Abstract: The preparation of liquefied lard at room temperature by two-step dry fractionation was investigated in this study. One-factor-at-a-time experiments and an orthogonal array design were done to explore crystallization temperature, cooling rate and crystal-growing time. Lard was heated to thermobalance and then cooled down at a certain rate to crystallizaiton temperature. The lard was kept at the crystallization temperature for the growth of crystals until the formation of crystal nucleus. Finally, the solid and liquid phases were separated by centrifugation. The optimal first dry fractionation conditions were crystallization temperature of 21 ℃, cooling rate of 2 ℃/h, and crystal-growing time of 14 h. The optimal second dry fractionation conditions were crystallization temperature of 16 ℃, cooling rate of 0.5 ℃/h, and crystal-growing time of 30 h. Under these conditions, the yields of liquefied lard in the first and the second dry fractionation were 81.59% and 79.93%, respectively. After the two-step dry fractionation, lard was liquid at room temperature.

Key words: lard, dry fractionation, liquefied lard