Pulsed Vacuum Drying of Persimmon Slices: Drying Kinetics, Physicochemical Properties, Microstructure and Antioxidant Capacity

Abstract

In order to explore an alternative drying method to enhance the drying process and quality of persimmon slices, pulsed vacuum drying (PVD) was employed and the effects of different drying temperatures (60, 65, 70, and 75 °C) on drying kinetics, color, rehydration ratio (RR), microstructure, bioactive compounds, and the antioxidant capacity of sliced persimmons were investigated in the current work. Results showed that the rehydration ratio (RR) of the samples under PVD was significantly higher than that of the traditional hot air-dried ones. Compared to the fresh samples, the dried persimmon slices indicated a decrease in the bioactive compounds and antioxidant capacity. The total phenolic content (TPC) of PVD samples at 70 °C was 87.96% higher than that of the hot air-dried persimmon slices at 65 °C. Interestingly, at 70 °C, the soluble tannin content and TPC of the PVD samples reached the maximum values of 6.09 and 6.97 mg GAE/g, respectively. The findings in the current work indicate that PVD is a promising drying method for persimmon slices as it not only enhances the drying process but also the quality attributes.

Comparative Study on the Influence of Various Drying Techniques on Drying Characteristics and Physicochemical Quality of Garlic Slices

“…The performance of the two models was evaluated using a wide range of statistical parameters such as the chi-square ( χ 2 ) parameter, residual sum squares ( RSS ), and coefficient of determination ( R 2 ), which were determined by the following equations [ 41 , 42 ]: where MR pre,i indicates experimental value and MR exp,i represents predicted value; N means the amount of experience, and n is the number of constants.…”

The effect of pretreatments on the drying of persimmon with infrared energy

“…Individually, pretreatment and variety and pretreatment interactions had a statistically significant effect on Δ L *, Δ a *, Δ b *, C , α °, and Δ E ( p < .05). Yang et al (2022) determined the Δ E value of persimmon slices dried with hot air (65°C) as 25.13. Yildiz et al (2023) sliced and pureed persimmon samples were dried by microwave (100 W) and convective drying (50 and 100°C) methods by applying different pretreatments.…”

“…Drying is one of the most widely preferred preservation methods to extend the fruit's shelf life and to ensure that it can be consumed for four seasons. While drying removes the water in the product, it also stops the development of microorganisms and biochemical reactions that may occur (Yang et al, 2022). Drying time, energy consumption, and nutritional properties for different products differ according to the drying method and the dried product.…”

“…Tukey test: no difference between the treatments shown with the same letters in the same column ( p > .05) ± standard deviation.The lowest chroma value in the Rojo Brillante variety was determined in the samples subjected to citric acid + ascorbic acid pretreatment. Individually, pretreatment and variety and pretreatment interactions had a statistically significant effect on ΔL*, Δa*, Δb*, C, α , and ΔE ( p < .05) Yang et al (2022). determined the ΔE value of persimmon slices dried with hot air (65 C) as 25.13 Yildiz et al (2023).…”

Optimization of the pulsed vacuum drying process of green walnut husk through temperature adaptive regulation

“…The WGHE with a pulsed ratio of 9 min: 3 min had the highest TASC. Previous research findings indicate that high drying temperatures can result in scorching and significant browning, while very low drying temperatures can lead to poor product quality and increased energy consumption (J. Wang et al., 2020; Yang et al., 2022). Extending the vacuum time can yield high‐quality products; however, it also corresponds to higher energy consumption (Jiang et al., 2021).…”