Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, College of Horticulture, Hainan University, Haikou 570228, China.
Key Laboratory of Germplasm Resources Biology of Tropical Special Ornamental Plants of Hainan Province, College of Forestry, Hainan University, Haikou 570228, China.
Molecules. 2021 Nov 19;26(22):7000. doi: 10.3390/molecules26227000.
Anthocyanins from flowers of the butterfly pea ( L.) are promising edible blue food colorants. Food processing often faces extreme pHs and temperatures, which greatly affects the color and nutritional values of anthocyanins. This study explored the color, spectra, storage stability, and antioxidant properties of anthocyanin extract (CTAE) at different pHs. The color and absorption spectra of CTAEs at a pH of 0.5-13 were shown, with their underlying structures analyzed. Then, the storage stability of CTAEs were explored under a combination of pHs and temperatures. The stability of CTAE declines with the increase in temperature, and it can be stored stably for months at 4 °C. CTAEs also bear much resistance to acidic and alkaline conditions but exhibit higher thermal stability at pH 7 (blue) than at pH 0.5 (magenta) or pH 10 (blue-green), which is a great advantage in food making. Antioxidant abilities for flower extracts from the butterfly pea were high at pH 4-7, as assessed by DPPH free radical scavenging assays, and decreased sharply when the pH value exceeded 7. The above results provide a theoretical basis for the application of butterfly pea flowers and imply their great prospect in the food industry.
蝶豆花（ L.）花朵中的花色苷是很有前途的可食用蓝色食用色素。食品加工经常面临极端的 pH 值和温度，这极大地影响了花色苷的颜色和营养价值。本研究探讨了不同 pH 值下花色苷提取物（CTAE）的颜色、光谱、储存稳定性和抗氧化性能。显示了 CTAE 在 pH 值为 0.5-13 时的颜色和吸收光谱，并分析了其潜在结构。然后，在 pH 值和温度的组合下探索了 CTAE 的储存稳定性。CTAE 的稳定性随温度的升高而降低，在 4°C 下可稳定储存数月。CTAE 还能抵抗酸性和碱性条件，但在 pH 7（蓝色）下比在 pH 0.5（品红色）或 pH 10（蓝绿色）下具有更高的热稳定性，这在食品制造中是一个很大的优势。通过 DPPH 自由基清除试验评估，蝶豆花提取物在 pH 4-7 时具有较高的抗氧化能力，当 pH 值超过 7 时，抗氧化能力急剧下降。上述结果为蝶豆花的应用提供了理论依据，暗示其在食品工业中有广阔的前景。
