Copigmentation and UPLC-ESI-MS/MS of anthocyanin in Ipomea nil as potential source of food colorant.

Anthocyanins are good alternative to synthetic dyes for food, pharmaceutical and nutraceutical industries. Owing to their wide occurrence in plant kingdom, an UPLC-ESI-MS/MS method was used to identify and quantify the constituents in flowers of Ipomea nil. The qualitative evaluation of I. nil results in the characterisation of acylated and non-acylated anthocyanins. Besides characterisation, the total phenolic contents in different fractions of I. nil were found to be 49.69 ± 1.74 and 331.54 ± 1.14 mg GAE/g, respectively. The total anthocyanins content was also determined by spectrophotometer and found to be 5.89 mg/100g of cyanidin-3-O-glucoside equivalent. The antioxidant activity of different fraction of I. nil was evaluated by different assays (DPPH●, ABTS●+ and FRAP). In the direction of natural colour stability, we had studied different stabilising agents/copigments and were found to provide stability up to 140 °C. The extracted anthocyanins were evaluated for acute oral toxicity studies and observed to be non-toxic and may direct the use of I. nil for human consumption.