Qualidade físico-química e microbiológica de hortaliças desidratadas ao sol e em secador laboratorial

Abstract

In Minas Gerais, Brazil, cabbage and ora-pro-nóbis are common hardwoods and it is conserved by desiccation can increase the shelf life and value. This study aimed to dehydrate Brassica oleraceae and Pereskia aculeata by sunlight and in laboratory dryer and determine its physical chemical and microbiological quality. The leaves disinfected were cut to a thickness of 5 mm and portions of 300 g were placed on dryer at 60°C and under the sun. The loss of moisture has monitored until stabilization of the weight and graphics were designed with mass variation. After humidity stabilization for 8 h, the samples were vacuum packaging and stored at room temperature for five days to physical, microbiological and chemical tests. The mass loss was more accentuated in first hours and subsequently decreased. The mass loss equations were: y=5.649x2 – 77.63x+301.0 for cut cabbage under sun drying; y=2.800x2 – 53.35x+300.2 for cut Ora-pro-nóbis under sun drying in the first 10 h; y=0.098x2 –2,099x+40.30 for cut Ora-pro-nóbis under sun drying in following 4h; y=1.449x2 –39,50x+300 for cut cabbage into artificial drying; y=1.637x2 –42.93x+300 for cut Ora-pro-nóbis under artificial drying; y=0,377x2 – 20,02x+293,0 for uncut leaves of Ora-pro-nóbis under artificial drying. It was not physical contaminants and Salmonella spp., besides counts of Coagulase positive Staphylococcus. and coliforms at 35°C below the allowed, for the two methods of dehydration. The humidity mean in dehydrated vegetables were 8.32 to 8.37% and proteins, 18.72 to 24.74%. The physical-chemical and microbiological quality of dehydrated B. oleraceae and P. aculeata under sunlight and in artificial dryer were satisfactory.