Modeling of vacuum puffing characteristics and color change of liquid honey

Abstract

Vacuum puffing of liquid honey, mixed with drying ingredients, was carried out in a vacuum dryer in order to model the puffing characteristics and color change of the mix. The drying ingredients i.e., maltodextrin (0.6kg/kg dry honey solid), glycerol monosteareate (0.02kg/kg dry honey solid) and tricalcium phosphate (0.02kg/kg dry honey solid) were mixed with the liquid honey. The puffing characteristics of the honey mix were carried out at various sample thickness (0.002, 0.003 and 0.004m) and vacuum chamber plate temperature (65, 70 and 75°C). Among the five drying models fitted to the puffing data, Page model was observed to predict the moisture content and puffing time data well at all experimental conditions with a relative deviation percentage value of less than 10%. Effective moisture diffusivity varied between 8.875×10−10m2s−1 and 4.132×10−9m2s−1. The effective moisture diffusivity was found to increase with increase in thickness of the honey mix and puffing temperature. Increase in temperature enhanced the temperature induced color change of the honey powder. Increase in thickness increased the total puffing time.