Study On Extraction, Properties And Application Of High Amylose Maize Starch

Maize starch is a carbohydrate that is important to humans.With the development of human survival and the rapid development of science and technology,there are more and more kinds of maize starch,and more and more fields are applied.However,in many types of maize starch,high-amylose maize starch with special potential is monopolized by foreign maize producers.China started late in related industries and developed slowly.Although China's high-altitude maize varieties with independent intellectual property rights have emerged,they have not been commercialized.The high amylose maize starch used in related industries still needs to be imported at high prices,which is detrimental to the healthy development of related industries.Therefore,it is a hot topic in the starch industry to develop a process for the production of high amylose maize starch and to investigate the properties and applications of high amylose maize starch.In this study,response surface methodology was used to optimize the enzymatic extraction process of domestic high amylose maize starch and compare the differences in properties between normal maize starch,foreign high amylose maize starch and domestic high amylose maize starch,and developed a High-altitude maize is a healthy biscuit made from raw materials.The main test results are as follows:1.Optimization of enzymatic extraction process for high amylose maize starch.The best process parameters were as follows: primary soaking temperature 58.9°C,secondary soaking temperature 49.3°C,soaking solution pH 4.19,soaking solution(300mL)total enzyme activity 349.6 U,theoretical extraction rate 59.60%.Under the experimental conditions,the average value of the extraction rate of high amylose maize starch was 58.98%,which was different from the theoretical value by 0.62%.2.The amylose content of the five starch samples was determined,and the appearance and structural characteristics of the starch samples were measured and compared.The results showed that the amylose contents of five starch samples of normal maize starch,G50-1,G50-2,G70-1,and G70-2 were 26.3%,51.6%,51.3%,69.0%,and 69.3%,respectively.With the increase of amylose content,the surface roughness of the starch was significantly reduced,the micro pits disappeared,and the starch granules became smoother,from a polyhedron with more regularity to a rod shape.Normal maize starch is A type and high amylose maize starch is B type crystal.At the same time,the weight average molecular weight and crystallinity ofstarch were both decreased,and the proportion of low molecular components of starch was increased.After comparison,it was found that,except for the degree of crystallinity,there was no significant difference in the structure and appearance properties between high-amylose starch with domestic independent property and high amylose amylose content imported from abroad.The reason why the crystallinity of the domestic high amylose starch is higher than that of the imported high amylose starch with the same amylose content may be that the branched chain of the domestic high amylose amylopectin is longer.3.The thermal properties of the five starch samples were determined and compared.The results of the rapid viscosity analysis curve show that the normal maize starch had obvious gelatinization below 100°C,while the high amylose maize starch with 50% amylose content showed only a slight gelatinization tendency without gelatinization,while the amylose The starch content of 70% did not show pasting tendency.At the same time,the solubility and swelling potential of high amylose maize starch were worse than that of normal maize starch under normal temperature and pressure,and the higher the amylose content,the greater the difference.Starch samples were subjected to high-temperature and high-pressure gelatinization,and their light transmittance and freeze-thaw stability after cooling were measured.The results showed that the light transmittance and freeze-thaw stability of starch paste also decreased with the increase of amylose content.4.In vitro digestibility tests and comparisons were performed on five starch samples.The results showed that the degree of difficulty in starch digestion was also related to the content of amylose in starch.The higher the amylose content,the higher the hard-to-digest fraction was,that is,the content of resistant starch in starch varied with amylose.The digestive properties of high amylose from different sources with nearly amylose content were also nearly the same.5.A high-amylose starch with a 70% amylose content was used to develop a health-care biscuit with a low glycemic index.Using high-alken-chain maizestarch as a raw material,the optimal amount of gluten and water was investigated.The optimized formula for this biscuit formula was: The ratio of gluten meal and high amylose maize starch was 100%.The ratio of gluten meal to high amylose maize starch was 9:91.The other ingredients were added as a percentage of the mixed meal.The added amounts were 12% of the blended edible oil.,Xylitol syrup 20%(ratio of xylitol to water 2:1),baking powder 3.5%,milk powder 4%,monoglyceride 0.1%,ammonium bicarbonate 1.5%,baking soda 0.8%,salt 1%,MSG 0.8%,additional water 55%.The sensory evaluation score of the tough biscuit made by the formulawas 90.28,the moisture content was 1.6%,the hardness was 831.13 g,the crispness was0.453 mm,the alkalinity was 0.37%,the color value L value was 87.01,the a value was-2.59,b value It was 23.97,and it was 90.29.The color was bright and uniform light yellow with a glycemic index of 67.33.It was a middle glycemic index food.