Assessment of freeze, continuous, and intermittent infrared drying methods for sliced persimmon.

Persimmons contribute positively to human health. Although off-season utilization typically presents a challenge due to permissions' perishable nature, it may become feasible through the implementation of appropriate drying methods. In this study, round sliced samples were dried to assess drying kinetics, modeling potential, color attributes, rehydration capacity, energy consumption (EC), cost index, and thermal properties. The fruits were subjected to distinct drying methodologies including freeze-drying, continuous infrared drying (300, 400, and 500 W), and intermittent infrared drying (PR = 1 [continuous], PR = 2 [30 s on-30 s off], and PR = 3 [20 s on-40 s off]). The duration of the drying process ranged from 40 to 390 min. It was determined that the most suitable models for depicting continuous and infrared drying kinetics of persimmon fruit were the Midilli et al. and Page models, whereas the Logarithmic model was identified as the optimal choice for characterization of freeze-drying kinetics. Assessment of EC revealed that both intermittent and continuous infrared drying methods incurred lower energy expenditure in comparison to the freeze-drying technique. Remarkably, throughout the course of the infrared drying processes, product surface temperatures varied between 106.33 and 22.65°C across different treatments. Despite its high EC, it has been found that high-quality products are produced by freeze-drying. However, infrared and intermittent infrared applications can be a low energy cost and feasible method for drying persimmon with a shorter duration. PRACTICAL APPLICATION: Persimmon is an important fruit with high nutritional value. However, as with many fresh products, they have a short shelf life. Within the scope of this research, three different drying methodologies were employed in the desiccation of persimmon specimens, and the impact of these methodologies on the overall qualitative attributes of the persimmon product was investigated. Despite its elevated energy consumption, the freeze-drying approach was found to yield high-quality products. Moreover, it was discerned that infrared drying represented a viable and expeditious alternative for drying the fruit, particularly when executed intermittently.

Influence of different drying techniques on drying parameters of mango

Abstract This research inspected the effects of freeze, microwave (120 and 350 W) and hot air (60, 70 and 80 °C) drying techniques on the color, drying characteristics, antioxidant capacity and total phenolic content of mango slices. Midilli et al., Two-term and Page models which exemplify drying characteristics are superior than alternative models. All of the color values (a, b, L, C, α and ΔE) were altered notably based on the used drying technique and colors nearest to the fresh sample were attained with freeze drying. In comparison to the fresh sample, the dried samples showed a decrease of 18.4-54.6% in antioxidant capacity. The total phenolic content value was notably highest one for the microwave dried sample at 350 W and the lowest one for a hot air dried sample at 80 °C (P<0.05). This research showed that microwave drying at 350 W is able to yield high-quality mango slices with the extra advantage of shortened drying time in relation to hot air and freeze drying.