Study on grainy crystals in edible beef tallow shortening

The slip melting points (SMP), thermal characteristics, structural properties, fatty acid compositions and triacylglycerol (TAG) compositions of the grainy crystals and surrounding materials in the edible beef tallow shortening (EBTS) were studied. The results showed that the TAG compositions of the grainy crystals changed greatly compared with their surrounding materials. The contents of low melting point TAGs (1-palmitoyl-2-oleoyl-3-linoleoyl-glycerol (POL), 1-palmitoyl-2, 3-dioleoyl-glycero l (POO), 1-stearoyl-2, 3-dioleoyl-glycerol (SOO)) descended, while that of higher melting point TAGs (1, 3-dipalmitoy-2-oleoyl-glycerol (POP), 1-palmitoyl-2-oleoyl-3-stearoyl-glycerol (POS), 1, 3-distearoyl-2-oleoyl-glycerol (SOS)) rose. The differential scanning calorimetry (DSC) melting curves of the grainy crystals showed three smaller endothermic peaks between 14 °C and 30 °C, which were more complex compared with that of their surrounding materials. X-ray diffraction (XRD) results showed that the grainy crystal was mainly of the β form.