30A-21 |
Oil holding capacity of plastic fats: Effects of intermediate melting point triacylglycerols |
F. JAHANIAVAL and Y. Kakuda. Dept. of Food Science, Univ. of Guelph, Guelph, ON N1G 2W1, Canada Fat crystals are capable of holding and retaining a certain amount of liquid oil within their crystal network based upon their composition, concentration, structure, crystal size, processing conditions and storage temperatures. Plastic fats are a good example where the liquid oil is trapped by fat crystals. This physical property of fat crystals can be called the oil-holding capacity (OHC), the "amount of liquid oil trapped by one gram of solid fat (based on SFC) at room temperature". The objective of this work was to determine the impact of IMP-TAG on the OHC of liquid oil/hard fraction blends, by adding varying levels of IMP-TAG and palm-canola stearin to four liquid oils (olive, safflower, canola and triolein) under supercooling (fast and slow) conditions. Oil-holding capacity (OHC) was investigated as a function of the composition of the intermediate melting point triacylglycerols (IMP-TAG, i.e. POP, POS and SOS) and stearins and two different processing conditions. Various palm-canola stearin and IMP-TAG blends (14%) were dissolved in 86% liquid oil and crystallized under fast and slow cooling conditions. Results showed that under fast cooling conditions the OHC of the oil/hard fraction blend increased when the concentration of IMP-TAG increased and stearin concentration decreased. The maximum OHC (per gram of solid basis) was observed when IMP-TAG was used. Under slow cooling conditions, the OHC increased as the concentration of stearin increased. RP-HPLC analyses showed that IMP-TAG were retained in the blend crystal structure when processed under fast cooling conditions. RP-HPLC analyses also showed that TAG with two saturates were retained in blend crystal structure, but TAG with only one saturate were not incorporated into the crystal structure. It was concluded that the TAG composition, processing condition and SFC were more important than total added solid fat in determining the OHC.
Session 30A, Food Chemistry: Lipids
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