lossofnutrients-180211051hsjeejh551.pptx

Shankhar raj Brasila sir
AFU, rampur

1. FOOD PROCESSING and QUALITY SHANKER RAJ BARSILA, PhD. APPLIED HUMAN NUTRITION ANU 401 B.Sc. Ag., B.Sc. Fisheries and B.V.Sc . And A.H. Agriculture and Forestry University, Rampur Spring semester 2021

2. WHAT IS FOOD PROCESSING??? Food processing is simply the transformation of raw ingredients into food. Food processing typically takes clean, harvested crops or butchered animal products and uses these to produce attractive, marketable and often long shelf-life food products.

3. What is the need of food processing? Once food is harvested, de t eri o rate i mm e d i a tely it b e gins to due to the following factors: (y e ast, mould, Micro-organisms bacteria) Intrinsic enzymes; Temperature; Moisture; and Insects and vermin.

4. Food processing involves the application of scientific principles to slow down the natural processes of food decay caused by micro-organisms, enzymes in the food or environmental factors such as heat, moisture and sunlight - and so preserve the foo d .

5. Aims of food processing To make food safe (microbiologically, chemically). To provide products of the highest quality (flavour , colour ,texture) To make food into forms that are convenient (ease of use)

6. Methods of food processing Physical Methods Chemical Methods Pasteurization Ph Balance Frying Control Of Water Activity Fermentation Use Of Food Additives Baking And Cooking Intermediate Moisture Foods (IMF) Blanching Irradiation Drying Canning Extrusion Cooking

7. Pasteurization is the process of heating a food usually a liquid to or below its boiling point for a defined period of time . The purpose is to destroy all pathogens, reduce the number of bacteria, inactivate enzymes and extend the shelf life of a food product Pasteurization

8. . Iodine The iodine content of milk varies greatly. A 20% reduction in iodine has been reported with pasteurization. . Vitamin C Vitamin c is sensitive to heat and oxidation; thus, losses have been reported to range from 0% to 20% following pasteurization . Enz y mes In particular, pasteurization destroys enzymes that contribute to immunity as well as the digestive enzymes

9. Other nutrients which are destroyed in pasteurisation but in small quantity are: Fruit and milk sugar Flavours Natural, antimicrobial properties Vitamin B-complex Only a 1% decrease in the biologic value of protein observed following pasteurization.

10. Frying differs from other methods of heat processing in that the cooking medium is hot oil. Frying is a unit operation which is mainly used to alter the eating quality of a food. Thermal destruction of micro-organisms and enzymes, and a reduction in water activity at the surface of the food are secondary advantages. Frying

11. Fat absorption by the food product varies from 10% to 40% depending on the time food is immersed in oil. ca u se s o xi d ation o f th e oi l t o fo r m a ran g e of volatile carbonyls, hydroxy acids, keto acids and epoxy acids cau si n g unp l easa n t fla v our s a n d darkening of the oil. Oxidation of fat-soluble vitamins in the oil results in a loss of nutritional value. Retinol, carotenoids are each destroyed and contribute to the changes in flavour and colour of the oil.

12. Vitamin B and C losses occurs but are very low. Thiamine is one of the most important vitamins of the b group. Fortunately, thiamine losses are lower in the case of frying, near about (30%). Vitamin E is lost along with the oxidation of unsaturated fatty acids during heating. Vitamin A In deep fried vegetables, losses of beta-carotene were twice as high as in shallow- fried foods. Some beta-carotene could migrate into the frying oil.

13. Fermentation in food processing typically is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts , combination bacte r ia , or a thereof, und e r anaerobic conditions Fermentation t h a t the usually a c t i on impli e s of microorganisms is desirable, and the process is used to produce alcoholic beverages such as Fermentation

14. EFFECTS OF FERMENTATION Instead of adding nutritional benefits to the food, fermentation decreases some vitamin and mineral availability. Many fermented foods, such as soy sauce, contain a significant amount of alcohol. According to research, the levels of vitamin B12 may be reduced by fermented foods. Anothe r acid t h at resul t s f rom ferme n tatio n is lactic acid . Lactic acid is a waste product

15. rang e . BAKING AND COOKING Baking is a food cooking method using prolonged dry heat acting by convection and not by thermal radiation normally in an oven but also in hot ashes, or on hot stones. Effects of baking and cooking Nutrient losses in the 5-15% Coagulation of proteins Caramelization of sugars Sometime minerals are changed to their unusable and poisonous inorganic state and vitamins are largely

16. EFFECTS OF REFRIGERATION &FREEZING water in foods form ice crystals which will break down the cell structure of some foods. When a food is frozen, its water expands. This causes two immediately destructive occurrences; The cell walls burst and the cell contents are spilled due to the internal water expansion; hence the cell's life is lost. Oxidation occurs where air reaches the frozen foodstuff; hence nutrients are lost.

17. Blanching is a thermal process used mostly for vegetable tissues prior to freezing, drying, or canning. Blanching i s a sligh t h eat treatment, using h o t water or steam carried ou t at Blanching is tempera t ures close to 10 ° c (212° f) for two to five minutes BLANCHING

18. are lost duri n g wa t e r- solu b le c o mp o nen t s blanching. Cell tissue structure is distorted Antioxidants The researchers said 2003 "journal of the science of food and agriculture" study as finding a 20 to 30% loss of phenolic antioxidants after blanching decrease and water-soluble prot e in th e amo u n t of in Blanching may carbohydrate, fat certain vegetables. EFFECTS OF BLANCHING Some minerals, water-soluble vitamins and other

19. Irradiation Irradiation is the controversial process of applying low doses of gamma radiation to food products. EFFECTS OF IRRADIATION Irradiation of food, like cooking (thermal treatment), causes a loss of vitamins food can develop off flavours Irradiation can change the structure of a protein The loss of texture (softening) is the main draw back from a qualitative point of view

20. d r ying Dehydration (or drying) is defined as ‘the application of heat under controlled conditions to remove the majority of the water normally present in a food by evaporation. Effects of drying Dried foods are higher in calories . Dried fruits may taste sweeter than fresh fruits due to the concentrated sugar content. Nutritional losses during drying are more due to the application of heat than to the removal of moisture. Generally, except for thiamine. Protein content of dried vegetable may be greater.

21. 9.Canning Canning is a method of preserving food in which the food contents are processed and sealed in an airtight container. Canning provides a typical shelf life ranging from one to five years. Effects C a : nn i n g i s a h i gh hea t pr o c e ss that can destroy nutrients Vitamins and phytonutrients are esp e ci a lly su s c e p t ible to Canning has no effect on proteins, carbohydrates and fats. degradation from heat. Mainly harm to canned food occurs when proper sterilization and head spacing is not done.

22. Ex t rusion i s th e pr oc ess i n w h i c h a food is EXT R USI O N compressed and worked to form a semi-solid mass. This mass is then forced through a restricted opening, to create a desired texture or shape. EFFECTS OF EXT R US I ON Slight increase of iron - bioavailability Creation of insulin-desensitizing starches, which are a risk-factor for developing diabetes Destruction of Vitamin A ( beta-carotene ) Denaturation of proteins .

23. Chemica l methods are simultaneously Chemical methods carried out with the physical methods. This means that the p H maintenance and control of water activity is involved in drying, refrigeration themselves. f oo d moistu r e a n d are d on e b y add i ti on of Intermediate pres e rvat i v e s additives. There are many food additives and effect will vary vastly with nature of additives used.

24. Chapter 1,3, 4,5,7,8,9.

25. .…THANK YOU….