Analysis of co-crystallized free phytosterols with triacylglycerols as a functional food ingredient

Abstract

This research focuses on the analysis of mixtures of free phytosterols (FPSs) with fully hydrogenated soybean oil (FHSO):soybean oil (SO) mixtures as a potential zero-trans substitute for various types of shortenings. Oil binding capacity as well as the thermal, rheological and structural properties of FHSO:SO blends containing 0, 20 and 25wt.% β-sitosterol or stigmasterol were investigated in this study. Differential interference contrast (DIC) microscopy and wide angle X-ray diffraction (WAXRD) revealed that co-crystallization of FPSs with FHSO:SO blends occurred. Polymorphic forms were characterized as a mixture of β′ and β for all samples. The addition of FPSs decreased oil loss (OL) of FHSO:SO samples. Melting profiles of the prepared FPS–TAG (triacylglycerol) blends were extended to higher temperatures compared to a commercial shortening. Rheological properties were comparable to those of commercial puff pastry shortening suggesting that FPS–TAG blends may be acceptable for bakery applications. FPSs co-crystallized with FHSO and SO may be a suitable trans-fat free substitute for a number of types of shortening, including puff pastry shortening. The manufacturing of co-crystallized /FPS-TAG matrices will possibly bring large economic benefits as their functionalization can potentially be achieved by using existing simple shear processing.