Efficiency and Quality Retention during Refractance window drying systems

His scientific efforts helped development and evolve the refractance window drying technique into InfraRWD. InfraRWD offers faster, more efficient and more economical drying than refractance window drying. The retention of food quality in a drying process rather than mere extension of shelf life has gained prominence because of consumers demand for more health-promoting foods. InfraRWD dryer can be used in three different mode, namely refractance window drying, infrared drying and infrared assisted refractance window drying.
In conclusion, this study revealed that RWD provides an appropriate drying temperature as an alternative to freeze-drying. RWD may improve dragon fruit drying, adding value to the food industry. Enhancing Food Processing: Refractance Window Dryer's Role in Nutrient Preservation has an immense advantage in terms of final product quality , 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 .

In an oxygen-free environment, it is highly recommended to use low temperatures necessary to avoid loss of phenolic compounds and antioxidant capacity due to the thermal and oxidative degradation. On the  other hand, RW drying rapidly heats the product which results in a faster release of the phenolic compounds in cell material. This argument was stated by other authors in studies on sweet corn or tomatoes who observed an increment in antioxidant capacity due to the heating process.
The peeled black carrots were treated by dipping in sodium hydroxide solution at three different concentrations (i.e., 0, 1 and 2% v/v). The treated samples were then processed into puree using pulper. The freshly prepared puree  was dried using batch type pilot scale refractance. Dal-Bó V., Freire J.T. Effects of lyophilization on colorimetric indices, phenolics content, and antioxidant activity of avocado pulp.
These compounds interact with amino groups from proteins and undergo Maillard reaction during the exposition to air at high temperatures, long drying times and the amount of water. In addition, color changes appear due the degradation of some thermosensitive compounds such as anthocyanins and carotenes, which results in a loss of functionality and color. A quick dehydration of the product to 15–20% moisture content can reduce Maillard reaction time. For this reason, the drying  methods are designed to accelerate the drying time in order to achieve the desired moisture content while reducing the browning time . Microwave drying is based on the volumetric heating occurring when electromagnetic waves pass through the material causing a molecules oscillation. This oscillation generates thermal energy that is then used to remove water from the wet material.

Hot water comes from the thermostatic bath and circulates to the container. All samples were placed on the Mylar film as a thin layer of 3 mm. Samples were taken each 10 minutes for microbiological analysis and moisture content determination until the drying process was completed.
Product quality shows good results as compared to drum drying, freeze-drying, spray drying, tray drying, etc. while being extremely energy efficient. Refractive window drying is a novel technology which can be use to dry the semi solid, puree and paste type of product. The advantage of this drying technology, its minimising drying time, and provides better quality product with higher retention of nutrients in comparison with other conventional drying techniques. Castoldi et al. investigated the drying of tomato powder using an RW dryer at different drying temperatures (65, 75, 85, and 95 °C) and two thicknesses . They showed that the lowest drying time was obtained at 95 °C temperature and 1 mm thickness.

Most studies on the RW technique have been carried out with fruits and vegetables in purée or juice; however, this technique is also attractive for drying of fruit and vegetable slices. On the other hand, Nutradry, an Australian company, produces a range of products including lycopene, beta-carotene, spirulina, barley grass, teas and herb blends . Jones patented a method producing a homogeneous dried material from either a mixture of foods or herb and food extracts by using the RW technique. The equipment required for RW drying is simple and relatively inexpensive as compared to freeze-dryers, which generally require large facilities to be economic. For drying a similar amount of product, the cost of an RW equipment is about one-third of the cost of a freeze-dryer, whereas the energy consumed by RW is less than half the energy consumed by a freeze-dryer . Potatoes are a widely consumed staple food and a key ingredient in numerous food products such as French fries, chips, mashed potatoes and various snacks.
The effect of slice thickness on the dehydration and rehydration characteristics of yam was studied in a Refractance Window TM type dryer constructed from a laboratory water bath. Yam slices 1.5, 3.0 and 4.5 mm thick were dried in a laboratory scale RW dryer where the water in the bath was maintained at temperature of 80 °C. The initial moisture content of the yam samples was 69% on a wet basis . The drying process was carried out until the final moisture content of the product was below 10% .
Design/methodology/approach-A lab-scale batch RWD of a closed-loop control system was designed, fabricated and evaluated for drying rates, evaporation rate, the energy of evaporation, energy efficiency and throughput. Findings-Drying rates at 95°C of 1.32 gg À1 min À1 and 0.854 gg À1 min À1 at 2 and 3 mm, respectively, for tomato, 0.6 gg À1 min À1 and 0.33 gg À1 min À1 at 2 and 3 mm for mango pulp were obtained. The dryer had an evaporation rate of 4.63 Â 10-4 kg/s and 4.25 Â 10-4 kg/s, the energy of evaporation of 1.05 kW and 0.96 kW and thermal energy efficiency of 25.64% and 21.73% while drying tomato and mango pulps, respectively. Dryer throughput of 0.6 kg/h of dried mango Pulp and 0.47 kg/h of dried tomato pulp was obtained. Originality/value-The designed RWD can be adequately used in laboratory experiments on different products to produce powders.

And A.K.; Investigation, M.S.; Resources, M.S., P.K., K.K.G. and A.S.; Writing—original draft, R.Z.; Writing—review & editing, R.Z., M.S., P.K. Hydrodynamic and Aerodynamic Forces on Floating Wind Turbine The aim of the study is to create a mathematical model of wind turbine tower floating on sea and conduct modal analysis specifically for spar buoy foundation. Discharges dried material through a discharge end; and receives product by way of the feed application tray at an opposite end. The method of claim 15, wherein the filtered air system is an HVAC unit with a cooling capacity and a heating capacity. Directing the conditioned air through at least one or more horizontal manifolds; and directing the conditioned air through air slits, connecting the at least one or more horizontal manifolds to the drying chamber.