Friday, 23 May 2014
The pungency or heat of a pepper depends on seven closely related alkaloids or capsaicinoids. In the early 1900s, Wilbur L. Scoville devised a test to determine the relative hotness of different peppers.
Capsaicin from a known weight of pepper was extracted with alcohol and mixed in various concentrations with sweetened water. Human tasters were asked to identify the point at which water neutralized the hotness.
The volume of water required for each sample was assigned a rating in Scoville units—the larger the number, the more water needed and the hotter the pepper. A high-pressure liquid chromatography test replaced this technique in the early 1980s, but the measurements are still expressed in Scoville units.
The following peppers are listed from most hot to least hot, according to Scoville units.
- Caribbean Red_______________________100,000–445,000
- Red _______________________________80,000–285,000
- Scotch Bonnet________________________80,000–260,000
Wednesday, 21 May 2014
GUAR is an important leguminous crop which is extremely drought resistant and can be grown in semi-arid regions. The guar bean has a large endosperm, which contains significant amounts of primary marketable product, guar gum.
The guar gum, also called guaran, is extracted from the seed of the leguminous shrub Cyamopsis tetragonolobus (Leguminosae), which is grown in arid and semi-arid regions of Sindh and Punjab. It is termed as the best substitute for locust bean gums. Manufacturing of gum from its beans gives such astonishing results that it is considered 'white gold'.
The guar is dicotyledonous (oval-shaped) seed having a diameter of about 8mm. Galactomanan is the essential ingredient of guar that gives it unique thickening, binding and stabilising properties.
In order to obtain pure galactomanan, the endosperm is separated from the hull and germ. The relative composition of a guar seed comprises 14-17 per cent hull, 43-47 per cent germ and 34-36 per cent endosperm. The production process is optimised to extract maximum levels of galactomanan from seeds of differing content by using a multi-stage grinding and sifting process. Guar is used as cattle feed and green manure and can be eaten as a green bean.
Guar plant grows well under a wide range of soil conditions. It thrives best in fertile, medium textured and sandy loam soils, with good structure and well-drained subsoil. Under irrigated condition it should be sown from April to July but in rain-fed regions sowing should be completed before monsoon.
The plant cannot stand water-logging conditions, although it is considered to be tolerant to both soil salinity and alkalinity. The crop tolerates high temperatures and dry conditions, and is adapted to arid and semi-arid climates. Ideally, guar requires two showers before sowing, one spell during budding and another one at the time of blossoming. Too much of precipitation can lead to vigorous vegetative growth, reducing the number of pods and/ or the number of seeds per pod, affecting the size and yield of seeds.
Guar is a photo-sensitive crop and it flowers and matures when sown in the kharif season. On maturity, the seedpods are brown and dry, and seed moisture content is less than 14 per cent. During harvesting, small plants are either uprooted or cut from the stem and kept in the open for drying. Seeds are taken out of the beans, either mechanically or manually at the farm level, so that they do not shatter.
The properties of guar powder, which make it useful in various applications, include its easy solubility in cold and hot water, film forming ability, resistance to oils, greases and solvents, good thickening agent, water binding capacity, high viscosity and functioning at low temperatures. Given the versatility in its use for food, feed and industrial applications, guar and its derivatives attract good demand from the industrial/food-processing sector. It is a useful fodder crop and as a leguminous plant it also adds nitrogen to the soil, thereby enriching soil quality. Crop residues (stubble and header trash) are a source of valuable, high protein animal feed. The crop can also be used to produce high quality hay.
Its seed (bean) is mainly used to produce guar gum, which has wide-ranging applications. In cosmetics, especially shampoos and toothpastes, guar gum is used primarily as a thickening and suspending agent. In beverages, it is used as stabiliser for preparing chocolate drinks and juices. Guar is also widely used in tobacco, leather, insecticides and pesticides, crayons, adhesives etc. Industrial application of guar gum includes the textile industry where guar gum's excellent thickening properties are used for textile sizing, finishing and printing. In the paper industry guar is used as an additive where it gives denser surface to the paper used in printing. In the explosive industry guar is mixed in ammonium nitrate, nitroglycerine and oil explosives, where it helps maintain the explosive properties of the product even in wet conditions. Guar is an important natural food supplement with high nutritional value, for weight gain and cholesterol reduction.
End uses of guar India accounts for 80 per cent of the total guar produced in the world and 70 per cent is cultivated in Rajasthan. Pakistan, Sudan and parts of US are the other major guar growing countries. Over 75 per cent of guar gum or their derivatives produced in India are exported mainly to US and European countries.
The consumption pattern of guar seeds is largely determined by the demand from the petroleum industry of the US and the oilfields in the Middle East. The US alone contributes to around 70,000 tons of guar and its derivatives demand. Also, in rest of the world, the trend of consumption has increased with time that has lead to the introduction of this crop in many countries
The world's total production of guar seed hovers around 10-15 lakh tones. In Pakistan, guar is grown in Punjab, Multan, Muzaffargarh, Layyah, Mianwali, Sargoda, Bahawalpur, Banawalnagar and Sindh province. Global demand for guar seed has increased over the years with a steep rise in demand in the recent times on account of its increasing use in petroleum industry.
The production of guar in Pakistan has slightly declined. Churi and Korma are in a good demand for cattle feed in domestic as well as overseas markets as the prices of oil meal are quite high this year. So, the overall fundamentals of guar looks strong as decline in arrivals expected in the off-season is likely to bring some premiums to the prices in the coming months.
There is an urgent need to make a plan to develop varieties with high production of guar gum. The production of guar and guar gum could be increased as it can be used inoil well drilling, ice cream, dairy products soups and gravies, bakery products, noodles, pet food, textile cosmetics pharmaceuticals explosives and mining industries. It is a natural product so it can be used in food products without any hazards.
There is possibility to grow two crops of guar in a year provided irrigation facilities are present. The world market for guar gum is estimated at somewhat 2-2.5 lakh tons annually. Guar should be promoted as a cash crop and should not be ignored and attention on it should be given as to other crops like cereals, fibre and oilseed crops.
Tuesday, 20 May 2014
Extraordinary full-length shot of the 'President': this 3,200-year-old tree is so huge it took 126 photos to show it all
- Tree in Nevada's Sequoia National Park is 3,200 years old and 247 feet tall
- National Geographic captured full-length shot using innovative technique
- Judged on mass, the 'President' is 'likely the biggest' tree on the planet
By KATE LYONS
Meet the ‘President’.
The giant sequoia tree in Nevada’s Sequoia National Park is 3,200 years old, has 2 billion leaves and stands 247 feet (74 metres) tall.
The portrait of the giant tree, taken by National Geographic, is actually a mosaic, made up of 126 photographs in order to capture the stunning full-length shot.
The President is by no means the tallest tree in the world – that honour goes to a California redwood, which stands 379 feet (116 metres) tall – but in terms of mass, it is one of the largest.
‘We know that there are trees that have bigger trunks, but when you add up all of the wood beside the main trunk – all of the limbs, all of the branches, all of the bio-mass above the ground – this tree is likely the biggest,’ said Steve Sillett from Humboldt State University.
The stunning shot of the tree was featured as a five page fold-out in the December 2012 edition of National Geographic.
‘The reason we want to do these portraits – people get it. When they see the tree in its totality without distortion, they gasp,’ said photographer Michael Nichols.
The photographic team captured the pictures using an innovative rigging technique, which was pioneered by Mr Nichols in 2009, when created an 84-image composite of a 300-foot-tall redwood tree.