Process and product characteristics of refractance window dried Curcuma longa

Abstract

This work addresses the optimality of hot water bath based refractance window drying (RWD) characteristics of 1 mm Curcuma longa (turmeric) slices. Mylar film thickness (125 to 350 µm) and water bath temperature (65 to 95 °C) have been considered as independent variables to evaluate drying kinetics and nutritional characteristics of the process product combination. Equilibrium drying time, moisture diffusivity, fitness of thin layer models, moisture content, total phenolic content, total flavonoids content, curcumin content, and antioxidant activity have been considered to evaluate the optimality of the RWD process parameters. It has been analyzed that while both parameters critically influence equilibrium drying time, only temperature had profound influence on nutritional characteristics.Practical ApplicationThere is a need for a fast‐drying method without significant loss in bioactive compounds. Refractance window drying (RWD) method is such a process. The study of RWD of turmeric slices will help in understanding the relations between different drying temperatures and mylar film thickness and its relation to nutritional characteristics of the product.

Improvement of phytochemical and quality characteristics of Dracocephalum kotschyi by drying methods

“…Also, drying D. kotschyi by RWD and RWD+ IRD increased the TFC. Talukdar and Uppaluri (2021) reported that the turmeric dried by RWD at 95°C had the maximum TFC. Since the high temperature of the RWD reduced the drying time, the samples were exposed to heat for a shorter time, and consequently, retained heat‐sensitive constituents.…”

“…Since the high temperature of the RWD reduced the drying time, the samples were exposed to heat for a shorter time, and consequently, retained heat‐sensitive constituents. Due to the fast drying time, the cellular integrity is not compromised, and the TFC in the cell structure is not oxidized but preserved (Hernández‐Santos et al, 2016; Talukdar & Uppaluri, 2021). The TFC in dried apples by RWD and RWD+ IRD was higher than in the hot‐air dryer.…”

Effect of Different Drying Systems on Drying Performance of Maraş Green Pepper (C.annum)

“…In the study it was determined that the activation energy values of dried peppers in RWD were lower than the other methods, therefore less energy was required for drying (Doymaz and İsmail, 2010). In the literature, the Ea values were calculated as 49.43-52.57kJ/mol for turmeric (Talukdar et al, 2021) and 41.3-31.1 kJ/mol for goldenberry (Puente -Diaz et al, 2020) in RWD, 43.9kJ/mol for dried pumpkin in FBD (Mujaffar and Ramsumair, 2019) and 47.10 kJ/mol for green pepper (Faustino et al, 2007) in CD. The findings agree with the literature.…”