Optimization study for refractance window drying process of Langra variety mango

Evaluation of Lipid Changes During the Drying Process of Cordyceps sinensis by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS)-Based Lipidomics Technique

Comprehensive analysis of the lipid content in Cordyceps sinensis samples is essential for optimizing their effective use. Understanding the lipid profile can significantly enhance the application of this valuable fungus across various fields, including nutrition and medicine. However, to date, there is limited knowledge regarding the effects of different drying methods on the quality of lipids present in Cordyceps sinensis. In this study, we employed a broadly targeted lipidomic strategy to conduct a comprehensive analysis of the lipid composition in Cordyceps sinensis subjected to various drying methods. A comprehensive analysis identified a total of 765 distinct lipid species from fresh Cordyceps sinensis (FC), vacuum-freeze-dried Cordyceps sinensis (VG), oven-dried Cordyceps sinensis (OG), and air-dried Cordyceps sinensis (AG). Among these, glycerophospholipids (GP) were the most abundant, followed by glycerides (GL) and sphingolipids (SP). In this study, a total of 659 lipids demonstrated statistically significant differences, as indicated by a p-value (p) < 1. Among these lipids, triglycerides (TG) exhibited the highest concentration, followed by several others, including ceramide-ascorbic acid (Cer-AS), phosphatidylethanolamine (PE), lysophosphatidylcholine (LPC), and phosphatidylserine (PS). OG was the fastest drying method; however, PCA and OPLS-DA analyses indicated that the most significant changes in the lipids of Cordyceps sinensis were observed under the OG method. Specifically, 517 differentially accumulated lipids were significantly down-regulated, while only 10 lipids were significantly up-regulated. This disparity may be attributed to the degradation and oxidation of lipids. The metabolic pathways of glycerolipid, glycerophospholipid, and cholesterol are critical during the drying process of Cordyceps sinensis. This study provides valuable insights that can enhance quality control and offer guidelines for the appropriate storage of this medicinal fungus.

Conductive hydro drying of ripened papaya: optimization and product characterization

This study addresses the product-process characterization of refractance window drying of ripened papaya, considering the abundant availability and underutilization of the perishable product. A statistical design approach with varied drying temperature, time and sample thickness has been adopted to characterize moisture content, total phenolic content, total flavonoid content, vitamin C, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The model fitting, analysis of variance, and numerical optimization showed that the quadratic model was the most suitable model for the response variables. The optimum process parameters were attained at a drying temperature of 90 °C, time 86.92 min, and sample thickness of 2.93 mm. The optimal responses were moisture content 2.81%, total phenolic content 305.58 mg GAE/g, total flavonoid content 51.92 mg QUE/g, DPPH radical scavenging activity 91.56% and vitamin C 219.88 mg/100 g. With such high essential nutrients, refractance window dried ripened papaya can be utilized for commercially viable value-added food products.

Developing mango powders by foam mat drying technology

Using mango purée from overripe mangoes to produce powders helped to solve agricultural product stagnation. The research investigates the effect of thickening additives, convection drying, and heat pump drying on bioactive compounds such as total phenolic content (TPC), total flavonoid content (TFC), color, and solubility of the final product. The obtained results showed that the mixture (gum arabic and maltodextrin in the ratio 50:50 w/w) at a concentration of 15% gave a good quality powder texture when dried by hot air convection at 55°C with TPC (21.24 ± 1.58 mg GAE/g dry weight [DW]) and TFC (0.34 ± 0.02 mg QE/g DW), respectively. In addition, the product has a high solubility of 64.35%, with the highest pass-through point of 17.11.

Refractance window drying of food and biological materials: Status on mechanisms, diffusion modelling and hybrid drying approach

Refractance window (RW) dryer has an immense advantage in terms of final product quality (textural and color attributes, nutrient retention), energy consumption, and drying time over other conventional dryers. RW is a thin film drying system and a technologically evolving drying process. RW drying is an energy-efficient (re-circulation of water) short drying process as the drying of food materials occurs due to a combined mode of heat transfer conduction, radiation, and convection (hot air circulates over film). The high-quality dried product is obtained because the product temperature remains below 80 °C. RW dryer application is not only limited to drying food products, but it can also be further used for improving the gelling and emulsion properties, formation of leather and edible film, and can be used for handling high protein products, drying leafy vegetables or marine foods as this process does not change any functional properties. Due to these advantages over other drying techniques, RW drying has gained academic and industrial interest in recent years. The industrial application of this technology at large scale is becoming difficult due because of large surface area requirement for mass production. Researchers are trying to scale-up by combing this technology with others technology (Infrared, ultrasound, solar energy, and osmotic dehydration). RW dryer is now extending from the food sector to other sectors like pharmaceutical, cosmetic, pigment, edible film formation, and encapsulation. Majority of the reviews on RW drying focuses on the product quality aspects. This review paper aims to comprehend the RW drying system more mechanistically to understand better the principles, diffusion models explaining the transfer processes, and emerging novel hybrid drying approaches.

Drying behaviour and optimization of drying conditions of pineapple puree and slices using refractance window drying technology

Refractance window drying technology can be used to produce high quality dried fruit products due to its excellent retention of heat sensitive nutrients, organoleptic properties and bioactive compounds. This study optimised conditions for drying of pineapple slices and puree using RWDT. i-optimal design in Design Expert software was used to generate temperature-thickness combinations in form of runs. The independent factors considered included drying temperature (70-90 °C) and thickness (2-3 mm), and the responses included drying time and vitamin C concentration. The optimum solutions generated for RW drying temperature and pulp thickness were 86.2 °C and 2.9 mm for puree and 78.9 °C and 2 mm for slices. The drying times for puree and slices were 58 and 96 min, respectively with corresponding vitamin C content of 64.88 and 46.83 mg/100 g. Drying kinetics of puree and slices were determined at optimal conditions. Drying was found to follow Modified Midilli et al. Model. Pineapple powder obtained using optimal RWD conditions had low water activity (0.41), high solubility (74.64%) and dehydration ratio (4.12). Pineapple reconstituted drinks were developed and evaluated for consumer preference. Acceptability was highest at 15% inclusion of pineapple powder.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13197-021-05302-2.

Optimization of drying conditions for Jackfruit pulp using Refractance Window Drying technology

Refractance window drying is a novel technology with high operational efficiency and high product quality retention compared with conventional drying methods. This study assessed the effect of refractance window dryer water temperature and pulp thickness on nutrient content and the antioxidant activity of jackfruit. Response surface methodology (RSM) was used to optimize the drying temperature and fruit pulp thickness. Optimal drying temperature and pulp thickness were found to be 93.4°C and 2.56 mm, respectively. The respective values for the response variables drying time (min), ascorbic acid (mg/100 g), antioxidant activity (mg/100 g AA equiv) and total carotenoid content (μg/g) were 60.47, 17.97, 82.34, and 13.34, respectively. Models for prediction of these values had R 2 values of .964, .980, .994, and .994, respectively, and nonsignificant lack of fit (p < .05). This indicates the suitability of the model in predicting the RWD operating conditions to produce quality dried jackfruit.

Factors Affecting the Time and Process of CMC Drying Using Refractance Window or Conductive Hydro-Drying

Intensive research on biodegradable films based on natural raw materials such as carboxymethyl cellulose (CMC) has been performed because it enables the production of transparent films with suitable barrier properties against oxygen and fats. Considering the importance of the production of this type of film at the industrial level, a scalable and continuous drying method is required. Refractance window-conductive hydro drying (RW-CHD) is a sustainable and energy-efficient method with high potential in drying this kind of compound. The objective of this study was to evaluate the factors (CMC thickness, heating water temperature, and film type) and radiation penetration depth that affect drying time and energy consumption. It was found that drying time decreased with increasing temperature and decreasing thickness. Similarly, energy consumption decreased with decreasing temperature and thickness. However, the drying time and energy consumed per unit weight of product obtained were equivalent when drying at any of the thicknesses evaluated. Film type had little effect on time and energy consumption compared to the effects of temperature and CMC thickness. The radiation penetration depth into the CMC was determined to be 1.20 ± 0.19 mm. When the thickness was close to this value, the radiation energy was better utilized, which was reflected in a higher heating rate at the beginning of drying.