Relationship between edible fraction and physical attributes of elabatu (Solanum melongena l. var.insanum) fruit

Solanum melongena var. insanum known as Elabatu is a popular vegetable and a functional food consumed in Sri Lanka and it has two main cultivars bearing small and large size fruits. The fruit comprises of both edible and inedible portions and the consumer pays for both at the time of purchase. Therefore, this study was conducted to fit multiple regression models for size attributes and edible portion (EP) of Elabatu fruits as it is important to breeders as well as consumers. Small fruits with green stripes (Cultivar 1) and large fruits with white/purple stripes (Cultivar 2) were used in this study. Mass, smallest diameter, largest diameter, largest to smallest diameter ratio (LS ratio), percentage of edible portion to total fruit mass (EP %) and the mass of edible portion were measured. A sample of 195 fruits was used from each cultivar and data were fitted to multiple regression models. The best fitting models selected based on R2 and least AIC values for cultivar 1 and cultivar 2 were 𝒀 = 𝜷𝟏𝑿𝟏+ 𝜷𝟑𝑿𝟑+ 𝜷4𝑿4+𝜷5𝑿5 – 𝜺 and 𝒀 = 𝜷𝟑𝑿𝟑 – 𝜷5𝑿5 + 𝜺, respectively.
Further, results revealed that the EP displays significant positive correlations (p < 0.0001) with LD, Mass, % of EP, and SD in both cultivars. In contrast to that, LS Ratio shows a significant negative correlation in Cultivar 1 (r = -0.207, p = 0.0037) and a significant positive correlation in Cultivar 2 (r = 0.232, p = 0.0009). Notably, Cultivar 2 shows stronger overall correlation coefficients.