TAMILNADU AGRICULTURAL UNIVERSITY Department of Soil Science and Agricultural Chemistry B.Sc (Agri) III Year-V Semester (2015-16) Mid Semester Examination SAC 301 - Crop and Pesticide Chemistry (2+1)
Date: 05.11.2015 Part- A
Time Duration – 1 Hour Choose the correct answer by
Max. Marks : 20 (15x0.5 = 7.5 marks)
A1. Wheat protein, which is responsible for elasticity__________ b) Gluten
a) Glutamine
c) Aleuron
d) Lipids
A2. The keeping quality of sesame oil is due to------------a)
Sesamol
b) Sesamolin
c) Sesamin
b) Filtration
c) Destraching
d) Samin
A3. Zein is extracted by a) Digestion
d) Reverse osmosis
A4. The spicy nature of chillies is due to ---------------------a) Capsanthin
b) Zeaxanthin
c) Cryptoxanthin
d) Capsaicin
A4. Palm oil is red in colour is due to _____________ a) β-carotene.
b) Mesocarp
c) Cholesterol
d) LDL and HDL
A6. The cyanogenic glucoside present in young sorghum seedlings is ----------------a) Dhurrin
b) Hordenine
c) Tomatine
d) Solanine
A7. The enzyme responsible for the inversion of sucrose in sugarcane is ----------a) Oxidase
b) Sucrose synthase
c) Phosphatase
d) Invertase
A8. Process of hydrolysis of fat by alkali is termed as ------------------a) Esterification
c) Saponification
b) Hydrogenation
d) Halogenation
A9. The coconut contains ___________ as predominant acid a) Oleic acids
b) Lauric acid
c) Linoleic Acid
d) Myrsitic acid
A10. The toxic principle present in subabul fodder crop is -----------------a) Oxalic acid
b) Saponin
c) H+CN-
d) Mimosine
A11. Why sunflower oil is recommended for heart patients? a) Saturated FFA
b) Un-saturated FFA
c) Lysine
d) Lauric acid
A12. Types of fibre’s__________ a) Yarn
b) Lint
c) Fuzz
d) All of them
A13. Which one of the following is leaf fibre________ a) Jute
b) Sisal
c) Flax
d) Sunn hemp
A14. The dose required kill 50% of the test organism is defined ________ a) EC50
b) LC50
c) LD50
d) All of them
A15. Which one of the following is plant origin pesticide a) Bacillus thuringiensis
b) Pyrethrum
c) Monocrotophos
d) Imidacloprid
Fill up the blanks
5X0.5=2.5
Lycopene A16. ________________________ pigment is responsible for the color of the tomato Polyphenol oxidase A17. The discoloration of brinjal fruit is due to high ______________________ activity Methionine A18. __________________amino-acid is the precursor of ethylene production in fruit tissue Charantin A19. Plant insulin present in bitter-gourd is _____________________________ Oxygen Radical Absorbance Capacity A20. ORAC expand _______________________________________________ Part-B: Short Notes Question B1 is compulsory and answers any four (Word Limits: Not Exceeding a Page) (1 X 2 = 2 mark) B1.Explain the steps involved in the biosynthesis of carbohydrates. Starch can be chemically fractionated into two types of glucan polymer: amylose and amylopectin. Amylose consists of predominantly linear chains of α- (l4)-linked glucose residues, each -1000 residues long. Amylose is usually branched at a low leve1 (approximately one branch per 1000 residues) by α-(1-6) linkages and makes up -30% of starch.
OR Chemical composition of Groundnut and its oil -Refer-
(4 X 2 = 8 mark) B2.Enlist and explain the antinutritional factors in cereals and its significance. Cereals are used as staple food almost all over the world. Cereals have rich in carbohydrates, vitamins and minrals. Minerals play a vital role in the maintenance of human health. Cereals and legumes are rich in minerals but the bioavailability of these minerals is usually low due to the presence of antinutritional factors such as phytate, trypsin inhibitor and polyphenoles. Phytic acid is most important anti-nutrient because it is found in most of the cereals and have strong ability to complex multi-charged metal ions, especially Zn, Ca and Fe and make them unavailable for human body utilization. The simple traditional household technologies such as roasting, germination and fermentation, cooking and soaking have been used to process the cereal in order to improve the nutritional quality.
B3.Briefly discuss about the post harvest changes that occur during ripening of fruits. Several major changes take place as fruits ripen, and taken collectively they characterise ripening processes. They include: Changes in carbohydrate composition, resulting in sugar accumulation and increased sweetness; Change in colour; Flesh softening and textural change; Formation of aroma volatiles; Accumulation of organic acids with associated development of flavour. B4.Enumerate the byproducts of sugarcane ant its uses.
Molasses Molasses is the by-product separated from 'C' grade sugar during the centrifuging of sugar crystals. The yield of molasses per ton of cane is in the range of 4 to 4.5%. The entire quantum of molasses produced is being used for captive consumption in our distilleries. Bagasse Bagasse is the fibrous residue from the sugar cane after extracting cane juice. We produce Steam and Power by using bagasse as fuel for the high pressure boilers in the Cogeneration power plants. Press Mud Press mud, the solid waste produced while processing sugar cane is rich in potassium, sodium, phosphorous and organic matters. Press mud is also a base material for producing bio-earth which is done by composting with spentwash, a liquid- waste generated out of distillery operation B5.Enlist the physical properties of fats and oils. This is an essential reference tool for professionals interested in the quality, trade, and authenticity of oils and fats. i.e Specific Gravity, Refractive Index, Iodine and Saponification Value, Titer, and Fatty Acid, Tocopherol, Tocotrienol, Sterol, and Triglyceride Composition. B6.i) Which is the sweetest fruit and why? Sapota (chikoo): Sapota composes of soft, easily digestible pulp made of simple sugars like fructose and sucrose. ii) How is papain extracted? Papain is obtained by cutting the skin of the unripe but almost mature papaya and then collecting and drying the latex which flows from the cuts. Tapping of the fruit should start early in the morning and finish by mid-late morning Two or three vertical cuts of 1-2mm deep are then made, meeting at the base of the fruit. The incisions are made using a stainless steel razor blade set into a piece of rubber attached to a long stick. The blade should not protrude more than about 2mm as cuts
deeper than 2mm risk juices and starch from the fruit pulp mixing with the latex which lowers the quality. Fruits should be tapped at intervals of about 4-7 days and for the first tapping it is usually sufficient to make only one cut. On subsequent tappings the two or three cuts are spaced between earlier ones. After about 4-6 minutes the flow of latex ceases. A dish is used to collect the latex and the latex is then scraped into a polythene lined box with a close fitting lid; such a box should be stored in the shade. The use of a close fitting lid and keeping the box in the shade are both important because they reduce the reactions which cause the loss of enzyme activity. Latex adhering to the fruit should be carefully scraped off and transferred to the collecting box. However, dried latex should not be mixed with fresh latex as this lowers the quality.
