Bacteriological studies on Iraqi milk products.

Samples from different types of domestic milk products including cheese, kishfa and gaymer were assessed for bacteriological quality over a 4-month period. A total of 400 samples were randomly selected across Mosul city and tested for faecal coliform counts, enteropathogenic Escherichia coli (EPEC) and enterotoxigenic E. coli (ETEC). Faecal coliforms were present at levels greater than 10(2) cfu/g in 72.5% and less than 10(2) cfu/g in 27.5% of samples. Of the 430 E. coli strains isolated from the 400 samples of milk products, 138 were serotypes of EPEC. These were found in 81 (40.5%) samples of cheese, 35 (23.8%) of kishfa and 22 (29.7%) of gaymer. During this period, 26 strains of ETEC were also isolated, all of which demonstrated heat-labile or heat-stable toxins. The high proportion of strains of three groups of E. coli showing resistance to antibiotics is discussed in relation to widespread use of antibiotics and the possible public health implication.     

Studies on the Bacillus flora of milk and milk products

Bacillus licheniformis and B. cereus were the most commonly isolated species of Bacillus found in milk at all stages of processing. Bacillus licheniformis was ubiquitous in the farm environment and counts in raw milks heat-treated in the laboratory were higher during the winter months, whilst B. cereus was associated with cattle feed throughout the year, and tended to be more common in raw milks during the summer months. Although B. licheniformis was usually isolated in larger numbers than B. cereus, this pattern changed after raw and pasteurized milks and reconstituted milk powders were pre-incubated at ambient temperatures, and B. cereus came to dominate the Bacillus population, reaching levels associated with enterotoxin production. Investigation of the growth kinetics of strains of both species showed that B. cereus grew faster than B. licheniformis at ambient temperatures. It is suggested that post-pasteurization contamination, which is commonly blamed for spoilage of milk and milk products by B. cereus, is not necessarily the most important source of this organism.     

Bacteriological and serological studies on Pasteurella multocida infection in rabbits

Bacteriological and serological examinations were made on Pasteurella multocida infection in two rabbit-breeding colonies. The organism was localized in the paranasal sinuses of 53 of 54 infected rabbits, excreting to the external nares of 49 rabbits. It was also isolated from the trachea and middle and inner ear of half of the infected animals and occasionally from the conjunctiva, lung and heart. The infection rate of the organism was very low (4.3%) in sucklings younger than a month old, but increased with advancing age, reaching nearly 100% in adults more than five months of age. A rapid increase of the infection rate was observed at two to three months of age. Serum antibody against somatic antigen of P. multocida was demonstrated in infected rabbits by use of the tube agglutination test, showing a close correlation with isolation of the organism in adults. Sucklings younger than one month of age from infected dams were significantly resistant to experimental nasal infection of P. multocida.     

A pooled analysis of the Iraqi and Seychelles methylmercury studies

Several epidemiology studies have investigated the impact of maternal exposure to methylmercury (MeHg) on childhood development of the central nervous system (CNS). In the present report, data from the Iraqi episode that occurred in 1970 from contaminated grain are integrated with those from a more recent study of a population with a high fish intake in the Seychelles Islands. The latter study had many more subjects whose mercury hair levels that were much lower and more representative of levels typically found in consumers whose MeHg exposure is from fish. The age of onset of talking (AOT), the age of onset of walking (AOW) and a combined measure (CM) that integrated the two were used as common scales of MeHg effect for the two studies. The first step of the analyses involved the construction of separate two‐dimensional cumulative frequency tables for each study for different groups spanning the range of hair levels and observed effect for each measure. Models were then fit to the values in the tables that were constructed from four components: (1) A dose‐effect function that related hair MeHg to the effect measure; (2) a frequency distribution describing population variability; (3) parameters to represent dose‐independent influences on effect; and (4) parameters to represent study dependent influences on effect. When the four submodels were assembled, a series of 1092 candidate models resulted which contained 3 to 7 parameters (e.g., slope, standard‐deviation, dose‐independent age of talking) whose value could be adjusted to improve the fit. After optimizing the fit of each model, a weighting algorithm that rewards for fit and penalizes for the number of parameters in the model was used to identify the best 200 models. The same algorithm was then used to assign a probability to each model in a probability tree. A two‐dimensional Monte‐Carlo simulation using the resulting function in combination with exposure values typical of U.S. consumers yielded predicted delays in AOT, AOW, and CM attributable to fish consumption in a variable and uncertain range of 0.000 to 1 day.     

Specialty products made from goat milk

Although it may not be important in certain parts of the world, the contribution of goat milk to the economic and nutritional wellbeing of humanity is undeniable in many developing countries, especially in the Mediterranean, Middle East, Eastern Europe and South American countries. Goat milk has played a very important role in health and nutrition of young and elderly. Goat milk has also been known for its beneficial and therapeutic effects on the people who have cow milk allergy. These nutritional, health and therapeutic benefits enlighten the potentials and values of goat milk and its specialty products. The chemical characteristics of goat milk can be used to manufacture a wide variety of products, including fluid beverage products (low fat, fortified, or flavored) and UHT (ultra high temperature) milk, fermented products such as cheese, buttermilk or yogurt, frozen products such as ice cream or frozen yogurt, butter, condensed/dried products, sweets and candies. In addition, other specialty products such as hair, skin care and cosmetic products made from goat milk recently have gained a further attention. Nevertheless, high quality products can only be produced from good quality goat milk. The quality milk should have the potential to tolerate technological treatment and be transformed into a product that satisfies the expectations of consumers, in terms of nutritional, hygienic and sensory attributes. Taste is the main criteria used by consumers to make decisions to purchase and consume goat milk and its products. Typical goat taste is considered as a quality component in certain goat cheese products. Farmers can produce more value-added products for the economic sustainability of their business and the dairy goat industry in general.     

Nutritional aspects of fermented milk products

Abstract Fermented milk products are a palatable and economical source of a wide range of nutrients. The nutrient composition is similar to that in milk, but concentrations of vitamins are in general a little lower, with the possible exception of folic acid. Concentrations of lactic acid, galactose, free amino acids and fatty acids are increased as a result of the fermentation. Lactose-intolerant individuals tolerate lactose when it is consumed in yoghurt better than when it is taken in the equivalent quantity of milk. The mechanism of this effect has not been clearly established. By far the greatest proportion of published material freely available in the West concerns yoghurt; reference is made to other cultured products where results are available to indicate interesting differences.     

Multiplication of Listeria in milk products

The results of the evaluation of the multiplication dynamics of Listeria cells in milk and Bifidok, a lactic acid product, are presented. The samples were inoculated on thioglycol agar and studied at different exposure time after incubation at 37 degrees C, 20 degrees C and 4 degrees C. The study revealed the intensive multiplication of Listeria cells in milk, also during storage in a household refrigerator. The presence of bifidobacteria mixed with kefir-producing culture in dairy products was shown to essentially inhibit the growth of Listeria cells which were not detected by bacteriological techniques on day 7.     

Selenium content of milk and milk products of Turkey. II

Selenium content of 1028 milk and milk products of Turkey are presented in this study. The selenium content of human milk (colostrum, transitional, and mature milk), various kinds of milk [cow, sheep, goat, buffalo, paper boxes (3%, 1.5%, 0.012% fat), bottled milk, condensed milk (10% fat), mineral added milk (1.6%), and banana, strawberry, and chocolate milk] and milk products (kefir, yogurt, Ayran, various cheese, coffee cream, ice cream, butter, margarine, milk powder, and fruit yogurt) in Turkey were determined by a spectrofluorometric method. The selenium levels of cow milks collected from 57 cities in Turkey were also determined. Selenium levels in cow milk varied with geographical location in Turkey and were found to be lowest for Van and highest for Aksaray. The results [milk (cow, sheep, goat, buffalo and human) and milks products] were compared with literature data from different countries.