Emulsification properties of hydrocolloids

被引:6
作者
Garti, N [1 ]
Leser, ME
机构
[1] Hebrew Univ Jerusalem, Sch Appl Sci & Technol, Casali Inst Appl Chem, IL-91904 Jerusalem, Israel
[2] Nestec Ltd, Nestle Res Ctr, CH-1000 Lausanne 26, Switzerland
关键词
hydrocolloids; gums; water-soluble polysaccharides; biopolymers; amphiphiles; macromolecules; emulsifiers; emulsions surface activity; guar; galactomannans; pectin; tragacanth; xanthan; Portulaca Oleracea;
D O I
暂无
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
Water soluble/dispersible polysaccharides, termed hydrocolloids or gums, are known as viscosity builders and/or gelling agents in aqueous systems. Technologists call them stabilizers, since they can improve long-term stability in systems consisting of water and oil. Many scientists claim that hydrocolloids are not true emulsifiers, since they do not actively adsorb onto liquid interfaces and the stability that they impart is mainly via increasing viscosity and decreasing mobility. Only certain hydrocolloids, such as gum arabic, were known to exhibit emulsification properties. The surface activity was proved to be derived from the anchoring ability of the hydrophobic proteineous moieties (attached to the polysaccharide backbone) onto the oil phase. The aim of this review is to demonstrate that certain hydrophilic (anionic or non-ionic) polysaccharides purified to a level of being almost protein-free can exhibit surface and emulsification properties inspite of their rigid and hydrophilic nature. The adsorption isotherms of the surface-active biopolymers ave similar to other macromolecular amphiphiles. The main gums to be discussed are those of the galactomannan family [locust bean gum (LBG), guar and fenugreek]. Other gums from less known sources (Portulaca Oleracea and Opuntia Ficus) also exhibit surface properties. It appears that the statements made by several authors claiming that hydrocolloids cannot be considered as emulsifiers, were inaccurate. It seems that the requirements for built-in hydrophobic moieties on the hydrocolloids' backbone internal structure, are not obligatory for active adsorption. Adsorption can be induced by a salting-out effect, resulting in semi-solid interfacial layers. Hydrocolloids can form thick birefringent gel-like mechanical barriers at the oil-water interface of emulsion oil droplets. This new category of natural-occurring hydrocolloid-emulsifiers should be reconsidered by food technologists and by other emulsion technologists for other industrial applications. Copyright (C) 2001 John Wiley & Sons, Ltd.
引用
收藏
页码:123 / 135
页数:13
相关论文
共 48 条
[1]  
AMIN ES, 1997, CARBOHYD RES, V56, P123
[2]  
ANDERSON DMW, 1986, GUMS STABILISERS FOO, V3, P79
[3]  
ANDERSON DMW, 1996, J CHEM SOC C
[4]  
[Anonymous], GUMS STABILIZERS FOO
[5]  
Bergenstahl B, 1988, GUMS STABILIZERS FOO, V4, P363
[6]   SHELF-LIFE STUDY OF OIL-WATER EMULSIONS USING VARIOUS COMMERCIAL HYDROCOLLOIDS [J].
COIA, KA ;
STAUFFER, KR .
JOURNAL OF FOOD SCIENCE, 1987, 52 (01) :166-172
[7]   EFFECT OF A PROTEINASE ON THE MACROMOLECULAR DISTRIBUTION OF ACACIA-SENEGAL GUM [J].
CONNOLLY, S ;
FENYO, JC ;
VANDEVELDE, MC .
CARBOHYDRATE POLYMERS, 1988, 8 (01) :23-32
[8]  
Darling D. F., 1987, Special Publication, Royal Society of Chemistry, V58, P1, DOI 10.1533/9781845698300.1
[9]   Acetylated pectic polysaccharides of sugar beet [J].
Dea, I. C. M. ;
Madden, J. K. .
FOOD HYDROCOLLOIDS, 1986, 1 (01) :71-88
[10]   EMULSIFYING BEHAVIOR OF GUM-ARABIC .1. EFFECT OF THE NATURE OF THE OIL PHASE ON THE EMULSION DROPLET-SIZE DISTRIBUTION [J].
DICKINSON, E ;
GALAZKA, VB ;
ANDERSON, DMW .
CARBOHYDRATE POLYMERS, 1991, 14 (04) :373-383