1. Phạm vi áp dụng:

Tiêu chuẩn này qui định các thuật ngữ và định nghĩa chính liên quan đến gạo

Tiêu chuẩn bao gồm các phần: khái niệm chung, kích thước, mức xát và chỉ tiêu chất lượng của gạo.

 Rice-Terms and Definitions

1. Scope of applications

This standard lays down general terms and definitions in relation to rice

It includes the following parts: general conception, size, milling degree, and quality factors of rice

2. General conception

2.1. Paddy: rough rice has retained its husk after threshing

2.2. Rice: paddy from which the husk, all or a part of bran, and the embryo, has been removed

2.3. Husked rice: paddy from which only the husk has been removed

2.4. White rice: Husked rice, from which all or part of the bran, and the embryo, has been removed

2.5. Glutinous rice, waxy rice, (Oryza sativa.L glutinosa): rice, the kernels of which have a white and opaque appearance

The colour and aroma of it are special. The starch of waxy rice consists mainly of amylopectin; after cooking, the kernel shaves have a tendency to stick together

2.6. Aromatic rice: Rice has an aromatic fragrance

2.7. Parboiled rice: Rice obtained from paddy or husked rice that has been soaked in water and subjected to a heat treatment so that the starch is fully gelatinised and followed by a drying process

2.8. Muddy rice: Rice contaminated by mould that can bee seen with the naked eye

2.9. Dirty apparent rice: Rice which has had its natural colour changed by attached foreign matter on the surface of the kernels

2.10. Consigment: certain amounts of rice received or despatched at one time covered by a particular contract or shipping document. Consigment may consist of one or more lots

2.11. Lot: certain amounts of rice of the same quality, the same name or same code, packed in the same kind of packages and delivered at the same time

2.12. Sample: An amount of rice drawn by a specified rule

2.13. Increment (primary sample): The amount of rice drawn from one point or a single container

2.14. Separate sample: Mixing all primary samples drawn from different positions of one package

2.15. Bulk samples: The sample obtained by bringing together and mixing the primary sample or separate sample

2.16. Laboratory sample: Prescribed quantity drawn from the bulk sample, representative of the lot, and intended for analysis or other examinations

2.17. Analytical sample: The sample drawn from a laboratory sample and intended for the examination

3. Size of rice kernel

3.1. Size of rice kernel: The length and the width of the unbroken rice kernel in mm

3.2. Average length of rice kernel: value obtained by calculating the arithmetic mean length of 100 unbroken kernels from a laboratory sample

3.3. Classification of kernels: Classes of rice based on the length of rice kernels

3.3.1. Very long kernel: Whole kernel that has a length exceeding 7.0 mm

3.3.2. Long kernel: Whole kernel that has a length more than, or equal to 6.0 mm, but less than or equal to 7.0 mm

3.3.3. Short kernel: Whole kernel that has a length of less than 6.0 mm

4. Milling degree of rice:

Removal degree of bran and embryo of rice

4.1. Extra-well milled: Rice obtained by milling husked rice in such a way that all layers of the bran, embryo and part of the germ have been removed

4.2. Well-milled: Rice obtained by milling husked rice in such a way that all external bran, germ and most of the internal bran has been removed

4.3. Reasonably milled: Rice obtained by milling husked rice in such a way that most of the germ and the bran have been removed

4.4. Ordinary-milled: Rice obtained by milling husked rice in such a way that a part of the bran and the embryo have been removed

5. Quality factors to rice:

5.1. Moisture: The loss of mass by heating rice at 105⁰C until the mass of sample reaches constancy

5.2. Impurities: (foreign matter) All the substances other than kernels of rice

5.2.1. Inorganic impurities: Fragments of stone, sand, bran, and insects, etc.

5.2.2. Organic impurities: Foreign seed, husk, bran, and insects, etc.

5.3. Whole kernel: An unbroken kernel and broken kernel, the length of which is greater than, or equal to 9/10 of the average length of a kernel(2.2)

5.4. Head rice: The whole kernel or part of kernel, the length of which is greater than 8/10 of the average length of a kernel

5.5. Broken kernel: The part of the kernel the length of which is equal to, or greater than 2,5/10 but less than, or equal to, 8/10 of the average length of a kernel and does not pass through a mental sieve with a perforation ö 1,4mm, and the size of a broken kernel to be determined by each grade of rice

5.5.1. Large broken kernel: The part of a kernel the length of which is equal to or greater than 5/10 but less than, or equal to, 8/10 of the average length of a kernel

5.5.2. Medium broken kernel: The part of a kernel the length of which is equal to, or greater than, 2,5/10 but less than or equal to 5/10 of the average length of a kernel

5.6. Small broken kernel: The part of a broken the length of which is less than 2.5/10 of the average length of a kernel that can pass through a mental sieve with perforation ö 2.0mm but does not pass through a mental sieve with a perforation ö 1,4mm

5.7. Chip: Fragments of a kernel, which pass through a mental sieve with perforation of ö 1,4mm but do not pass through a mental sieve with a perforation of ö 1,0mm

5.8. Other types of rice: (admixture) Rice kernels the size and shape of which are different from destination rice kernel

5.9. Yellow kernel: Rice kernels that have a part, or all part, that turn to a visible yellow colour

5.10. Chalky kernel: Rice kernels (except for waxy rice) whole or ¾ surface of which has an opaque and floury appearance

5.11. Damaged kernel: Rice kernels the quality of which were reduced obviously due to moisture, fungi, insect and other causes

5.12. Heat damaged kernel: (Using for parboiled rice): Rice kernels the natural colour of which have changed as a result of a microbiological activity, biochemical reaction, and/or due to overheating

5.13. Immature and malformed kernel: Rice kernels are unrice and/or badly developed

5.14. Red kernel: Rice kernel having a red colour covering more than one-quarter of its surface

5.15. Red streaked kernel: Rice kernel with red streaks, the length of which is greater than, or equal to, one-half of the length of kernel; but the surface covered by these red streaks is less than one-quarter of the whole surface of kernel

5.16. Undermilled rice kernel: Rice kernels covered by bran streaks, the length of which is greater than or equal to the length of the kernel or the surface of bran streaks is greater than one-quarter of the surface of the kernel

5.17. Foreign odour: Not the natural aroma of rice

5.18. Insect free-rice: Rice free from living insects, and less than five dead insects per kg

5.19. Insected rice: Rice in which there are less than, or equal to, five living insects per kg but which should be free of sitophilus granarius

5.20. Chemical residue: Residues of chemicals in rice

 Gạo trắng-yêu cầu kỹ thuật

White rice-Specifications

 1. Phạm vi áp dụng

 Tiêu chuẩn này áp dụng cho các loại gạo thuộc giống lúa Oryza sativa.L

Tiêu chuẩn này không áp dụng cho gạo nếp (glutinous rice) từ giống lúa Oryza sativa.L glutinosa và các sản phẩm được chế biến từ gạo

2. Tiêu chuẩn trích dẫn

 TCVN 4733-89, Gạo yêu cầu vệ sinh

TCVN 1643:1999, Gạo-phương pháp thử

TCVN 5645:1999, Gạo-Phương pháp xác định mức xát trắng

TCVN 5646:1999, Gạo-Bao gói, ghi nhãn, bảo quản và vận chuyển

3. Yêu cầu kỹ thuật

3.1. Các chỉ tiêu cảm quan của gạo (màu sắc, mùi và vị) phải đặc trưng cho từng giống, loại gạo đó, không biến màu, không bị hư hỏng và không có mùi vị lạ.

3.2. Yêu cầu về chất lượng của từng loại gạo được qui định trong bảng 1

3.3. Yêu cầu vệ sinh Theo TCVN 4733-89

4. Phương pháp thử

4.1. Các chỉ tiêu chất lượng của gạo được xác định theo TCVN 1643-1992

4.2. Mức xát trắng của gạo được xác định theo TCVN 5645:1999

5. Bao bì, ghi nhãn, bảo quản và vận chuyển: Theo TCVN 5646-1992

 Bảng 1-Chỉ tiêu chất lượng của gạo trắng