Effect of Different Extraction Methods on Stablity of Anthocyanins Extracted from Red Onion peels (Allium cepa) and Its Uses as Food Colorants

Abstract

he present work was carried out to produce a natural red color (anthocyanins) from red onion peels (Allium cepa) by four different solvent for coloring some food product. The results showed that acidified ethanol (0.01%Hcl) had the greatest efficient in extracting red onion peels anthocyanins followed by acidified methanol (0.01% Hcl), while acidified distilled water (0.01%) and distilled water are the less effective. At low pH(2.0and3.0),natural anthocyanins extracts exhibited their greatest stabilities. Red onion peels anthocyanins extracts by acidified methanol was heated for 30 min at temperatures of 40, 60, 80 and 100◦c retained 99.16, 98.79, 91.56 and 69.45 %, respectively. The highest stability of anthocyanins extracted by both of acidified methanol and ethanol was at 40 to 80◦c until holding time reached to 60 min. Color and overall acceptability of hard candy containing 0.3% natural anthocyanins extracted from red onion peels by acidified methanol recorder highly score with synthetic color (Allure).On the other hand, glazing jelly containing 0.25% natural anthocyanins extracted from red onion peels by all solvents recorded closely score with synthetic color.