Publication Details
Abstract
The current study focused on extending the storage life of pasteurized milk by taking advantage of nanoparticles of the biopolymer known as chitosan, where the nanoparticles were synthesized based on a green technology, meaning that it does not have any negative harm to the synthetic material. The laboratory-synthesized nanoparticles were characterized by a size ranging from 100 to 140 nanometers when examined immediately after the anthesis and the size when examined two weeks after the anesthesia, the size was 115-220 nm, using a transmission electron microscope (TEM) of the type Philips CM10. By studying the inhibitory action of the nanoparticles in the Muller-Hinton agar culture medium, it was found that the synthesized particles have the ability to combat the pathogenic Bacillus cereus bacteria that form blackboards when using different concentrations (0. 25 - 0. 5 - 1%), where it was found that the best diameter of the contrast corona was (14-15 mm at the two concentrations (0. 5) (1) sequentially When testing the biological validity of pasteurized milk at a temperature of 5 semen for a period of -1-15-30 days of storage and after adding nano-chitosan using the three aforementioned concentrations, it was found that the number of B. cereus It was varied as it reached on the first day when using the three concentrations 10 FU/ml 1 x, but on the fifteenth day the numbers were as follows 10 CFU/ml 2 x 10 -3 x 10 - 5 x and according to the concentrations (0. 25) - 0. 5 - 1% On the thirtieth day, the bacterial numbers decreased in pasteurized milk fortified with nanoparticles of chitosan, and the result was as follows (10 CFU/mL (10) - 10 - 2 x relative to the three concentrations, respectively). This result was an indication of the effectiveness of nanoparticles of chitosan in preventing cell growth. vegetation and the formation of new spores compared with the number of Bacillus cereus, which is approximately 107 CFU/ml x when pasteurized milk is stored for 15 days at a temperature of 5°C. It indicates contamination of milk and its products. It has been observed that increasing the concentration of added nano-chitosan increases the antimicrobial activity.