Bacterial contamination of food

Most of the bacteria are transmitted via food and water as a result of contamination with feces.

The main bacteria that cause food infections via colonization in the intestinal via colonization in the intestinal tract are Salmonella, Listeria monocytogenes, Yersinia enterocolitica and Shigella.

None of the bacteria can multiply in food or water or indeed outside the body of the host in which they developed. If they occur in food or water, one hopes that they will be inactivated or killed before they can infect a consumer or the vehicle.

There are a number of reasons and sources which result in the prevalence of bacterial contamination in food products, such as:
*Premises which are difficult to clean
*Lack of staff discipline
*Incorrect staff and product flow
*Poor air quality
*Incorrect direction of air movement

Food that is cooked and then not contaminated before being served is unlikely to serve as a vehicle for most of the bacteria.

Salmonella is the second most common cause of illness traced to contaminated foods and water. Foods most susceptible to Salmonella contamination are meat, fish, poultry, eggs and dairy products.

Much of the bacterial contamination of foods in restaurants, commissary kitchens and commercial processors are due to the poor personal hygiene of workers. Failure to wash hands after using the bathroom, sneezing and coughing into food, and picking noses and skin blemishes can all transmit pathogenic bacteria to food.
Bacterial contamination of food

Food sources of protein and amino acids

Proteins are made up of long chains of building blocks called amino acids. Human obtain protein from both animal and plant foods.

Foods in meat, poultry, dry peas and beans, eggs, and nuts group and in the milk, yoghurt and cheese group contribute an abundance of high quality protein. The protein of these foods contain ample amounts of all the essential amino acids relative to human bodies’ need for them, and the rest of the diet provides protein-sparing energy and needed vitamins and minerals.

Eggs provide the optimal mixture of essential amino acids among food sources; hence, eggs receive the highest quality rating compared with other foods.

Two others, the vegetable group and the grains group, contribute smaller amounts of protein, but they can add up to significant quantities. These foods tend to lack one or more of the essential amino acids. However, there is an exception – soya beans contain all of them.

Mixtures of plant proteins can serve as a complete and well balanced source of amino acids for meeting human physiological requirements.

However, the combination of right foods is necessary to obtain the necessary levels of both the essential or indispensible amino acids.

Protein content of wheat and flour is considered one of the best single indices of bread making quality.

Protein often occurs in foods in physical or chemical combinations with carbohydrates and lipids.
Food sources of protein and amino acids

Best food sources of calcium

Calcium is the most profuse mineral in the human body. One to two percent of an adult’s body weight is comprised of calcium.

Calcium is a major mineral essential for healthy bones and teeth. There are several minerals known to be essential to the human body and which must be obtained from food.

The remaining calcium can be found in blood, extracellular fluid, muscle and other tissues.

Good plant sources of calcium include calcium set-tofu, green leafy vegetables, calcium-fortified plant based beverages, broccoli, legumes, Chinese cabbage, nuts, whole grains, seeds and nuts.

In the United States, an estimated 72 percent of calcium comes from milk, cheese and yoghurt and from foods to which dairy products have been added such as pizza, lasagna, dairy desserts. Of all the dairy products nonfat milk is the most nutrient dense because of its high calcium content and low fat and calorie content.

Calcium requirement can be achieved by including foods in the diet that naturally contain calcium, through calcium-fortified foods, the use of supplements or by a combination of these.

Drinking hard water can provide 200 mg of calcium daily but soft water contains almost none. Other calcium rich foods include black molasses, edible seaweeds, watercress, parsley and dried figs. Non yoghurt is another excellent source of calcium.

Although grains are not particularly rich in calcium, the use of calcium containing additives in these foods accounts for a substantial proportion of the calcium ingested by people who consume a large amount of grain.

Fortification with calcium for a number of foods that do not naturally contribute calcium – such as orange juice, other beverages and ready to eat cereals is becoming commonplace in the United States.

The body absorbs 25 to 75 percent of dietary calcium, depending on a variety of factors including age, presence of adequate vitamin D, the body’s need for calcium and calcium intake. Dairy products are a good source of calcium in a form that is easy for the body to absorb.

Calcium absorption is particularly high during pregnancy and infancy, and is at its lowest in old age.

Without sufficient vitamin D, calcium bone mineralization can be disrupted and this disruption will affect the structural integrity of the skeleton.

Deficiency of calcium may lead to poor bone and teeth formation. Severe deficiency may cause rickets in children and osteomalacia on adults.
Best food sources of calcium