INTRODUCTION TO FOOD SCIENCE AND TECHNOLOGY AND THEIR PRODUCTS VEGETABLES- FRUITS. Chapter 18

Transcription

1 INTRODUCTION TO FOOD SCIENCE AND TECHNOLOGY VEGETABLES- FRUITS AND THEIR PRODUCTS Chapter 18

2 Part of plant that is eaten: Earth vegetables Roots Sweet potatoes, carrot Tubers Potatoes Bulbs Onion Herbage vegetables Leaves Cabbage, spinach, lettuce Petioles (leaf stalk) Celery Flower buds Cauliflower, artichokes Sprouts Asparagus Fruit-vegetables Legumes Peas, green beans Cereal Sweet corn Vine fruits Squash, cucumber Berry fruits Tomato, egg plant Tree fruits Avocado

3 Typical percentage composition of edible portion of foods of plant origin. Food CHO Protein (<3%) Fat (<0.5%) Ash Water (>70%) Potatoes 18,9 2,0 0,1 1,0 78 Carrots 9,1 1,1 0,2 1,0 88,6 (like milk) Radishes 4,2 1,1 0,1 0,9 93,7 Asparagus 4,1 2,1 0,2 0,7 92,9 Green bean 7,6 2,4 0,2 0,7 89,1 Peas 17,0 6,7 0,4 0,9 75,0 Lettuce 2,8 1,3 0,2 0,9 94,8* Banana 24,0 1,3 0,4 0,8 73,5 Orange 11,3 0,9 0,2 0,5 87,1 Apple 15,0 0,3 0,4 0,3 84,0 Strawberry 8,3 0,8 0,5 0,5 89,9 Melon 6,0 0,6 0,2 0,4 92,8

4 QUALITY OF FRUITS AND VEGETABLES Affected by: 1) Pre-harvest condition Botanical variety of fruits and vegetables Method of cultivation- irrigation frequency,fertilizer use, Soil composition, Climate and weather conditions during plantation and growth 2) Harvest condition Degree of maturity at harvest (unripe, mature-optimum for harvesting, ripe-optimum for eating, early senescence, senescence-unedible form ) Mechanical or hand harvesting condition

5 QUALITY OF FRUITS AND VEGETABLES 3) Post-harvest condition Transport conditions Storage conditions Processing conditions

6 QUALITY LOSS 1) Physical changes Loss of turgor [Equilibrium moisture level within cells]. Turgor depends on existing osmotic forces: the semi-permeable membrane allows for passage of water in and out (transpiration) When plant tissues are damaged during storage, freezing, cooking or from other causes, denaturation of the proteins of the cell membranes occur, resulting in the loss of permeationselectivity. Water and dissolved substances are free to diffuse out of the cells and leave the remaining tissue in a soft and wilted condition.

7 QUALITY LOSS 2) Chemical Changes: Vitamin C oxidation Change from starch to sugars(bananas) 3) Enzymatic changes: Enzymatic browning is due to polyphenol oxidase enzyme Tissue softening is due to pectinase enzymes. 4) Microbiological changes: Yeasts and molds: Example: Oranges can easily be infected with Penicillium digitatum. Antimicrobial agents can be used for avoiding them. CA-Controlled Atmosphere storage can also help.

8 Rate of resp. ideal for eatingclimacteric point harvest time FRUITS Climacteric fruits Continue ripening after harvesting. Apricots Peaches Banana Tomatoes Plums Non-climacteric fruits Do not ripen after harvesting. Grapes Cherries Oranges Strawberries (No climacteric point)

9 core Yield of SS juice: 40-50% of fruit ORANGE JUICE PRODUCTION Mechanical Washing Soil+dirt flavedo albedo segments Selection and sorting Juice extraction Filtering Spoilt fruits Solid wastes Deaerator Single strength (SS) juice 12-13% dry matter Concentration by evaporating (Juice Concentrate:65% dry matter)

10 SSjuice Juice Concentrate Pasteurization Aseptic packaging Bottles, cans, paper-packs Packaging Heat treatment: 1) 65 C 30 min 2) 135 C few sec. (HTST)

11 POST-HARVEST PRACTICES FOR VEGETABLES Receival of raw material Washing with jets of water Sorting-selection Dehydration Size grading Peeling, cutting, slicing Blanching (100 C, 5 min) Next slide Packaging [Dried vegetables or fruits] Freezing Packaging [Frozen vegetables]

12 Cooking Brining Deaeration Sealing of cans Retorting (~125 C, 25 min) Cooling Warehouse packing labelling Canned vegetables Getting rid of micro organisms

13 INTRODUCTION TO FOOD SCIENCE AND TECHNOLOGY BEVERAGES AND CONFECTIONERY PRODUCTS CHAPTER 19 CHAPTER 20

14 BEVERAGES Some beverages are consumed for their nutritive value (e.g. milk) yet others are consumed for their thirstquenching properties, for their stimulating effects, or simply because their consumption is pleasurable. Carbonated nonalcoholic beverages or soft drinks soda pop Nonalcoholic, non-carbonated stimulating beverages- coffee, tea. Carbonated or noncarbonated mildly alcoholic beverages beer, wine Distilled liquors: whiskey, vodka, gin, cognac, raki

15 Soft drink manufacture Treated water Syrup (all other ingredients*) tank Deaerator Syrup pump Metering (Synchrometer) CO 2 Cooler - Carbonator Can or bottle filter Container closure *sweeteners, flavours, colorants etc.)

16 BEER PRODUCTION (BREWING) Grains: barley (wheat or rice) Malt* bin Mashing: mild cooking Yeast(saccharomyces) Water Filtering Brewing Hops** Hops (Boil 2.5 hours) removing Starter tank *çimlendirilmiş arpa(enzymes) **şerbetçiotu(color, aroma) Fermentation 4.6%ethanol(9 days) Lagering(Aging) Yeast removing

17 BEER PRODUCTION Carbonation Filtering Can, bottle or barrel Rinsing or cleaning Filling Sealing or crowning Marketing Warehousing Palletizing Labeling Pasteurizing Case packing

18 WINE PRODUCTION Maturing of grape (natural yeast Saccharomyces ellipsoideus) Crushing of grapes SO 2 treatment Filtering(for white wines) Fermentation %alcohol (27 C 4-10 days) Racking Aging (several months to years) Clarification and stabilization pomace

19 WINE PRODUCTION If wine contains <17% alcohol; Heat pasteurization or cold pasteurization Bottling

20 COFFEE Both tea and coffee contain virtually no nutritional value in themselves and are consumed entirely for their refreshing and stimulating effect. Coffee beans Roasting (200 C 5 min) WATER Grinding Brewing Coffee cherry

21 Black Tea Withering the plucked leaves to soften them and partial drying Passing the withered leaves under rollers to rupture cell walls and to release the enzymes and juices Fermenting the rolled leaves by exposing them to air about 27 C 2-5 h. Drying the fermented leaves in ovens at about 93 C. 4% moisture, inactivating the enzymes.

22 CONFECTIONERY AND CHOCOLATE PRODUCTS(Ch. 20) Confectionary products s can be divided into two broad categories: Those in which sugar is the principal ingredient and Those which are based on chocolate. Sugar based confections include: nougats, fondants, caramels, taffees and jellies. Chocolate based confections: chocolate-covered confections, chocolate-panned confections, chocolate bars, chocolate-covered fruits, nuts and cremes. Many other ingredients including milk products, egg white, food acids, gums, starches, fats, emulsifiers, flavors, nuts, fruits, are used in candy-making.

23 Ingredients Sucrose: Sugar from sugar cane or beet. Invert sugar: Sucrose can be hydrolyzed by acids or enzymes into two monosaccharides glucose and fructose. The hydrolyzed mixture of fructose (levulose) and glucose (dextrose) is called invert sugar. Its use can prevent or help control the degree of sucrose crystallization. Corn syrups: Viscous liquids containing dextrose, maltose, higher sugars and dextrins that are produced by the hydrolysis of corn starch using acid or acid-enzyme treatment. Example: HFCS(high-fructose corn syrup)

24 Ingredients Sugar substitutes: The abilityof sucrose to cause dental cavities and its caloric content have led to the use of sugar substitutes in some confections. Bulk sweeteners (alcohol derivatives of sugars are not fermentable by bacteria in the mouth, do not contribute to cavities, but do have caloric values as sucrose, e.x. Sorbitol, xylitol, mannitol) High-intensity sweeteners (caloric and non-caloric) saccharin, sucralose, thaumatin, aspartame, Acesulfam K, do not have bulking or mouthfeel of sugar.

25 COCOA &CHOCOLATE PRODUCTION Fermented and dried beans Cleaning Roasting Breaking and winnowing Nib-shell mixtures Nib Shell germ Germ free nib Fig in Potter) Next

26 To Cocoa manufacture Milling Cacao mass (Chocolate liquor) 55%fat To Chocolate manufacture

27 COCOA-CHOCOLATE PLANT OPERATIONS Cocoa manufacture Chocolate manufacture Press cake Alkalization Removal of excess moisture Fat pressing Cocoa butter Addition of sugar, flavor, milk and cocoa butter Mixing Refining Conching Grinding Tempering Sifting Cocoa powder Molding Plain or milk chocolate Enrobing Chocolate coated goods