Isothermal crystallization behavior of lard at different temperatures studied by DSC and real-time XRD

Abstract

Differential scanning calorimetry and real-time X-ray diffraction using synchrotron radiation were used to study the isothermal crystallization formation mechanism of lard at 18, 20, 22 and 24°C. At 18°C, lard crystallized in three steps. A potential mechanism for these three steps was proposed. In the first step, part of the melt (the trisaturated triacylglycerols (TAGs)) crystallized in α crystals adopting a double length structure (2L), while the second step consisted of a polymorphic transition of these 2Lα crystals to β' crystals with a triple length structure (3L). Extra 3Lβ' crystals consisting of monounsaturated TAGs were also formed directly from the melt. In the third and last step, β crystals were formed due to a second polymorphic transition of trisaturated 3Lβ' crystals to β crystals adopting a 2L structure.Above a cut-off temperature of 20°C lard crystallized in two steps: no formation of α crystals could be observed and 3Lβ' crystals (trisaturated and monounsaturated TAGs) were formed directly from the melt. This proposed mechanism implies that lard crystallization is characterized by an overlap of fractionated crystallization and polymorphic transitions.

Effect of Meat Type, Animal Fatty Acid Composition, and Isothermal Temperature on the Viscoelastic Properties of Meat Batters

“…The fatty acid composition of the two types of lard is shown in Table and was in line with other studies (Marrikar & Yanty, ; Nur Illiyin, Marikkar, Aimi, Iran, and Miskandar, ; Steen et al., ). Variation in the fatty acid composition can be ascribed to differences in rearing factors such as age, sex, breed, feeding, and physiological state (Gandamer, ).…”

“…Moisture, protein, fat and pH were measured in triplicate. Fatty acid composition of lard from the "U" and "S" fat (Belgian and Italian pork backfat, respectively) was determined by gas chromatography according to the method of Steen et al (2015). Fatty acid composition was measured in quadruplicate.…”

Effect of Meat Type, Animal Fat Type, and Cooking Temperature on Microstructural and Macroscopic Properties of Cooked Sausages

“…The fatty acid composition of Belgian (generally having a lower degree of saturation) and Italian (generally having a higher degree of saturation) pork back fat was determined by gas chromatography (Steen et al, 2015). Only details on palmitic (C16:0), stearic (C18:0), oleic (C18:1) and linoleic acids (C18:2) will be presented, as these were the four main fatty acids accounting for about 90% of the total fatty acids present.…”

“…Lard was obtained from the fat fractions by a rendering process (Steen et al 2015), equilibrated at 7 °C for 1 week, and subsequently the melting profiles were analyzed using differential scanning calorimetry (DSC) and hardness via texture analysis. The DSC experiments were performed on a Q2000 DSC with a refrigerated cooling system and autosampler (TA Instruments, New Castle, DE, USA).…”

In situ formed ionic liquids in lard oil as high‐performance lubricants for steel/steel contacts at elevated temperature

“…This raw material is cheap, renewable, and generally environmentally friendly. The major component of LO is triacylglycerides (TAGs), which are composed of 3 fatty acids connected by a glycerol centre (Scheme ), and the fatty acid compositions are 20 to 29% palmitic acid (C16:0), 11 to 19% stearic acid (C18:0), 24 to 51% oleic acid (C18:1), and 3 to 19% linoleic acid (C18:2) . It is well known that LO has better thermal stability than most of vegetable oils, such as rapeseed oil and soybean oil, both of which have high content of the relatively unstable linoleic (C18:2) and linolenic (C18:3) fatty acids, respectively .…”