紫甘薯饮料中花青素的稳定性研究

研究了不同pH值紫甘薯饮料中花青素的色泽光谱特性以及pH值、温度、抗坏血酸、糖、光照等因素对紫甘薯饮料中花青素稳定性的影响。结果表明,pH值为2.2、3.0、4.0时花青素较稳定,随着pH值的升高,稳定性逐渐降低;高温处理对紫甘薯花青素的稳定性的影响较显著,温度越高,花青素的保留率越低;抗坏血酸的加入会加速花色苷的降解;葡萄糖和乳糖的加入对花色苷的稳定性无影响;Fe与花青素类物质形成络合物,降低了花青素的稳定性,其他的金属离子对花色苷的稳定性影响不大;光照使花青素稳定性降低,自然光在短时间内影响较小,花色苷在白炽灯和紫外灯照射下降解速度加快。

Study on the stability of anthocyanin in purple sweet potato beverage

The spectrum characteristics of anthocyanins in purple sweet potato beverage with different pH was analyzed, besides, the effect of pH, temperature, Vc, sugar, and light on the stability of anthocyanin from purple sweet potato beverage were studied. The results showed that the anthocyanins had better stability at the pH of 2.2, 3.0, 4.0. The stability gradually decreased along with the pH increased. High temperature had obvious effect on the stability of purple sweet potato antho-cyanins and the higher the temperature was, the lower retention of anthocyanin had. Vc could accelerate the degradation of anthocyanins. Glucose and lactose had no effect on the stability of anthocyanins. Clathrate which formed of Fe3＋and antho-cyan might reduce the stability of anthocyanins, however, other metal ions had no influence almost. The stability of antho-cyanins decreased under the light. Natural light had no obvious impact in a short period of time. Incandescent light and ul-traviolet lamp could speed up decomposition of anthocyanin.