Classification of Fruits & Their Uses — Composition, Pigments, Ripening, Browning & Culinary Applications
Food Production · Part 4 · Module 7
Classification of Fruits & Their Uses — Composition, Pigments, Ripening, Browning & Culinary Applications
Fruits are nature’s most versatile culinary ingredient — raw, cooked, preserved, carved, juiced, and garnished. From the chemistry of ripening to the enzyme causing browning, here is the complete guide to fruit science and cookery.
🍎 5 Classifications of Fruits
🍑 Stone Fruits
Apricots, Cherries, Damsons, Greengages, Nectarines, Peaches, Plums
🍏 Hard Fruits
Apples, Crab Apples, Pears
🍓 Soft Fruits
Bilberries, Blackberries, Black/Red Currants, Blueberries, Cranberries, Grapes, Gooseberries, Loganberries, Raspberries, Strawberries
🍋 Citrus Fruits
Lemons, Oranges, Limes, Grapefruit, Mandarins, Clementines, Kumquats, Pomelos, Tangerines, Tangelos
🌴 Tropical Fruits
Bananas, Carambola (Starfruit), Dates, Figs, Guavas, Kiwifruit, Lichees, Mangosteens, Mangoes, Melons, Passion Fruit, Papayas, Persimmons, Pineapple, Rhubarb, Sharon fruit
🔬 Fruit Composition
Nutritive Value of Fruits
✦ Fruits = very poor source of protein and fat. Exception: Avocado (28% fat)
✦ High moisture content (75–90%) → highly perishable
✦ Good source of fibre · Poor source of calories · Exception: Banana (good calorie source)
✦ Ripe fruit: higher sugar (sucrose, fructose, glucose) than unripe
✦ Poor source of iron. Exceptions: Watermelon, Custard Apple (Sitaphal)
✦ Best source of Vitamin C: Guava. Citrus fruits also good sources
✦ Apples: provide mainly fibre, little nutritive value
✦ Jackfruit flavour = due to 13 esters
✦ High moisture content (75–90%) → highly perishable
✦ Good source of fibre · Poor source of calories · Exception: Banana (good calorie source)
✦ Ripe fruit: higher sugar (sucrose, fructose, glucose) than unripe
✦ Poor source of iron. Exceptions: Watermelon, Custard Apple (Sitaphal)
✦ Best source of Vitamin C: Guava. Citrus fruits also good sources
✦ Apples: provide mainly fibre, little nutritive value
✦ Jackfruit flavour = due to 13 esters
🎨 Fruit Pigments
4 Fruit Pigments
Chlorophyll (Green): Guava, gooseberry, country apples
Carotenoids (Yellow/Orange): Mangoes, papaya, orange, musk melon, jackfruit, peaches, pineapple
Anthocyanins (Red/Blue/Purple): Grapes, blueberries, plums, cherries
Anthoxanthins (White/Cream): Guava, apple, gooseberry, pears, custard apple, banana
Carotenoids (Yellow/Orange): Mangoes, papaya, orange, musk melon, jackfruit, peaches, pineapple
Anthocyanins (Red/Blue/Purple): Grapes, blueberries, plums, cherries
Anthoxanthins (White/Cream): Guava, apple, gooseberry, pears, custard apple, banana
🌱 Ripening of Fruits
Chemical Changes During Ripening
Enzymes that increase during ripening: Lipase, Peptic Enzymes, Invertase, Chlorophyllase, Peroxidase
Changes during ripening:
✦ Colour: green → yellow/orange/red (chlorophyll breaks down, carotenoids/anthocyanins exposed)
✦ Softening: protopectin → pectin → (over-ripe) pectic acid
✦ Decrease in acidity · Increase in sugar · Increase in volatile substances and essential oils
✦ Starch → Sugar: Banana at harvest = 20% starch + 1% sugar → reversed when ripe
✦ Astringency decreases
Optimum ripening conditions: ~20°C temperature + 90–95% relative humidity
Artificial ripening: Smoking also used to ripen fruits
Changes during ripening:
✦ Colour: green → yellow/orange/red (chlorophyll breaks down, carotenoids/anthocyanins exposed)
✦ Softening: protopectin → pectin → (over-ripe) pectic acid
✦ Decrease in acidity · Increase in sugar · Increase in volatile substances and essential oils
✦ Starch → Sugar: Banana at harvest = 20% starch + 1% sugar → reversed when ripe
✦ Astringency decreases
Optimum ripening conditions: ~20°C temperature + 90–95% relative humidity
Artificial ripening: Smoking also used to ripen fruits
🍎 Browning in Fruits
Enzymatic Browning — How & Prevention
Cause: When tissues cut/injured → polyphenolase enzyme contacts polyphenols → oxidises to orthoquinones → polymerize to brown pigments. Examples: cut apple, banana.
Optimum pH for polyphenolase: 5–7. Optimum temp: 43–50°C
Prevention Methods:
1. Heat (Blanching): 100°C for 2–10 minutes inactivates enzyme
2. Acid (pH change): Citric acid or malic acid (lemon juice) → lowers pH to 4.0 → inhibits enzyme
3. Antioxidants: SO₂, sulphites, bisulphites, sodium metabisulphite dip
4. Remove oxygen: Vacuum packing, water submersion, coating with syrup
Optimum pH for polyphenolase: 5–7. Optimum temp: 43–50°C
Prevention Methods:
1. Heat (Blanching): 100°C for 2–10 minutes inactivates enzyme
2. Acid (pH change): Citric acid or malic acid (lemon juice) → lowers pH to 4.0 → inhibits enzyme
3. Antioxidants: SO₂, sulphites, bisulphites, sodium metabisulphite dip
4. Remove oxygen: Vacuum packing, water submersion, coating with syrup
Culinary Uses of Fruits
Fruit drinks · Garnishes · Sauces · Coulis · Chilled soups · Salads · Jams and Jellies · Fruit carving (now a professional career specialisation)
🎯 UGC NET Key Points — Part 4 Module 7
◆ 5 fruit classifications: Stone, Hard, Soft, Citrus, Tropical
◆ Avocado = exception → 28% fat · Watermelon/Custard Apple = good iron sources
◆ Best Vitamin C source: Guava · Good calories: Banana
◆ Jackfruit flavour: due to 13 esters
◆ 4 fruit pigments: Chlorophyll (green) · Carotenoid (yellow/orange) · Anthocyanin (red/purple) · Anthoxanthin (white)
◆ Ripening enzymes: Lipase, Peptic Enzymes, Invertase, Chlorophyllase, Peroxidase
◆ Banana harvest: 20% starch + 1% sugar → reversed when ripe
◆ Ripening optimum: 20°C + 90-95% RH
◆ Enzymatic browning: polyphenolase enzyme + polyphenols + O₂ → brown pigments
◆ Prevention: Blanching / Citric acid / Sulphites / Remove oxygen
◆ Avocado = exception → 28% fat · Watermelon/Custard Apple = good iron sources
◆ Best Vitamin C source: Guava · Good calories: Banana
◆ Jackfruit flavour: due to 13 esters
◆ 4 fruit pigments: Chlorophyll (green) · Carotenoid (yellow/orange) · Anthocyanin (red/purple) · Anthoxanthin (white)
◆ Ripening enzymes: Lipase, Peptic Enzymes, Invertase, Chlorophyllase, Peroxidase
◆ Banana harvest: 20% starch + 1% sugar → reversed when ripe
◆ Ripening optimum: 20°C + 90-95% RH
◆ Enzymatic browning: polyphenolase enzyme + polyphenols + O₂ → brown pigments
◆ Prevention: Blanching / Citric acid / Sulphites / Remove oxygen