|Topic:||Patchimaporn Udomkun, Marcus Nagle, Busarakorn Mahayothee,
Donatus Nohr, Alexander Koza, Joachim Müller. (2015) Influence of air drying
properties on non-enzymatic browning, major bio-active compounds and
antioxidant capacity of osmotically pretreated papaya. LWT - Food Science and Technology 60(2): 914–922. DOI: 10.1016/j.lwt.2014.10.036
|Abstract:||This study aimed to investigate the effect of air drying parameters such as temperature, specific humidity and velocity, on non-enzymatic browning behaviour and on bio-active compounds and antioxidant properties of osmotically pretreated papayas. Convection drying was conducted under through-flow mode at four temperatures (50, 60, 70, 80 °C), three air velocities (0.2, 0.5, 0.7 m/s) and two specific humidity levels (10, 25 g/kg dry air). Higher drying temperatures resulted in a significant decrease in moisture content and polyphenol oxidase activity, while degree of browning and 5-hydroxymethylfurfural increased. The antioxidant activity and total phenolic compounds increased with temperature and as well with decreasing air velocity. In contrast, specific humidity did not have a major effect on quality attributes of dried samples, except for carotenoid contents. This study has shown that drying parameters can decompose and/or enhance carotenoids contents in dried papayas. To obtain the product with highest level of bio-active compounds and lowest possible melanoid formation, treatment with temperature of 70 °C, specific humidity of 10 g/kg dry air and velocity of 0.2 m/s proved to be the most suitable option. Based on these results, optimization of the process, particularly drying temperature, should be considered with respect to preserving product colour and biochemical properties.
|Author:||Asst. Prof. Busarakorn Mahayothee, Ph.D.