Chemical Preservation Methods

Method 1: Canning
Processing and sealing food airtight containers is called canning. Canning began after the French military in 1795 offered a cash prize of 12,000 francs for a new food preservation method. By 1806, Nicolas Appert had a proven method of packaging that prevented microorganisms contaminating from the food he canned. Since then, cans and jars have been used both commercially and in homes to can large quantities of all types of foods.

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Method 2: Pickling
Pickling makes use of vinegar or brine to preserve food and extend its shelf life.

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Method 3: Drying
Removing water from food and thereby inhibiting bacterial growth in foods is the method of food preservation known as drying. This method has been around since ancient times. Today solar or electric food dehydrators are used to speed this drying process and makes it possible to dry food even in humid conditions.

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Method 4: Smoking
The process of burning or smoldering plants in order to flavor, cook or preserve food is known as smoking. In the United States and other parts of North America, mesquite, hickory, mesquite, pecan, oak, alder, maple, and fruit-tree (apple, cherry, and plum) woods, such as apple, cherry, are used for smoking.

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Method 5: Freezing
Freezing, in food processing, method of preserving food by lowering the temperature to inhibit microorganism growth. The method has been used for centuries in cold regions, and a patent was issued in Britain as early as 1842 for freezing food by immersion in an ice and salt brine. It was not, however, until the advent of mechanical refrigeration that the process became widely applicable commercially. In 1880 a cargo of meat shipped from Australia to Britain under refrigeration accidentally froze, with such good results that the process was at once adopted for long-distance shipments and other storage. In the 20th century quick, or flash, freezing was found to be especially effective with certain types of food.

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Example:
Apples, pears, peaches, plums, apricots, bananas, cantaloupe, strawberries, blueberries, carrots, celery, maize, green beans, potatoes, and tomatoes are among the fruits and vegetables that may be dried.

Why does food need to be dried?
Drying inhibits the growth of bacteria, yeasts, and mold through the removal of water.

1. DISCUSS AND JUSTIFY WHETHER FREEZING IS A GOOD TECHNIQUE IN FOOD PRESERVATION.
Freezing delays spoilage and keeps foods safe by preventing microorganisms from growing and by slowing down the enzyme activity that causes food to spoil. As the water in the food freezes into ice crystals, it becomes unavailable to those microorganisms that need it for growth.

2. WHAT ARE THE EXAMPLES OF FOOD THAT CAN BE PRESERVED USING LOW TEMPERATURE PROCESSING, AND BRIEFLY DESCRIBE HOW THIS METHOD CAN HELP PRESERVE THE FOOD.
Example: Fruit and meat.
Foods are stored at low temperatures to prevent the growth of microorganisms, activity of enzymes, and purely chemical reactions. Freezing prevents the growth of most foodborne microorganisms and refrigeration temperatures slow down the growth of microorganisms. Refrigeration below 5 °C effectively retards the growth of many foodborne pathogens. The cooling rate is important in controlling the growth of microorganisms. A slow cooling of food allows time to microbial growth. This can occur in a large volume of hot or warm food in a big container. Refrigerated foods have limited shelf life due to microbial growth. In frozen foods, microorganisms will not grow, but there will be survivors after long storage. Rapid thawing is desirable to control microbial growth. The killing rate of microorganisms is rapid at the beginning of freezing. There are four distinct low-temperature methods for the preservation of foods namely room-temperature storage, chilling, refrigeration, and freezing.

Tempeh is made from the whole fermented soybean, to create a very dense, cake like product that contains more probiotic & health benefits than its more well-known sister Tofu. It is more textured, chewier & also much higher in protein.
2. Tofu

Tofu is also made from fermented soybean but is more sponge like & grainy in comparison to Tempeh. It can easily absorb flavours & is therefore very versatile in recipes. It is a great source of protein important for the growth & repair of tissues. It also contains phyto-oestrogen compounds – important for hormone balancing (particularly in menopause)
Always choose non-GMO sourced soya. The negative effects reported in the press, come from the highly processed soy protein isolate.
3. Yoghurt

Yoghurt is one of the most popular fermented products available. Ensure you choose organic, natural & probiotic rich yoghurt for maximum health benefits.

WHAT IS YOUR OPINION ON THE SAFETY OF FERMENTED FOOD?
In my opinion, fermented foods may cause some initial side effects, such as gas and bloating. If fermenting at home, always follow recipes to avoid spoilage and read nutrition labels when consuming store-bought products. Some products may contain high levels of added sugar, salt, and fat — so it’s important to read nutrition labels to make sure you’re making a healthy choice. Thus, fermented foods are considered safe for most people.