BT 1008: Plant Resources Lecture 5 - Vegetables PDF

BT 1008: Plant Resources Lecture # 5 Dr. Jinendra Dissanayake Department of Plant Sciences Syllabus ❖ Renewable and non-renewable resources ❖ Traditional uses and potentials of plants as sources of  Food & Beverage plants - Vegetables  Spice & Essential oils  Medici...

BT 1008: Plant Resources Lecture # 5 Dr. Jinendra Dissanayake Department of Plant Sciences Syllabus ❖ Renewable and non-renewable resources ❖ Traditional uses and potentials of plants as sources of  Food & Beverage plants - Vegetables  Spice & Essential oils  Medicines  Wood & Fiber products  Natural products and processing (eg. Latex, narcotics?)  Alternative energy resources  Environmental sensors ❖ Sustainable utilization and conservation of plants Vegetable Crops  Vegetables ❖ These are the edible plants/ plant parts which are eaten cooked or raw ❖ Many plant parts are used as vegetables ✓ soft stems ✓ leaves ✓ flowers & inflorescence ✓ underground storage organs ✓ fruits ✓ seeds and seedlings  Vegetables Vegetables can be broadly grouped into three categories: eg. ❖ Earth vegetables ❖ Fruit vegetables ❖ Leafy vegetables Do you know what earth vegetables are ? Can you give an example for such a vegetable? Earth Vegetables = Root crops  Root crops ❖ These included roots, stems or leaves forming underground storage organs ❖ Underground parts are fleshy with high water content ❖ Therefore, cannot easily be stored/ transported/ marketed ❖ High in carbohydrates, low in proteins and fats ❖ Staple food in some areas/ countries South Most production is concentrated in Central and America, Central Africa and South and East Asia. The main producers are China, Nigeria and ❖ Consumed as vegetables Brazil.  Solanum tuberosum (Potato) ❖ Belongs to Family Solanaceae ❖ First domesticated in Peru ❖ Then, Spanish introduced it worldwide Have you seen a potato plant, flowers and fruits ? Sprouting potato - can be toxic due to Solanine, an alkaloid present in sprouts Do you want to grow your own potatoes? In potatoes, ❖ Lower branches grow into soil, then the tips swell due to storage of food, and form into tubers ❖ Grown in cool moist climate ❖ Uses ✓ A staple food in temperate region ✓ A vegetable in tropical region ✓ Used for feeding livestock ✓ Industrial uses: produce starch, industrial alcohol, alcoholic beverage, dextrin and adhesives solanine Manihot esculenta (Manioc/Cassava)  Manihot esculenta ❖ Belongs to Family Euphorbiaceae ❖ Origin - Brazil ❖ It is a lowland tropical crop ❖ Important as a starch source in many African, South American countries ❖ Short lived shrub paduru ❖ We eat tubers which are swellings on adventitious roots ❖ 5 -10 tubers per plant ❖ Edible part – pith  Manihot esculenta ❖ Contains a cyanogenic glycoside – Linemarin gives a ‘bitter’ or ‘sweet’ based on concentration ❖ Linemarin is hydrolyzed to HCN (Hydrocyanic acid, extremely poisonous) in the presence of the enzyme linamarase. It happens when tissue is damaged (specially, during cooking) ❖ Uses  Eaten boiled or roasted tubers  Cassava flour is available  Tapioca  Used to prepare alcoholic beverages  Starch is used as food, adhesives, laundry, paper  Ipomoea batatas (Sweet potato) ❖ Belongs to Family Convolvulaceae ❖ We eat tubers produced by adventitious roots from nodes. ❖ There are yellow fleshed varieties due to high vitamin A. ❖ Uses  Eaten as boiled or baked tubers  Made into flour  Source of starch, alcohol  Aroids ❖ They are the members in Family Araceae ❖ They are Herbaceous monocots ❖ We eat tuberous rhizome or corms ❖ It is a staple food in some tropical countries ❖ Calcium oxalate is accumulated in leaves, tubers of these plants and can be poisonous. ❖ Uses  Corms – boiled, baked or roasted  Young leaves – vegetable  Some examples for aroids Alocasia macrorrhiza (Habarala) Stem modified to form a corm below the soil surface Colocasia esculenta (Gahala) Cylindrical corm Xanthosoma sagittifolium (Kiri ala) Long flask shaped tubers  Dioscoreas = Yams ❖These are the members in Family Dioscoreaceae ❖ Herbaceous climbers with rhizomes or tubers  Yams ❖ A staple food in some tropical countries ❖ Eaten boiled or roasted  Dioscorea alata – Purple yam  D. esculenta – Lesser yam  D. bulbifera – Air potato  ……………… Elephant yam Other than potatoes, sweet potatoes and manioc, have you hadseen/ eaten ariods and yams ? Similar to ‘underutilized fruits’, there are local root crops (eg. yams and aroids) which are considered as ‘underutilized root crops’. Have you seen “Innala” in the market like this? Up to now, we leant about the root crops that are mainly eaten as staple food. These also can be used as a vegetable. Next, we learn about the root crops mainly used as vegetables. Root crops mainly used as vegetables  Daucus carota (Carrot) ❖ Occur in Mediterranean region  What colour are carrots?  Daucus carota (Carrot) ❖ Family Umbiliferae ❖ Herbaceous biennial - harvested annually ❖ Has a short stem with a tapering tap root ❖ Food is stored in outer cortical region ❖ Contain antioxidants which may protect against cancer ❖ Uses  Beta vulgaris (Beet) ❖ Family Chenopodiacea ❖ It has a short stem with spherical tuberous tap root ❖Two groups of cultivars Sugar beet & Table beet ❖ Contains Betanin, an antioxidant ❖ Uses Root crops in Family Cruciferae Fleshy tap root is consumed in them. ❖ Raphanus sativus (Radish) ❖ Brassica rapa (Turnip)  Root crops in Family Alliaceae ❖ Underground storage organ is a bulb (formed by thickening of leaf bases due to storage of food) ❖ Used as a vegetable or seasoning agent  Allium cepa (Onion) ❖ Biennial herb grown as an annual ❖ The outer leaf bases are thin, fibrous and dry followed by leaves with thickened bases ❖ Characteristic odour due to Sulphur compounds (an enzymatic action during tissue injury) A. cepa var. aggregatum A. cepa var. cepa  Allium sativum (Garlic) ❖ Bulbs are composed of a disc like stem, thin dry scales (the bases of foliage leaves) and small bulbs/cloves (axillary buds) ❖ Used for seasoning of food and as medicine since ancient times  Allium ampeloprasum var porrum (Leeks) ❖ A little or no bulb formation ❖ Leaves (leaf sheath) used as a vegetable and for seasoning  Use of garlic in ancient times File:All Gizah Pyramids.jpg “Archeologists have discovered paintings of garlic, dating back to 3200 B.C, in Egyptian tombs.”  Vegetable Crops ❖ Earth vegetables ❖ Fruit vegetables ❖ Leafy vegetables Fruit Vegetables  Fruit Vegetables ❖ Botanically, these are fruits, but eaten cooked. ❖ Not a concentrated source of nutrients ❖ Provides supplementary dietary substances (vitamins, minerals) and adds variety and flavour to our meal. ❖ Fruits and seeds of legumes and even cereals can be used as vegetables. eg.You already know some examples under legumes, cereals and fruits  Lycopersicon esculentum (Tomato) ❖ Family Solanaceae ❖ Origin – South America ❖ Fruit type – Berry ❖ Uses ✓ Eaten cooked, or raw in salad ✓ Seed oil used in salad oil, margarine, soap ❖ Tomato is the model organism for studying of fruit ripening ❖ The Flavr Savr TM (1994) ✓ A slow-ripening tomato variety ✓ The first genetically modified food item to be given license for human consumption ✓ Used an antisense approach to prevent production of polygalacturonase (PG) ✓ Due to which ripening is delayed ✓ Therefore, has a longer shelf life  Vegetables in Family Solanaceae Solanum melongena (Eggplant/ Brinjal) Capsicum annum var grossum (Sweet pepper/ Capsicum) the quality of having a sharp ❖ Variable colour and pungency strong smell or taste: Due to the chemical “Capasaicin” (Spiciness is measured in SH units) ❖ has < 100 Scoville Heat Unit (SHU) dried sweet peppers ground to to a fine powder. like miris kudu Paprika powder is made from sweet bells and use to make curries red.  Vegetables in Family Cucurbitaceae eg. melons, cucumber, gourds ❖ Fruit type – Pepo Cucurbita maxima (Pumpkin)  Has a South American origin  It is a herbaceous annual vine Have you heard of the “Giant pumpkin” ?  Giant pumpkin ❖ Recorded in 2016 (October 2016) ❖ Weighed 1026 kg Giant pumpkin Giant Pumpkin Regatta - a sporting event rowing on a pumpkin Cucumis sativus (Cucumber) ❖ Uses Benincasa hispida (Ash gourd) ❖ Large fruit – white flesh covered with white wax ❖ Vegetable and used in confectionary Lagenaria siceraria (Bottle gourd) ❖ Young fruit use as a vegetable ❖ Mature fruit is used as multipurpose containers Luffa acutangula (Ridged gourd) ❖ Young fruit is used as a vegetable Luffa cylindrica (Smooth loofah) ❖ Mature fruit as a bath sponge ❖ Young fruit as a vegetable Luffa Products Momordica charantia (Bitter gourd) ❖ Has a pendulous green fruit ❖ Immature fruit ✓ bitter taste ✓ Therefore, steeped in salt water Trichosanthes anguina (Snake gourd) ❖ Long cylindrical fruit with tapering ends  Other fruit vegetables Hibiscus esculentus (Okra/Ladies finger) ❖ Family Malvaceae ❖ Tender fruit (high mucilage content) Artocarpus altilis (Bread fruit) ❖ Fruit type - syncarp (formed from whole inflorescence) ❖ Large axis with aborted flowers – edible portion  Other fruit vegetables Artocarpus heterophyllus (Jack fruit) ❖ Large syncarp with hexagonal spines. ❖ Edible part – perianth ❖ Mature and immature fruits as well as ripe fruit are eaten.  Vegetable Crops ❖ Earth vegetables ❖ Fruit vegetables ❖ Leafy vegetables  Leafy vegetables ❖ Stem/ leaves of leafy vegetables eaten raw/ cooked ❖ Has a high water content ❖ Has high in salts, vitamins and fibre  Leafy vegetables Brassica oleraceae var. capitata (Cabbage) ❖ Short thickened stem surrounded by overlapping leaves in whorls (forms compact head) Brassica oleraceae var. botrytis (Cauliflower) ❖ Edible part – fleshy inflorescence and leaves ❖ Brassica oleraceae var. gemmifera Edible buds ❖ Brassica oleraceae var. gongylodes Swollen stem Lactuca sativa (Lettuce) ❖ Leaves arranged spirally in rosettes  Tropical herbage vegetables Mostly they are annuals Eaten cooked or raw ❖ Amaranthus spp. (Thampala/Amaranth) ❖ Centella asiatica (Gotukola) ❖ Basella alba (Spinach) ❖ Alternanthera sessilis (Mukunuwenna) Meat Analogue  Wrap up ❖ Edible plants which are eaten cooked or raw ❖ Many plant parts are used as vegetables - soft stems - leaves - flowers and inflorescence - underground storage organs - fruits - seeds and seedlings ☺ In this session, we have learnt ❖ Traditional uses and potentials - Food sources Cereals Legumes Fruits Vegetables In next session, we will learn about ❖ Traditional uses and potentials as - Beverage Plants  Possible questions ❖ From which plant do you obtain tapioca? ❖ Give an example for an edible aroid. taro(purple yams) ❖ Give two examples for root crops where the tap root is the edible part. carrot beet