| The Konjac Glucomannan (KGM) is a kind of polysaccharide which is extracted from konjac corms, with many kinds of physiological health care functions, such as adjusting lipid metabolism, sugar metabolism, losing weight, anti-cancer and so on. Its application in food industry, pharmacy, chemical industry and some other fields is becoming more and more widely, but its physical and chemical properties are not very stable without chemical modification, so its application is restricted. After the modification of KGM with sodium hexametaphosphate and H2O2, the esterified KGM (EKGM) and oxidized KGM (OKGM) were obtained.This research is for the purpose of studying the stability of viscosity , transparency, molecular distribution of EKGM and OKGM, then the two new kinds of food additives were applied into yogurt, the best parameters of fermentation were optimized, new series of yogurts with much better organoleptic properties were developed.The main contents and results of this research were as following:(1) The esterifiable reaction of PKP and sodium hexametaphosphate (SHMP) was optimized by the L9(34) orthogonal experiment, the best reaction conditions are: PKP : SHMP (w/w) is 8: 1, the reaction pH is 1.5, the reaction time is 1h, the reaction temperature is 60 ℃. The highest content of phosphorus in EKGM is 0.4607%.(2) Generally speaking, the viscosity of EKGM gel is much higher than that of PKP gel and OKGM gel, compared with the viscosity of PKP gel, that of EKGM gel and OKGM gel have no obvious change along with the time variation after their stability of viscosity, because of that, the EKGM and OKGM gel showed better stability than that of PKP gel.(3 ) Compared with the surface of PKP granules, the surface of EKGM granules are smoother, without obvious edge angles and ravines, which were learned from their electron microscope scanning pictures. The reason why the surface of EKGM granules have above exterior shapes is because the strong cross linking effect among those polysaccharide... |
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