提取方式对大豆膳食纤维理化及功能特性的影响

Effect of Different Extraction Methods on Physicochemical and Functional Properties of Soybean Dietary Fiber

生物解离大豆残渣中膳食纤维含量丰富,为明晰生物解离提取法对大豆膳食纤维的改性效果,获取高品质大豆膳食纤维,本研究测定生物解离大豆膳食纤维的纯度、理化性质及功能特性,并与水提法天然大豆膳食纤维,化学法、发酵法及挤压膨化法改性大豆膳食纤维进行对比。结果表明:生物解离大豆膳食纤维纯度可达82.58%,其中可溶性膳食纤维含量约占总膳食纤维的60%,属于优质膳食纤维;生物解离膳食纤维的持水性、持油性、膨胀性和溶解性分别为6.87 g/g、5.48 g/g、8.22 mL/g和5.07%,均明显高于其他方式提取的膳食纤维。功能特性测定结果表明,不同方式提取的膳食纤维功能特性强弱次序均为生物解离膳食纤维>挤压膨化法改性膳食纤维>发酵法改性膳食纤维>化学法改性膳食纤维>水提法膳食纤维。生物解离膳食纤维在pH 7.0时对Pb^(2+)、As^+、Cu^(2+)3种重金属离子吸附能力分别为351.2、304.1、214.1μmol/g。此外,生物解离大豆膳食纤维的葡萄糖吸收能力、α-淀粉酶抑制能力和胆汁酸阻滞指数分别为6.56～35.78 mmol/g、18.42%和33.12%～35.52%,均显著高于其余提取方式的膳食纤维。因此,生物解离提取法对大豆膳食纤维改性效果显著,生物解离残渣可作为一种新型的膳食纤维来源进行开发应用。

The residue from biological dissociation(BD)of soybeans can be considered as a rich source of dietary fibers due to its richness in dietary fibers.In order to investigate the effect of BD on the quality of soybean dietary fiber and hence to obtain high-quality soybean dietary fiber,the chemical composition,physicochemical and functional properties of the resulting soybean dietary fiber were determined and compared with those obtained from water extraction,chemical treatment,fermentation and water extraction following extrusion pretreatment.The results showed that the purity of dietary fiber prepared by BD was 82.58%,and approximately 60%of the total dietary fiber was soluble,suggesting that high-quality dietary fiber was obtained.The water-holding capacity,oil-holding capacity,expansibility and solubility of dietary fiber from BD were 6.87 g/g,5.48 g/g,8.22 mL/g and 5.07%,respectively,which were significantly higher than those of dietary fibers from other extraction methods.The results of functional properties showed that the functional properties of dietary fibers from different extraction methods were in the decreasing order of BD,extrusion,fermentation,chemical extraction,and water extraction.In addition,the adsorption capacity of BD dietary fiber toward Pb2+,As3+,and Cu2+were 351.2,304.1 and 214.1μmol/g at pH 7.0,respectively.The glucose adsorption capacity,α-amylase-inhibitory activity and bile acid retardation index were 6.56–35.78 mmol/g,18.42%,and 33.12%–35.52%,respectively,which were significantly higher than dietary fibers from other extraction methods.Therefore,the residue from biological dissociation of soybeans has good physicochemical and functional properties,indicating that it has great potential for application in the food industry as a new source of dietary fiber.