Ultra High Pressure Effect On The Performance Of Polysaccharide Gel And Application Research

This paper took various single and compound gels as research objects, studied effects ofdifferent high-pressure treatment conditions on gel properties. The study chose compound gelof carrageenan and konjac glucomannan, which has a strong pressure resistance, as gel baseof low-acid fresh fruit jelly. Then practical application of high-pressure treatment on freshfruit jelly was studied by orthogonal experimental design. The following results wereachieved:1. In order to establish connection between sensory evaluation and instrumental analysisof gels, which can supply instructions for quality control of various gels, this paper studiedchange rules of gel concentration and texture factors and the correlation between sensoryevaluation and instrumental analysis. Texture results showed that there is a linear relationbetween hardness, chewiness and concentration of agar, carrageenan, carrageenan-konjaccompound gel and Mesona blume gel. Due to the correlation between sensory evaluation andinstrumental analysis, it could be found that there is an extreme significant correlation(P<0.01) of hardness, chewiness and cohesiveness between sensory evaluation andinstrumental analysis results. In addition, prediction models between them were built,providing rapid determination of products’sensory qualities with a base.2. With the purpose of studying effects of different high-pressure treatment conditions ongel structure and properties, five kinds of food gels and gel products (agar, carrageenan,compound gel, Mesona blume gel) were processed by high-pressure and their change rules oftextures were observed. According to texture factors and water holdup results, agar,carrageenan and Mesona blume gel’s structure were significantly (P<0.05) destroyed whenpressure was higher than300MPa. As the pressure holding time went on, texture changes ofthree gels mentioned above weren’t obvious. But texture changes decreased as theirconcentration increased. Different concentrations of carrageenan-konjac compound gumunder different pressure and different time of ultrahigh pressure processing can well keeporiginal gel performance, which explain its’ strong pressure resistance. So we select the kindof gum as base to further application research.3. Choosing carrageenan-konjac compound gum with strong pressure resistance as thelow acidity jelly glue base, we research effects of high-pressure treatment temperature,pressure holding time, pressure, pretreatment and sterilization on fresh fruit (blue berry andcherry tomato) jelly quality and optimizing sterilizing conditions, influence of combination ofhigh-pressure and heat treatment on relative indexes of fruits were observed. Pre-experiments results showed that high-pressure process could maintain better shapes of blue berries andcherry tomatoes comparing with thermal sterilization. By using the multi-index test,optimized sterilization conditions were pressure300MPa, temperature35℃and pressureholding time5min due to orthogonal table. Order of the influence of various factors onmicroorganism was: pressure> temperature> time.