State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
Ultrason Sonochem. 2019 Nov;58:104641. doi: 10.1016/j.ultsonch.2019.104641. Epub 2019 Jun 22.
Lard with a substantially reduced cholesterol content through aqueous enzyme extraction is an attractive source of lipid in healthy and nutritious emulsion food product development. The objective of this study was to elucidate the crystallization behavior (4-20 °C) of emulsions prepared from low-cholesterol lard in relation to protein emulsifier (2 and 4% whey protein isolate, WPI) and ultrasound (475 w, 5 min) treatments. The physicochemical properties and fat crystallization pattern of the emulsions were investigated. Emulsions with 4% WPI were superior to those with 2% WPI on interfacial adsorption and crystal size reduction. Ultrasonic treatment of prepared emulsions further decreased fat crystal size, promoted small and uniform crystal distribution, and slightly destabilized emulsions. Protein concentration and ultrasonic treatment had no obvious effect on crystal transition from β' to the more stable β-form based on X-ray diffraction. The melting properties determined by differential scanning calorimetry indicated that emulsified lard had a lower onset melting temperature than bulk lard, and with ultrasound treatment, the melting enthalpy increased remarkably. The ultrasound-induced change in fat crystalline structure and emulsion meta-stability may be valuable to the manufacture of healthy, emulsion-incorporated food products.
通过水相酶提取使猪油的胆固醇含量大幅降低，是开发健康、营养的乳液食品的有吸引力的脂质来源。本研究的目的是阐明与蛋白质乳化剂（2%和 4%乳清蛋白分离物，WPI）和超声处理（475w，5min）相关的低胆固醇猪油乳液的结晶行为（4-20°C）。研究了乳液的物理化学性质和脂肪结晶模式。与 2%的 WPI 相比，4%的 WPI 更有利于界面吸附和减小晶体尺寸。制备乳液的超声处理进一步减小了脂肪晶体尺寸，促进了小而均匀的晶体分布，并略微使乳液不稳定。基于 X 射线衍射，蛋白质浓度和超声处理对晶体从β'向更稳定的β形式的转变没有明显影响。差示扫描量热法测定的熔融性能表明，乳化猪油的起始熔融温度低于块状猪油，而超声处理后，熔融焓显著增加。超声处理引起的脂肪晶体结构和乳液亚稳性的变化可能对制造健康的、含乳液的食品产品具有重要价值。
