Techno-Economic Analysis of a Refractance Window Dryers

The responsibility for the publication content rests with the publishers providing the material. Please refer to our Terms and Conditions. Fat content was determined by using petroleum ether as a solvent in the Soxhlet apparatus (Model SCS2, Pelican equipment’s Chennai) in triplicates Refractance Window Dryer according to the procedure given in AACC method. The result was expressed as percent fat using Eq.2. If you think you should have access to this content, click to contact our support team. You may be able to access this content by logging in via your Emerald profile.
The increase of TPC with the temperature was also reported from hazelnut , sachainchi , and cashew . Infrared radiation from the mylar sheet may have the capability to cleave covalent bonds and liberate the binding antioxidants such as flavonoids, carotene, tannin, ascorbate, flavoprotein, or polyphenols from repeating polymers. Hence the better result in RW-dried samples is due to IR radiations as they have a tendency to cleave the covalently bound phenolic compounds. Drying rates at 95°C of 1.32 gg−1min−1 and 0.854 gg−1min−1 at 2 and 3 mm, respectively, for tomato, 0.6 gg−1min−1 and 0.33 gg−1min−1 at 2 and 3 mm for mango pulp were obtained. Optimization study for refractance window drying process of Langra variety mango. Fruit and vegetables have high nutritional value such as vitamins, minerals, carotenoids, phenolic compounds, flavonoid compounds, non-flavonoid compounds, etc.

In drying, aw is an important parameter as it helps in determining the quality of the product. It also plays a significant role in walnut lipid oxidation as controlled water activity decreases oxidative rancidity in walnuts. The maximum water activity was found in the sundried sample at 0.69 ± 0.015 and minimum water activity i.e. 0.32 ± 0.017 was found in RW dried sample treated at 90 °C.
Novel drying techniques emerging as outcome of laboratory-based research may yet prove to have a positive impact on the food industry in terms of scalability, energy efficiency, cost and end-product quality. Refractance window drying is one such technique that gained a lot of attention in recent years, owing to the numerous benefits it claims. The technique involves drying purees and liquids placed over a thin infrared transparent film that essentially forms a ‘window’ through which drying occurs.
These components affect importantly from high temperatures. In spray drying, tunnel drying, drum drying, etc. techniques apply high temperatures at different times . The shorter the exposure time to heat, the lesser changes occur in the color, flavor, aroma and nutritional  value of the product. In addition, better retention of bioactive compounds such as vitamins, minerals and phenolic compounds in the product and better inhibition of microbial growth during the drying process are provided with RWD technology. Mylar film thickness is an important parameter, and the film mechanical strength decreases with increasing film thickness.

The physiochemical characteristics of the dried apple slices including flavonoid content, total phenolic compounds, antioxidant activity, vitamin C content and color were measured. In addition, the energy consumption and energy efficiency of the dying methods were evaluated. Results showed that combining ultrasound and infrared with conductive hydro-drying can result in higher drying rates  and lower product moisture content. Quality of UIACHD dried apple slices was close to the freeze-dried products and it was significantly better than the cabinet dried products. Moreover, the energy efficiency of UIACHD was considerably better than the cabinet dryer and the freeze-dryer. The results of this study showed that combining ultrasound and infrared with conductive hydro-drying can lead to an energy-efficient process with good quality retention ability.
We have also been empowered to assist some of our customers with these issues. In a perfect world, we would get all that we need from fruits and vegetableswhile they’re still fresh. IC50 value was calculated to determine the concentration of the sample required to inhibit 50% of radical.

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. On the other hand, Refractance Window drying is a novel drying system which converts foods into flakes or powders11. Here, thermal energy is transferred from hot water (95–97 °C), which is circulated beneath a plastic conveyer belt and used to dry a thin layer of product on the belt surface12. Studies have suggested that using a thin plastic belt which is transparent to infrared radiation creates a “window” for thermal energy to become transferred from hot water to wet food material13. Refractance WindowTM-Drying is one such novel fourth-generation drying technology which has recently gained huge attention due to its several advantages.
Two optimisation systems were formulated; one for a nanoemulsion made from formulation A and the other for a nanoemulsion made with formulation B , both having  minimum moisture and water activity after RW drying. The water activity of the flakes was measured using an AquaLab Series 4 aw meter (Decagon Devices, Inc., Pullman, WA) after the samples were stabilized at 25 °C for 30 min31. The measurements were performed in triplicate.
While  swimming underwater, I looked up to see that the water’s surface acted like a mirror, only allowing me to see something floating on it but almost nothing else. I knew water was the best heat transfer medium in nature and wondered if perhaps water could be used to provide the energy needed to dry products. If so, it might do so more efficiently and without damaging the delicate and valuable nutrients in the food. Modeling of drying process in RW dryer and investigating the role of different parameters and heat transfer mechanisms in the process. Authors who have researched food area-related contact angles have based their work on studying the properties of materials’ surfaces in response to contact with liquid foodstuffs (i.e. interfacial interactions). Their usefulness as a mechanism for predicting interactions between liquids and solid surfaces (i.e. biofilms, membranes, heat interchange or packed food surfaces) has been studied by authors like Güleç et al.47.