JNU-UPM International Joint Laboratory on Plant Oil Processing and Safety, Department of Food Science and Engineering, Jinan University, Guangzhou, Guangdong 510632, China.
School of Science, Monash University Malaysia, Bandar Sunway 47500, Selangor, Malaysia.
Food Chem. 2024 Dec 15;461:140879. doi: 10.1016/j.foodchem.2024.140879. Epub 2024 Aug 13.
Currently, the poor whipping capabilities of anhydrous milk fat (AMF) in aerated emulsion products are a major obstacle for their use in beverages like tea and coffee, as well as in cakes and desserts, presenting fresh hurdles for the food industry. In this study, the mechanism of action of diacylglycerols (DAGs) with different carbon chain lengths and degrees of saturation on the partial coalescence of aerated emulsions was systematically investigated from three fundamental perspectives: fat crystallization, air-liquid interface rheology, and fat globule interface properties. The optimized crystallization of long carbon chain length diacylglycerol (LCD) based on stearate enhances interactions between fat globules at the air-liquid interface (with an elastic modulus E' reaching 246.42 mN/m), leading to a significantly reduced interface membrane strength. This promotes fat crystal-membrane interactions during whipping, resulting in a thermally stable foam structure with excellent shaping capability due to enhanced partial coalescence of fat globules. Although Laurate based medium carbon chain length diacylglycerol (MCD) promoted fat crystallization and optimized interface properties, it showed weaker foam properties because it did not adequately encapsulate air bubbles during whipping. Conversely, oleate long carbon chain length diacylglycerol (OCD) proved to be ineffective in facilitating fat crystal-membrane interaction, causing foam to have a subpar appearance. Hence, drawing from the carefully examined fat crystal-membrane interaction findings, a proposed mechanism sheds light on how DAGs impact the whipping abilities of aerated emulsions. This mechanism serves as a blueprint for creating aerated emulsions with superior whipping capabilities and foam systems that are resistant to heat.
目前，无水奶油（AMF）在充气乳液产品中的较差搅打起泡能力是其在茶和咖啡等饮料以及蛋糕和甜点中应用的主要障碍，这给食品工业带来了新的挑战。在这项研究中，从三个基本方面系统地研究了不同碳链长度和饱和度的二酰基甘油（DAG）对充气乳液部分聚结的作用机制：脂肪结晶、气液界面流变学和脂肪球界面特性。基于硬脂酸的长链二酰基甘油（LCD）的优化结晶增强了气液界面处脂肪球之间的相互作用（弹性模量 E'达到 246.42 mN/m），导致界面膜强度显著降低。这促进了搅打过程中脂肪晶体-膜相互作用，形成具有出色形状保持能力的热稳定泡沫结构，因为脂肪球的部分聚结得到增强。尽管基于月桂酸的中链二酰基甘油（MCD）促进了脂肪结晶和优化了界面特性，但由于在搅打过程中不能充分包裹气泡，其泡沫性能较弱。相反，基于油酸的长链二酰基甘油（OCD）在促进脂肪晶体-膜相互作用方面效果不佳，导致泡沫外观不佳。因此，根据仔细研究的脂肪晶体-膜相互作用发现，提出的机制阐明了 DAG 如何影响充气乳液的搅打起泡能力。该机制为具有优异搅打起泡能力和耐热泡沫体系的充气乳液的创建提供了蓝图。
