Changes in physico-chemical characteristics of bitter gourd fruits harvested at different stages in controlled environments

Abstract

The study, conducted during 2021-2022 at the experimental farm of the Centre for Protected Cultivation and Technology (CPCT), Division of Vegetable Science, ICAR-IARI, New Delhi, evaluated the impact of different harvesting stages on quality and storage life of two bitter gourd verities (Pusa Rasdar and S-32) grown under polyhouse conditions. Results showed that S-32 achieved the longest fruit length (19.87 cm) at 24 days after pollination (DAP), while Pusa Rasdar had the largest fruit diameter (6.23 cm) and highest fruit weight (153.22 g). Pusa Rasdar also recorded the highest fruit juice content (61.65%) at 24 DAP. However, S-32 exhibited greater chlorophyll levels, with the highest chlorophyll-a (10.12 µg g⁻¹ FW), chlorophyll-b (4.56 µg g⁻¹ FW), and total chlorophyll content (14.68 µg g⁻¹ FW) at 16 DAP. The maximum total carotenoids content was recorded in S-32 (3.63 µg g⁻¹ FW) at 24 days after pollination while in Pusa Rasdar (2.36 µg g⁻¹ FW). In S-32 fruits, the highest saponin content (0.95 mg g⁻¹ DW) and maximum charantin levels (0.39 mg g⁻¹ DW) were observed at 16 DAP, highlighting their superior biochemical composition at this stage. The findings reveal that S-32 lines exhibited better retention of quality attributes, such as saponin and charantin, than the Pusa Rasdar variety. Notably, S-32 lines superior over Pusa Rasdar in term of physical and biochemical parameters full fill the commercial and nutritional needs of consumers.