Effect of Emulsifiers on the Quality of Palm Oil Based Shortening during Variable Temperature Storage

The quality and processing characters of shortening are strongly influenced by the temperature fluctuation during storage and handling. Some chemical components, especially the presence of emulsifiers in shortening formula might be attributed to the quality change of shortening in response to temperature fluctuation. In this work, the effect of emulsifiers on the mechanical properties, crystalline structure, and crystalline transformation of fat was investigated with a palm oil-based shortening under varied storage temperature (4°C, 12 h - 28°C, 12 h, cycle reciprocating). Results show that the shortening without emulsifiers deteriorated easily with a severe separation of liquid oil and reduction of hardness, which was owing to the aggregation of crystals, and the appearance to high proportion of β crystals at the later stage in storage (day 7 and day 14). However, the addition of the emulsifiers such as sorbitan monopalmitate (SMP), Glyceryl monostearate (GMS), and Glycerol monopalmitate (GMP) ameliorated the production of β crystals effectively. Among the tested emulsifiers, the shortening adding GMS showed the best quality, which remained stable in multiple cycles up to 14 times. The findings will guide the use of emulsifiers in palm fat processing.