Fruit Preservation

∆ Nicholas Appert (1810) : Invented the technique for preserving foods in a glass containers called Appertizing.

∆ Gay Lussac : Spoilage of food due to oxidation could be prevented by exclusion of air from the container.

∆ Louis Pasteure: 

Heat treatment of food at a sufficiently high temp to kill the majority of the microorganisms and by preventing their access to the food inside the container by sealing it hermetically (Air tight) is called Pasteurization .

∆ Blanching 

Treatment of fruits and vegetables with boiling water or stream for short period followed by cooling prior to canning to loosen the skin so that it facilitates close filling in the can and drives out the air from the tissue.

e g.Important in beet root and tomato ; temp more than 100°C.

6) Syruping /Brining: 

The cans are filled with hot sugar for fruits and with hot brine for vegetables

The object of adding syrup or brine :

To improve the taste and to fill up the interspace between the fruits fruits and vegetables in the can and to facilitate fortune processing.

The ideal temp to add syrup /brine is 79-82°C for Syruping/Brining

7) Jam : 

Soluable solid 68% , fruit pulp 45%, temp 105°C , in sweet fruit add citric acid.

8) Jelly :

Soluable solid 65% and fruit pulp = 45% 

Temp- 105.5, Semi solid gel sparkling colour.

Max Pectin: 6g /100g fruit as calcium pectate in Lime peel /orange peel

Marmalade : like jelly but made from citrus fruits

Fruits juices:

a) Pure fruit juice : 

Natural juice pressed out of a fruit and remains practically unaltered in its composition during its preparation and preservation.

b) Squash :

Consists essentilly of strained juice containing moderate quantities of fruit pulp to which cane - sugar is added for sweetening

e g. 

c) Cordial : 

Sparkling clear , sweetened fruit juice from which all the pulp and other suspended materials have been completely eliminated

e g. Lime juice cordial

d) Sherbat and Syrup

Clear sugar syrup which has been artificially flavoured sherbats of khas , Sandal , Santra

e) Fruit juice concentrate: 

Fruit juice concentrated by removal of water by heat or by freezing 

e.g. Carbonated beverages

Puree: 

Juices of thick consistency like peach , plum , apricot or concentrated thickened juices is called Puree.

Nector : Pulpy fruity juices like mango , banana , papaya , apricot 

Cocktail /Ade : Juices diluted with water and sugar .

Candy : Fruit preserved by coating and impregnating with a sugar syrup.

Chemical Preservatives:

∆POTASSIUM METABISULPHITE:

     Potassium Metabisulphite (K2S2O5 or K2O.2SO2)

It gives SO2 after reacting with fruit acids which (SO2)Acts a micro -oeganism poison .

The max quantity of SO2 in squashes and cordials is 350 ppm i.e 0.62g /kg = 0.06%

∆ SODIUM BENZOATE:

Juices having pH 3.5 -4.0 

( In most of the juices ) - 0.06 - 0.1 % 

For less acid juices : At least 0.3%

Potassium meta bisulphite is more commonly used because of:

a) Better preserving action

b) help to retain the colour of the beverage for a longer period.

c) Being a gas , helps in preserving the surface layers of the juice 

d) Being highly soluable in juices , better mixing 

e) Excess of SO2 cam be removed by heating.

✍️Agricos Vaishnavi Nimkar

Contact No. 7666441799