Abstract: Pectin is a natural polysaccharide present in the cell wall of higher plants, which plays an important role in the textual and nutritional properties of fruit and vegetable-based products. There are two types of pectin: high methoxy pectin (HMP, with methoxy content ≥ 7%) and low methoxy pectin (LMP, with methoxy content < 7%). LMP has good stability, gelling and thickening properties, and is widely used in dairy products since it brings a special flavor to fermented milk and increases the viscosity and stability of the product. However, the yield of LMP is low due to the limitations of production and processing conditions. Therefore, the conversion of plant-derived HMP into LMP through de-esterification can meet the industrial demand for LMP. This review outlines the current status of the application of LMP in the dairy industry and its preparation methods including acid de-esterification, alkaline de-esterification, enzymatic de-esterification and amidation, and discusses the effects of these methods on the structure of pectin. Hopefully, this review will provide a theoretical basis for the industrial production and wide application of LMP.

Key words: low methoxyl pectin; pectin structure; dairy products; de-esterification; progress

摘要： 果胶是高等植物细胞壁中的一种天然多糖，在果蔬制品的质构特性和营养特性方面均发挥着重要作用。果胶可分为高甲氧基果胶（high methoxyl pectin，HMP，甲氧基含量≥7%）和低甲氧基果胶（low methoxyl pectin，LMP，甲氧基含量＜7%）两类。LMP具有很好的稳定、凝胶及增稠特性，被广泛应用于乳制品加工产品，在为发酵乳带来特殊风味的同时，增加了相应产品的黏稠度和稳定性。但由于生产及加工技术条件等的限制，LMP产量较低。因此，将植物原料中的HMP经脱酯转化成LMP，可满足工业上对于LMP的需求量。本文综述LMP在乳品领域的应用现状及国内外LMP的制备方法，包括酸法脱酯、碱法脱酯、酶法脱酯和酰胺化法及这些方法对于果胶结构的影响，以期为LMP的大量生产及更广泛应用提供理论依据。

关键词: 低甲氧基果胶；果胶结构；乳制品；脱酯；研究进展