PREPARATION OF CANNED PRODUCTS

Aim of the experiment: To study about the preparation and storage of canned products.

Objectives:

1.      To know the methods of preparation and preservation of canned products.  

2.      To know the difficulties, precautions to be taken and technical know-how of the final product’s quality.

Materials required:

1.      Fruit/ vegetables

2.      Sugar

3.      Salt

4.      Vinegar

5.      Spices for flavour  (Cardamom and black pepper)

6.      Cans/ glass bottles

7.      Steamer

8.      Gas/ induction

Relevant information:

            The process of sealing food stuff hermetically (airtight, protected from outside agencies) in containers and sterilizing them by heat for longer storage is known as canning. In 1804, Nicolas Appert in France invented a process of sealing foods hermetically in containers and sterilizing them by heat. In honour of the inventor canning is also named “appertizing”. Saddington, in England, was the first to describe a method of canning foods in 1807. In 1810 Peter Durand, another English man, obtained the first British Patent for canning of foods in tin containers. William under Wood in 1817 introduced the canning of fruits on a commercial scale in the USA.

            Fruits and vegetables are canned in the season when the raw material is available in plenty. The canned products are sold in the off-season and give better returns to the farmers.

Principles:

            Canning is done at or above 100°C. In the case of fruit which is acidic, they are canned at 100°C, while in the case of vegetables that are non-acidic, can be canned at 116-121°C. Here high temperature can be obtained by using steam pressure, which helps in pasteurizing the product. Due to this the microbes and enzymatic load in the product is greatly minimized even becoming zero, which helps the product to be stored for longer durations.

Method of canning:

            For canning, fruits and vegetables should be fresh, ripe but firm and evenly matured. It should be free from all blemishes, insect damage, mechanical injury and malformation. Overripe fruit is generally infected with microorganisms and would yield a pack of poor quality. Under-ripe fruit will shrivel and toughen on canning. The vegetables should be tender except tomatoes and free from soil, dirt etc. Tomatoes should, however, be firm, fully ripe and deep red colour. The fruits and vegetables pass through several processes in canning as detailed below.

Observations:

Quantity of product taken = __________

Quantity of syrup/brine used=___________

Amount of final product prepared=__________

Precautions:

1.      The freshly harvested fruit/vegetables that are not soft should be used for canning.

2.      Grading is mandatory to obtain good quality canned products.