Allulose‐crystallized fruits: Effect of non‐thermal air‐drying and UV‐A light dehydration of osmotic solutions

Abstract

AbstractThe purpose of this research was to confirm the suitability of allulose to produce crystallized fruits under nonthermal conditions and the suitability of UV‐A light dehydration to concentrate the osmotic solutions. Mangoes and apples were subjected to osmotic drying with either sucrose or allulose, which was followed by an air‐drying step at room temperature to further concentrate the crystallized fruits. There was no significant difference in the dehydration kinetics parameters between the two sugars in each crystallized fruit. Color evaluations showed that allulose was able to better preserve the color of the original raw fruits in the final crystallized samples. Electron microscopy images suggested a more uniform diffusion of allulose as compared to sucrose for both fruits. Similarly, liquid chromatography and infrared spectroscopy analyses confirmed the successful absorption of both sugars into both fruits, with allulose having a final higher concentration in both mango and apple (51.7 ± 5.6% and 70.8 ± 7.7% w/w, respectively) as compared to sucrose (48.6 ± 2.9% and 58.3 ± 3.4% w/w, respectively). UV‐A light dehydration showed to be able to increase the recovery of the sugars from osmotic solutions better than in conditions without UV‐A light exposure. When only air flow was used, it was possible to remove 85.3 ± 4.6% and 78.6 ± 0.6% of the original moisture in the sucrose and allulose solutions, respectively. In contrast, under UV‐A light dehydration, the percentage of the original water removed from the sucrose and allulose solutions was 95.2 ± 1.8% and 83.1 ± 1.9%, respectively.Practical applicationsThere is an increasing trend toward producing foods that are healthier for the general population. The use of rare sugars like allulose offers a promising alternative to accomplishing this. In addition, it has become imperative to develop processes that are more sustainable. The use of air‐drying at room temperature can represent an effective approach to develop more sustainable food manufacturing processes. More specifically, the use of UV‐A light dehydration (which is a non‐thermal food dehydration technique) for the recovery of solutes or the concentration of osmotic solutions can also represent an effective aid in this type of processes.