番茄皮渣膳食纤维的理化性质及其结构表征

Study on the Physiochemical Properties and Structural Characteristics of the Dietary Fiber in Tomato Pomace

番茄皮渣是番茄制品加工业的副产物,其中富含对人体有益的膳食纤维,但是目前对番茄皮渣的综合利用程度不高。本研究通过考察番茄皮渣膳食纤维的持水力、膨胀力、持油力、葡萄糖吸附值、葡萄糖延迟指数等指标评价其理化性质,并借助红外光谱、扫描电镜、气质联用等技术设备分别对其官能团结构、微观结构及单糖组成进行表征。实验结果表明:番茄皮渣膳食纤维的持水力、膨胀力、持油力和葡萄糖吸附值分别为9.33 g/g、9.29 m L/g、9.84 g/g和19.206 mmol/g,在透析30 min时GRI达到最高36.78 mmol/g。可溶性膳食纤维的结构分析表明其具有明显的糖酯特征吸收峰;组成该可溶性膳食纤维的单糖主要是半乳糖,其次是阿拉伯糖和木糖;超微结构分析表明番茄皮渣SDF为不规则片状结构,且具有蜂窝状孔洞。番茄皮渣膳食纤维是一种高品质功能性食品原料或辅料。

Tomato pomace is a byproduct in the tomato processing industry, and is rich in dietary fiber （DF） which is beneficial to humans. However, the degree of comprehensive utilization of tomato pomace is very low. The objective of this study was to evaluate the physiochemical properties of the DF in tomato pomace by measuring the water holding capacity （WHC）, swelling capacity （SC）, oil holding capacity （OHC）, and glucose adsorption capacity （GAC）. In addition, the structures of functional groups, microstructure, and monosaccharide composition were characterized by infrared spectroscopy （IR）, scanning electron microscopy （SEM）, and GC-MS, respectively. The WHC, SC, OHC, and GAC of the DF in tomato pomace were 9.33 g/g, 9.29 mL/g, 9.84 g/g, and 19.206 mmol/g, respectively. The glucose retardation index （GRI） reached 36.78 mmol/g after 30 min of dialysis. The analysis of the structure of soluble DF （SDF） in tomato pomace showed the characteristic absorption peak ofglycolipids. The major monosaccharide in SDF was galactose, followed by arabinose and xylose. According to SEM results, SDF had an irregular sheet-like structure, with honeycomb-like holes. The DF in tomato pomace is a kind of raw or auxiliary material for high-quality functional foods.