From the scientists that helped the development of the Refractance Window Dryer
InfraRWD dryers are produced by NFDS Arge, a start-up founded in Konya, Turkey. The founder, Ismail Tontul PhD, extensively used the refractance window in his PhD thesis as can be evidenced from several publications he produced. 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.
Selected publications from our team
The founder of InfraRWD and the team published a range of publications on the refractance window drying and other drying techniques. Some of these papers were outlined below.
Effects of different drying methods on the physicochemical properties of pomegranate leather (pestil) [2017, LWT, 80: 294-303)
In this paper, a local fruit-based snack (fruit leather) was dried by hot air drying, microwave-assisted drying, and refractance window drying. The study showed that refractance window drying is more advantageous in terms of drying time, chemical properties, and heat-induced contaminants compared to other drying techniques. Moreover, this study also demonstrated that refractance window drying can be used in film type products instead of powders or flakes.
Functional properties of chickpea protein isolates dried by refractance window drying [2018, International Journal of Biological Macromolecules, 109: 1253-1259]
This was the first study on the drying of protein isolates using the refractance window drying technique and comparing its effectiveness with freeze drying. The study showed that the refractance window drying resulted in better water holding capacity and emulsion stability. On the other hand, solubility, oil holding capacity, and foam stability of the freeze dried protein isolates were better. The study also showed that drying techniques have a clear effect on the functional properties of protein isolates.
Physical and microbiological properties of yoghurt powder produced by refractance window drying [2018, International Dairy Journal, 85: 169-176)
In this paper, yoghurt powder was produced using the refractance window drying and freeze drying. Yoghurt powder production is challenging since microbial inactivation must be prevented. While freeze drying lasted for48 h, refractance window drying was reported to last for 25-40 min depending on the temperature used. The results of the paper showed that 50ºC drying temperature caused less inactivation of yoghurt bacteria during drying and provided less inactivation during storage of the powder. Therefore, refractance window drying is a promising technique for yoghurt powder production.
Convective and refractance window drying of cornelian cherry pulp: Effect on physicochemical properties [2018, Journal of Food Process Engineering, 41(8): e12917]
Cornellian cherry pulp, a rich source of bioactive compounds was dried by both refractance window drying and convective drying. Refractance window drying not only provided a less drying time of 15-20 minutes but also resulted in better quality in terms of colour, ascorbic acid, and total monomeric anthocyanin content. Additionally, it did not cause the formation of HMF, which is a heat-induced contaminant.
The impact of refractance window drying conditions on the physical and microbiological properties of kefir powder [2021, Food Bioscience, 43: 101317]
Instant kefir powder production was dried by both refractance window drying and freeze drying. Refractance window drying showed great advantages in physical properties over freeze drying. The survival of beneficial microorganisms in kefir powders by refractance window drying was higher at 50°C than other drying temperatures. This suggests that refractance window drying at low temperatures can be used in probiotic-rich products.
Production of egg powders using refractance window drying technique [upcoming]
Egg powders are used in different food formulations because of their functional and technological properties. In a nationally-funded project, our team studied the effect of refractance window drying on different egg products (egg white, egg yolk, and whole egg). A wide range of temperatures was studied in this project. The best drying conditions in each egg product were determined. Refractance window drying provided drying of egg products without color change, technological properties loss, and oxidation.