Sateh Mahomod Al-saeed
General Commission for Scientific Agricultural Research- Department of Food Technology,
Faculty of Agriculture,Damascus University,
This study aims to know the fact of the sterilized milk in Syria through the following:
Studying the physical, chemical and sensual characterization of the fresh sterilized milk which is sterilized by several methods, and bottled in various cans (UHT method is filled in carton packets, UHT method is filled in polyethylene sacks, continuous sterilization method filled in bottles, Basin sterilization method is filled in plastic cans); also the study of changes took place on the said sterilized milk types, and Which stored at 30 °C for a period of six months.
Upon receiving the samples of sterilized milk they were subjected to comprehensive evaluation (chemical, microbial, and sensual) in order to find out the quality of the fresh sterilized milk; it was found that the milk sterilized traditionally and filled in plastic cans was not compatible to requirements of Syrian standards as regards the percentage of the non-fatty dry material, while (UHT/sacks) was not compatible to requirements of Syrian standards as regards the both percentage of the non-fatty dry material and fat . The results indicated that sterilized milk samples were free of the known preservatives and known adjusting acidity materials. The test of incubating samples indicated that there is a high percentage of cans of both types (continuous/bottles) and (UHT/sacks) are incompatible with health provisions of Syrian standards.
The results of storing the milk samples at 30 °C for the period of six months, indicated the increase of the values of proteolyses signs in the four types of sterilized milk and in specifically (UHT/sacks) milk during storage. Results referred to the increase of HMF value in sterilized milk by the old traditional methods in comparing to the milk sterilized by the (UHT) modern method; which indicates to the extremity of the thermal treatment and its influence in the milk components in the old methods of sterilization ; results also indicated that studied characteristics changed slightly in (UHT milk/ packets), while the changes in the studied characteristics were the most in the type (UHT/sacks).
Results showed the efficacy of sterilizing and filling of (UHT/packets) and (traditional/plastic cans) since none of them was microbial decayed during storage period , while 2.56% of the (continuous/ bottles) was decayed after 14 days of storing, and (12.82%) of (UHT/sacks) were decayed after 21 days .
Results referred to the initial physical and sensual changes started in (UHT/sacks), (continuous/bottles), (traditional/plastic cans) and (UHT/packets) after 75 – 105 – 120 and 135 days of storage respectively .