Occupation of Selling Preserved Food
In Thailand there are various types of food produced from agricultural products depending on the specific region. Processing such agricultural products into cooked food is another career option for those who are interested.
Preserving food today utilizes processing technology to simultaneously process a great number of raw materials into cooked food or convenience food. Today’s food preservation techniques are considerably better than those used in the past in terms of hygiene, smell, appearance, taste, texture, and quality. Agricultural food preservation requires a basic knowledge of science, business, and management as well as knowledge of processing agricultural products. The purpose for such an activity is to completely change the product or to improve the product in terms of color, smell, and texture as well as to improve nutrition.
Cooked food refers to food that has been cooked or processed for preservation. Cooked food can be eaten immediately when needed; either heated up or not. Examples of this include canned food and dairy products such as milk.
Convenience food means food that is cooked and processed for preservation. Like cooked food, it can be kept for a long period as well. Convenience food needs to be prepared before consuming; for example, concentrated juice should be mixed with water before drinking, and so should curry paste.
Processing and preserving food: the primary purpose for such processes is to eliminate microorganisms which cause decomposition. Due to the fact that there are a wide variety of agricultural products, there is a need to study and experiment with preservation technologies in order to learn how to best prolong the product’s quality. For example, using steam to eradicate microorganisms in canned food, utilizing gamma rays to suppress or stop enzyme reactions resulting in a slower chemical transformation as well as to limit the growth of microorganisms. Food preservation methods widely used nowadays are as follows:
- Food preservation using high temperatures such as canned food.
- Food preservation using refrigeration such as frozen food products.
- Food preservation by drying such as Pla-haeng (dried fish) and ground coffee.
- Food preservation by pickling such as soy sauce and vinegar.
- Food preservation by irradiation such as irradiated onions.
1. FOOD PRESERVATION USING HIGH TEMPERATURE METHODS
Food containers have improved considerably. At first, cans made from tin were widely used; however, due to the fact that tin has become more difficult to find and is now more expensive, a tin coated steel can is used instead which greatly reduces the amount of tin used. A can made from aluminum, which is lightweight but can be easily distorted, is most often used to contain juice, milk, or other beverages. The use of aluminum cans is not as common as that of tin coated steel cans. Apart from the container, the type of food is also an important factor that should be considered, in the sense that what level of temperature is needed to eliminate microorganisms in the preserved food. Heat will basically change the food condition from fresh food to cooked food that is ready to eat, so one might add certain ingredients in the process and doing so is called “Food processing”.
Ingredients put in meat dishes may include meat, vegetables, and spices while those that are added to desserts include syrup for fruits. Canned or bottled food processing requires a certain amount of heat both to cook the food and to kill the microorganisms. The level of heat used depends on the type of food. If the temperature is too high, it will overcook the food making it unsavory. However, if the temperature used is too low, there might be some microorganisms remaining leading to the container swelling and exploding. Therefore, food preservation using a high temperature method is a process to eliminate microorganisms in the sealed container in order to prevent any decomposition from both microorganisms and enzyme reactions in the food itself. There are 3 levels of food sanitization which include sterilization, commercial sterilization, and pasteurization.
Sterilization refers to a food preservation process which uses high temperature and pressure in order to completely eliminate existing microorganisms.
Commercial sterilization is a food preservation method using high temperature to eliminate most of the microorganisms in food so that it may be consumed without harm and kept for a longer period of time at normal temperatures.
Pasteurization refers to a food preservation process utilizing a lower than boiling point temperature (below 100 degrees Celsius) to partly eliminate the microorganisms. However, the process should be used together with other methods such as refrigeration, or maintaining pH, sugar, or salt levels.
Food and technology scientists classify canned food into 2 categorizes which are:
1. Acid foods refers to the food that has a pH lower than 4.5. Most of these are fruits such as pineapples and oranges, or sour vegetables such as tomatoes and roselles.
2. Low acid foods have a 4.5 pH or higher. Most of these are meat and vegetables such as beef, pork, fish, baby corn, and asparagus.
Process of Food Canning
1. Buying ingredients
2. Washing and trimming ingredients
3. Picking out and categorizing ingredients
4. Boiling them for a short time
5. Canning, bottling
6. Adding water into the can / bottle <----- preparing spices or water
7. Emptying the can/ bottle
8. Sealing the container
9. Sanitizing with heat
10. Chilling the can
11. Applying a label on the can/ bottle
12. Packing in a box
13. Storing in a room
14. Distributing the product
1.1 Tools used in producing the canned food
In general, tools and machines used in producing canned food must not be harmful towards one’s health and must be well-cleaned. A reusable container must not be made from toxic substances. It must be designed so that it is easy to clean in order to prevent left over food material. Preferably it should not be made from an absorptive material except for certain purposes such as a wine cask. Tools and machines used in the factory vary depending on the types and categories of the products, but they can generally be classified into 3 categories which are:
- Tools and instruments necessary to the production processes.
- Machines used according to the production processes.
- Machines used according to the types of product.
1.1.1 TOOLS AND INSTRUMENTS NECESSARY TO THE PRODUCTION PROCESS
This section includes tools and instruments that are necessary for food processing entrepreneurs particularly for manufacturing canned food, regardless of the business size.
1) Weighing instruments which are generally used to weigh or measure the volume of things such as ingredients and spices. It is necessary to have various sizes of these instruments.
2) Temperature measuring instruments are one of the most essential instruments in the food production process maintain the correct temperature for proper cooking and sterilization
3) Salt measuring instruments
4) Sugar measuring instruments
5) pH meters
6) Heat penetration equipment are instruments used to calculate the length of time needed in the sanitization process after putting the food into a container. Such an instrument is called a Thermocouple. It measures the temperature at which the heat reaches the product in the can.
7) Instruments measuring the size of the can seams. The quality of the cover and body attachment of the can is very important. It must be up to standards otherwise the can will leak.
8) Instruments measuring pressure in a can are utilized in order to determine whether there are any leaks in the can. This is done by pumping air into the can until the required level of pressure is met, then submersing it in water. If there are leaks in the container, air bubbles will come out from the seam in which the can seam machinery will need to be adjusted
1.1.2 MACHINES USED IN THE PRODUCTION PROCESS
Machines used in manufacturing canned food are generally classified according to the production processes which include:
- Washing, preparing, and trimming ingredients
- Scalding
- Cooking
- Containing
- Emptying the container
- Sealing the container
- Sanitization
1.1.3 MACHINES USED FOR THE TYPES OF PRODUCT:
Machines used vary depending on the types of the food manufactured; for instance, machines used in producing canned pineapple might be different from those used in manufacturing canned fish.
1.2 Cleaning the place of production
In “Hygienic” terms, the most crucial part to consider is the level of microbes since they could significantly harm the consumer’s health. Therefore, the amount of such microorganisms on both people and machines must be controlled by:
1) Not allowing any contact from animals or insects.
2) Providing staff with aprons which prevent any contaminations from those who produce or serve the products and their clothes and providing staff with a cap or a scarf to prevent their hair from falling into the product.
3) Always keeping all machines, instruments, tables, water bowls, and kitchens clean in order to eliminate food scraps which will foster microbe growth.
4) Dumping all the food scraps every day.
5) Keeping the stock room, storage area, refrigerator, and cold storage clean.
6) Orderly arranging all the machines and instruments in order to be convenient and prevent any damage.
7) Providing sufficient restrooms for staff.
8) Arranging an annual health check program for staff.
9) Coordinating with an “Inspector” from the government for suggestions and to establish good coordination.
10) Improving processes as suggested by the “Inspector”.
1.3 Eliminating food scraps, garbage, and waste from the factory
Releasing wastewater is also important since it may negatively affect two aspects which are:
1) Hygiene and safety in production, impurities may easily contaminate the production processes.
2) Safety towards the environment: releasing water containing food scraps will disturb the neighbors and letting out production wastes into nearby water sources will cause troubles and difficulties for those who live near the river.