Fat Crystal Migration and Aggregation and Polymorphism Evolution during the Formation of Granular Crystals in Beef Tallow and Palm Oil

Abstract

Six rectangular block all beef tallow (BT)-based and all palm oil (PO)-based model shortenings prepared on a laboratory scale, denoted BTMS and POMS, respectively, were stored under two storage conditions, (1) constant temperatures (5 and 20 °C, respectively and (2) temperature fluctuations (5 °C for 12 h and 20 °C for 12 h for a cycle), to induce granular crystals. The fat crystal migration and aggregation, sensory evaluations, and polymorphism evolutions during the formation of granular crystals in the above samples were investigated systematically. In comparison to the constant temperature storage, the crystal growth and hierarchical aggregation process were more quick and the conversion rate of the β-form crystal was also faster in both BTMS and POMS under temperature cycling storage and, concomitantly, easier to induce the formation of granular crystals. From the comprehensive analysis of crystal sizes and the sensory evaluation results, it can be concluded that the detection threshold for graininess ranged from 40 to 90 μm, with the smaller size being perceived only at higher crystal concentrations. The possible formation mechanism and the realistic control approaches for granular crystals in plastic fats also are clarified in the present study.

Physicochemical Properties of Palm Oil‐Based Puff Pastry Model Margarines Related to Their Baking Performance in Long‐Term Storage

“…[14] Despite being of smaller size, the large spherical agglomerates observed in PMF-M at 18 weeks' storage ( Figure 7) are similar to granular crystals observed in fat blends containing palm oil. [19,35] An increasing proportion of large crystals during storage may result in increasing interactions between the different crystal structures, which may lead to sintering and to the formation of a stronger network during storage. [36] Therefore, rearrangements in the TAG mixture of PMF-M probably resulted in modifications at the microscopic level, which further modified the macroscopic textural properties (hardness and brittleness increase) and the baking performance of the margarine, as revealed in the reduction of the puffing effect.…”

Granular Crystals in Palm Oil Based Shortening/Margarine: A Review

“…[5][6][7][8][9][10][11] The presence of these liquid oils and soft fats can contribute to significant change in fat polymorphism, solid fat content (SFC) and melting behaviour of the fat blends but can also cause instability issues of the fat based products, especially in long term storage at low temperature. [12][13][14][15][16] For palm oil based shortenings and margarines, the most prevalent quality deterioration in storage is the appearance of granular crystals resulting in a graininess feeling for customers.…”

“…39,40 In general, fat crystals of palm oil are needle-like crystals under the β′ form, which has an appropriate size for trapping liquid oil inside the crystal networks of shortening and margarine. 1,14,41 However, the polymorphic transition β′ → β of palm fat can occur in longterm storage. Unlike β′ crystals, β crystals are often spherulite particles with a size in the range of 20−40 μm.…”

Enzymatic Interesterification of Lauric Fat Blends Formulated by Grouping Triacylglycerol Melting Points

“…In this study, lauric fat blends were chosen from H5 to H15 formulations, as this interval contained suitable amounts of hard fractions, where H5 formulation contained a minimum amount of hard fractions (5 % high melting TAGs) while H15 formulation contained a maximum amount of fractions (15 % high melting TAGs) in the production of shortening [1]. The high melting fraction needs to be carefully controlled, as it may give undesired organoleptic and textural properties even if only a small amount of that fraction is found in the fat blends [4]. These initial blends were then interesterified by sn-1,3 regioselective lipase using two strategies.…”

“…These lauric fat blends comprise medium and high melting fractions where the amount of both fractions can be adjusted to a desired level using melting TAG group formulation [1]. Although blending different oils and fats appeared to be a favored choice because of its simplicity, the liquid phase separation [2,3] and formation of relatively coarse crystals [4] can sometimes not be avoided, as TAG composition is limited by the origin of raw materials [5]. As vegetable oils and fats used in blends are commonly in their natural form, lauric fat blends may have some limited applications as plastic fats due to their specific chemical composition [6,7].…”