Effects of betalain loaded microcapsules based on sugar beet on the physicochemical properties and shelf life of processed cheese

Abstract

In recent years, the application of natural antioxidants and preservatives has attracted considerable attention in the food industry due to growing concerns over the health risks associated with synthetic additives. Betalains, natural pigments extracted from sugar beet, are known for their potent antioxidant properties and were investigated in this study to enhance the shelf life and stability of processed cheese. Betalain microcapsules were prepared using the ionic gelation technique, with sodium alginate and guar gum as encapsulating agents at concentrations of 0.25, 0.5, 0.75, 1.0, 1.5, and 2.0 mg/g. Betalain microcapsules were characterized through assessments of particle size distribution, entrapment efficiency, cumulative release profile, and morphological features. Statistical analysis was conducted using a completely randomized design (CRD) with Minitab 16 at a 95% confidence level, and treatment differences were assessed via Duncan’s multiple range test. The results demonstrated that both encapsulation efficiency and release rates increased with betalain concentrations up to 1.5 mg/g, followed by a significant decline (p ≤ 0.05). Microcapsules exhibited a spherical and homogeneous morphology, while higher concentrations (> 1.5 mg/g) resulted in larger particle sizes and noticeable agglomeration. Increasing betalain concentration up to 1.5 mg/g also led to a significant reduction in peroxide value, iodine index, and pH, accompanied by a rise in titratable acidity (p ≤ 0.05). Treatments with 2.0 and 2.5 mg/g showed minimal additional changes. Moreover, betalain stability in processed cheese samples significantly decreased during storage (p ≤ 0.05). Microbial analysis indicated that the use of betalain microcapsules effectively suppressed microbial growth compared to the control, with slower microbial progression over five months of storage (p ≤ 0.05). Based on physicochemical, microbiological, and structural analyses, the formulation containing 1.5 mg/g of betalain was identified as the optimal treatment.