Effect Of Microwave Heat Treatment On The Quality Of Milk

Research Article
Roy J., Latif UI., Mujnibeen MSA., Kabir MS., Islam MI and Alam KS
Milk, Microwave heat treatment, Physical parameters and Chemical parameters.

Preservation is the prime concern for milk, which can be preserved for long time without any changes of nutritional values by applying new techniques rather than conventional methods. The objective of this study was to investigate the changes occur in physical and chemical qualities of milk after microwave heat treatment. Raw milk was collected from the local dairy farm and being kept in ice boxes directly taken to the laboratory. Six samples were prepared and among them five samples were tested at different temperatures and times in a microwave oven and one sample was used as raw milk sample. The physical parameters and chemical parameters were considered to evaluate the quality of milk samples. The colour, flavour, texture and specific gravity of raw and microwave heated milk samples were similar. But the acidity of raw milk (0.141 %) and microwave heated (S2, S3, S4, S5 and S6 were 0.128, 0.129, 0.130, 0.130 and 0.131 % respectively) milk differed to a great extent. Significant differences in the tested milk samples were also observed. The overall mean for carbohydrate, fat, protein, ash, solid-not-fat, total solid and water contents of milk samples were 5.09 %, 4.08%, 3.49%, 0.93%, 9.52%, 13.60%, and 86.39% respectively and excluding protein and ash content all microwave heated milk were significantly (P˂0.05) higher than those of unheated milk. It was found that despite of the same temperature, the mean values except ash and water content differed in case of time variation such as S2 (70°C for 2 min) gave the higher values than S4 (700C for 1 min). Analysis of the tested samples showed that milk could be heated in a microwave not more than 90°C temperature and the milk does not get spoiled before one week.