Sdudies On Properties Of Long Life Noodle

It is inevitable with aging for starch-based foods in storage for some time, which affectsthe edible qualities of the products. When the long-life(LL) noodle is on the shelf for twomonths or so, then it shows the phenomenon of serious harm to its edible qualities, viz. brittleand easily broken, chewness and toughness decreasing. Therefore, it has an important role onproduction and storage of long life noodle to research the storage properties of long lifenoodle, and delay or inhibit starch retrogradation of products effectively.In order to improve the storage quality of long life noodle, this subject was based onstarch retrogradation, which was the main aspect causing quality deterioration of long lifenoodle, and methods were discussed to delay starch retrogradation by means of improvingprocess and adding food additives, and at the same time, anti-aging mechanism of LL noodlewas explored. The results showed that:①The optimal processing were that the cooking time was5min, washing time was1min,washing temperature was5℃. The noodles prepared on this condition had a relatively highdegree of gelatinization, and sensory and texture quality were also in good range.②As measuring with degree of gelatinization, it was found that the aging of LL noodlehad basically completed in approximately two weeks. Texture test found that hardnessindicator of texture profile analysis(TPA) was not a suitable index to evaluate the agingdegree of the LL noodle, while tensile strength and extensibility of tensile experiment couldbe used as an index besides the degree of gelatinization. And the seventh day that agingtended to smooth was selected as a test point of tensile properties.③Among the thirteen additives, eight kinds of improvers showed an obvious inhibitoryeffect on the aging of LL noodle. They were improvers of A, C, E, H, I, L, M, N.④According to the effects of these additives on the texture behavior and sensory quality,it showed that: the substances that could improve the storage tensile properties of LL noodlewere emulsifier of A, hydrophilic colloid of C, improvers of L, M, G and H. Moreover, theaddition of hydrocolloids within a certain range had a more significant improvement on initialquality of LL noodle, and improvers of M had a significantly improving effect on the surfacestate and the extensibility of LL noodle, but decreased the toughness of the sample.⑤Through orthogonal test and principle component analysis, the optimal formula was:E0.3%, D0.05%, H1.0%and M1000ppm.⑥Primary studies on mechanism of compound formula to the quality of long life noodle were done in the end of this report, and when compound formula was added, the results ofDSC(Differential Scanning Calorimetry) showed that the value of△H of LL reduced, and tosome extent, the degree of LL noodle retrogradation reduced. Then the result of X-rayDiffraction showed that there was crystal structure existed in LL noodle during storagewhether or not to add additives, but the strength of sample added by compound formuladereased. Finaly the result of SEM (Scanning Electron Microscope) showed that the LLnoodle added by the formula had uniform texture, starch granules dispersed evenly, however,after a period of storage, the network of the sample un-added by additives became relativelycompact.