Biochemical analysis of calyx of Mesta (Hibiscus sabdariffa)

Mesta or roselle calyx, is in high demand for both nutritional food and cosmetic applications due to its superior quality. Various biochemical compounds in fresh mesta calyx as well as in preserved frozen and dried form, have been studied. Using spectrophotometric methods, chlorophyll a, chlorophyll b, β-carotene, lycopene, L-ascorbic acid, thiamine, riboflavin and niacin content were estimated. One gram of fresh mesta calyx contains 0.94 mg of chlorophyll a, 1.77 mg of chlorophyll b, 3.19 μg of β-carotene, 0.003 - 0.005 μg of lycopene, 7.14 mg of L-ascorbic acid, 2.34 μg of thiamine, 44.23 μg of riboflavin and 1.35 mg of niacin. Preservation methods affects the nutritional value of mesta calyx. In frozen conditions, the chlorophyll a content degraded to 0.62 mg/g, while in dried preservation, jt slightly increased to 0.96 mg/g. Chlorophyll b showed a decrease in preservation methods, degrading by 1.44 mg/g in frozen and 0.66 mg/g in dried conditions. β-carotene content was decreased by 1.19 μg/g in frozen condition and 1.04 μg/g in dried condition. L-ascorbic content was also degraded in frozen preservation 5.07 mg/g and 0.57 mg/g during dry preservation at room temperature. Thiamine content was decreased by 1.6 μg/g in frozen and by 0.16 μg/g in dried preservation. Similarly, riboflavin content fell to 10.13 μg/g in frozen conditions and to 11.53 μg/g in dried conditions. Conversely, niacin content was found increased to 5.54 mg in frozen preservation and to 3.56 mg in dry preservation. Overall, nutrient content during preservation, most bio-compounds were degraded; however chlorophyll a was increased in dried mesta calyx and niacin content was increased in both frozen and dried preservation over a year of storage. Mesta calyx is a rich source of chlorophyll, L-ascorbic acid and riboflavin.