Study On Physicochemical And Nutritional Characteristics Of Primary Components In Light Liquid Produced By Production Of Wheat Starch

Light liquid phase was the by-product of wheat starch produced by decanter centrifuge In this paper,the physicochemical and nutrition characteristics of protein and starch in the light liquid phasewere studied,The possibility of using light liquid phase and its production hydrolysis by xylanase as prebiotic was evaluated, which will provide the theoretical direction for further study and exploitation of light liquid phase.Firstly, the comparison of protein nutritive value of light liquid phase , wheat gluten and wheat flour were studied., Furthermore, the digestibility of protein in the light liquid phase was studied under the simulated condition of protein vitro digestibility, then the thermodynamics of protein in the light liquid phase was obtained through the DSC thermo analysis, the results showed that amino acid score and nutritive value of protein in light liquid phase were both higher than wheat flour and gluten; and the digestibility of protein in light liquid phase were lower than soy protein and gluten, which proved that light liquid phase can be digested easily. The results of DSC showed that the denaturation temperature was 69.89℃and the denaturation enthalpy was lower than other cereal and soybean protein, which demonstrated that light liquid phase.had higher thermo sensitivity and less thermo stability. Secondly, the physicochemical characteristics of A type starch , B type starch and the starch from light liquid phase were compared, it showed that starch from light liquid phase had a much more smooth surface, the majority of granules took on elliptic shape and the minority were irregular polyon shape, its particle size distribution was among 1～5μm, and it had a smaller light transmittance, a larger precipitation volume, lowest solubility and swelling capacity, while it had better freeze thawing stability than the other two types of starch and its amylase content was 15.8%. Then X-ray diffractometer spectrum of light liquid phase showed it was typically A starch structure cristalization and the degree of crystallization was lower than both A type starch and B type starch. The RVA profile thermodynamics analysis revealed that it had the smallest disintegration value and was hardest to gelatinize and the peak temperature was 67.69, respectivly. The vitro digestibility of three types of starches and their correspondingly pasted starches were studied. Starch from light liquid phase had the highest content of SDS fragments61%. It also had a superior digestibility than A and B type starch and the blood sugar indexes GI were predicted to be 103.3%, which both belonged to hyperglycemia food field.Finally, the light liquid phase was evaluted as a prebiotic which showd that a less prominent effect on the inhibition of pethogenicenterobecteria , however, exerted a significant effect on enhancing the growth of the lactobacillus. With the increased addition of light liquid phase powder and powder hydrolyzed with enzyme, the lactobacillus bulgaricus had a visibly growth, especially at the concentration of 5g/L. In summary, light liquid phase powder could be exploited and utilized as prebiotic.