Quantitative understanding of Refractance Window drying
On the other hand, HVEF showed a dominant effect on drying kinetics only at low air velocities (0.2 m/s). In addition to the above advantages, the drying equipment, energy consumption, and operation costs are lower than those of tray, freeze, drum, and spray drying methods. For example, the cost of the WR drier can be between one-third and one-half the cost of freeze drying . Compared to other drying systems such as drum drying or convection drying, production costs can be up to 70% lower . However, despite these advantages, FD has always been recognized as an expensive process for manufacturing a dehydrated product . In recent years, some relatively new drying techniques such as Refractance Window drying and cast-tape drying have been developed for drying of food products [14–17].
Refractance Window drying equipment costs up to 80% less and uses significantly less energy compared to other drying methods. Rehydration ratio of dried black carrot ranged from 4.99 to 6.30. The minimum rehydration ratio was observed for samples pre-treated in 2%NaOH solution and dried at 90 °C water temperature whereas maximum was found for untreated samples dried at 70 °C. Refractance Window Dryer The linear term of water temperature had significant positive effect on rehydration ratio . This can be owing to overheating of the product surface causing development of an impervious layer making it difficult for the dried product to rehydrate to its actual volume and shape33,37. Total phenolic content of dried black carrot ranged from 22,876.40 to 23,444.30 mg/100gdw.
Dried restructured fruits can be healthy snacks with very attractive sensory characteristics depending on the drying method. Cast-tape drying and conductive multiflash drying are novel technologies with great potential to produce high-quality dried products at an industrial scale in a relatively short time. This study provides important results regarding the most suitable drying processes setup for producing high-quality dried restructured pineapple. In the present study, the effect of Refractance Window drying on the functional properties of chickpea protein isolates was investigated and compared to freeze drying at different pH levels. The functional properties investigated were protein solubility, water and oil holding capacity, emulsifying properties, foaming properties, flocculation and coalescence indices and textural properties.
A study reported 23%, 41%, and 45% losses in TAC on in the coloured potato flakes following RWD, DD, and FD, respectively. A. Monsalve-Gonzalez, G. V. Barbosa-Cánovas, R. P. Cavalieri, A. J. Mcevily, and R. Iyengar, “Control of browning during storage of apple slices preserved by combined methods. 4-hexylresorcinol as anti-browning agent,” Journal of Food Science, vol.
However, this macroscopic approach to quantify the transport of water during the first falling rate period of drying commonly involves the determination of an effective water diffusivity . Chaaban, H.; Ioannou, I.; Chebil, L.; Slimane, M.; Gérardin, C.; Paris, C.; Charbonnel, C.; Chekir, L.; Ghoul, M. Effect of heat processing on thermal stability and antioxidant activity of six flavonoids. Castoldi, M.; Zotarelli, M.F.; Durigon, A.; Carciofi, B.A.M.; Laurindo, J.B. Production of tomato powder by refractance window drying. The total flavonoid content was quantified following the colorimetric method described by Zhishen et al. , using rutin as a standard and performing spectrophotometric reading at 450 nm . The results were expressed in milligrams of rutin per 100 g of sample .
Mathematical models of drying processes are useful for describing process behavior and extrapolating it to different operating conditions . Despite the fact that these models can provide good regression for experimental data under very specific conditions, there is no way to obtain general equations that describe every product’s drying process . ANN models provide several advantages over conventional modelling techniques, due to their learning abilities and ability to fit nonlinear processes. As a result, ANNs have been found to be more advantageous in predicting drying kinetics accurately and can easily be applied to non-linear processes .
We believe that our industrial dryers are not just machines, but solutions that can help transform business. Table 5.Effects of process factors on the drying yields (g/h-m2). And C.I.O.-M.; methodology, R.D.M.-T.; validation, R.D.M.-T.; formal analysis, R.D.M.-T., E.S.-R., C.V.-P. And C.I.O.-M.; investigation, R.D.M.-T., E.S.-R., C.V.-P.
Similarly, energy consumption decreased with decreasing temperature and thickness. However, the drying time and energy input per unit weight of product obtained were equivalent when drying at 1.5 or 3.5 mm. That is important for deciding the amount of sample to be dried as a function of operating cost and final product quality when exposed to high temperatures for a longer time.
Conditioned air supply manifold 120 at the discharge end 111 of the belt 110 provides conditioned air 102. According to another embodiment, the air injected into the dryer is ambient air taken from outside the room or outside the building in which the dryer is installed. 3 illustrates a dryer exhaust manifold, according to one embodiment. & Chakraverty, A. Thin layer convection-drying of mushrooms.
For pulp production, the dragon fruit slices were ground in a mixer and sieved using a 40-mesh size, with the resulting pulp spread out in a thin layer 5 to 8 mm thick. After drying, the texture of the dried product was analyzed using a texture analyzer (TA-XT plus model, Micro-Systems, UK). Then, the dried product was ground into powder using a mixer grinder . The resulting powder was sieved and packed into LDPE pouches for further analysis.
The use of hot water as the heat transfer medium and at temperatures just below boiling is a design feature that is unique to this drying method. First mechanism which was proposed for RW drying suggested that in this type of dryer, thermal energy from circulating hot water is transported to the wet product via a plastic interface which is relatively transparent to infrared radiation. During RW drying, the three modes of heat transfer are active which include conduction , convection , and radiation (C. I. Nindo & Tang, 2007). Developed equipment that uses solar energy and operates under a vacuum.