Edible bigels are being developed to replace plastic fats in the food industry due to their ability to form semi-solids with controllable properties. In this study, biopolymer hydrogels were formed using modified corn starch with chitosan, betaine, and vanillin, whereas oleogels were formed from insect wax in soybean oil. The impact of varying the hydrogel-to-oleogel ratio on the properties of bigels was then examined. The rheological, oil-binding capacity (OBC), water-oil distribution, structural, and 3D printing characteristics of the bigels were evaluated. Higher hydrogel-to-oleogel ratios resulted in improved rheological properties of bigels. Hydrogen bonding, electrostatic interactions, and covalent Schiff base bonds played an important role in the formation and properties of the hydrogels. In contrast, the mechanical strength of the oleogels was mainly attributed to van der Waals attraction between the insect wax crystals. The optimized bigels had good OBC and mechanical strength. Furthermore, increasing the hydrogel-to-oleogel ratio induced a transition from W/O to O/W type structure in the bigels. A study of the potential application of the bigels as edible inks showed that bigels with a high hydrogel-to-oleogel ratio had better 3D printing characteristics. The findings of this study suggest that bigels can be successfully used as solid fat substitutes.
Qilong Xie,Dekui Sun,Yangying Han,Litao Jia,Bo Hou,Shuhui Liu,Debao Li
The previously reported procedure for the determination of the total phthalate in fatty food involved the extraction of phthalates using chloroform/methanol followed by the removal of the solvents before alkaline hydrolysis requiring 20 h and derivatization of phthalic acid. In this study, a phase-transfer catalyst (tetrabutylammonium chloride) was used in the liquid–liquid heterogeneous hydrolysis of phthalates in oil matrix shortening the reaction time to within 25 min. The resulting phthalic acid in the hydrolysate was extracted by a novel molecular complex based dispersive liquid–liquid microextraction method coupled with back-extraction before high-performance liquid chromatography coupled with photodiode array detection. Under the optimal experimental conditions, the linearity of the method was in the range of 0.5–12 nmol/g with the correlation coefficients ( r ) >0.997. The detection limit (S/N = 3) was 0.11 nmol/g. Intraday and interday repeatability values expressed as relative standard deviation were 3.9 and 7.1%, respectively. The recovery rates ranged from 82.4 to 99.0%. The developed method was successfully applied for the analysis of total phthalate in seven edible oils.