制造过程对可溶性大豆多糖结构和产物起泡性的影响

通过控制酸水解、碱脱酯和蛋白酶解条件探讨可溶性大豆多糖制造过程对于产物结构和起泡性的影响。可溶性大豆多糖(SSPS)的结构采用单糖组成、重均分子量、酯化度、蛋白含量进行表征,起泡性用泡沫膨胀率(FE)和泡沫稳定性(FS)表征。结果表明,酸水解过程会破坏SSPS主链结构进而使分子量逐渐降低,但不影响酯化度和蛋白质含量;随着分子量的降低,SSPS的FE逐渐增大,但FS逐渐降低。碱脱酯过程不影响产物分子量,但可以使酯化度和蛋白含量同步降低,产物的FE和FS也同步下降。将低分子量高甲酯含量SSPS采用蛋白酶水解,获得具有相同分子量和酯化度、不同蛋白质含量的SSPS。起泡性结果显示随着蛋白含量的下降,SSPS的FE和FS均同步下降。上述结果说明,相比于酯化度,蛋白质含量和分子量对大豆多糖的起泡性具有更为重要的作用。

Effect of processing parameters on the structure of soybean polysaccharide and its foaming properties

Soluble soy polysaccharides (SSPS) with different structure characteristics were obtained by controlling the conditions of acid hydrolysis, alkaline de-esterification and proteolysis. The effect of processing on the structure characteristics of SSPS and its foaming properties were discussed in details. The structure properties of SSPS were characterized by monosaccharide composition, average molecular weight, degree of esterification (DE), and protein content. The foaming properties of SSPS were expressed by the foam expansion rate (FE) and the foam stability (FS). The results showed that the acidic hydrolysis process could degrade the SSPS main chain structure and gradually reduce the molecular weight pf SSPS, but could not affect the DE and protein content. With decreasing of molecular weight, the foam expansion rate (FE) of SSPS increased, while the foam stability (FS) decreased. The alkaline de-esterification process did not affect the molecular weight, but reduced the DE and protein content simultaneously. The FE and FS of the product also decreased simultaneously with the decreasing of the DE and protein content. SSPS with different protein content was obtained by proteolysis. Proteolysis did not affect the molecular weight and DE of the product. The results of FE and FS showed the FE and FS of SSPS decreased simultaneously with the decreasing of protein content. All these data suggested that the protein content and average molecular weight of SSPS played a more critical role in its foaming properties compared with the DE. The findings should be of value for the preparation of SPI with good foaming performance.