The study of suitable drying time and physical characteristic of pork slices dried using microwave followed by hot air

Abstract

The objectives of this research were to determine the suitable times of pork slices drying using microwave followed by hot air and to find specific energy consumption during drying. The physical characteristic (color and hardness) and the sensory test of dried pork slices were also investigated. Pork slices with the sizes of 50x50x1.3 and 50x50x2.2 millimeters were dried using the microwave at the powers of 160, 320, 480, 640 and 800 watts until the samples did not burn during drying. Then, the samples were dried using hot air at a temperature of 110oC until the moistures of the samples were lower than 20% dry basis. Based on the experimental results, it was found that the suitable times of the samples drying using microwave were 50-600 seconds which depended on the microwave powers and the pork thicknesses. In hot air drying period, drying times of the samples with thicknesses of 1.3 and 2.2 millimeters were 30 and 45 minutes, respectively. The microwave powers had no significant effect on the redness (a value) and yellowness (b value) of dried pork, the hardness of dried pork, and the specific energy consumption (P<0.05). The pork thicknesses had the significant effect on the lightness (L value) and yellowness (b value) of dried pork, the hardness of dried pork, and the specific energy consumption (P<0.05). Moreover, sensory scores of the dried pork obtained from this research were close to those obtained from the local market.