Abstract

The purpose of this study was to examine the use of beetroot (Beta vulgaris L.) extracts as natural colorant and antibacterial additives in Rayeb milk. Citric acid: ascorbic acid (2:1) (BCA) and citric acid (0.2%) (BC) were used as extraction solvents of beetroot. Antibacterial activity; minimum inhibitory concentration (MIC), minerals content (calcium, iron, phosphorus, potassium, and selenium), and phytochemical screening were determined in BCA and BC extracts. Moreover, the antibacterial potential, microbiological analysis, and pH were estimated for Rayeb milk supplemented with beetroot extracts after storage for different periods; 0 time, 5, and 10 days. Sensory evaluation was also carried out after 0 and 10 days of storage of Rayeb milk samples. Results of disc diffusion assay showed that both beetroot extracts were more effective against Pseudomonas aeruginosa, and less effective against Escherichia coli. The lowest MIC was determined for both extracts. Rayeb milk supplemented with extracts showed antibacterial potential toward the tested bacteria. Addition of beetroot citric acid: ascorbic acid (2:1) extract to Rayeb milk; led to a decrease in its total bacterial count, and increase in number of Lactic acid bacteria (LAB). Colored RBCA extract had more acceptable flavor and color. Results of the current work suggested that beetroot extracts could be used as natural additives to Rayeb milk with several advantages including; their antibacterial potency, positive effects on the phytochemical and chemical composition of Rayeb milk.

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