Fruit characters and physico-chemical properties of roselle (Hibiscus sabdariffa L.) in Thailand—A screening of 13 new genotypes

Abstract

Thirteen roselle (Hibiscus sabdariffa L.) genotypes were identified originating from 8 generations with phenotypic selection. The fruit characters, fresh and dry weight of calyxes and physico-chemical properties were evaluated to identify each genotype and compared with two commercial cultivars. There were differences in fruit characters among the 13 roselle genotypes, especially regarding variation in the calyx color from white to purple and a larger fruit size than in the commercial cultivars. The yield based on the fresh weight and dry weight of calyx categorized nine genotypes in the high yield group which was higher than for the commercial cultivars. The physico-chemical properties of roselle calyx extracts indicated that the pH ranged from 2.26 to 2.47 and the total titratable acidity ranged from 21.60 to 36.00 g malic acid/100 g dry weight. Six roselle genotypes had significantly higher anthocyanin content than the commercial cultivars and these six genotypes had a positive correlation with pH and a negative correlation with L* (lightness) and b* (yellowness) values. The highest anthocyanin contents were 1948.43 mg/100 g dry calyx and 1181.80 mg/100 g dry epicalyx. In conclusion, the 13 new roselle genotypes had greater potential than the two commercial cultivars as they could be used as good sources of anthocyanin extract and high yielding roselle.