Physicochemical characteristics of dried ivy gourd in a single slope solar dryer

Abstract

AbstractIvy gourd with a good amount of potassium (K) and calcium (Ca) offers greater benefit to human health. Studying the drying mechanism of fresh ivy gourd is very important for subsequent processes and the quality of the product. The present study is intended to perform a mineral analysis (K and Ca), ash content and color parameter (L*, a*, b*, C*, H*, and whiteness and yellowness index) of solar‐dried ivy gourd. Drying experiments are performed in a single slope solar dryer and open sun drying. During the drying process, the temperature of the dryer is maintained from 45 to 75°C, undergoing forced convection drying (air velocity of 1 m/s). Fresh and dried ivy gourd samples had high amounts of Ca (379.26–4992.24 mg/kg) and K (330.63–14690.24 mg/kg). The highest mineral values were determined in the ivy gourd samples dried inside a forced convection solar dryer. Open sun (L*43.29, a*−0.57, b*16.78, C*16.78, h*88.05), natural convection (L*41.74, a*−1.74, b*15.82, C*15.98, h*83.54) and forced convection (L*41.72, a*−2.02, b*15.81, C*15.94, h*82.72) revealed better color values in the dried ivy gourd samples. The moisture is reduced from 93.5% to 10% wet basis in the natural and forced convection solar dryer within 9 and 6 h, whereas it took 10 h under open sun drying. Forced convection solar dryer dried the ivy gourd sample in a minimal time with better mineral retention and color parameter values when compared to natural and open sun‐dried samples.