Food spoilage can be seen through a number of changes in smell, colour, taste and touch. Food spoilage is a disagreeable change in the food’s normal state. Food can spoil due to various reasons.
Oxygen:
Air is made up of 78% nitrogen, 21% oxygen and a 1% mixture of other gases. It is essential for life but because it is colourless, odorless and tasteless it is often forgotten that it can cause food to spoil and have a deteriorative effect on fats, food colours, vitamins, flavours and other food components
Microorganisms:
There are different types of microorganisms. Aerobes (bacteria that require oxygen to grow), anaerobes (bacteria that grow in the absence of oxygen) and facultative anaerobes (bacteria that can grow under either condition).
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This leads to food spoilage. There are many oxidizing enzymes. Catalase and peroxidase are two kinds of enzymes that cause darkening in sliced and diced vegetables. The browning of vegetables caused by these enzymes comes with off-flavours and odors.
Oxygen:
Oxygen provides conditions that will enhance the growth of microorganisms ans cause damage to food with the help of enzymes. It can also cause food to spoil by itself. It can cause oxidation. Short chain carbon compounds are formed when lipids oxidize and theses compounds have strong and undesirable odors and flavours. The off-odors and sharp and acrid and can smell a bit fishy or perfume-like.
Moisture:
Water is present in all foods as percent water and influences the appearance, texture and flavour of the food. Water is essential in all food. 70% of the weight of unprocessed foods is water and even dry foods such as green beans contain some water. Fresh fruits and vegetables contain the most water- between 90% and 95% water. The amount of water in different fruits and vegetables is shown below:
Apples
There are numerous types of bacteria that can be found in every environment. Each bacterium has different morphology which includes shape, texture and pigment production. These bacteria also have different food requirements which are important in being able to identify a microorganism. Microorganisms are a diverse group containing all bacteria a single cell prokaryotic organism that is found in every type of environment, archea single cell microorganism that lacks nuclei and almost all microorganisms are protozoa a unicellular eukaryotic organism. By identifying the causative agent of a bacterium within an individual, an antibiotic can be developed to prevent health issues. Microorganisms are also used to make certain food products for human consumption. An example of this would be the production of yogurt. It has probiotics that help with digestive abnormalities amongst other things. Probiotics are microorganisms that are consumed to provide health benefits in the body. Probiotics work by replacing the disturbed microbe with ones that are useful to digest. With the methods that wer...
When the aerobic organisms in the body consume all the oxygen present, anaerobic organisms from the digestive system begin to multiply. They consume macromolecules (proteins, carbohydrates, lipids) and form acids and gases in the p...
What are microorganisms? They are organisms that you have to view with a microscope. The three that I will be discussing are bacteria, viruses, and prions. Of the three, a bacterium is the only one that can be helpful to us in many situations, and they are also the most diverse organism on the earth. The structure, reproduction, and the diseases bacteria, viruses, and prion cause are all different. Let’s begin to compare these microorganisms.
Microorganism is a living thing that cannot be seen by naked eye and is so small in size. Microorganism usually can be seen through microscope because microscope have the ability to see small thing using various magnification. The examples of microorganism are bacteria, fungi, protozoa, algae and virus. Among all of the microorganisms, bacteria have the greatest advantages in preserving food and beverages. Bacteria are generally harmless but can produce enzymes that can alter the structure the food. In extreme cases, bacteria can secrete toxic substances that can cause the food to spoil.
Williams (2006) define water as a clear, tasteless, odourless fluid. Water is a vital nutrient for good health posner (1998). Most of our body weight (60-70%) is made up of water. Wretlid (1999) explain that water is important in human body because, it help to control our body temperature, carries nutrients and water product from our cell, and it needed for our cells to function help us to lose weight, for the heath skin, fight infections, get rid of toxins, health heart, prevent join pains and arthritis, boost energy, prevent constipation and reduce chances of cancer. World Health Organisation recommended that, adults drink 8 glasses of fluid daily or more in hot weather or during physical activity. This fluid doesn’t have to be water alone.it can also obtain from juice, milk, soap as fruit and vegetables Garrow
In this experiment, we will explore the properties of fresh potato extract in Phosphate buffer pH6 containing the enzyme polyphenol-oxidase and measure the different concentration of this enzyme activity by observing the production of pink/gold melanin, when 0.1% catechol and phosphate buffer pH6 is mixed into the solution. At this stage of the experiment, we are assuming that all other variables that can act as inhibitors of the enzymatic activity such as temperature or pH levels are under control. Fruits and vegetables are known to have small amounts of catechol and polyphenol-oxidase (enzyme), which are the cause of the production of browning effect in the out-layer skin or liquid of the fruit or vegetable when it is damaged. Polyphenol-oxidase
Bacterial cells, like plant cells, are surrounded by a cell wall. However, bacterial cell walls are made up of polysaccharide chains linked to amino acids, while plant cell walls are made up of cellulose, which contains no amino acids. Many bacteria secrete a slimy capsule around the outside of the cell wall. The capsule provides additional protection for the cell. Many of the bacteria that cause diseases in animals are surrounded by a capsule. The capsule prevents the white blood cells and antibodies from destroying the invading bacterium. Inside the capsule and the cell wall is the cell membrane. In aerobic bacteria, the reactions of cellular respiration take place on fingerlike infoldings of the cell membrane. Ribosomes are scattered throughout the cytoplasm, and the DNA is generally found in the center of the cell. Many bacilli and spirilla have flagella, which are used for locomotion in water. A few types of bacteria that lack flagella move by gliding on a surface. However, the mechanism of this gliding motion is unknown. Most bacteria are aerobic, they require free oxygen to carry on cellular respiration. Some bacteria, called facultatibe anaerobes can live in either the presence or absence of free oxygen. They obtain energy either by aerobic respiration when oxygen is present or by fermentation when oxygen is absent. Still other bacteria cannot live in the presence of oxygen. These are called obligate anaerobes. Such bacteria obtain energy only fermentation. Through fermentation, different groups of bacteria produce a wide variety of organic compounds. Besides ethyl alcohol and lactic acid, bacterial fermentation can produce acetic acid, acetone, butyl alcohol, glycol, butyric acid, propionic acid, and methane, the main component of natural gas. Most bacteria are heterotrophic bacteria are either saprophytes or parasites. Saprophytes feed on the remains of dead plants and animals, and ordinarily do not cause disease. They release digestive enzymes onto the organic matter. The enzymes breakdown the large food molecules into smaller molecules, which are absorbed by the bacterial cells. Parasites live on or in living organisms, and may cause disease. A few types of bacteria are Autotrophic, they can synthesize the organic nutrients they require from inorganic substances. Autotrophic bacteria are either photosynthetic or Chemosynthetic. The photosynthetic bacteria contain chlorophyll that are different from the plant chlorophyll. In bacterial photosynthesis, hydrogen is obtained by the splitting of compounds other than water.
There are many kinds of air pollution. The ones I want to talk about are the ozone, acid rain, carbon monoxide and toxic air contaminants. Ozone is formed when hydrocarbons and nitrogen oxide react in sunlight. Therefore, ozone is at its peak during hot summer days. Exposure to high levels of ozone can have serious consequences on your health. It can cause respiratory disease, loss of pulmonary elasticity, and premature aging of our lungs. Next, is acid rain, which occurs in the atmosphere in the form of sulfur and nitrogen oxide. These pollutants can have serious damaging affects on aquatic, forest and wildlife ecosystems, as well as deterioration of buildings. Carbon monoxide is another form of pollution. It reduces the blood?s ability to carry oxygen. If a human is exposed to higher levels, it can cause chest pains, angina attacks or even death.
They also describe microbes as organisms that are often too small to be seen without the aid of a microscope. Microbes, also known as microorganisms, can be broken down into four classifications that are bacteria, viruses, fungi, and protozoa.
Microbes are everywhere in the biosphere, and their presence invariably affects the environment in which they grow. The effects
Food borne illnesses are caused by consuming contaminated foods or beverages. There are many different disease-causing microbes, or pathogens. In addition, poisonous chemicals, or other harmful substances can cause food borne illnesses if they are present in food. More than two hundred and fifty different food borne illnesses have been described; almost all of these illnesses are infections. They are caused by a variety of bacteria, viruses, and parasites that can be food borne. (Center 1)
Excess temperature completely destroys and denatures vitamin C by increasing the oxidation rate. Extreme temperatures kill the enzyme ascorbic acid oxidase which is found mainly in fruit and vegetables.
Every organism requires a specific environment in order to survive. Bacteria alike, different types of bacteria are able to survive and reproduce in different types of environment. Some factors that affect the growth of bacteria include temperature, presence of certain gases and pH of the medium it is in.
Water comes from a variety of sources. All beverages, juices and fluids we consume are sources of water for our body. Even solid food contains water. Vegetables such as cucumber, lettuce and celery may have up to 90% water. Protein rich food such as meat and fish could contain two-thirds to one half of their weight of water. Even carbohydrates like grains, although do not appear to be watery could contain water as much as one third of their weight. Fats such as butter or margarine contain very little water. Some water may come from within our body because of energy metabolism but the amount is insignificant.
Food Preservation is the ways to retain the food quality in a longer times. It is to prevent the food decomposition and fermentation. Besides that, food preservation not only to prevent the food getting spoilt in a long period of time but also preserved the colour, taste and the food nutritive value. Nowadays, food preservation has become more and more important component in the food industry as the consumers expect that able to purchase those foods that are out of season or imported from other countries. Furthermore, there are few reason why food preservation is important in our daily life such as preservation foods when they are in season it may added variety choices in our meals for example smoke meats and