Stability assessment of emulsion of carotenoids extracted from carrot bio-waste in flaxseed oil and its application in food model system

Abstract

The research was conducted on the stability assessment of emulsion of carotenoids extracted from carrot-pomace in omega-3 rich flaxseed oil, followed by converting this emulsion into freeze-dried powder, and its application as natural functional colorant in the preparation of flavored milk. The study indicated that emulsion was stable over a range of pH (5–9), temperature (forewarming to HTST pasteurization) and ionic strength (0.1–0.75 M NaCl) except at pH 4, sterilization temperature and 1.0 M NaCl based on zeta potential and particle size of emulsion analysed at these conditions. Ten percent (out of 8, 10 and 12%) of freeze-dried emulsion was selected for addition as a natural functional ingredient in flavored milk on the basis of organoleptic evaluation. The fat, protein, total solids, total carotenoid content and antioxidant value (in terms of ABTS and reducing power assay) of developed product were significantly higher (p < 0.05) than control. The whiteness index of control was significantly higher (p < 0.05) than the developed product, while reverse was true for yellowness index. However, both the products showed total color difference of 34.65. The research concludes that carotenoid-rich emulsion can be efficiently freeze-dried and used as a functional natural colorant in flavored milk for providing it better bio-functional attributes over control.