Incorporation of Orange Peel Polyphenols in Buttermilk, Maltodextrin and Gum acacia suspension Improve its Stability

Orange peel extract is frequently used as a food coloring ingredient and comprises bioactive substances like antioxidants. The objective of this study was to extract phenolic compounds from orange peel and encapsulate them in buttermilk to evaluate the physical properties and shelf life of buttermilk. Three different solvents (80% ethanol, 80% methanol, and water) were used to optimize the polyphenol extraction. The aqueous orange peel polyphenols (OPP) were encapsulated in buttermilk. The ratios between OPP and gum acacia were 1:10, 2:10, and 3:10 (w/v). 10% (w/v) maltodextrin (DE 18) was added to suspension and homogenized. Encapsulation efficiency (%EE) was assessed for capsules while physicochemical and microbial parameters of buttermilk were assessed during refrigeration storage at 4 ± 1 oC (fresh, 5, 10, and 15 days). The ethanolic extract had the highest extraction yield (25.57%), total phenolic content (130.6 mg GAE/100 g), total flavonoid content (85.26 mg RE/ 100 g), and DPPH levels (79.32%). Increasing the amount of OPP and gum acacia ratio greatly enhanced the buttermilk’s phenolic contents and antioxidant activity. A higher EE (95.20%) was observed when using OPP: wall materials at the proportion of 3:10. Increasing the proportion of OPP in the polyphenol-enriched buttermilk decreased the pH, total viable count, total coliform count and increased titratable acidity and total soluble solids. Color analysis suggested that increasing the OPP decreased the color parameters of the encapsulated buttermilk. However, the addition of OPP had no appreciable influence on the sensory qualities of buttermilk. This study evinced that OPP can be used to enrich polyphenols and increase the shelf life of buttermilk.