Results and discussion
The goal of this study was to enrich palmitoleic acid. As shown in Table
2, palmitic acid is the most abundant saturated fatty acid in the
SPOMFs, accounting for 33.59% of total fatty acids, followed by oleic
acid (32.16%), and palmitoleic acid (27.17%).
First, the optimal temperature for low-temperature crystallization was
evaluated, and then solvent type, substrate ratio of SPOMFs to solvent
(w/v) and crystallization time during the first crystallization stage
were optimized to improve the results of crystallization. Some residual
saturated fatty acids still remained in the collected liquid fraction 1,
thus a secondary crystallization was performed at -40 °C to remove
these, and this resulted in the liquid fraction 2. Then, the liquid
fraction 2 was subject to molecular distillation to yield a concentrated
palmitoleic acid final product.