Food, nutrition, and pharmaceutical scientists are trying to elucidate the major factors impacting the bioavailability of macronutrients (e.g., lipids) and micronutrients (e.g., vitamins) so as to improve their efficacy. Currently, there is still a limited understanding of how food matrix effects impact digestion and bioaccessibility determined under the INFOGEST model, which is currently the most widely used standardized in vitro gastrointestinal model. Therefore, we examined the impact of corn oil concentration on lipid digestion and β-carotene bioaccessibility using model food emulsions. For all oil concentrations tested (2.5 to 20%), complete lipid digestion was achieved using fed-state gastrointestinal conditions, which could only be seen if a back-titration was performed. The particle size and negative surface potential on the mixed micelles formed at the end of the small intestine phase both increased with increasing oil concentration, which was attributed to the generation of more free fatty acids. The β-carotene bioaccessibility increased when the oil concentration was raised from 2.5 to 10% due to the increased solubilization capacity of the mixed micelles, but then it decreased when the oil concentration was raised further to 20% due to precipitation and sedimentation of some of the β-carotene. The maximum β-carotene bioaccessibility (93.2%) was measured at 10% oil. These results indicate that the oil concentration of emulsions influences β-carotene bioaccessibility by altering digestion, solubilization, and precipitation processes. This knowledge is important when designing more effective functional or medical food products.
This study investigated the possibility of using a phase separation, mixing, and enzymatic gelation approach to construct seafood analogs from plant protein-polysaccharide mixtures with properties mimicking real seafood. Heat-denatured pea protein (10%, w/w) and pectin (0–1%, w/w) were mixed to produce phase separated biopolymer blends. These blends were then subjected to mild shearing (350 rpm) to obtain fiber-like structures, which were then placed in molds and set by gelling the pea proteins using transglutaminase (2%, w/w). The appearance, texture, and cooking properties of the resulting scallop analogs were characterized and compared to those of real scallop. The presence of the pectin promoted the formation of a honeycomb structure in the scallop analogs, and microscopic orientation of the proteins was observed in the plane parallel to the applied shear flow. Lower pectin concentrations (0.5%, w/w) led to stronger gels with better water holding capacity than higher ones (1.0%, w/w). The appearance and texture of the plant-based scallop analogs were like those of real scallop after grilling, indicating the potential of using this soft matter physics approach to create plant-based seafood analogs. One of the main advantages of this method is that it does not require any expensive dedicated equipment, such as an extruder or shear cell technology, which may increase its commercial viability.