The Effect of Seasonal Variation on the Chemical and Microbial Quality of Raw Milk Samples Used in Qazvin, Iran (original) (raw)
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TURKISH JOURNAL OF VETERINARY AND ANIMAL SCIENCES, 2019
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Asian Food Science Journal
Aims: To isolate, identify and characterize thermoduric psychrotrophic bacteria from locally available market samples of pasteurized milk. Study Design: Market samples of pasteurized milk were collected, subjected to laboratory pasteurization and thermoduric psychrotrophic bacteria were enumerated after 10 days of storage at 7ºC.The isolates obtained were identified by 16S rRNA sequencing and subsequent blasting. The isolates were characterized in terms of haemolytic, lipolytic and proteolytic activities. Selected isolates were also assessed for their decimal reduction time at 63ºC. Place and Duration of Study: Verghese Kurien Institute of Dairy and Food Technology, (Formerly College of Dairy Science and Technology), Mannuthy, Thrissur, Kerala between September, 2019 to March, 2021. Methodology: A total of 42 market samples of pasteurized milk belonging to seven different brands were assessed for their thermoduric psychrotrophic bacterial population. The thermoduric psych...
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Irish Journal of Agricultural and Food Research, 2018
In this study, the effect of storage temperature (2 or 4°C) on the composition of milk and microbiological load was investigated over 96 h. Milk samples were collected from farm bulk milk tanks after one complete milking and stored at 2 or 4°C over 96 h. Total bacterial count (TBC), psychrotrophic bacterial count (PBC) and proteolytic bacterial count (PROT) were affected by storage time and temperature and varied significantly between farms (P < 0.05). The levels of TBC, PBC and PROT bacterial count increased from 4.37 to 6.15 log cfu/mL, 4.34 to 6.44 log cfu/mL and 3.72 to 4.81 log cfu/mL, respectively, when the milk was stored for 96 h at 2°C. The milk samples stored at 4°C had higher increases in these bacterial counts after 72 h in comparison to milk samples stored at 2°C. The casein fraction content was lower in milk samples stored at 4°C, which could be due to high levels of PROT bacteria or enzyme activity in these samples. Milk stored for 96 h at 2°C has less impact on co...