B. M. A. Amer, “Thin layer drying kinetics of mango puree in refractance window drying system,” Misr Journal of Agricultural Engineering, vol. B. Byaruhanga, “Optimization of drying conditions for jackfruit pulp using refractance window drying technology,” Food Science & Nutrition, vol. Refractance Window™ drying has primarily been studied to compare with other drying processes in terms of various quality attributes such as nutrition, flavor, color, aroma and antioxidant compounds.
Look for a provider within the industry that has a history of customer support. Take advantage of the energy-conserving features of the newest dryer designs, as these will become increasingly important. Because you will be living with it for a long time, make sure your new dryer is a good match for your product. Abonyi et al. showed a high retention Refractance Window Dryer of product quality as compared to other conventional methods of drying (including freeze-drying), in experiments with carrots purée and strawberries purée. For instance, content of beta-carotene in carrot purée was reduced by only 9.9% when drying with RW technique, whereas 57% of beta-carotene was lost when drying in a drum drier.
Therefore, a compromise among all influencing factors should be made (Vega-Mercado et al., 2001). Similarly, Ismail, Aly, and Atallah have found that the pH values of freeze-dried yoghurt powders with 0.11 mbar did not show a statistical difference from fresh yoghurts as well. In another study, Tontul, Ergin, Eroğlu, Küçükçetin, and Topuz determined the pH values of yoghurt powders lyophilised under 0.02 mbar pressure between 4.13 and 4.14. It is thought that these differences between the studies are due to the differences in pH values of the fresh yoghurts used in drying, rather than the process conditions. The content of bioactive compounds in the fresh and dehydrated samples was measured to evaluate the impact of the operating conditions on the quality of the final product.
In this study, however, although the process temperatures for RW drying were higher than oven drying, the rehydration capability of RW dried jackfruit powder was higher than that of oven dried jackfruit powder. Zielinska et al. studied the CD (60 °C and 90 °C), VMD and their combination CD (60 °C and 90 °C)-VMD in blueberry drying process. As explained above, degradation of anthocyanins results in color degradation due to the location of these compounds in the material as they are mainly situated in the blueberry outer layer. The authors have found that the content of anthocyanins was higher if the samples were dried with VMD when compared with CD. However, when comparing all the methods used in this study, the CD at 90 °C combined with VMD was found to be the most suitable drying method regarding the retention of anthocyanin in blueberries and color preservation.
A RW dryer can preserve color,9heat sensitive vitamins and phytochemicals that some of them will be discussed in the following section. Ochoa-Martínez, C.I.; Quintero, P.T.; Ayala, A.A.; Ortiz, M.J. Drying characteristics of mango slices using the Refractance WindowTM technique. Quality retention in strawberry and carrot purees dried with refractance window system. Antioxidant activity for dried passion fruit was 367.6 mg vitamin C equivalent/100 g of powder. For the uncertainty analysis the Monte Carlo procedure was used to statistically quantify… Order fitted the reaction processes to best represent the mechanical extraction. Removal of TMP in the secondary effluent by Fe was achieved.
In another study, a solar dryer using a PV-T solar collector was used in a tomato drying system to provide the required electrical energy. The results showed that the electrical energy required to dry tomato slices is from 0.65 to 1.4 kWh. The results also showed that as the drying temperature decreases, both the solar heat fraction and the ratio of solar electricity to consumed electricity increased (Dorouzi et al., 2018).
As expected, as the sample thickness decreased and the drying temperature increased, the water loss was higher for every film. The main objective of the work was to evaluate the factors affecting the drying time and energy consumption in the RW-CHD drying of CMC. The radiation penetration depth into CMC and the effect of operating conditions on drying time and energy consumption were determined.
Drying rate curves illustrated that the whole drying process happened in the falling rate period. Additionally, from initial drying to the moisture content of about 0.5 kg/kg, the drying rate increased with the increase of drying temperature and air velocity or decreased with the increase of sample thickness. The moisture effective diffusivity was determined both neglecting shrinkage and considering shrinkage. The drying activation energy of American ginseng slices was 46.64 kJ/mol determined by Arrhenius relationship. The moisture effective diffusivity and drying activation energy of American ginseng slices were compared to other biomaterials and related issues were also discussed. The current work is useful for designing air impingement drying system, evaluating and saving energy consumption of American ginseng slices.
Rehydration ratio elevated when the salt solution used for rehydration and the weight gain was more irrespective of temperature. Superior rehydration was noticed when the slices were dried at 80°C, and it was relatively poor at 85°C and 75°C. Refractance window drying is a novel fourth-generation drying technology that is employed to dry heat-sensitive products like juices and purees to retain the product colour, aroma, antioxidant compounds, and nutritional properties. Sehrawat R., Nema P.K., Kaur B.P. Quality evaluation and drying characteristics of mango cubes dried using low-pressure superheated steam, vacuum and hot air drying methods.
This drying technique outperforms the conventional method due to reduced drying temperature, drying time, energy consumption, and greater quality retention. The researchers have found that results of RW dried potato14, carrot15, tomato16, goldenberry17 and aloe vera18 had maximum quality retention. Considering the advantage of RWD technique, the present study was planned to dry black carrot puree using RW dryer then fermented with freeze dried LAB to produce reconstituted Kanji. Drying is a fundamental process in the food industry, especially for highly perishable foods, such as fruits and vegetables, because they tend to have short durability post-harvest, resulting in economic and environmental losses. The Refractance Window is a suitable technique for fruits and vegetables as it maintains the nutritional quality of the raw material in the dry product.
Effects of vacuum level and microwave power on rosemary volatile composition during vacuum–microwave drying. Alañón M.E., Palomo E.S., Castro L., Viñas M.G., Pérez-Coello M.S. Changes produced in the aroma compounds and structural integrity of basil (Ocimum basilicum L.) during drying. Oikonomopoulou V.P., Krokida M.K. Novel aspects of formation of food structure during drying. Calín-Sánchez Á., Figiel A., Lech K., Szumny A., Martínez-Tomé J., Carbonell-Barrachina Á. Krokida M.K., Philippopoulos C. Rehydration of dehydrated foods. Weil M., Sing A.S.C., Méot J., Boulanger R., Bohuon P. Impact of blanching, sweating and drying operations on pungency, aroma and color of Piper borbonense.