5 Basic Methods or Ways of Preserving Food

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Meat, fish, fruits, and vegetables are highly perishable because they spoil easily. Once food is spoiled, it is no longer fit for consumption since it may cause loose bowel movement or LBM or may trigger other stomach reactions. Foods spoil because of molds and bacteria; they eat the food and they live in it.

To preserve food, molds and bacteria should be killed. Their growth should be stopped and there are 5 common ways to do that:

#1 By keeping food at low temperature.

Food placed in the refrigerator doesn't spoil for some time. That's why people who have refrigerators could buy a whole week supply of food. Meat, fish, vegetables, and fruits can be kept in the freezer for a long period of time without spoiling them. In the market you will notice some fish are stored inside the containers with ice in it to keep them fresh.

Refrigeration and freezing are probably the most popular forms of food preservation today. In refrigeration, the bacterial action on the food is slowed down; it takes a week or two to spoil. In freezing, bacterial action on the food is stopped. Bacteria are completely inactive if frozen.

Almost all foods - meat, vegetables, fruits beverages and other foods can be preserved in refrigerator and freezer. Taste and texture of foods has no effect in refrigeration while in freezing, it has minimal effects on vegetables and fuits, and no effect on the taste of meat. Due to the minimal effects of refrigeration in foods, it has been accounted as popular form of preservation.

#2 By drying

Drying preserves some foods. Dried fish and meat are preserved foods. Legumes are preserved by drying, too. Mongoes, garbanzos, beans, are examples of dried seeds. They can be kept for a long time. Raisins are dried grapes.

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Dehydration. To preserve some foods you have to dehydrate them. Dried fruits, potatoes in a box, dried vegetables, powdered milk, pasta, powdered soups, powdered sauces, and powdered meat you see in the grocery store are dehydrated products.

When foods are dried, bacteria will become inactive. So, foods in air-tight containers will last for a long time.

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Freeze-drying is a special form of drying. All moisture are removed and food taste won't be affected than normal dehydration.

In freeze-drying, food is frozen and placed in a strong vacuum. This is used when making instant coffee. This also works well on fruits like apples.

#3 By adding substances called preservatives.

Substances that are used for preserving food are called preservatives. Sugar, salt, spices, saltpeter, and vinegar are examples of preservatives. Smoke also preserves some foods. Ham and bacon are cured by smoking. Candied fruits are preserved by sugar.

Salting, especially of meat, is an ancient preservation technique. The meat covered by salt does not spoil because bacteria cannot thrive in salty environment. Moisture in food is also drawn out by salt. When meat is salted in cold weather, it will last for years.

Pickling. In the past, this was widely used to preserve meat, fruits and vegetables. Today, it is used to make pickles such as pickled cucumbers. Preservative qualities of vinegar and salt are combined to produce pickles. Salt and vinegar inhibits the growth of bacteria.

How to make pickled cucumbers? Soak cucumbers in 10% saltwater brine for several days. Then, rinsed and stored in vinegar to preserve them. It's that simple!

#4 By sterilization

Using heat to kill bacteria is a good way to preserve food. This is called sterilization. Canned foods and preserved foods in jars have been sterilized.

#5 By excluding air

Foods kept where air cannot reach them is preserving by excluding air. Canned foods kept air out of the food. Canning is one of the most common ways of preserving food. Many foods can be canned. Sometimes it’s cheaper to buy canned foods than to can them at home. Preserving food at home is expensive if you need to buy the food to be preserved. The materials and equipment for preserving, like wide-mouthed glass jars, rubber, and pressure cooker, are costly. However, when there is good harvest, canning should be done so the food would not be wasted. Canned products should be kept in a cool, dry place. The jars of fruits, vegetables, and other preserves should be labeled properly. Shelves should be kept clean and arranged well so cans and jars could be seen easily.

Canning. This has been around for many years since 1825. People can store foods in can for a very long time. The food in the can must be boiled to kill the bacteria and the can must be sealed - can be either before or while the food is boiling. The food in the can does not spoil because it is completely sterile. Once you open the can, you have to refrigerate its contents because bacteria will begin destroying the food.

Generally, cans are considered as being metal, but any sealable container - glass jar, plastic pouch or foil - can serve as a can. For example: milk in a box on the shelf is considered as "canned milk." Canned milk is made sterile by using ultra high temperature pasteurization, so even at room temperature it does not spoil.

Refrigeration and freezing are preferred to canning. Why? Because in canning you have to boil the food which can alter its taste and texture, and its nutritional content.

The various parts of a plant cell.

1. Cell Membrane:

The function of the cell membrane is to allow waste material to exit the cell. The cell membrane forms a barrier between the inside of the cell and the outside, so that the chemical environments on both sides can be different. It regulates the movement of materials into and out of the cell.

2. Cell Wall

The function of the cell wall is to provide structural support and to control the amount of water entering the cell. The cell wall is a wall that allows the circulation and distribution of water, minerals, and other small nutrient molecules into and out of the cell. It gives rigid support from which stable structures like leaves and stems can be produced. It can also sense the presence of pathogenic microbes and control the development of tissues within the cell because of its storage site of regulatory molecules

3. Golgi Body

The Golgi body stores, packages, and distributes the lipids and proteins made in the endoplasmic reticulum. It puts proteins into packages, called vesicles.

4. Rough Endoplasmic Reticulum

The function of the rough endoplasmic reticulum is to synthesize and exports proteins and glycoproteins.

5. Lysosomes

The purpose of lysosomes are to digest things. They could be used to digest food or break down the cell when it dies. Lysosomes are The cell’s garbage disposal system. They clean up while patrolling the cell. This organelle breaks down large molecules into many smaller molecules by using their special proteins. The smaller molecules can be used as building blocks for other large ones. Lysosomes also kill and digest invading organisms.

6. Cytoplasm

The function of the cytoplasm is to distribute oxygen and food (nutrients) to other parts of the cell and it supports all parts inside the cell. It has three main functions: storage, energy, and manufacturing. The cytoplasm containsnutrients that have been dissolved which help for the dissolving of waste products.

7. Nucleolus

The nucleolus is where ribosomes are made. The nucleolus disappears during cell reproduction. This is because ribosomes are not needed when cells reproduce.

8. Vacuole

The function of the vacuole is to store water, nutrients, and other substances that cannot be used right away. They tend to be larger in plant cells because plants are watered. When they are well watered, water collects in cell vacuoles producing

rigidity in plants. Each plant cell has a large, single vacuole that stores compounds, helps in plant growth, and plays a significant structural role for the plant.

9. Ribosomes

Ribosomes are the protein builders or protein synthesizers of the cell.

10.Chloroplast

Chloroplasts are the food producers of the cell. They contain chlorophyll, the green pigment that is needed for photosynthesis. Through the process of photosynthesis, green plants use the energy from the sun to convert it into sugar. The main purpose of this organelle is to produce sugars and starches.

11.Nucleus

The nucleus regulates all cell activity. It contains chromosomes, structures made up of genetic information, that direct a cell’s growth and reproduction.

12.Nuclear Envelope

The nuclear envelope surrounds the nucleus and all of its contents. It is similar to the cell membrane around the whole cell. There are pores and spaces for RNA andproteins to pass through while the nuclear envelope keeps all of the chromatin and the nucleolus inside.

13.Smooth Endoplasmic Reticulum

The function of the smooth endoplasmic reticulum is to package proteins for transport, synthesize membrane phosolipids, and releases calcium. Some other functions of the smooth endoplasmic reticulum include transformation of bile pigments, glycogenolysis (the breakdown of glycogen), and detoxification of many drugs and chemical agents.

14.Mitochondria

The function of the mitochondria is to provide the cell with energy. Through the process of respiration, the mitochondria uses oxygen to change sugar into energy. It gives out energy by combining sugar molecules with oxygen to make carbon dioxide and water.

15.Amylosplast

The amylosplast is an organelle in some plant cells that store starch.

16.Druse Crystal

The druse crystal, often found in plant vacuoles, is a granular type of crystal usually composed of calcium oxalate. The druse crystal is said to deter herbivory.

17.Centrosome:

The centrosome is an area in the cell where microtubules are produced. Microtubules carry out a variety of functions, ranging from transportation to structural support.

During cell division, the centrosome divides, and both parts move to opposite sides of the cell.

18.Raphide Crystal:

The raphide crystal, usually composed of calcium oxalate, is a needle kind of crystal often found in plant vacuoles. It is thought to slow down herbivory.

19. Golgi Vesicles:The Golgi vesicles carry the proteins and lipids to take them to other parts of the cell or to the outside of the cell.