Agriculture, cilt.13, sa.1887, ss.1-21, 2023 (SCI-Expanded)
A significant vegetable in the Cucurbitaceae family, the bitter gourd (Momordica charantia L.)
is widely recognized for its beneficial health properties, including anti-diabetic, anti-carcinogenic,
anti-inflammatory, anti-ulcer, antiviral activities. With a total of three Brix values (50, 60, and 70) and
three different dipping times (10, 20, and 30 h), the goal of the current study was to identify the proper
sugar and grape molasses solutions (pekmez) and dipping times for osmotic pre-treatments of bitter
gourd samples to make it sweet and widely consumed. In the present study, mathematical modeling
of drying processes, moisture content and water activity, total color changes, total phenolic contentantioxidant
activity, and carotenoid contents were assessed. As a result of 13 different mathematical
modeling tests, “Diffusion Approach”, “Logarithmic” and “Midilli et al.” models were the best
models, giving the highest R2 and lowest X2-RMSE values. There were samples that were dipped at
50 Brix grape molasses, which decreased below the 10% wet basis (w.b.) limit in the shortest time
with 180 min, in a 10 h dipping time. The samples were dipped in 60 Brix sugar, which fell below
the same limit in the shortest time with 135 and 165 min, respectively, at 20 and 30 h dipping times.
The highest total phenolic and carotenoid contents were found in 30 h dipping time in 60 Brix grape
molasses with 8296.87 mg/kg and 10 h dipping time in 50 Brix sugar solutions with 89.22 mg/kg,
respectively. While the phenolic content was higher in all samples dipped in grape molasses, the
carotenoid content was higher in all samples dipped in sugar, which was one of the most important
results of the study.