Chemical and thermal characteristics of milk‐fat fractions isolated by a melt crystallization

Abstract

Anhydrous milk fat (AMF) was fractionated by a two-stage dry fractionation process to produce three fractions: high melting (HMF), middle melting (MMF), and low melting (LMF). The HMF (m.p. 42~ exhibited a broad melting range similar to a plastic fat. The MMF (m.p. 33~ resembled the original AMF (m.p. 31~ but with slightly higher solid fat content. The LMF (m.p. 16~ was liquid at ambient temperature. Differences in the thermal properties of these fractions were attributed to the triacylglycerols (TAG) and their fatty acid composition. Saturated TAG with carbon numbers of 36-54 were concentrated in the HMF; whereas unsaturated TAG of carbon number 36-54 predominated in the LMF. Likewise, the longchain saturated fatty acids were significantly higher and the long-chain unsaturated fatty acids were significantly lower in the HMF fraction. Binary blends of milk-fat fractions with a range of melting profiles were produced by mixing HMF with AMF, MMF, or LMF. Laboratory-prepared fractions were similar to commercially available fractions.JAOCS 73, 1647-1652 (1996). KEY WORDS: Dry fractionation, fatty acid, milk fat, thermalproperties, and triacylglycerol composition.Anhydrous milk fat (AMF) is a complex mixture of triacylglycerols (TAG), comprised of at least 60 different fatty acids, with unique chemical and thermal properties. In its original form, milk fat lacks certain physical and functional properties, which limits its utilization (1-5). For example, milk fat lacks the appropriate plasticity and hardness for use in pastries, and its melt profile results in poor spreadability and promotes softening in chocolate (5). The functionality of milk fat may be enhanced by separating AMF into various fractions that have unique functional properties. Proposed food applications for AMF fractions include spreads and cold-spreadable butters, puff pastries, biscuits, shortbreads, cakes, pourable frying oils, cocoa butter replacement in chocolate and confectionery products, and in ice cream and whipped creams (1-5).

Isothermal crystallization behaviour of milk fat in bulk and emulsified state

“…Due to the rapid cooling applied, the crystallization starts in the metastable a-polymorph (Dimick, Reddy, & Ziegler, 1996;Lavigne & Ollivon, 1997;van Beresteyn, 1972;Woodrow & Deman, 1968). at 20 C) (ten Grotenhuis et al, 1999;van Aken, ten Grotenhuis, van Langevelde, & Schenk, 1999;van Aken & Visser, 2000).…”

Melting behavior of blends of milk fat with hydrogenated coconut and cottonseed oils

“…The weighted average of the SFC of the original oils was calculated as: [1] where HVO represents hydrogenated vegetable oil and X and Y are the percentages of AMF and HVO in the blends.…”

“…The blending of milk fat with vegetable oils has been used to increase the buttery flavor of vegetable fats and change the physical properties of milk fat. For example, milk fat alone does not have the appropriate plasticity and hardness for use in pastries (1), but blending of milk fat with vegetable oils and fats results in a significant alteration of the physical properties of milk fat. Of particular interest to milk-fat producers is the development of milk-fat blends with vegetable oils and fats for confectionery, pastry, baking and other applications.…”

Caracterización de grasas para caldos deshidratados

“…A partir de los datos de las áreas parciales y del área total del pico correspondiente a la fusión (determinados usando el programa de cálculo numérico del calorímetro), se calculó el porcentaje de sólidos (o su equivalente porcentaje de líquido) a cada una de las temperaturas elegidas durante dicha transición, tal como se menciona en la literatura (Amer, 1985;Fouad, 1990;BonA/ankar, 1992;Bornaz, 1994;Dimick, 1996).…”