at 80? for 30 min,centrifuged at 4000 r/min for 15 min,dried at 40 ? for 24 hours,and pulverized to obtain rice starch-fatty acid complex.The effects of fatty acids on the properties and quality of rice starch were studied,as well as the effect of the compound on the quality of rice noodles.The conclusions are as follows:Through the Fourier transform infrared spectroscopy,composite index and determination of fatty acid content,we found that rice starch and fatty acid compound is formed by the hydrophobic interaction of the complex.When the complex was gelatinized,it was found that the initial temperature(To),the peak temperature(Tp),the final gelatinization temperature(Tc)and the enthalpy change value(? H)of the complex were decreased by 5?,10?,10? and 0.3,respectively.After adding 2%fatty acids and rice starch composite,the solubility of rice starch decreased by 11%?2%,the swelling degree decreased by 2%?4%,the agglomeration decreased by 5%?14%,and the freezing and thawing stability increased by 5%?10%,which added stearic acid after the change in the nature of the property than the addition of oleic acid changes significantly.When the amount of fatty acid added is 4%and placed for 1 to 2 days,the hardness value decreases by 130 g and 110 g,the elasticity increases by about 0.1,the chewiness value increases by about 20 g,and the adhesion decreases about 40,indicating that the addition of fatty acids is conducive to improving the stability of the texture index.With the fatty acid content,the reaction temperature and the stirring time were increased gradually.The rice starch with stearic acid,oleic acid to form composite index of fatty acid content increased gradually.The complex index and fatty acid content of the complex that rice starch and fatty acid formed increased gradually.The optimum conditions for the synthesis of rice starch and oleic acid were 4%of the leic,the reaction time was 30 min and the reaction temperature was 83?.The optimum conditions of starch and stearic acid were 4%stearic acid,31 min reaction time and 83 ? reaction temperature.Adding 10%of the compound in the rice noodles,the short powder and cooking loss reduced by 1%to 2%,hardness reduced by 100g,elasticity and chewiness increased by 0.05 and 20 respectively.At the same storage time,the rice noodles without adding the compound had a higher hardness value than the rice noodles to which the 10%compound was added,while the elasticity and chewiness were relatively small.This shows that the addition of complexes is beneficial to improve the quality of rice flour.