Effect of Microwave Treatment on Chemical Composition and Microbiological Quality of Milk | ||
| Journal of Food and Dairy Sciences | ||
| Article 1, Volume 8, Issue 2, February 2017, Pages 65-72 PDF (245.97 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jfds.2017.37118 | ||
| Authors | ||
| Shaymaa S. Bakry1; M. A. Mohran2; Nanis H. Gomah2; E. A. Y. Essawy1 | ||
| 1Food Technology Res. Institute, Agricultural Research Center, Giza, Egypt | ||
| 2Dairy Science Department, Assiut University, Egypt | ||
| Abstract | ||
| Nine samples of raw milk; 3 buffalo, 3 cow and 3 mixed (1 buffalo: 1 cow) were exposed to different periods of microwave treatment (0second, 30 seconds, 60 seconds, 90 seconds, 120 seconds, 150 seconds and 180 seconds) to evaluate changes in chemical composition and microbial load in milk samples during microwave treatments. Also, these samples were stored for 7 days at refrigeration temperature to follow up changes in chemical composition and microbiological status during storage. In addition, a comparison between pasteurized and microwaved milk was carried out. Results showed that moisture content was decreased with prolonging microwave periods while fat, protein, ash, specific gravity and acidity were increased. Total bacterial count, lactic acid bacteria, lipolytic bacteria, proteolytic bacteria, Psychrotrophic bacteria, yeasts and molds count were decreased or disappeared with prolonged time of microwave treatment and no coliform bacteria were detected after treatment. At the same time, pasteurized milk was higher in moisture content than in microwaved milk but lower in acidity, protein, ash and fat contents. Total bacterial count, lipolytic, proteolytic and psychrotrophic bacterial counts were higher in pasteurized than microwaved milk samples. No coliform bacteria, yeasts, molds and L.A.B. were detected neither in microwaved milk nor in pasteurized milk. | ||
| Keywords | ||
| microwave; Milk; pasteurization; microbiological evaluation; Coliform bacteria; Chemical composition | ||
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