Oleogel design based on emulsions using food grade polymers is a potential strategy for replacing saturated and trans fats. The aim of this paper is the characterization of sunflower oil-based oleogels structured by a non-surface-active polysaccharide, xanthan gum (XG), in combination with different structuring agents, through an emulsion template approach, which consists in the dehydration of the continuous phase of an oil/water emulsion. Four types of molecules with different origins were used: a synthetic one, polysorbate Tween 80, and other three from natural sources: a protein (whey protein, WP), a lipid (soy lecithin, SL) and a polysaccharide (locust bean gum, LBG).
Croissants are made using solid fats that predominantly contain saturated fatty acids and trans fatty acids. In this study, an oleogel consisting of sunflower oil structured with hydroxypropyl methylcellulose was used as a conventional fat replacer in puff pastry thus improving its nutritional profile. Oleogel (OG)-shortening (SH) blends were prepared as a fat replacer for partial (50, 60, 70%) and full shortening (100%) substitution. These replacements implied a reduction of up to 45% of saturated fat and an increase of up to 47% of unsaturated fat, especially monounsaturated fatty acids. Physical characterisation was conducted using texture profile analysis and penetration tests to evaluate the oleogel effect on a baked croissant matrix structure. Sensory analysis was also performed to evaluate the organoleptic properties of the croissant. Shortening replacement using oleogel resulted in croissants with lower saturated fat content, lower bite firmness, and a texture profile similar to croissants made with commercial shortening. The presence of oleogel up to 100% did not contribute negatively to the firmness or springiness of the croissants, although they became chewier and more cohesive as the oleogel increased. In terms of sensory perception, the SH50:OG50 croissant sample was the most similar to the solid fat control. The use of sunflower oil-cellulose-based oleogel was suitable for the formulation of puff pastry products with a healthier fat profile while maintaining the physical and sensory characteristics of conventional croissants.
The reformulation of chocolates seeks to find innovative alternatives to cocoa butter (CB) that are more economical and adhere to nutritional recommendations to replace saturated fats with unsaturated ones. In this research, chocolates were elaborated by substituting CB with an oleogel (OG) formulated with hydroxypropyl methylcellulose (HPMC) as an entrapper of sunflower oil by using the foam-templated approach. Four different CB/OG blends were prepared and characterized as potential CB substitutes (100/0 control), at replacement levels of 30%, 50%, 70% and 100% (70/30, 50/50, 30/70 and 0/100 blends), and subsequently, CB/OG-based chocolates (CB/OG-Ch) were formulated (100/0-Ch, 70/30-Ch, 50/50-Ch, 30/70-Ch and 0/100-Ch). Both the CB/OG blends and the CB/OG-Ch counterparts were characterized by dynamic and stationary rheology, hardness, thermal parameters, microstructure, and oil-binding capacity; in addition, the lipid profile of the chocolates was analyzed, and a sensory analysis was performed. Increasing the OG proportion in the CB/OG blend weakens the rigidity and strength of the fat-crystal network conferred by the CB, and decreases both its viscoelasticity and thermal parameters, but the differences between all the different properties and parameters of the CB/OG-Ch samples diminished in presence of the other ingredients used in the chocolate formulation. Sensory analysis evidenced that it is possible to replace up to 70% of CB with the OG, although from a technological point of view a replacement level of 50% would seem more appropriate. As compared to 100/0-Ch, 50/50-Ch and 30/70-Ch involve saturated fat reductions of 55% and 37%, respectively.
Cocoa butter (CB) is a main ingredient in pastry due to the unique functional properties of its fat, which is high in saturated fatty acids (SFAs). However, excessive consumption of SFAs is associated with the occurrence of several chronic diseases. This study researched the partial or total replacement of CB by an oleogel (OG) formulated with a healthier lipid profile, for mixed systems that would allow a partial substitution of CB in confectionery products. The “emulsion-templated approach” was used to develop a sunflower oil-HPMC-based OG. Different CB:OG ratios were formulated increasing the percentage replacement of CB by OG from 50 to 100%. Rheological and textural properties were determined and compared with a CB control at 20 and 10 °C. Oil-binding capacity was also analyzed. The systems showed a solid-like behavior, with higher elastic than viscous modulus, which increased with CB concentration. Compared with 20 °C, at 10 °C there was an increase in connectivity, viscoelasticity, and consistency of the systems, in response to a more complete CB crystallization. The replaced systems also presented a better lipid profile than CB. This evidence suggests that formulated CB:OG system at 50:50 ratio could become useful as a CB equivalent in chocolate products.
This study investigated the texture properties and fat digestibility of new spreadable chocolate creams formulated with an emulsion composed of milk fat and a cellulose ether as a fat source. The spreadability was analysed at 20 °C and compared with a commercial spreadable cream formulated with palm fat. Structural changes in the creams after the in vitro oral and gastric digestion stages were evaluated; lipid digestibility was determined by titration with NaOH during intestinal digestion. Spreadability tests showed the spreads were similar. After oral digestion, the commercial spread showed an increase in extrusion force because of flocculation induced by saliva, an effect not observed in spreads with cellulose ether. Digestibility determination showed lower values for the reformulated spreads. Therefore, milk fat-cellulose ether based emulsions offer an alternative to achieve reformulated spreadable creams, with physical properties similar to those of commercial products but providing reduced fat content and lower lipid digestibility, without compromising the quality of the final product.
In this work, the design of low moisture (10%) oil/water emulsions based on sunflower oil were investigated, as well as their application in a bakery cream as a conventional fat replacer. The emulsions were dehydrated to reach 10% moisture content, achieving highly concentrated vegetable oil gel emulsions of different consistencies and qualities. Physical properties of the dried emulsions were evaluated by texture, microstructure, and oil loss determination. The reformulated bakery creams with the dried emulsions obtained from 47% oil showed better spreadability, viscosity, and viscoelasticity properties. A shortening replacement with the dried emulsion obtained from 70% initial oil caused a negative impact on the creams’ consistency, with lower viscosity and lower hysteresis area, revealing a weakness of structure. This research provided new knowledge about the structuration of vegetable oils through concentrated emulsions and their application as a source of healthy fat in creams for bakery applications.