Effect of Fatty Acid Composition of Monoglycerides and Shear on the Polymorph Behavior in Water‐in‐Palm Oil‐Based Blend

Abstract

Effect of the fatty acid composition of monoglycerides and shear on the polymorphic behavior in a water-in-oil (W/O) emulsion semi-solid fats blend was investigated. The bulk fat blend and the W/O emulsion fat blend with added either unsaturated or saturated monoglycerides were prepared using a rapid cooling heat exchanger, and the polymorphic transitions from b 0 to b-form during storage were compared by X-ray diffraction. The peak intensity of the b-polymorph of the samples with added saturated monoglycerides was stronger than that of unsaturated monoglycerides, and the peak intensity of the b-polymorph of the W/O fat blend emulsions was stronger than that of the bulk fat blends. The polymorphic transition to the b-form during storage of the W/O emulsion fat blend was promoted by the applied shear. In contrast, that of the bulk fat blend was retarded by shear. These results suggested that fatty acids, which combined to monoglycerides on the surface of water droplets, influenced the polymorph transformation of the fat crystal network in a continuous semi-solid fat phase because of the acyl-acyl interactions between the fatty acid residues of the monoglycerides and triacylglycerols in the fat crystal network.

Effect of Triacylglycerol Compositions and Physical Properties on the Granular Crystal Formation of Fat Blends

“…The size of granular crystals in Sample 2 increased rapidly from Day 3 to 1 week, and this period corresponded to the period in which the β/β’ ratio increased. The behavior observed in this study was similar to the previous report (Shiota et al, ). We suggested that the state change of POO associated with repeatedly melting and solidifying during thermal thawing involved the polymorph transition of POP.…”

“…These results suggested that POO promotes β‐type crystal formation. Shiota et al () suggested that granular crystals are more likely to be produced in mixtures in which the proportion of β‐type crystals gradually increases during storage (Shiota et al, ). The size of granular crystals in Sample 2 increased rapidly from Day 3 to 1 week, and this period corresponded to the period in which the β/β’ ratio increased.…”

Effect of Shearing on Crystallization of Palm Oil-Based Fat Blends

“…The non-uniformly Needles: crystals with primary bonds, platelets: crystals with secondary bonds, gray needles and platelets, b and e: melting crystals with primary and secondary bonds at a higher temperature, wavy fragments: crystals with transitioning to the β-form, gray background: oil. ing in bulk fat blend based on palm oil (Shiota et al, 2011). This is consistent with the effect of lab-scale compression or shearing in the present study.…”

External factors affecting polymorphic crystallization of lipids

“…The study of fat crystallization under shear was initiated half a century ago, as we described earlier . Since this review, detailed work on natural fats has been reported by many researchers . These studies clearly demonstrate that applying shear increases the rates of polymorphic crystallization and transformation of lipids, and modifies the aggregation of nanocrystals of the crystal network.…”