Preparation of edible coating from Cassava Starch and Rosemary essential oil and its effect on shelf life and quality of Muffin

Abstract

Edible coating solutions prepared using cassava starch in different ratios (100, 50 and 25%), gelatin and chitosan including rosemary essential oil were used to improve the physicochemical and antibacterial properties of edible films, and study the effect of these edible coating solutions on the shelf life and quality of muffins. The results showed that the addition of chitosan, gelatin, and the incorporation of rosemary with cassava starch film has caused a decrease in the tensile strength; an increase was observed in the elongation at the breaking point; and the permeability of the water vapor and gas films has decreased. The changes in the surface of these films were confirmed by film microstructure (SEM) analyses. The muffin samples were divided into uncoated (control) and coated samples with different edible coating solutions and stored at room temperature for 6 weeks. Shelf life was determined by the appearance of undesirable indications on muffin samples during sensory evaluation of color, odor, taste, texture, and overall acceptableness on different storages. The microbiology analysis results revealed the inhibition effect of rosemary essential oil on the growth of spoilage micro-organisms and recorded the lowest load of total bacterial count (TBC), yeast, and molds. Texture Profile Analysis (TPA) showed an increase in firmness, gumminess, and chewiness and a decrease in cohesiveness. The best treatment for the utilization of films using gelatin and chitosan, including rosemary essential oil and cassava starch is due to its ability to minimize weight loss, given the lowest water activity (aw) and having an extended shelf life. This can be attributed to increase the barrier properties of the coating film formed on the muffin surface, which reduces oxidative rancidity and decreases the peroxide value compared to other treatments.