甜菜果胶乳化活性及稳定性

Emulsifying Activity and Stability of Sugar Beet Pectin

甜菜果胶是一种从甜菜粕中提取的酸性阴离子多糖,主链由鼠李糖和半乳糖醛酸组成,侧链数量丰富,主要由鼠李糖、阿拉伯糖、半乳糖、果糖等一些中性糖组成。其中中性糖末端与蛋白质共价连接,赋予了甜菜果胶良好的乳化性质。本研究主要探究了甜菜果胶的乳化特性并与柑橘果胶进行对比。考察了甜菜粕产地、果胶质量浓度、pH值、温度、贮藏时间等对乳液特性(粒径分布、平均粒径、Zeta-电位和浊度变化)的影响。研究结果表明,产地不同对甜菜果胶结构组成影响较大,以甜菜果胶制备的乳液粒径显著小于柑橘果胶乳液,且乳化活性更高。当甜菜果胶质量浓度为10~25 mg/m L时,乳液在4周的贮存期内保持良好的稳定性,而柑橘果胶乳液粒径显著增加。pH 2~6的范围内,果胶粒径基本保持不变。25~85℃升温过程中,柑橘果胶乳液粒径大幅增加。说明甜菜果胶具有良好的乳化活性和稳定性。本研究为甜菜果胶的实际应用提供了理论指导。

Sugar beet pectin （SBP） is an acidic anion polysaccharide extracted from beet pulp. The backbone of SBP is comprised of rhamnose and galacturonic acid, which are rich in neutral sugar side chains, including rhamnose, arabinose, galactose and fructose. The proteins are covalently attached to the end of the neutral sugar side chains, contributing to the excellent emulsifying properties of SBP. This paper focuses on a comparison of the emulsifying properties of SBP and citrus pectin （CP）. The effects of the growing area of sugar beet pulp, pectin concentration, pH, thermal treatment and storage time on the emulsifying properties （including drop size distribution, average particle size, zeta-potential, and turbidity） of the pectin were investigated. It was found that the geographical origin of sugar beet pulp showed a great in？uence on the protein composition in SBP. The drop size of the emulsion prepared with citrus pectin was much larger than that of SBP emulsion, and the former also exhibited poorer emulsifying activity. Emulsions coated with 10–25 mg/mL sugar beet pectin maintained good stability during the storage period （four weeks）, while the droplet size of citrus pectin emulsion increased signi？cantly. Emulsion droplet size remained stable in the swrange of pH 2–6. The droplet size of CP emulsion increased signi？cantly during thermal treatment （25–85 ℃）. This study veried that SBP exhibited excellent emulsifying activity and emulsion stability.