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Abstract
This research reports the interaction of polyglycerol esters (PGE) with sorbitan tristearate (STS) and sorbitan monostearate (SMS), as oleogelators in the structuring of a low-saturated fat blend (palm stearin:canola oil, 20:80 ratio, 19.7% saturated fatty acids, SFA). PGE was mixed with either STS or SMS at different ratios (0:100, 20:80, 40:60, 60:40, 80:20, and 100:0) and added to the fat blend (by stirring at 80 °C) at 3, 6, and 9% levels. The use of oleogelators caused an increase in the SFA content from 19.7 to 21.7–26.5% in a dose-dependent manner; however, the effect of STS or SMS ratio on SFA was not significant (p > 0.05). The use of SMS with PGE could not modify the melting point of structured fats, but when PGE was used with STS, the melting point of fat decreased as the STS ratio increased (p < 0.05). The solid fat content (SFC) curve of fats containing higher STS to PGE ratios was sharper, while that of samples structured using higher SMS ratios was flatter. Structured samples showed higher values of storage, loss, and complex moduli than the initial blend in a temperature sweep test. The PGE-STS mixes resulted in a longer induction period of oxidation than the PGE-SMS mixes. Moreover, the highest oxidative stability was obtained at 20:80 and 40:60 ratios of STS (p < 0.05). The structured fats can be used in the production of soft-tub margarine, Vanaspati, and all-purpose shortening as confirmed by comparison of SFC curve and melting point of structured samples to those of commercial ones.