Encapsulation of wheat germ and probiotic bacteria Bacillus licheniformis using guar gum and maltodextrin by freeze drying method to increase the shelf life of wheat germ

As a byproduct of the milling process, wheat germ provides a rich source of minerals, vitamins, tocopherols, phytosterols, amino acids, and important fatty acids. However, the high levels of unsaturated oil and high levels of enzymes lead to a reduction in wheat germ's nutritional value during storage, which severely reduces the product's shelf life. The purpose of this study was to use guar gum and maltodextrin together with the freeze-drying encapsulation technique to extend the shelf life of probiotic wheat germ containing Bacillus licheniformis. In this regard, the durability of the encapsulated probiotic wheat germ was assessed for 360 days of storage using three different ratios of maltodextrin to guar gum, including 1 to 0.3, 0.1, and 0.03. The tests were carried out using a completely random design, and the averages were assessed using Duncan's test with a significance level of 5%. The effect of time on the changes in oxidation indices of the encapsulated wheat germ was evaluated positively. During 360 days of storage, the encapsulated sample with maltodextrin and guar gum in all examined ratios significantly reduced the total acid value (P< 0.05). In comparison to samples without probiotics, the inclusion of B. licheniformis probiotic considerably reduced the values of the total acid number and TBA index (P< 0.05). In the probiotic treatment, the levels of peroxide, anisidine, totox, mold, and yeast significantly increased with longer storage times (P< 0.05).