GRAIN GRADING (QUALITY, STANDRDS)

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1 GRAIN GRADING (QUALITY, STANDRDS) Pimol Wutisin Postharvest Engineering Research Group, Agricultural Engineering Research Institute, Department of Agriculture.

2 RICE STANDARDS IN THAILAND Definition Rice Standards means the minimum specifications of rice of each type and grade for domestic and international trade. Rice means nonglutinous and glutinous rice (Oryza sativa L.) in whatever form. Paddy means rice that is not yet dehusked. Cargo rice (Loonzain rice, Brown rice, Husked rice) means rice that is dehusked only.

3 White rice means rice that is obtained by removing bran from Cargo nonglutinous rice. White glutinous rice means rice that is obtained by removing bran from Cargo glutinous rice. Parboiled rice means nonglutinous rice that has passed through the parboiling process and has its bran removed.

4 Rice classification means rice kernels of various lengths specified which are the mixture of rice kernels of each class in accordance with the specified proportion. Classes of rice kernels mean classes of rice kernels which are classified in accordance with the length of the whole kernel.

5 Classes of rice kernels mean classes of rice kernels which are classified in accordance with the length of the whole kernel. Parts of rice kernels mean each part of the whole kernel that is divided lengthwise into 10 equal parts. Whole kernels mean rice kernels that are in whole condition without any broken part, including the kernels that have length as from 9 parts onward.

6 Head rice means broken kernels whose lengths are more than those of Brokens but have not reached the length of the whole kernel. This includes split kernels that retain the area as from 80% of the whole kernel. Brokens mean broken kernels that have the length as from 2.5 parts but have not reached the length of Head rice. This includes split kernels that retain the area less than 80% of the whole kernel. Small brokens C1 mean small broken kernels that pass through round hole metal sieve No.7. (1.75mm.)

7 Red kernels mean rice kernels that have red bran covering the kernels wholly or partly.

8 Yellow kernels mean rice kernels that have some parts of the kernels turn yellow obviously. This includes parboiled rice kernels that are light brown partly or wholly.

9 Black kernels mean parboiled rice kernels that are black for the whole kernels, including kernels that are dark brown for the whole kernels. Partly black kernels mean parboiled rice kernels that have black or dark brown area on the kernels as from 2.5 parts onward but not reaching the whole kernels. Peck kernels mean parboiled rice kernels that have obviously black or dark brown area on the kernels not reaching 2.5 parts.

10 Chalky kernels mean nonglutinous rice kernels that have an opaque area like chalk covering the kernels from 50% onward.

11 Damaged kernels mean kernels that are obviously damaged as can be seen by the naked eyes due to moisture, heat, fungi, insects or other.

12 Immature kernels mean rice kernels that are light green, obtained from immature paddy. Other seeds mean seeds of other plants than rice kernels. Foreign matter means other matter than rice. This includes rice husk and bran detached from rice kernels.

13 Milling degree means the degree to which the rice is milled. Sieve means round hole metal sieve No.7, that is 0.79mm. (0.031 inch) thick and with hole diameter of 1.75mm. (0.069 inch). The unit "per cent" means percentage by weight except for per cent of grain classification which is percentage by quantity.

14 Moisture Content of Rice The moisture content of rice of all types and grades is specified not exceeding 14%.

15 Classes of rice kernels are divided into 4 classes as follows: Long grain Class 1 is whole kernel having the length exceeding 7.0 mm. Long grain Class2 is whole kernel having the length exceeding 6.6 mm.upto 7.0 mm. Long grain Class is whole kernel having the length exceeding 6.2 mm. upto 6.6 mm. Short grain is whole kernel having the length not exceeding 6.2 mm

16 Milling degree is divided into 4 degrees as followed: Extra well milled is the removal of bran entirely to the extent that the rice kernel has a specially beautiful appearance. Well milled is the removal of bran entirely to the extent that the rice kernel has beautiful appearance. Reasonably well milled is the removal of large amount of bran to the extent that the rice kernel has a reasonably beautiful appearance. Ordinarily milled is the removal of some portions of bran only.

17 Types of rice are divided into 4 types as follows: 1. White rice 2. Cargo rice (Loonzain rice, Brown rice, Husked rice) 3. White glutinous rice 4. Parboiled rice

18 The machines involved in grading of paddy and rice are: (1) rotating graders (paddy); (2) trieurs (paddy and rice); (3) sieves (rice); and (4) volumetric mixers (rice).

19 (C) Grain A can be separated from either B or C by thickness or length; B from C by length. (D) Grain A can be separated from either B or C by length; B from C by length.

20 Principle of grading using a trieur.(length) (B) Grading of white rice is identical except the size of the indents is different. (C) A screw conveyor (1) discharges the short grain at the centre of the lower end of the trieur, the overflow (2) is the long grain.

21 Rotating grader(thickness) (A) The rotating cylinder can be a (1) perforated sheet or (2) wire screen (B) The operation of this machine is the same as the wire coil reel except that when other slot meshes are required the cylinders must be changed.

22 Grading of white rice by oscillating grading sieves. (A) A single tray sieve. (B) A double tray sieve. (C) Two single tray sieves used in series. (D) During the operation of the sieve the grains are continuously accelerated and decelerated and separation efficiency is reduced.

23 Grades of White rice are divided into 13 grades 1. White rice 100% Grade A 2. White rice 100% Grade B 3. White rice 100% Grade C 4. White rice 5% 5. White rice 10% 6. White rice 15% 7. White rice 25% Super 8. White rice 25% 9. White rice 35% 10. White rice 45% 11. White broken rice A1 Extra Super 12. White broken rice A1 Super 13. White broken rice A1 Special

24 Grades of Cargo rice are divided into 6 grades 1. Cargo rice 100% Grade A 2. Cargo rice 100% Grade B 3. Cargo rice 100% Grade C 4. Cargo rice 5% 5. Cargo rice 10% 6. Cargo rice 15%

25 Grades of White glutinous rice are divided into 3 grades 1. White glutinous rice 10% 2. White glutinous rice 25% 3. White glutinous broken rice A1

26 Grades of Parboiled rice are divided into 9 grades 1. Parboiled rice 100% Sorted 2. Parboiled rice 100% 3. Parboiled rice 5% Sorted 4. Parboiled rice 5% 5. Parboiled rice 10% Sorted 6. Parboiled rice 10% 7. Parboiled rice 15% 8. Parboiled rice 25% 9. Parboiled broken rice A1

27 White rice 100% Grade A Grain classification, comprising of: Long grain Class 1 not less than 70.0%, the rest shall be Long grain Class 2. Of all these there may be Long grain Class 3 not exceeding 5.0% Grain composition, comprising of: Whole kernels not less than 60.0% Brokens having the length as from 5.0 parts onward but not reaching 8.0 parts not exceeding 4.0%. The rest shall be Head rice having the length as from 8.0 parts onward. Rice and matter that may be present: Chalky kernels not exceeding 3.0% White glutinous rice not exceeding 1.5% Paddy not exceeding 5 grains per 1 kg. of rice Milling degree: Extra well milled

28 White broken rice A1 Extra Super obtained from the milling of White rice 100% Grain composition, comprising of: Brokens having the length not reaching 5.0 parts and not passing through sieve No.7 not exceeding 10.0% The rest shall be broken having the length as from 5.0 parts onward. Of all these there may be Whole kernels not exceeding 15.0%, and Small white brokens C1 not exceeding 1.0% Rice and matter that may be present: White glutinous rice not exceeding 1.5%, of this there may be Small white glutinous brokens C1 not exceeding 0.5% Foreign matter not exceeding 0.5%

29 Standards for White broken rice Grain Composition (%) Rice and matter that may be present, not exceeding (%) White glutionus rice Grades Obtained from the milling of White rice Whole kernels Whole Kernels and Brokens having the length as from 6.5 parts onward, combined Brokens having the length as from 5 parts onward Brokens having the length not reaching 6.5 parts and not passing through Sieve No.7 Brokens having the length not reaching 5.0 parts and not passing through Sieve No.7 Small broken s C1 Total (including C1) Small brokens C1 Foreign matter A1 Extra Super 100% A1 Super 100%, 5%, 10% A1 Special 15%, 25% Super < less than > more than 0 = NIL equal or less than equal or more than not specified

30 Cargo rice 100% Grade A Grain classification, comprising of: Long grain Class 1 not less than 70%, the rest shall be Long grain Class 2 and or Class 3. Of all these there may be Short grain not exceeding 5.0% Grain composition, comprising of: Whole kernels not less than 80.0% Brokens having the length as from 5.0 parts onward but not reaching 8.0 parts not exceeding 4.0%. The rest shall be Head rice having the length as from 8.0 parts onward. Rice and matter that may be present: Red kernels not exceeding 1.0% Yellow kernels not exceeding 0.5% Chalky kernels not exceeding 3.0% Damaged kernels not exceeding 0.5% White glutinous rice not exceeding 1.5% Paddy not exceeding 0.5% Undeveloped kernels, Immature kernels, Other seeds and Foreign matter either singly or combined not exceeding 3.0%

31 Standards for Cargo rice Grain Classification (%) Grain Composition (%) Rice and matter that may be present, not exceeding (%) Grades Class1 (>7.0 mm.) Long Grain Class 2 and or 3 (> mm.) Short grain ( 6.2 mm.) Size of Head rice (parts) Size of Brokens (parts) Whole Kernels He ad ric e Brok ens Red kern els Yello w kern els Chalky kernels Damag ed kernels Whit e gluti nous rice Undeveloped, Immaturekernels, Other seeds and Foreign matter, Singly or comblned Padd y 100% Grade A % Grade B % Grade C % % % < less than > more than 0 = NIL equal or less than equal or more than not specified

32 White glutinous rice 10% Grain composition, comprising of: Whole kernels not less than 55.0% Brokens having the length as from 3.5 parts onward but not reaching 7.0 parts not exceeding 12.0% Of this there may be brokens having the length not reaching 3.5 parts and not passing through sieve No.7 not exceeding 0.7%, and Small white broken C1 not exceeding 0.3% The rest shall be Head rice having the length as from 7.0 parts onward. Rice and matter that may be present: White rice (not including Glutinous rice not yet transformed) not exceeding 15.0% Red kernels and or Undermilled kernels not exceeding 2.0% Yellow kernels not exceeding 1.5% Damaged kernels not exceeding 0.5% Paddy not exceeding 10 grains per 1 kg. of rice Undeveloped kernels, Immature kernels, Other seeds and Foreign matter either singly or combined not exceeding 0.5% Milling degree: Well milled

33 Standards for White glutinous rice Grain Composition (%) Rice and matter that may be present, not exceeding (%) Brokens and Small brokens C1 Grad es Size of Head rice (Parts) Size of Brokens (parts) Whol e kern els Head rice Total (including brokens not passing through sieve No. 7 and C1) Brokens not reaching the minimum specified parts and not passing through sieve No.7 Small broken s C1 White rice (excludin g glutinous rice not yet transform ed) Red and or Undermill ed kernels Yello w kern els Damag ed kernels Undeveloped, Immature kernels, Other seeds and Foreign matter, Singly or combined Paddy (Grains per 1 kg.) Milling degree 10% < Well milled 25% Ordinarily milled < less than > more than 0 = NIL equal or less than equal or more than not specified

34 Parboiled rice 100% Sorted Grain classification, comprising of: Long grain Class 1 and Class 2 not less than 60.0%, the rest shall be Long grain Class 3. Of all these there may be Short grain not exceeding 10.0% Grain composition, comprising of: Whole kernels not less than 80.0% Brokens having the length as from 5.0 parts onward but not reaching 8.0 parts not exceeding 4.0%. Of this there may be brokens having the length not reaching 5.0 parts and not passing through sieve No.7 not exceeding 0.5%, and Small parboiled broken C1 not exceeding 0.1% The rest shall be Head rice having the length as from 8.0 parts onward. Rice and matter that may be present: Red kernels and or Undermilled kernels not exceeding 0.5% Yellow kernels not exceeding 0.25% Black kernels not exceeding 0.1% Partly black kernels and Peck kernels combined not exceeding 1.5%, of which Partly black kernels shall not exceed 0.5% Damaged kernels not exceeding 1.0% Glutinous rice not exceeding 1.5% Paddy not exceeding 3 grains per 1 kg. of rice Undeveloped kernels, Immature kernels, Other seeds and Foreign matter either singly or combined not exceeding 0.2% Milling degree: Extra well milled

35 Standards for Parboiled rice Grain Classification (%) Grain Composition (%) Rice and matter that may be present, not exceeding (%) Long grain Brokens and Small brokens C1 Partly black and Peck kernels Grades Clas s 1+2 (>6. 6 mm., 7.0 mm.) Cl a ss 3 ( > m m.) Sh ort gra in ( 6.2 m m.) Size of Head Rice (parts) Size of Broken s (parts) W h ol e K er ne ls He ad ric e Total (including brokens not passing through sieve No. 7 & C1) Brokens not reaching the minimum specified parts and not passing through sieve No. 7 S m all br ok en s C1 Red and or Under milled Kernel s Ye llo w Ke rn els Bl ac k K er ne ls Partl y blac k kern els total Dam aged kern els Gluti nou s rice Undevelo ped, Immatur e kernels, Other seeds and Foreign matter, singly or comblned Pa dd y (G rai ns pe r 1 kg.) Millin g degre e 100% Sorted Extra well milled 100% Extra well milled 5% Sorted Well milled 5% Well milled 10% Sorted Well milled 10% Well milled 15% Reaso nably well milled 25% < Ordin arily milled

36 Standards for Parboiled broken rice A1 Grain Composition (%) Matter that may be present, not exceeding (%) Grades Obtained from the milling of Parboiled rice Whole kernels and brokens having the length as from 6.0 parts onward, combined Brokens having the length not reaching 6.0 parts and not passing through sieve No.7 Small brokens C1 Other seeds and Foreign matter A1 Various grades < less than equal or less than > more than equal or more than 0 = NIL not specified

37 Thai Hom Mali Rice Standards shall be divided into the following 2 types: 1. White rice; 2. Cargo rice.

38 Standardized Thai Hom Mali Rice of white rice type shall be divided into 8 kinds : 1. White rice 100% Grade A; 2. White rice 100% Grade B; 3. White rice 100% Grade C; 4. White rice 5% 5. White rice 10% 6. Cargo rice 15%; 7. White broken rice A 1 Extra Super; 8. White broken rice A 1 Super.

39 White Rice 100 % Grade A Long grain class 1 not less than 70.0%, the rest shall be Long grain class 2 Of all these there may be Long grain class 3 not exceeding 5.0% Whole kernels not less than 60.0% Size of Broken having the length >=5.0 / <8.0mm not exceeding 4.0% Size of Head rice >=8.0mm Chalky kernels not exceeding 3.0% White glutinous rice not exceeding 1.5% Paddy not exceeding 5 grains per 1 kg. of rice Extra well milled

40 White Rice 100 % Grade B Long grain class1 not less than 40%, the rest shall be Long grain class2 / class 3 Of all these there may be Short grain not exceeding 5.0 % Whole kernels not less than 60.0 % Size of Broken having the length >=5.0 / <8.0mm not exceeding 4.5%. Of this may be broken having the length not reaching 5.0 parts and not pass through sieve No.7 not exceeding 0.5%, and Small white broken C1 not exceeding 0.1% Size of Head rice >=8.0mm Yellow kernels not exceeding 0.2 % Chalky kernels not exceeding 6.0 % Damaged kernels not exceeding 0.25 % White glutinous rice not exceeding 1.5 % Paddy not exceeding 7 grains per 1 kg of rice Undeveloped kernels, Immature kernels, Other seeds and Foreign matter either singly or combined not exceeding 0.2 % Extra well milled

41 White Rice 100 % Grade C Long grain class1 not less than 30 %, the rest shall be long grain class 2 / class 3 Short grain not exceeding 5.0 % Whole kernels not less than 60.0 % Broken having the length >=5.0 / <8.0 parts not exceeding 5.0 %. Of this may be broken having the length not reaching 5.0 parts and not passing through sieve No. 7 not exceeding 0.5 %, and Small white broken C1 not exceeding 0.1 % Size of Head rice having the length as from 8.0 parts onward Yellow kernels not exceeding 0.2 % Chalky kernels not exceeding 6.0 % Damaged kernels not exceeding 0.25% White glutinous rice not exceeding 1.5 % Paddy not exceeding 7 grains per 1 kg of rice Undeveloped kernels, Immature kernels, other seeds and foreign matter either singly or combined not exceeding 0.2 % Milling degree as Extra well milled

42 Thai Long Grain White Rice Rice Types / Broken Standard / Analysis 5% 10% 15% 25% 35% 45% LONG GRAIN CLASS 1 >7.0mm Not less than, % ** ** ** SHORT GRAIN < 6.2mm, % Maximum WHOLE KERNELS Not less than, % Broken & Small, Broken C1, % Max Red and/or Undermilled Kernels, Not exceeding, % Yellow Kernels, Not exceeding, % Chalky Kernels, Not exceeding, % Damage Kernels, Not exceeding, % White Glutinous Rice, Not exceeding, % Undeveloped, Immature, other seed and Foreign Matter singly or combined Not exceeding, % Paddy (Grain per 1 kg of rice) or % Maximum Moisture, % Maximum Milling Degree * B B C D D D * Milling Degree: A=Extra Well Milled B=Well Milled C=Reasonably Well Milled D=Ordinarily Milled ** Long grain class 1, class 2 and class 3 either singly or combined.

43 White broken rice A 1 Extra Super Grain composition comprising of: brokens having length not reaching 5.0 parts and not passing through sieve No. 7 by not more than 10.0%; the remainder shall be brokens having length as from 5.0 parts onward;of the whole quantity there may be not more than 15.0% whole kernels and not more than 1.0% small white brokens C 1. Rice and matters that may be present: white glutinous rice not exceeding 1.5%; of this quantity there may be not more than 0.5%small white glutinous brokens C 1 foreign matters not exceeding 0.5%.

44 White broken rice A 1 Super Grain composition comprising of: brokers having length not reaching 6.5 parts and not passing through sieve No. 7 for the entire quantity; of this quantity there may be not more than 15.0% brokens having the length as from 6.5 parts onward and whole kernels combined and not more than 5.0% small white brokens C 1; Rice and matters that maybe present: white glutinous rice not exceeding 1.5%; of this quantity there may be not more than 0.5%small white glutinous brokens C 1 foreign matters not exceeding 0.5%.

45 Standardized Thai Hom Mali Rice of cargo rice type shall he divided into 6 kinds as follows: 1. Cargo rice 100% Grade A; 2. Cargo rice 100% Grade B; 3. Cargo rice 100% Grade C; 4. Cargo rice 5%; 5. Cargo rice 10%; 6. Cargo rice 15%.

46 Cargo rice 100% Grade A Grain composition comprising of: whole kernels by not less than 80.0%; brokens :from parts by not more than 4.0%; the remainder shall be Head rice having length as from 8.0 parts onward. Rice and matters that may be present: red kernels not exceeding 1.0% yellow kernels not exceeding 0.5% chalky kernels not exceeding 3.0% damaged kernels not exceeding 0.5% white glutinous rice not exceeding 1.5% paddy not exceeding 0.5% underdeveloped kernels, immature kernels, other seeds and foreign matter either singly or combined not exceeding 3.0%.

47 Cargo rice 100% Grade B Grain composition comprising of: whole kernels by not less than 80.0%; brokens :from 5.0 parts 8.0 parts by not more than 4.5%; the remainder shall be Head rice having length as from 8.0 parts onward. Rice and matters that may be present: red kernels not exceeding 1.5%; yellow kernel not exceeding 0.75%; chalky kernels not exceeding 6.0%; damaged kernels not exceeding 0.75%; white glutinous rice not exceeding 1.5%; paddy not exceeding 1.0%; underdeveloped kernels, immature kernels, other seeds and foreign matter either singly or combined not exceeding 5.0%.

48 Cargo rice 100% Grade C Grain composition comprising of: whole kernels by not less than 80.0%; Brokens: from 5.0 parts 8.0 parts by not more than 5.0%; the remainder shall be Head rice having length as from 8.0 parts onward. Rice and matters that may be present: red kernels not exceeding 2.0%; yellow kernel not exceeding 0.75%; chalky kernels not exceeding 6.0%; damaged kernels not exceeding 0.75%; white glutinous rice not exceeding 1.5%; paddy not exceeding 1.0%; underdeveloped kernels, immature kernels, other seeds and foreign matter either singly or combined not exceeding 5.0%.

49 Cargo rice 5% Grain composition comprising of: whole kernels by not less than 75.0%; Brokens: having length as from 3.5 parts but not reaching 7.5 parts by not more than 7.0%; the remainder shall be Head rice having length as from 7.5 parts onward. Rice and matters that may be present: red kernels not exceeding 2.0%; yellow kernel not exceeding 1.0%; chalky kernels not exceeding 6.0%; damaged kernels not exceeding 1.0%; white glutinous rice not exceeding 1.5%; paddy not exceeding 1.0%; underdeveloped kernels, immature kernels, other seeds and foreign matter either singly or combined not exceeding 6.0%.

50 Extended Use of Rice (Processing Rice byproducts) Rice Husks Over 90% of the rice husks in Thailand are utilized in fuel for commercial rice mill steam generators. To increase the fuel's effectiveness, rice husks are burned and compressed into briquettes. If carbonized, these briquettes could become a highquality charcoal. Rice Bran approximately 40% of the rice bran is extracted for cooking oil. The remaining 60% are utilized in animal feed production.

51 Rice Bran Oil (extracted from the rice bran) Rice bran oil is a highquality cooking oil because it could decrease the blood cholesterol level. Broken Rice Approximatele 70% of the broken rice produced in Thailand is used as feeding ingredients or made into instant noodles and snacks.

52 Rice Flour Rice flour, made from 30% of the broken rice produced in Thailand, is used to produce rice pasta, chips, and other snacks, as well as cereals. It could also be a substitute for wheat flour products. Rice Starch (main component of milled rice) Rice starch is used as a thickener in making sauces, desserts, and sweet syrup. It contains the endosperm of grain, which makes up approximately 92% of milled rice weight (dry weight).

53 Straw Rice straw has various uses in Thailand. Approximately 10% of the straw are utilized as a medium to grow mushrooms, 50% are used for animal feeds, 30% are used in paper making, and the rest are burnt away in other food production process. Rice used in Beverage Making Many alcoholic beverages are made from rice (i.e. broken rice). Some of the examples include sake or saki, traditionally called rice wine, and beer.

54 Rice Paper The pith of rice paper trees is used to make rice paper. This type of rice product is particularly used in cigarette wrapping; some are edible, such as those used in wrapping candies. Rice Glue Rice glued is made by dissolving a proportional ratio of rice in boiling water. Source: FAO publication.

RICE SPECIFICATIONS SHEET

RICE SPECIFICATIONS SHEET COMMODITY NAME: JASMINE RICE 100% (92% PURITY). The Jasmine rice that mixed with 8% or less other breeds of rice compared by the total weight and Jasmine must be 92% pure call