From these equations, it was possible to obtain response surfaces that illustrate these effects. Antioxidant activity (%), as presented in the Table 4, showed an increase from 0 to 24 h of fermentation. Kwaw et al.42 discovered a relationship between polyphenolic and antioxidant activities.
In another study, Calderón-Chiu et al. investigated the effects of osmotic pretreatment on sugar beet drying using an RW dryer. According to the results, increasing the drying temperature from 60 °C to 85 °C reduced the drying time by 150%. In another study on drying Aloe vera, the percentage of powder yield was 2.60, 2.60, 2.55, and 2.52% Enhancing Food Processing: Refractance Window Dryer's Role in Nutrient Preservation at 50, 60, 70, and 80 °C, respectively. HPLC chromatogram obtained for the dried samples showed that the Aloin amount decreased from 10.6 to 1.7 ppm by increasing temperature from 50 to 80 °C (Gulia et al., 2010). Drum drying, developed for liquid products, causes severe quality loss in product due to exposure to high temperatures ( °C).
The hot water beneath the film is recirculated to improve thermal efficiency. The belt moves at the desired speed while the drying process takes place. The drying rate curves for RWD, oven drying, and solar drying are shown in Figure 2. The figures indicate that the drying rate rapidly increases with time to a maximum value and then decreases.
Boukouvalas C.J., Krokida M.K., Maroulis Z., Marinos-Kouris D. Effect of material moisture content and temperature on the true density of foods. Wojdyło A., Figiel A., Lech K., Nowicka P., Oszmiański J. Effect of convective and vacuum–microwave drying on the bioactive compounds, color, and antioxidant capacity of sour cherries. Ahmed M., Akter M.S., Eun J.-B. Optimisation of drying conditions for the extraction of β -carotene, phenolic and ascorbic acid content from yellow-fleshed sweet potato using response surface methodology. Pham N.D., Khan M., Karim M. A mathematical model for predicting the transport process and quality changes during intermittent microwave convective drying. Wojdyło A., Lech K., Nowicka P., Hernández F., Figiel A., Carbonell-Barrachina Á. Influence of different drying techniques on phenolic compounds, antioxidant capacity and colour of ziziphus jujube Mill.
This decrease was more pronounced in tests performed at higher temperatures, e.g., Experiment 6 (84.1 °C). The thermosensibility of phycocyanin during dehydration has also been observed in other studies using different techniques . Nonetheless, some operating conditions tested herein led to significant phycocyanin levels in the dried material. Black carrots are rich in bio-actives but underutilized owing to their short-term availability and perishable nature.
The nutrition found in fresh, whole foods is unparalleled. In a perfect world, we would get all that we need from fruits and vegetableswhile they’re still fresh. In a perfect world, we would get all that we need from fruits and vegetables while they’re still fresh. Marques, L.; Silveira, A.; Freire, J. Freeze-drying characteristics of tropical fruits.
The refractive index mismatch between the water and the food is significantly reduced at the point of contact, resulting in less reflection and increased thermal energy transfer into the food . The RWD system offers better retention of phytochemical parameters compared to other drying technologies . It is a new, energy-efficient, and eco-friendly drying technology that can benefit the food industry when selecting new drying technologies .
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.
Therefore, the hot air reduces the products surface unbound moisture while the microwave energy eliminates the bound moisture from the inside of the product via volumetric heating. Dried apple slices have a good market potential as a raw material in many processed foods and can be an alternative to deep fat fried chips for health-conscious consumers. This work focuses on assessing the efficacy of developed FIR assisted RW drying system in terms of drying time, energy, and quality attributes in comparison with conventional drying methods.
The unpredictable weather makes the traditional drying of various farm produce under the sun harder. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. O. Ngadi, “Structure and irregularities of surface of fried batters studied by fractal dimension and lacunarity analysis,” Food Structure, vol. M. Rahman, M. Miaruddin, M. F. Chowdhury, M. H. H. Khan, and M.-E. Rahman, “Preservation of jackfruit by osmotic dehydration,” Bangladesh Journal of Agricultural Research, vol.
As explained in the previous sections, the conventional methods of drying are more susceptible to physical and chemical degradation in the final product. For this reason, it is essential to use an appropriate drying method for each product and select the adequate conditions that will reduce possible changes to a minimum. In the following section, some of the physical parameters influenced by the drying methods are described. Moreover, Table 1 and Table 2 summarizes all the drying methods and their effect on quality parameters discussed in this section. Intermittent microwave convective drying significantly reduces drying time and improves product quality compared to convection drying and overcomes the problem of overheating that persist in continuous microwave convective drying.