India ranks second in terms of fruits and vegetable production in the world, As per National Horticulture Database published by National Horticulture Board, during 2014-15 India produced 86.602 million metric tonnes of fruits.
Fruits containing high moisture contents and nutrients are perishable in nature. Due to improper cold chain infrastructure, about 16 percent of fruits of vegetables, were lost, according to an analysis of production data between 2012 and 2014.We have been practicing several preservation techniques from ancient days, one of them being production of fruit jams.Fruits converted into jams can be used for over a year.So lets focus on Jam Production Process.
Jam means the product prepared from sound, ripe, fresh, dehydrated, frozen or previously packed fruits including fruit juices, fruit pulp, fruit juice concentrate or dry fruit by boiling its pieces or pulp or puree with nutritive sweeteners namely sugar, dextrose, invert sugar or liquid glucose to a suitable consistency. It may also contain fruit pieces and any other ingredients suitable to the products. It may be prepared from any of the suitable fruits, singly or in combination. It shall have the flavour of the original fruit(s) and shall be free from burnt or objectionable flavours and crystallization.
FSSAI specifications for jam production
|TSS(Total soluble solids)||65%|
|Preservative||40 ppm of SO2|
Jam Production Process
Ripe firm fruits received for jam production are sorted and graded according to their color, sensory appeal. spoiled fruits are removed from the lot.This can be done using hand picking, color sorters.
for effective washing of fruits, 200 ppm of chlorine can be used in water. pH and temperature should be maintained, to prevent fruits from getting damaged or bruised. Dump and spray washers can be used in industries.
fruits can be hand peeled as in case of citrus and apple, mechanical peelers and automated peeling machines containing blades are generally used in industries. Some fruits don’t require peeling. Pitting is sone in fruits containing hard inner stones.
Pulping is done to remove seed and core part. Various pulping machines are available in market for fruits such as mangoes, peaches, tomatoes, bananas, draw berries and celeries etc.
The gap between the sieve and rotor can be adjusted to suit different type of size and qualities of materials to be pulped.
- Addition of sugar
Required amount of sugar and pectin is added to the fruit pulp/juice. Water can be added ,if needed. sugar, binds to the water molecules and frees up the pectin chains to form their network.
Adding more pectin results in harder jam and using more sugar can make it sticky.
Boiling is the most important step in jam making, which require a lot more patience. After keeping the above prepared mixture on heat, we need to wait till the sugar dissolves. Slowly, whole room will get filled by the fruity smell and a netwok like pectin
A foamy scum may form on the surface of the jam; this is normal and can be removed by adding a little butter (about 20g) to break the surface tension or by skimming it off with a spoon while your mixture is cooling.
- Addition of citric acid
Specified amount of citric acid is added while boiling itself. We heat the mixture upto 105 C or 68-70%TSS to ensure proper setting of jam. Sheet test can also be performed to check jam.
Sheet test – small portion of jam is taken in spoon and cooked a bit, and allowed to drop, if product drops as sheet or flakes, jam is made perfect, otherwise boiling is continued.
- Filling into bottles
Jam is poured hot into the sterilized bottles , and it is allowed to cool down by putting into water bath, waxing by paraffin wax or other waxes can be done, and finally metal caps are vacumn capped on the jars.
Canned jam should be kept in cool, dry pkaces away from sunlight.
Shelf life of canned jam is around one year.