Effect of fluidized bed drying on physicochemical and microbiological properties of Mexican fresh cheese

Abstract

Artisan Mexican fresh cheese traditionally made from raw milk, is often salted and susceptible to changes caused by enzymes and spoilage microorganisms, generating alterations in the product at the sensory and nutritional level. The main purpose of this study was to evaluate the effect of fluidized bed drying on physicochemical and microbiological properties of Mexican fresh cheese. A 23+2(3)+1 rotatable central composite design was used to establish the fluidized bed drying conditions. The factors were drying time 60, 90 and 120 min, drying air temperature 50, 60 and 70 °C, and particle size 0.5, 2 and 3.5 cm. The analysis of variance indicated that time and drying temperature affected significantly (p ≤ 0.10) on response variables of dried cheese. According to results the lowest values at the end of the process of moisture content, water activity, color difference, NaCl, fat, energy consumption and production cost were: 0.31%, 0.22, 6.63, 1.50%, 38.07%, 0.5293 kW and 72.11 $·Kg−1 respectively. The highest values for viability, protein content and production were: 6.66 log UFC·g−1 of lactobacillus, 39.45% and 0.0556 Kg·h−1 respectively.