COMPOSITIONAL AND BACTERIOLOGICAL QUALITY OF HEAT TREARTED MILK MARKETED IN NAMIBIA

Production of fresh farm milk in Namibia is low due to the arid climate that prevails in the country, low pasture availability and a high milk demand. This scenario has forced Namibia to import dairy products to meet its needs from neighbouring South Africa, South America and Europe. Namibia imports different brands of fresh full cream milk including Parmalat, Clover, Super milk to add on to its own brands such as Namdairies, UNAM milk and others from private and commercial farms in bulk or in plastic sachets and bottles. Generally, milk quality is determined by its safety, shelf life and nutrition. The presence of different brands of milk makes it difficult for milk consumers in Namibia to choose the brand they would prefer including assessing their value for money. The aim of the project was to determine the quality of full cream milk brands marketed in Namibia by assessing their proximate composition, titratable acidity, pH, protein stability, total plate count and Coliform bacteria as indicator bacteria for the presence of pathogens, using standard dairy procedures and AOAC methods. The results of the study indicated that all imported brands of pasteurised full cream milk in Namibia were not significantly different from each other and were safe and stable, and nutritionally of good quality. They were practically the same in composition and bacteriological quality. Butterfat ranged from 3.4 to 3.7%, density from 1.029 to 1.032g/cm³, total solids from 12.3 to 13.0%, solids-not-fat from 8.6 to 9.7%, moisture content from 87.10 to 87.70%, acidity as lactic acid from 0.15 to 0.17% and pH from 6.4 to 6.7. The total plate count (TPC) ranged from 0 to 40 cfu/cm³ and there were no Coliform bacteria found in all the brands. The local products were not statistically different in composition from imported brands, with fat ranging from 3.3 to 3.7%, density from 1.029-1.032g/cm³, TS from 12.3-12.9% and SNF from 8.6-9.4% though they were not standardized but heat treated. The total aerobic counts and Coliforms were the same as those of imported milk brands. The statistical analysis showed that there were no significant differences at p<0.05 among the brands and between the brands of the imported and local milk in Namibia as they were all within the South African Standard Specifications. All the brands were, however, regarded as good, stable and safe for consumption.