Crystallization modifiers in lipid systems

Abstract

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.

Modified soybean lecithins as inducers of the acceleration of cocoa butter crystallization

“…The measurements of the SFC were performed at temperatures of 10,15,20,25,30,35, and 40°C, using the NMR spectrometer. Samples were analyzed in duplicate and the values are reported as the mean of two measurements.…”

“…It is reported in the literature that phospholipids can cocrystallize with the TAGs due to structural similarity [15] and act as hetero-nuclei, promoting an increase of the crystallization rate by the direct catalytic action as an impurity [5]. By the same point of view, small solid particles and impurities present in the lecithin product can be considered as surface active agents and can act like emulsifiers [29,30].…”

“…The second mechanism, accepted by most authors, states that the emulsifiers and triacylglycerols could co-crystallize due to the similarity of their chemical structures. On the other hand, structural dissimilarities should cause delays in nucleation, inhibiting crystal growth [5,14,15].…”

Crystallisation of palm olein under the influence of sucrose esters

“…Sucrose esters (SEs) are derived from esterification (fatty acids and sucrose) or transesterification (sucrose and fat) reactions (Ribeiro et al ., ). SEs are used in many food products and are recognised as potential modifiers for the crystallisation of fats and oils.…”

Influence of crystal promoters on sensory characteristics of heat‐resistant compound chocolate

“…The additives can either inhibit crystal growth by acting as crystal inhibitors or increase the rate of crystallisation and be used as crystal promoters. Apart from their role on crystallisation, they can also influence temperature stability, rheology and polymorphic stability (Ribeiro et al, 2015). In chocolate, crystal promoters can promote formation of appropriate stable polymorphic fat crystals to obtain products with good snap, colour, contraction and gloss.…”