The Effect of Biopolymer Type, Temperature and Relative Humidity on the Physicochemical Characteristics and Stability of Microencapsulated Bioactive Compounds of Saffron

The purpose of this research was to encapsulate the bioactive compounds of saffron (colour, taste and aroma) in order to manufacture a high-economic-value product. For this purpose, the effect of different bio-polymers, Maltodextrin, Whey protein and Gum arabic on the stability of microencapsulated bioactive compounds of saffron with the spray dryer was evaluated. The result showed that the encapsulation efficiency and the amount of saffron compounds were highly affected by type of biopolymers, relative humidity and temperature during the drying process and storage. The picrocrocin and safranal content in microcapsules prepared with whey protein were at the highest compared to the other wall materials, whereas in the case of colour strength, maltodextrin showed better protection for the crocin .This research suggested that the microcapsules containing maltodextrin has a better quality in terms of both efficiency (mass production) and protection of bioactive compounds among other wall materials (whey protein and gum arabic) and can be recommended to the industry. At all the temperature examined, as the relative humidity increased, the loss rates of crocin, safranal and picrocrocin rose and reached its maximum at 75% relative humidity. The results showed that with increasing temperature and humidity, particularly at 45 ° C and 75% humidity, the spherical from (morphology) of micro-capsules has been changed and the number of cavities and dents widely increased. Also as the relative humidity increased, glass transition temperature of maltodextrin decreased.