Fruit and Nuts © PDST Home Economics
Nuts A fruit of a plant that consists of a hard shell surrounding a soft kernel Popular examples: Almonds, Brazil nuts, Cashew nuts, Coconuts, Hazelnuts, Pecans, Pistachio nuts, Peanuts (ground nuts/ monkey nuts), Walnuts
Nuts
Nutritive Value of Nuts Protein: Good source of LBV protein Fat: High in polyunsaturated fats therefore high in calories Carbohydrates: Good source cellulose especially peanuts & hazelnuts Vitamins: Small amount vitamins B Minerals: Contain Iron and Calcium Water: Low about 5%
% Composition of 100g of Peanuts Protein: 28.1% Fat: 49% Carbohydrates: 8.6% fibre Vitamins: B1 (0.23mg), B2 (0.10mg), Niacin (20mg) Minerals: Calcium (61mg, RDA 800mg), (Iron 2mg, RDA 10mg) Water: 5% Kilocalories per 100g: 586
Dietetic Value of Nuts Can function as a source of protein in a main course vegan dish Add texture & variety to meals Can be used in sweet & savoury dishes Keep well, easy to store Available whole, flaked, chopped, ground High in calories must be restricted in low calorie diets Some people are allergic to nuts and must avoid them
Uses in Cookery Vegan main course e.g. nut loaf or vegetable and nut stir fry Ingredient in many biscuits, cakes, sweets, desserts e.g. pear & almond tart Used in salads to add protein, fat, texture e.g. waldorf salad Toppings sprinkled on desserts e.g. flaked almonds on top of strudle. Healthy snack or part of packed lunch e.g. cashew nuts Almond paste (marzipan) icing on cakes or used for sweets
Fruits Eaten for vitamins especially vitamin C, minerals, antioxidants, fibre, water, colour, flavour texture
Classification of Fruit Citrus Hard fruit Stone fruit Berries Other Lemons Oranges Limes Grapefruit Plums Apricot Peaches Nectarines Cherries Mango **Avocados **Olives Blackberries Strawberries Blueberries Raspberries Gooseberries Blackcurrants Banana Pineapple Grapes Figs Dates Kiwi Rhubarb
Average Composition of Fresh Fruit Protein Fat Carbo-hydrates Vitamins Minerals Water 0.5% 0% 5-10% A, C Calcium Iron 80-90%
Nutritive Value of Fruit Protein: Fruit lacks protein. Fat: Fruit lacks fat except for avocados and olives. Carbohydrates: Sugar is in all fruit in the form of sucrose, glucose and fructose. Starch is found in under-ripe fruit. Pectin is found in ripe fruit cell walls Cellulose (fibre) is found in the cell walls also especially pears, apples, oranges, melons. Vitamins: All fruit has vitamin C especially blackcurrants, strawberries, citrus and kiwi. Yellow/orange/red fruit has beta carotene (pro vitamin A). Minerals: Small amount iron and calcium. Bananas good for Potassium. Water: All fruit has high water content.
Dietetic Value of Fruit Add greatly to the variety of colours, flavours and textures in the diet. Useful in low calorie diets, low cholesterol and high fibre diets because high in water & fibre and low in fat. Anti-oxidants vitamin C and beta carotene help prevent heart disease, cancer etc.. Can be eaten raw or cooked in a wide variety of sweet and savoury dishes. Healthy snack, cheap and needs no preparation except washing and perhaps peeling.
Buying & Storing Fruit Buying In season Usable amount Good quality, ripe Avoid pre-packed Firm, good colour, no discolouration or mould Storing Cool, dark, ventilated place. Use quickly Remove packaging Remove spoiled or damaged fruit
Preparing and effects of cooking Wash to remove chemicals Eat raw when possible Don’t peel or peel thinly Avoid steeping in water Use sharp stainless steel knife Effects of Cooking Vitamin C destroyed Minerals and vitamins dissolve into coking liquid Cellulose & texture softens Microbes killed Enzymes destroyed Absorb water and swell Over cooking causes loss of colour, texture flavour
Ripening of Fruit Ripening begins during growth and continues after harvesting Unripe fruit is less palatable than ripe Changes that happen during ripening: Enzymes change starch to sugar making fruit sweet and juicy Insoluble pectose changes to soluble pectin Ethylene gas that helps ripening is made in some fruit (bananas) Fruit changes colour, texture and flavour
Decaying of Fruit Once ripe, fruit only stays good for a while, then it decays Softer fruit with thin skin e.g. grapes, decay faster than hard fruit with tougher skin e.g. pears Changes during decay: Water loss and shrinkage Bruises & soft spots develop Enzymes and microbes attack the fruit Juices released onto surface make mould and yeast grow, these rot the fruit
Processing Fruit Method Suitable Fruit Effects Freezing Berries Apples Rhubarb Enzymes & microbes inactivated Texture changes – ice crystals Not much change to food value, colour, texture Canning Pears Peaches Mandarines Pineapple Change in colour flavour texture Loss of vitamin C Enzymes & microbes destroyed If canned in syrup, higher in sugar and calories Dehydration Raisins Prunes Figs Currents Loss of water and vitamins Enzymes and microbes destroyed Texture, colour and taste changes Higher in sugar due to less water Irradiation not allowed in EU Dried fruit Microbes and enzymes destroyed Prevents sprouting and decay Resembles fresh fruit, some vit loss
Organic Produce Grown without use of chemical fertilisers or pesticides or preservatives In Ireland 320 organic fruit & vegetable growers Increase demand due to awareness of dangers of overuse of chemicals Organic farming less intensive and must comply with rules on fertilisers, pest, weed and disease control Organic certificate can only be got from 3 agencies recognise by Dept of Agriculture: 1. The Irish Organic farmers and growers association. 2. Organic Trust Ltd. 3. Demeter Standards (Biodynamic Agriculture Association) Organic products will carry the symbol of one of these associations Because organic farming is more labour intensive and has lower yields products are more expensive
Symbols of Organic Certification Organisations