有机酸对甘薯紫色素热稳定性与抗氧化性的影响

Effect of Organic Acid on Heat Stability and Antioxidant activity of Sweet Potato purple pigment

甘薯紫色素在酸性条件下呈稳定的红色,可作为天然红色素。优化了甘薯紫色素提取条件,研究4种有机酸不同浓度对甘薯紫色素热稳定性及抗氧化性的影响。结果表明,苯甲酸、乙酸和乙二酸可显著提高甘薯紫色素的热稳定性,程度依不同浓度而异,而抗坏血酸则显著降低其热稳定性。苯甲酸、乙酸、乙二酸和抗坏血酸可以显著提高甘薯紫色素加热后的抗氧化性,程度依不同浓度而异。

Sweet Potato purple pigment showed red color in acidic solution. Therefore it can be used as nature pigment additive. In this study, the conditions of extracting sweet potato purple pigments were optimized. The effect of four different organic acids with varied concentration on the stability and antioxidant activity was studied. Results showed that benzoic acid, acetic acid and oxalic acid enhanced the stability of purple sweet potato pigment against heat treatment significantly, and the extent of enhancement varied with different concentration, while ascorbic acid had a negative impact and declined its stability significantly. Benzoic acid, acetic acid, oxalic acid and ascorbic acid increased antioxidant activity of purple sweet potato pigment significantly after heated, the extent of enhancement varied with different concentration.