Research Of Action Mechanism On Cross-linked Acetylated Starch In Low-sugar Jam

With the improving of people’s living standard，demand of jam is more and morewidely. Low-sugar jam has become more and more popular because of the high sugarcontent of traditional jam. Now the thickers used for low-sugar jam are pectin, xanthangum, sodium alga acid, sodium carboxymethylcellulose and so on. Modified starch hasgood water-retaining property and can increase the moisture in low-sugar jam. Noscientific information is available in literature about modified starch as thicker inlow-sugar jam. This subject research the action mechanism about modified starch inlow-sugar jam.This subject mainly research the microstructure of jams by the rheologicalexperiments, scanning electron microscopy (SEM) and Laser particle analyzer. Besides,physicochemical properties of jams are determined to guarantee the veracity ofexperiments.First, determining the properties of modified starch specifically used for jam. Theresults indicated that this starch is acid-resistant, shearing resistance, high transparencyand excellent storability, so it can use for the preparation of low-sugar jams.Second, analyzing the experimental data of rheology, the SEM micrographs andthe change of partical size, the results showed that the system form a more fine andhomogeneous network after adding modified starch. High temperature makes the starchgranular swelling, the pore at particle surface is open, so one or several substances inthe original system penetrate into the starch granules and combines with starch to formnetwork. Hydrophilic groups in cross-linked acetylated starch made substances insystem combine with water molecule stable, so that the system is water retention andstability. We guess the substance penetrate into the starch granules is pectin. Besides,through the research, low-sugar jam added20%cross-linked acetylated starch meet therequirements best.At last, analyzing the physicochemical properties of samples according to thechange of additive amount of modified starch, additive amount of sugar and pH value inorder to verify the conclusions is reliable or not. The research showed the sequence ofwater-retaining property of sample:20%cross-linked acetylated starch,25%,15%. Whenthe additive amount of modified starch and sugar are unchanged, Water holding capacityis best when the pH is3.5. Meanwhile, when the additive amount of modified starchand pH is unchanged, Water holding capacity is the best when the additive amount ofsugar is15%. Viscosity increases with the additive amount of modified starch, pH valueand the additive amount of sugar. The additive amount of modified starch is almost no effect to the color of samples. When the additive amount of modified starch is25%, theflowability is too strong, when the additive amount of modified starch is15%, theflowability is best.