science of sugar candies and jellies.

 How are the sugar candies been made?  we always wonder how the science creates such a sweetest product 

on the earth and also the bitterest part in this world.. but anyways lets think about the sweetest part of the 

world.. that is the sugar candies and jellies from kids to the older people most of them will are addicted to 

its flavour, texture , taste ... but the science behind them is not known to all... lets know something about 

the science behind the candies and jellies today.

anyone thought that why do the jams or jellies which do not get affected by microoragnisms and they do 

not get spoit very often? the reason is they are preserved by sugar. this method of preservation is called sugar preservation. 

how does it happen?

sugar acts as preservative by the process called osmosis.sugar attracts all the available water and the 

awater is transferred from the microorganisms into the concentrated sugar syrup. the microflora is 

dehydrated and cannot multipy further. the main thing is the concentation of the sugar 

in the sugar preserved product should be approximately  more than 68% ,the water activity should not 

be reduced approximately below 0.845. 

the water activity is sufficient to inhibit the mesophilic bacteria and yeast but not check the mould 

attack.

due to this there are various methods has been adapted to prevent the attacks of the moulds in the sugar 

preserved products such as jams and jellies. and hence the use of the chemical preservatives to attain 

the antiseptisation of the surface of the product.

most of these sugar preserved products are done by the citrus fruits in which acid is present and hence 

they somewhat help us in preserving the product.

lets discuss about the products in brief:

JAM:

jam is usually made from the pulp of the whole fruit. the jam has three amin constituents namely pectin 

, sugar and acid. the pectin is the long chain of sugar  molecules and they are naturally found in plants.

 especially in fruits they are found in  cores and  peels. when boiling the jam releases the pectin from it.

a long chain can bind via intermolecular interactions and forming a gel network.

this gel network is generally setting point of the jam. it is almost happens at the temperature of 104 

degree celcius.

JELLIES:

it is prepared by the boiling of fruit juices or fruits of sound quality, with or without water, adding 

nutritive sweetners, and concentrating to such a consistensy that gelatinization takes place on cooling. 

the product shall not be syrupy, stickyor gummy , and shall be clear, transparent and sparkling.

CANDIED FRUITS:

candied fruits are first impregnented with cane sugar or glucose syrup and subsequently drained free of

 syrup and dried. the candy must be plumped , sweeter and flavourful and does not be sticky.

the most suitable fruits for candying are peach, peels of orange, gooseberry, pineapple, cherry, papaya, 

lemon, etc..some of the types of candied fruits are:

glazed fruits:

these are the candies where they are covered with a glassy layer of sugar. it gives a glossy apperance 

and it is much sweeter to eat...

crystallized fruits:

these are the candies where the sugar is sprinkled or rolled on the fruits.. either the sugar which are 

found to be powdered are thrown on them or the crystal one is thrown on them .. it creates a sparkling 

appearance and has  a sweeter taste.