Studies On The Changes Of The Quality Of Fine Dried Noodles During Storage Period

Fine dried noodles of fully enclosed package and semi-closed package were stored atthree different temperatures, such as10℃, room temperature and40℃respectively. Thispaper principally study on the changes of the basic physiochemical indexes, the relativecontent of fat, the gelatinisation properties of noodle flour and texture characteristics, in orderto obtain the rule of quality changes in fine dried noodles during the storage periods.The test results of the changes of basic physicochemical indexes showed that themoisture content, gluten index and the best cooking time were all gradually decreased, thewater absorption and dry weight loss gradually increased as the storage time increased underdifferent storage temperatures.The lipids from fine dry noodle flour were extracted by Soxhlet extraction and the yieldwas about0.35%. Though there are few lipids in fine dried noodles, they are very importantto the noodle quality. The lipids were subjected to gas chromatography (GC) for the analysisof fatty acid composition after methyl esterification. The main components contain linoleicacid, palmitic acid, oleic acid, linolenic acid and stearic acid. Linoleic acid is the richest fattyacid in noodles (60%of the total fatty acids). As the storage time increased, the total acidityin noodles is increased. A positive correlation was found between the oxidation velocity andthe saturation of lipids. The increase of total acidity in noodles was contributed to theoxidation and decomposition of lipids in noodles. The relative content of saturated fats wasincreased as time was prolonged, while the unsaturated fats decreased. Lipids in noodles ofsemi-closed package, and the storage temperature higher, speed the oxidation anddecomposition.The results of RVA tests of the noodle flour showed that these gelatinisation propertyindexes such as peak viscosity, lowest viscosity, final viscosity, breakdown and setback are allincreased gradually in the storage process. Fine dried noodles in semi-closed package, thestorage temperature higher, all of the RVA parameters are higher. Pearson coefficientsindicated that the RVA parameters were positively correlated with water absorption and dryweight loss. A negative correlation was observed between the RVA parameters and the glutenindex, the best cooking time, moisture content. Pearson coefficients between RVA parametersand the basic physicochemical indexes were improved when the temperature is higher.The results of cooked noodles TPA tests showed that under different storagetemperatures, TPA parameters of cooked noodles except for adhesiveness, all the other parameters decreased as the storage time prolonged. The test results of extensograms on thequality of cooked noodles showed that distance and force of extension decreased during thestorage period. Pearson coefficients between starch properties, water absorption, dry weightloss and extensograms parameters showed that they were negatively correlated. The distanceand force of extension positively correlated with the gluten index, the best cooking time,moisture content.