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In recent years, the demand for fried products with lower oil content has increased. Therefore, in this study, the effect of different hydrocolloid coatings including sodium alginate (0.50 and 1.00%), calcium alginate (0.50 and 1.00%), and soy protein isolate (4.00 and 5.00%) on oil absorption and quality properties of eggplant slices during different frying times [0, 90, 180, 270, and 360 seconds] were evaluated. The results showed that the samples pretreated with hydrocolloids had lower moisture loss and oil absorption than the control sample. In this regard, among the treatments, calcium alginate (1.00%, with a moisture content of 16.66% based on dry weight and the oil absorption of 0.11 g/g food) and soy protein isolate (5.00%, with the moisture content of 33.66% based on dry weight and the of oil absorption of 0.26 g/g food) had the highest and lowest function, respectively. The moisture content of the fried samples decreased with the frying time increase from 90 to 270 s. Meanwhile, the frying efficiency of calcium alginate coated samples, in all four examined times, was higher than the other treatments, which showed the highest value in 90 s (93.12%). The lowest efficiency was observed in the control sample at 360 s (49.51%). The L* values in the samples coated with soy protein isolate were lower than the other samples, which could be due to the increase in Millard reaction. Coating the eggplant samples with calcium and sodium alginate resulted in desirable sensory parameters for 90 s. Overall, the results of this study showed that the use of calcium alginate coating (1%) could lead to the production of low -fat fried eggplant without adversely affecting the sensory and qualitative properties of the product. [ABSTRACT FROM AUTHOR]

Concerns about the environmental issues have increased the tendency to package the food stuffs with natural biopolymers. However, the use of these compounds has limitations such as the weakness in mechanical, barrier and optical properties. Alginate, as a biopolymer, has a good film forming potential; meanwhileit has poor moisture barrier properties.In order to overcome this problem, in this study, the calcium alginate film was coated with two types of lipids including sunflower oil (as a liquid oil) and tallow (as a solid fat) at two concentrations (0.5 and 5%, with and without 0.1% lecithin). Afterward, the physicochemical, barrier, and mechanical properties of the produced films were investigated. The results showed that thelamination of the alginate films with tallow fat increased the film thickness, which increased with the fat concentration. In addition, sunflower oil significantly reduced the permeability of the films to water vapor, that was more evidentin 0.5% sunflower oil coated film. The results also showed that the use of these hydrophobic materials for the coating of alginate films changed the color properties and the turbidity of the films. The mechanical properties of the film, including tensile strength and elongation at the breaking point, improved by coating the alginate film with 0.5% tallow fat.Thickness, water vapor permeability, and the mechanical properties were not affected by the addition of lecithin. The SEM images proved the formation of small holes or cracks on the films surfaces.In general, this study showed that sunflower oil or tallow fat can be used as natural compounds to improve the properties of calcium alginate-based edible films, depending on the goals of packaging. [ABSTRACT FROM AUTHOR]