脂肪的结晶是影响基于脂肪的产品的结构和性质的决定性物理事件。这些加工食品的稳定性由脂肪物理状态的变化和它们的结晶行为的改变来调节。像多态转换这样的问题,石油运移,脂肪开花的发展,缓慢结晶和结晶聚集体的形成脱颖而出。脂质系统结晶行为的改变一直是食品加工的战略问题,瞄准泰勒制造的产品,降低成本,提高质量,增加不同工业脂肪的适用性和稳定性。在这方面,在理解控制脂肪结晶的复杂机制方面的进步导致了策略的发展,以调节脂肪结构的常规过程,基于结晶改性剂的使用。已经评估了不同的组件,例如特定的甘油三酯,偏甘油酯(单酰基甘油和二酰基甘油),游离脂肪酸,磷脂和乳化剂。关于这些特定添加剂或少量脂质对脂肪系统结晶行为的影响的知识和专业知识代表了当前油脂工业加工的关注焦点。本文对结晶调节剂在脂质系统中的应用进行了全面的综述,尤其是棕榈油,可可脂和通用脂肪,突出显示:i)删除,在脂肪基质中添加或分馏少量脂质;ii)使用成核剂来改变结晶过程;iii)通过使用乳化剂来控制脂质基质中的结晶。讨论了将这些成分添加到脂质系统中与成核现象有关的问题,晶体生长,形态学,热行为和多态性,目的是为读者提供与脂肪和油结晶相关机制的完整全景。
Crystallization of fats is a determinant physical event affecting the structure and properties of fat-based products. The stability of these processed foods is regulated by changes in the physical state of fats and alterations in their crystallization behavior. Problems like polymorphic transitions, oil migration, fat bloom development, slow crystallization and formation of crystalline aggregates stand out. The change of the crystallization behavior of lipid systems has been a strategic issue for the processing of foods, aiming at taylor made products, reducing costs, improving quality, and increasing the applicability and stability of different industrial fats. In this connection, advances in understanding the complex mechanisms that govern fat crystallization led to the development of strategies in order to modulate the conventional processes of fat structuration, based on the use of crystallization modifiers. Different components have been evaluated, such as specific triacyglycerols, partial glycerides (monoacylglycerols and diacylglycerols), free fatty acids, phospholipids and emulsifiers. The knowledge and expertise on the influence of these specific additives or minor lipids on the crystallization behavior of fat systems represents a focus of current interest for the industrial processing of oils and fats. This article presents a comprehensive review on the use of crystallization modifiers in lipid systems, especially for palm oil, cocoa butter and general purpose fats, highlighting: i) the removal, addition or fractionation of minor lipids in fat bases; ii) the use of nucleating agents to modify the crystallization process; iii) control of crystallization in lipid bases by using emulsifiers. The addition of these components into lipid systems is discussed in relation to the phenomena of nucleation, crystal growth, morphology, thermal behavior and polymorphism, with the intention of providing the reader with a complete panorama of the associated mechanisms with crystallization of fats and oils.