Foodis the important things in our life. Food is acting as fuel to our body. Foodalso supply protein and mineral to support body development and growth. Somenutrients needed by body to recover the parts that are broken. Therefore, foodis very important to our life. One of the problems when talking about food is food preservation. As we know, food is containingbacteria or microorganism.
This microorganism in food causing the food begin torot or spoilage. The food that rotten can’t be consumed because it will harmour body. The rotten food also decreasing the nutrients contained in fooditself. Since long ago, human kind hasconducted research about how to preserve food. The purpose to preserve food isto extend shelf life, maintain sensory properties, maintain or improvenutritive properties, ensure safety, make the food is easy to consume or easyto digested by body and make the economic value increase. After so manyresearch and experiment, the scientist found the ways or methods to preservefood and the methods has divided into 5 major different methods.
Thefirst methods is heating process. Heating process is a methods using hightemperature around 500 C-1500C to eliminatesmicroorganism that contained on food so the shelf life of the food product canbe extended. Sometimes, the nutrients inside the food will be damaged inexchange.
The example of this method is blanching and pasteurization. Accordingto (BAT in the Food, 2005) blanching operationsare designed to expose the entire product to high temperatures for a shortperiod of time, by using steam heating (with temperature above 1000C)indirectlyfor fruit juices and directly for vegetables while pasteurization is theprocess of heating a liquid to below the boiling point (900C-1000C)to destroy microorganisms. Sometimes the pasteurization methods can use hightemperature above the boiling point but short time exposure, this process thatwe called Ultra High Temperature or UHT. The example product is milk, yoghurt,green beans porridge.
The second is low temperature treatment.Low temperature treatment is a methods exposing food or saving food in the lowtemperature below 40C. This methods divided into 2 that isrefrigration and freezing. Refrigeration is defined as the science ofmaintaining the temperature of a particular space lower than the surroundingspace (Khemani, 2008) . Based on (Robinson, 2013) statement, freezing process is acombination of the beneficial effects of low temperatures at whichmicroorganisms cannot grow, chemical reactions are reduced, and cellularmetabolic reactions are delayed. The difference between two methods is thetemperature.
The temperature used in refrigaration is 00C- 40Cwhile the freezing methods using 00C to 40C belowfreezing point. Both methods allow the food shelf life to be extended becauseof the germ and microorganism inside food will be inactivated. This methodmakes the food lost some nutritive value.The next method is dehidration ordrying. Food dehydration is the process of removing water from food bycirculating hot air through it, which prohibits the growth of enzymes andbacteria.
It can makes food to be stored longer than usual. Based on International Journal of Food Nutrition andSafety written by (Ahmed, 2013), dried foods can bestored on room temperature until a month or longer because the water inside the food has beenreduced so the microorganism inside food can’t grow because lack of water. Somefood can’t be preserve with this method. Some fruit can’t be dried such aswater melon and pumpkin. The example product is fish, dried meats, dates.The next is Acidification. According toJournal that written by (Ekanayake, 2010) “Acidfication is process foracidifying and preserving a food product.
The process can include providing afood product having an initial pH, acidifying the food product to a final pH toproduce an acidified food product”.In simple, acidification methods is a method that makes food has pH below 7.The acid makes microorganism can’t grow because microorganism only grow if thepH is around 7. So, the process prevent the microorganism from multiplying. Theexample of this method is pickling,sugaring and salting. The question is why the sugaring and salting is concludedinto acidification method? Sugaring and Salting is method to preventmicroorganism from multiplying and they creates thin “layer” that has pH below7 or above 7.
The next method is packaging. Packagingis used to wrap food and separating food from the environtment. “Packagingprovides protection, tampering resistance, and special physical, chemical, orbiological needs” this statement is said by (Claudio, 2012) in his book. This prevent the bacteriaon the outside can’t get contact with the food. So the food shelf life can beextended. Packaging method needs to be combined with other methods such as theheating process so the microorganism inside the food can disappear. Somepackaging method also create vacuum space inside the package such as canningmethod.Food preservation methods divided intofive groups which is Heat Treatment, Low Temperature Treatment, Drying,Acidification, Packaging.
Food Preservation is a way to make food shelf lifeextended, safety to be consumed and makes the economic value rising up. This isthe main reasons why the food preservation research still studied until now.Besides, the food preservation research still continue for the sake efficiency,easy to comercialize, long shelf life food,and gaining more nutrition value.