Evaluation of far-infrared drying on the quality properties of zucchini slices: influence of operating parameters

This research aimed to estimate how sample thickness (3, 5, and 7 mm), air velocity (0.5, 1.25, and 2 ms^(-1)), and infrared lamp power (1000, 1500, and 2000 W) affected the drying characteristics of zucchini slices in a far-infrared dryer. The design of drying tests, which illustrates the relation between input and output variables, was carried out by response surface methodology. Then, the effect of these independent factors on the moisture content (drying time), water activity, total phenolic content, potassium content and total color change was determined. To predict the responses, the most accurate mathematical models were selected using analysis of variance. The results revealed the drying time declined by decreasing the sample thickness and air velocity and increasing the infrared lamp power. Total phenolic content and potassium content had increased multifold after the drying process. An enhancement in sample thickness and infrared lamp power had a positive effect on both of these contents. The minimum and maximum values of total color change were 5.54 and 13.96, respectively. The dried zucchini produced by far-infrared drying is a high-value product that has the potential to be used in food and pharmaceutical industries or in the treatment of diseases as a booster meal.