Fruit preservation

Types of preservation fruits which helps in fruit processing

1. FRUIT PRESERVATION

2. PRESERVATIVES Preservatives are defined as "chemical agents, which serve to retard, hinder or mask undesirable change in food ". These changes may be caused by microorganisms, by the enzymes of food, or by purely chemical reactions.

3. NEED OF PRESERVATION When the availability of food is more than the present use it is preserved for future consumption. Preservation helps the food to be available in off-season and in any place.

4. PRINCIPLES OF PRESERVATION Prevention or delay of microbial decomposition Keeping out microorganisms (asepsis) Removal of microorganisms e.g. by filtration. Hindering the growth and activity of microorganisms e.g. by low temperature, drying, anaerobic conditions or chemicals. Killing the microorganisms e.g. by heat or radiations. Prevention or delay of self decomposition of food Destruction or inactivation of food enzymes e.g. by blanching. Delay of chemical reactions e.g. by prevention of oxidation by means of an antioxidant.

5. METHODS OF PRESERVATION Temporary preservation : In this method growth of microorganisms is only retarded or inhibited for short time like steeping preservation, with chemical preservatives . Two chemical preservatives. Potassium metabisulphite Sodium benzoate   Permanent preservation : In this method the growth of spoilage microorganisms are completely destroyed by different means like, drying, canning, freezing etc

6. CANNING Canning involves the application of temperatures (to food) that are high enough to destroy all microorganisms present in sterilized containers to prevent re-contamination and to preserve the food.  Canned fruit

7. SHELF-LIFE OF PROCESSED PRODUCTS Normally at ambient conditions of storage the processed products will have a minimum shelf life of 6 months.  Canned products will have one year shelf life at ambient conditions of storage itself.  The shelf life of  others  can be doubled by storing at refrigerated conditions.

8. DRYING

9. DRYING OF FRUITS The methods of fruit and vegetable drying are Sun drying Drying by mechanical driers,  osmotic dehydration , Spray drying , Foam mat drying , Freeze drying .

10. SUN DRYING Sun drying is an old and traditional method of drying. It is limited to climates with a hot sun and a dry atmosphere and to certain fruits such as raisins, prunes figs, apricots, pears and peaches. It is a slow process. Vegetables like french beans, curd chilli are preserved by this method . Fruit bars, raisins, dehydrated products from fruits like fig, pomegranate and vegetables like onion, carrot, cauliflower, okra, mushrooms  etc.

11. Sun drying

12. Mechanical dryer

13. Osmotic dehydration The moisture is drawn out from all cell tissues. The water is then bound with the solute, making it unavailable to the microorganisms. In osmotic dehydration of fruits, the method involves the partial dehydration of fruits by osmosis in a concentrated sugar solution or syrup. Fruits such as apple, banana, cherry, citrus, grapes, guava, mango, papaya, pineapple, plum, etc. Osmotic Dehydration can remove 30-50% of the water from fresh ripe fruits e.g mangoes, pineapple, banana, sapota and papaya etc.

14. Osmotic drying

15. SPRAY DRYING Thin fruit juices like pine apple , citrus are dried to a powder in spray driers in which the liquid is atomized and sprayed into a hot air stream for almost instant drying.

16. Freeze dryer

17. Freeze drying Freeze drying is a method of drying involving freezing and then the sublimates of the ice under vacuum. Removal of water from a product while it is frozen by sublimation is called freeze drying. Fresh flavours and textures are better preserved by freeze-drying. Freeze-dried fruits and vegetables generally  have better texture and rehydration quality. As fresh fruit, salads and dairy products to be stored safely for longer periods, particularly during warm weather.

18. Freeze drying of tomato Freeze drying of fig

19. FREEZING PRESERVATION Freezing may preserve foods for long periods of time provided the quality of the food is good to begin with and the temperature of storage is far enough below (-18  ) the actual freezing temperature of food for long preservation.  IQF or Quick freezing process? In this case the lower temperatures (–32   to –40  ) to freeze foods. The crystals are formed and the time of freezing is greatly reduced. In quick freezing, large amount of food can be frozen in a short period of time

20. The products that can be prepared from major fruits are: Mango : Pulp, canned juice, canned slices, osmotically dried slices, beverages, fruit bars, jams.   Grapes : Wine, Raisin, RTS beverage, concentrated beverages, canned berries. Banana : Chips, beverages, clarified juices, mixed fruit jam.   Pineapple : Canned slices, RTS beverage, concentrated beverages, canned juice, fruit bars etc.   Papaya : Tutti-frutti, fruit bar, mixed fruit juices, mixed fruit jam. Passion fruit: Concentrated juices, blended juices.   Butter fruit: Bread spread   Custard apple: Beverages, mixed fruit jam.   Guava : Clarified fruit juices, jelly, jam. Apple : Juice, jam, fruit bar.

21. PACKAGING MATERIAL Packaging materials must be moisture- vapour resistant Durable and leak proof Not become brittle and crack at low temperatures Resistant to oil, grease or water Protect foods from absorption of off-flavors or odours Easy to seal Easy to mark. Good freezing materials include rigid containers made of aluminum, glass, plastic, tin or heavily waxed cardboard; bags and sheets of moisture-vapor resistant wraps; and laminated papers made especially for freezing.

22. Wooden pallet Different packing materials

23. Packing material for fruits and leafy vegetables

24. NET PACKING OF APPLES Box packing

25. Modified atmospheric packaging Modified atmosphere conditions are created inside the packages by the commodity itself and / or by active modification. Commodity – generated or passive MA is evolved as a consequence of the commodity’s respiration. Active modification involves creating a slight vacuum inside the package and replacing it with a desired mixture of gases Another active modification technique is the use of carbon dioxide or ethyl absorbers (scavengers) within the package to prevent the build-up of the particular gas within the package. This method is called active packaging. Compounds like hydrated lime, activated charcoal, magnesium oxide are known to absorb carbon dioxide while iron powder is known to absorb carbon dioxide. Potassium permanganate, squakna and phenyl methyl silicone can be used to absorb ethylene within the packages

26. MAP

27. Controlled Atmospheric This refers to a storage atmosphere that is different from the normal atmosphere in its composition, wherein the component gases are precisely adjusted to specific concentrations and maintained throughout the storage and distribution of the perishable foods .

28. OTHER PRODUCTS FROM FRUITS Squash Jam Jelly Candy

29. REFERENCES http:// www.iihr.res.in/faq/FAQ.htm http:// agridr.in/tnauEAgri /