植物蜡及液态植物油构建油凝胶的物性研究

以米糠蜡、棕榈蜡、蜂蜡3种食品级植物蜡为凝胶剂,葵花籽油、油茶籽油、亚麻籽油、棉籽油为基料油,构建了植物油基油凝胶,系统分析了油凝胶的外观形态、持油能力、微观结构、硬度、晶型及熔化结晶行为。结果发现,棕榈蜡基油凝胶涂抹性能优良,蜂蜡基油凝胶在三者中具有最高的持油能力。微观分析表明,米糠蜡形成的油凝胶晶体结构较为清晰,呈细长的针状;蜂蜡形成的油凝胶晶体结构最为细小,呈细小的针状;棕榈蜡形成的油凝胶,针型细密,并呈絮状结晶。晶体密度及样品硬度均随凝胶剂质量分数增加而增加。油凝胶的晶型与凝胶剂质量分数、基料油的种类无太大关系,主要取决于凝胶剂的种类。熔化结晶行为表明,凝胶剂种类相同时,随着其质量分数的增加,油凝胶的结晶/熔化峰值温度均升高。

Physical properties of oleogels strutured by vegetable wax and liquid vegetable oil

Three kinds of edible vegetable waxes, rice bran wax, palm wax and beeswax, were used as gelling agents, and sunflower seed oil, oil-tea camellia seed oil, linseed oil and cottonseed oil were used as base oil to construct vegetable oil-based oleogels. The appearance, oil holding capacity, microstructure, hardness, crystal form and melting crystallization behavior of the oleogels were systematically analyzed, respectively. The results showed that the palm wax-based oleogel had excellent coating performance and beeswax-based oleogel had the highest oil holding capacity among the three wax-based oleogels; microscopic analysis showed that the crystal structure of rice bran wax-based oleoyel was clear and a slender needle-like; the crystal structure of beeswax-based oleogel was the smallest and was fine needle-like; the sample with palm wax as gelling agent, the needle shape was fine and flocculated. Both the crystal density and the hardness of the sample increased as the amount of the gelling agents increased. The crystal form of the oleogels had little to do with the gelling agents mass concentration and the type of the base oil, and mainly depended on the type of gelling agents. Melting crystallization behavior analysis showed that the same gelling agent type, and as the gelling agent mass concentration increased, the crystallization/melting peak temperature of the oleogel increased.