Study On Fresh-cut Purple Sweet Potato Noodles

Noodles that originated in China has always been a pivotal position in 2000 years. But in recent years, the traditional white noodles can not meet the the growing demand of consumers, while the color noodles that add some natural crops welcomed by the people. Purple sweet potato contains large amounts of anthocyanins, selenium, mucin, gangliosides, DHEA (dehydroepiandrosterone) unique functional factor having a variety of health functions. Therefore, the purple sweet potato noodles are strongly welcomed by consumers. But there is few study about the purple sweet potato variety’s screening, choice of whether cooked powder and how to improve the percentage content of purple sweet potato in noodles. These issues have greatly restricted the development of purple sweet potato noodles industry. The purpose of this article is solving the problems above, and aiming to make some contribution to the purple sweet potato noodles industry. The main conclusion of the study are as follows:(1) The degradation of anthocyanins in purple sweet potato powder processing was studied. It shows that with drying temperature increased, the amount of anthocyanin degradation also increased. And anthocyanins lose more than 40% at 50℃.(2) This study was performed to finish the initial screening of Tao Zi, Kawa Yamamura, Ling Zi, Vietnam purple sweet potato and Japan new purple. The basic nutrition of the whole wheat flour, color, and the texture indicators, the cooking quality, and the sensory evaluation after making noodles are concerned as indicators. The result shows that Ling Zi shows a better quality in terms of the above characters the other four varieties.(3) Compared the quality of purple potato noodles made by uncooked and cooked purple potato powder. The study shows that the amount of anthocyanins in the cooked powder is much higher than that in uncooked powder while varieties of anthocyanins are similar. The amylose, amylopectin, starch, and protein content in cooked powder are lower than the uncooked powder, and both crude fiber and fat content are substantially the same. About the texture indicators and cooking characteristics, purple sweet potato noodles made by uncooked powder are better than cooked powder. The main reason for this phenomenon is higher anthocyanins makes adverse effect on noodle quality. However, purple sweet potato noodles made by cooked powder are better than made by uncooked powder on color and sensory evaluation perspective.(4) Compared the quality of purple potato noodles made by the peeled purple potato and the unpeeled uncooked powder. It shows that the unpeeled powder has a little higher anthocyanin content and lower amylose, amylopectin, starch, fat and protein content than the peeled powder. However, the crude fiber of the unpeeled powder is higher than the peeled powder. Purple sweet potato noodles made by unpeeled powder has a better quality than made by peeled powder. Because moderate crude fiber in purple sweet potato skin contributes to the quality of noodles.(5) This study was performed to evaluate the affect of soy protein, sodium carboxymethyl cellulose, salt, wheat gluten and xanthan gum on the 30% of the fresh-cut purple sweet potato noodles. The evalution standards contain texture indicators, the cooking quality, and the sensory evaluation. The results show that soy protein, wheat gluten and xanthan gum can improved the quality of 30% fresh-cut purple sweet potato noodles, and each optimum dosage of them is 2%,4% and 0.6%. Sodium carboxymethyl cellulose and salt can not improved the quality of 30% fresh-cut purple sweet potato noodles.(6) This study was performed to evaluate the effect of texture indicators, the cooking quality, and the sensory evaluation of 30% fresh-cut purple sweet potato noodles by the response surface analysis of composite modifier. We get the best composite modifier of fresh-cut purple sweet potato noodles that is 3.75% wheat gluten,2% soy protein,0.63% xanthan gum. The various quality of fresh-cut purple sweet potato noodles has greatly improved after using this recipe. Compare with the white noodles, texture indicators and cooking quality are close or reach the white noodles indicators.