Fruit and vegetable processing technology.pptx

Food technology is a branch of food science that addresses the production, preservation, quality control and research and development of food products

1. Fruit and Vegetable processing technology 2 Lecturer: Osman Hassan Ali

2. Learning Objectives At the end of this Lecture, students should be able to:- Define Fruit and vegetable, Classify them based on different criteria and their quality and safety attributes Understand important composition (with their respective effect) of Fruit and vegetable and factors affecting the ripening process Discuss the proper harvesting, handling and storage of Fruit and vegetable. Explain the production of Fruit juice, tomato paste and tomato ketchup. 3

3. 1. Introduction Fruits and vegetables, the perishable commodities, important ingredients in the human dietaries. seasonal in nature high nutritive value they make significant nutritional contribution to human well- being.

4. Cont’d What is Fruit? Fruit is the mature ovaries of plants with their seeds. Commonly eaten alone or as a dessert. What are Vegetables? A vegetable is any edible (eatable) part of a plant that does not have a role in the plant’s reproductive cycle, such as the roots, stems, leaves, or flowers. Often eaten as part of a main course or a side dish.

5. 2. Classification Of Vegetables A) Based On Edible Part Root crops - carrot, radish, beet, turnip, and sweet potato. Stem vegetables - asparagus and potato. Leafy crops - lettuce, cabbage, celery, spinach, Immature flower buds-cauliflower , broccoli, and artichoke Immature fruits - cucumber, okra, sweet corn, and eggplant Mature fruits- cucurbits (pumpkin, white gourd, squash, muskmelon, and watermelon), tomato, and pepper.

6. B) Based On Temperature Warm- season crops are adapted to 18~29 ° C, intolerant to frost and mostly grown for edible fruits. Cool- season vegetables have optimum growth at cooler temperature and are shallower rooted and smaller sized. Asparagus, Brussel sprouts, broccoli, cabbage, celery, garlic, onion, pea ,

7. 3. Classification Of Fruits Depending on shape, cell structure, and type of seed Berries: usually quite small- Strawberries, blackberries, raspberries, blueberries,…. Citrus fruits : High citric acid Sweet limes, oranges, tangerines, sour oranges,… Drupes: Contain single pits- Apricot, sweet cherry, peach, plums.

8. Cont’d Grapes: Green grapes, black grapes, seedless grapes. Melons: Large and have a tough outer rind Musk melon, water melon. Pomes : contain many pits- Apples, pears.

9. B) Depending on natural habitat Temperate- zone Fruits Apple, Strawberry … Subtropical Fruits Orange, Avocado… Tropical Fruits- require warm temperature Mango, Banana….

10. 4. Fruit And Vegetable Processing The main objective of fruit and vegetable processing is to S upply , Wholesome , Safe, Nutritious and Acceptable food to consumers throughout the year. Reduce fruit and vegetable losses; Replace imported products

11. Cont’d The quality of processed fruit products depends on their quality at the start of processing ; Maturity at harvest, Harvesting methods, and postharvest handling procedures Maintenance in fresh fruits between harvest an d process initiation.

12. Cont’d Quality attributes of fresh fruits and vegetables include appearance, texture, flavor, and nutritive value. Appearance factors include size, shape, color, and freedom from defects and decay. Texture factors include firmness, crispness, and juiciness. Flavor components incorporate sweetness, sourness (acidity), astringency, bitterness, aroma, and off- flavors. Nutritional quality is determined by a fruit’s content of vitamins (A and C are the most important in fruits), minerals, dietary fiber, carbohydrates, proteins, and antioxidant phytochemicals (carotenoids, flavonoids, and other phenolic compounds).

13. Cont’d Safety factors that may influence the quality of fresh fruits include Re sidues o f Pesticides, Presence of Heavy Metals, Mycotoxins Produced By Certain Species of Fungi, a nd Microbial Contamination.

14. 5. Chemical Compositions Water- Vegetables contain generally 90- 96% water while for fruit normal water content is between 80 and 90%. Contains soluble substances (Sugars, Salts, Water soluble pigments & Organic Acids) Insoluble substances remain as Colloidal Nutritive Components Provide plenty of vitamin & minerals Poor caloric contribution Fruits like bananas give fairly good amount of calories (116 kcal/100g).

15. Cont’d A. Carbohydrates D igestible and indigestible parts (sugars and starches vs pectin and cellulose material). Ripe fruit contains a higher percentage of sugar than unripe fruit and the sugar is chiefly in the form of sucrose, fructose and glucose. Polysaccharides (Cellulose & Hemicellulose )* * Give rough texture to Fruits

16. Cont’d B. Proteins & Fat s Poor source (Except: Avocado - 28% Fat) C. Vitamin & Minerals Their important nutritional aspect Vitamin A is found in yellow- orange fruits and vegetables and leafy, green vegetables. Vitamin C is found in citrus fruits, tomatoes and green, leafy vegetables. high in minerals such as (iron and calcium)

17. Cont’d Organic Acids Lower in concentration Desirable acid-sugar balance - for pleasant taste. C hanges with maturity and affects flavour. Sourness property! Arise as metabolic product of cells Most fruits (Citric & Malic acid) Grapes are rich in (Tartaric & Oxalic acid) Most vegetables contains Acetic acid, Citric acid, Formic acid,…

18. Cont’d 4) Pigments Reason for diversified fruits and vegetables colour Fr uits may contain individual or a combination of pigments Example: Orange (Carotenoids + Chlorophyll) Types (Water soluble (Flavonoids)& Fat soluble pigments) Major Pigments in fruits Pigment Colour Fruits Type Chlorophyll Green Unripe fruits Fat soluble Carotenoids Yellow- orange Mango & Papaya Fat soluble Anthocyanins Red- purple Grapes, blueberries, Water soluble Carotenoids: the red and orange pigment  Pre cursor of vitamin A Chlorophyll: green pigment of leaves

19. Cont’d 5) Flavour Substances Flavour is imparted by volatile compounds* * Aldehydes, Ketones, Esters & Ethers Combination of volatile compounds Unique & desired flavour Some fruits contain essential oils which are also important flavour contributors. Some vegetable have strong flavour - Sulphur compounds Irritation behaviour of onion- Volatile sulphur compounds

20. Cont’d 6/ Pectic Substances derivatives of carbohydrates methylated polymer of galacturonic acid. Act as cementing substance between cells Stages of Pectic substance Protopectic- Insoluble molecule Present in unripe fruits gives firm texture to unripe fruits. Pectin (Pectinic acid)- Intermediate compound in ripe fruit Pectic Acid- Present in overripe fruits

21. Cont’d 7/ P olyphenols Polyphenols are phytochemicals Responsible for astringency & tartaric taste Protein- phenolic polymer interaction- complex formation Hazy precipitation observed in apple juice

22. 8) Enzymes contain a number of enzymes can have undesirable or desirable consequences. the post- harvest senescence and spoilage of fruit and vegetables; oxidation of phenolic substances in plant tissues by phenolase (leading to browning reaction; The phenolase changes the phenols into melanin, which has a brown colour. Fruit cut parts come in contact with air Release of Phenol oxidase on the cut surface Oxidation of Phenol to produce Quinones in the presence of polyphenol oxidase & air Polymerization of Quinones to form brown pigment (melanosis) & discoloration

23. Cont’d Factors essential for enzymatic browning are Presence of Oxygen Presence of enzyme in active form * Optimum condition (T ° =40- 50 ° C; pH= 6- 7) Ways to prevent enzymatic browning Cut of oxygen * CAS & MAP Inactivate enzymes * Blanching Other methods * Alteration of pH , applying antioxidants & reducing agents

24. Cont’d Starch- sugar conversion in plant tissues by amylases ;(Ripening) post- harvest demethylation of pectic substances in plant tissues CONTROL : temperature, water activity, pH, chemicals which can inhibit enzyme action, alteration of substrates, alteration of products and pre- processing control.

25. 6. Harvesting, handling and Postharvest changes The total time between harvesting and processing may also be an important factor in maintaining the quality and freshness of fruit. Minimizing the delays. Losses in fresh fruits between harvest and processing may be quantitative (e.g., water loss, physical injuries, physiologica l breakdown , and decay) or qualitative (e.g., loss of acidity, flavor, color, and nutritive value ). proximity of the processing centre

26. Cont’d Different harvest regimes for Fruits and vegetables Appropriate maturity stage required for optimum quality Cellular Respiration continue after harvest i.e. taking in O 2 and giving off CO 2 , heat and moisture mechanical damage during harvesting hastens respiration rate and spoilage Fruits continue to Respire Mature ripen Overripe

27. Maturity Vs Ripeness Maturity is the condition when the fruit is ready to eat or, if picked, will become ready to eat on further ripening. Ripeness is that optimum condition when color, flavor and texture have developed to the peak. Some fruits are picked when they are mature but not yet ripe (e.g. cherries, peaches, banana…).

28. Ripening: major post harvest change in fruits Ripening pattern vary , 2 categories Climacteric ripen after harvest Non Climacteric ripen before harvest Climacteric Non- Climacteric Apples Banana Mango Peach Plum Pawpaw avocado Citrus Cherry Pineapple melon strawberry

29. 6.1 Changes During Ripening The process of fruit ripening is chiefly regulated by a gaseous plant hormone called ethylene and different enzymes. Colour change (Green Yellow Orange Red) breakdown of chlorophyll (chlorophyllase). Synthesis or exposure of carotenoids and anthocyanin pigments occur Softening (Protopectin Pectic Pectic Acid) pectic enzymes hydrolysis of hemicelluloses

30. Cont’d Increase in Sugar content , Volatile substances, Essential oil, Astringent property, Decrease in Starch content and Acidity All these changes produce a pleasant flavour .

31. Cont’d The optimum temperature and humidity for ripening are about 20 oC and 90- 95 percent relative humidity. Ripening of fruits can also be done artificially by smoking.

32. 6.2 Chemical fruit ripening/Artificial Ripening Natural process of fruit ripening is accelerated by using certain chemicals. Known as Induced ripening Mostly applied for Banana & Mango Artificial inducers- smoking of Ethylene gas Calcium Carbide ( for Mango) Ethephon

33. Controlled storage conditions can extend the shelf life of produce Modified atmosphere packaging (MAP): Principle is to replace the internal atmosphere of fresh produce by flushing with nitrogen or carbon dioxide and this will lead to extension of shelf life GMP & GHP + MAP Inhibit spoilage / extend shelf life 7. Storage of Fruits and Vegetables

34. After flushing the material is sealed in a package to prevent oxygen entry . Normal air composition (78%, Nitrogen; 20% oxygen and 0.03% carbon dioxide) is modified within the package to: Reduces respiration Retards growth of aerobic organisms Cont’d

35. Controlled atmosphere storage(CAS): Principle is similar to MA storage involve modification of the gas composition. Reducing oxygen and increasing carbon dioxide in the store Combined with low temperature. Reducing rate of respiration

36. 8. Range of products Jams, Fruit Wines Marmalades Paste Purees Tomato Sauce Jellies, Juices, Canned products Freeze products

37. Fruit Juice Processing

38. Fruit Juice Processing * Farm / Market * Mature & mould free * Remove mouldy & badly damaged fruits * Use potable water * size & colour * Peeling & cutting (optional) * Skin & seed separation * Pre pasteurized (80-90°C for 10-15min); pre sterilized can /bottles Filling unpasteurized juice in bottles; Heating (88-90°C for 10- 20min) Cooling * Product name, Manufacturer, Composition, PD , BBF, Batch, Prod. Time * Cool, dry & Protect from light Inspection Washing Fruit Reception Sorting/Grading Pulping/Crushi ng Pasteurization Filling Labelling Storing Depending on the type of Juice Deaeration Centrifugation Preservatives

39. Fruit Juice Processing

40. Tomato Ketchup/ Sauce Processing

41. * Inspection (redness, MC, mature, clean, wholesome) * Size, Colour * Soaking in water (50°C), remove mud easily * T°= 55- 60°C * Pulper (skin & seed separation) *Pulp – flesh part * Vacuum evaporator * 25% or more TSS * Filling in sterilized bottles / cans TSS: Total Suspended Solid * No Ingredient  Tomato Paste * Product name, Manufacturer, Composition, PD , BBF, Batch, Prod. Time * Storage (0- 4°C) Ingredients Sorting Soaking & Washing Tomato Reception Slicing, Heating & Crashing Pulping Cooking & Concentration Filling & Pasteurization Labelling & Storing Formulation

42. Paste Made from any Fruit Tomato paste is common Production procedure Mashing any fruit to a smooth & thick mixture Boiling to evaporate water Mixing by constant stirring to prevent burning Concentration of solid in final product to 36% Pasteurize to prolong shelf life