Comparative Effect of Adding Synthetic Citric Acid to Natural Lemon Juice (<i>Citrus aurantiifolia</i>) on the Stability of <i>Hibiscus</i> Drinks Stored at 4&deg;C and 37&deg;C

Abstract

The general objective of the work is to compare the effect of the addition of synthetic citric acid compared to the addition of natural fruit juice of Citrus aurantiifolia on the conservation of drink based on red chalice H . sabdariffa . The tests were carried out over a period of 5 weeks at 4 &deg;C and 37 &deg;C with seven batches of beverage samples prepared at the rate of a calyx/water ratio of 1/40 (kg·kg -1 ) and added respectively citric acid at 1, 2 and 4 g&middot;L -1 and lemon juice at 10, 20 and 40 mL·L -1 . The characterization of the different batches of beverages was carried out from day one. A follow-up of the residual anthocyanin content and the intensity of the red coloring were carried out over five weeks. The anthocyanin concentration was determined by the pH-differential method. The red color degradation index is determined based on the CIELAB color system (L*, a*, b* and L*). R and Minitab 18 software w as used for data processing. The results of the monitoring of the parameters showed that the concentration of 1 g AC L -1 retains 2.7 mg more of the anthocyanins than adding 10 mL JC L -1 and longer maintains red color when stored at 4 &deg;C and 37 &deg;C /5 weeks. The 2 g AC L -1 and 4 g AC L -1 ratios have the same effects as the addition of 20 and 40 mL of lemon juice, all accelerating the degradation of anthocyanins and the red color. After 5 weeks of storage at 37 &deg;C , the effect of the temperature combined with the increase in the acidity of the samples (2 to 4 g AC L -1 and 20 to 40 ml JC L -1 ), have accelerated the total disappearance of the red color on all samples.