To achieve a more even wither turning over the leaf carefully once or twice is suggested. The upward passage of air through the bed of leaves usually results in the bottom of the bed being withered first and the upper leaves last. The ideal qualities of air required for withering are low dry bulb temperatures and high hygrometric differences with ample supply. The good essence of withering is well ventilated withering lofts and access of drawing large volumes of air by the trough fans. So, in a well designed, balanced factory, an optimum load of 30kg per meter square for a peak crop anticipated in a single day has been the basis for the design of trough capacity. The other fan supplies air just to control any heat developed. Conservation of electrical energy is also possible by switching “off” one of the fans after the required degree of physical wither is achieved. Reasonably even – wither is achieved in wider troughs. Sizes vary between 12′ and 15′ of width and 60′ and 120′ of length. However, nowadays wider troughs with two axial fans are preferred. The width of the standard (conventional) trough is 6′ and its length varies between 60′ and 120′. The dimensions of the trough in most of the factories vary considerably. But the dry bulb temperature of air after mixing should not exceed 35☌.Ĭurrently in most of the south India tea factories trough withering is practiced. Whenever the hygrometric difference is below 3☌, hot air is mixed in suitable proportion or heat energy is supplied to increase the hygrometric difference with the concomitant rise in the dry bulb temperature of air. The current of air performs a two functions viz., conveying heat from the leaf as well as carrying away the water vapor through a bed of green leaves to achieve physical withering. The evaporation of moisture in the green leaf is brought about by blowing or moving air over the leaf in the withering trough. WITHERING is the first and fore most steps involved in tea manufacture. Steps in CTC tea manufacture includes, withering of harvested crop, green leaf shifting, reconditioning, rolling, fermentation, drying, grading & sorting and packing. But this process results in teas with good flavor and aroma. The maceration is less as against CTC processing. In orthodox type of manufacture, the withered leaves are rolled on specially designed orthodox rollers which twist and crush the leaves thereby rupturing the cells. Enzymatic action is higher in the CTC type of manufacture. There is complete maceration of the leaves and the resulting powdery material is referred to as “cut dhool“. CTC refers to the Crush, Tear & Curl process where the withered green leaves are passed in-between two rollers rotating in opposite directions. Tea manufacturing is normally carried out in two ways, (i) CTC and (ii) orthodox. This results in the initiation of a series of biochemical and chemical reactions with the uptake of atmospheric oxygen and formation of oxidized polyphenolic compounds that are characteristic of tea along with volatile flavor compounds that impart characteristic aroma to tea. Large schools of feeding black drum have been known to dredge the ocean floor and leave turbid plumes that are visible from the air.Black tea manufacturing technology essentially involves disruption of the cellular integrity of tea shoots, thereby enabling the mixing up of substrates (polyphenols) and the enzymes (polyphenol oxidases). Use their barbels to sense food and pharyngeal teeth to crush and consume shellfish. Larger drum feed on hard-shelled mollusks such as oysters, clams, and mussels. Young black drum feed on amphipods, mollusks, marine worms, shrimp, crabs, and small fish. The drumming sound created by schools is loud enough to be heard outside of the water. During spawning, males and females produce a loud drumming sound by vibrating muscles against their swim bladder. Females can produce 11 million to 60 million eggs each year. Highly productive, spawning 20 to 30 times during a season. Spawn from January through April in the Gulf of Mexico, congregating in large schools in waters between 10 to 165 feet deep. Adults are found offshore and inshore along the coast, depending on the season. Juveniles inhabit shallow estuarine nursery areas and move to open bayous and bays by their first summer. Bottom dwellers, commonly found around structure such as oyster beds, docks, and bridge pilings. Abundant in the northern Gulf of Mexico, especially near the Mississippi River Delta. Native to the Atlantic Coast of North America from New England through the Gulf of Mexico and down to South America.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |