关键词: 油脂组成；油脂结晶；部分聚结率；冻融循环；搅打特性?

Abstract: To elucidate the intrinsic connection between the fatty acid composition and crystallization properties of oils and the freeze-thaw stability and whipping properties of whipping cream emulsion, this study investigated the impacts of palm kernel oil (PKO), fully hydrogenated palm kernel oil (FHPKO), palm kernel stearin (PKS), and palm oil stearin (POS) on the quality of non-dairy whipping cream subjected to 1, 3 and 5 freeze-thaw cycles. The results revealed that the stability and whipping properties of frozen-thawed lauric acid-rich oil emulsion were generally superior to those of its palmitic acid-rich counterpart. For lauric acid-rich fat, the higher the proportion of fatty acids with 18 carbons, the better the emulsion stability and whipping properties. The initial melting temperature of PKO, with the higher oleic acid (C18:1) content, was the lowest, and the crystals formed were small and had poor thermal stability. The stability of PKO emulsion subjected to five freeze-thaw cycles was the strongest, and its overrun was higher, but the height of PKO-based whipped cream decreased significantly after 6 hours. The crystals formed by FHPKO, with the highest stearic acid (C18:0) content, were small and dense. After 5 freeze-thaw cycles, the proportion of interfacial proteins in FHPKO emulsion, which exhibited strong stability, the highest overrun and the best aeration stability, slightly decreased. In contrast, PKS, with the highest myristic acid (C14:0) content, formed fine granular crystals and showed the most serious partial coalescence of fat globules, resulting in the largest emulsion viscosity and particle size, the lowest overrun, and syneresis in whipping cream. POS, of which palmitic acid (C16:0) was the major fatty acid, had the highest initial melting temperature and could form large coarse crystals. The proportion of interfacial proteins in POS emulsion undergoing 5 freeze-thaw cycles was the lowest, leading to significant partial coalescence of fat globules, emulsion instability, low overrun and syneresis in whipping cream. This study provides theoretical support for the production of whipping cream with high freeze-thaw stability and excellent whipping characteristics.

Key words: fatty acid composition; fat crystallization; fat partial coalescence; freeze-thaw cycles; whipping properties