GB/T 24534.1-2009Cereals and pulses -- Determination of hidden insect infestation -- Part 1: General principles (English PDF)

Foreword

GB/T 24534 "cereals and pulses - Determination of hidden insect infestation" includes the following four parts.

--- Part 1. General;

--- Part 2. Sampling;

--- Part 3. Reference method;

--- Part 4. Rapid methods.

This section GB/T 24534 Part 1.

This section identical with ISO 6639-1. 1986 "Determination of cereals and pulses hidden insect infestation - Part 1. General." for ease of use, this section made the following editorial changes.

--- Remove the ISO 6639-1. 1986 Foreword;

--- Remove the ISO 6639-1. "Introduction" section 1986;

--- The ISO 6639-1. 1986 Table 1 using symbols and text annotation part, to direct expressed in words.

This part is proposed by the National Food Authority.

This part of the National Grain and Oil Standardization Technical Committee centralized.

This section drafted by. National Food Reserve Chengdu Grain Storage Research Institute.

1 Scope

This section GB/T 24534 specifies the basic principles of grains and legumes - Determination of hidden insect infestation.

This section applies to the determination of cereals and legumes hidden insect infestation.

2 Terms and definitions

The following terms and definitions apply to this part of the GB/T 24534 of.

When the initial inspection sample can immediately live insects were found infected with the naked eye on the surface.

Present in the food grain naked eye can not be immediately found insect infestation. Mainly from the production of food grains in the egg development from the immature stages of insects, or for feeding into the interior of grain and grain borers insects formation of infection.

Cereals and legumes, or one of them.

3 Overview

Some insect species against Ideal complete food grains, and generally spend a significant portion of the life cycle in the food grains, including all Larval feeding period. Other species use the holes and cracks on the grain into the grain and take food inside the grain, resulting in a sample of these insects or a group of food are not easily discovered hidden infections.

Most of the small grain pests, body length less than 2mm ~ 3mm, secretive behavior, color gray. Usually in the dim light fly species or high flying, so unless its population is very large and significant events, or even if they live in freedom outside food grains, and has structure as mentioned above hidden infection, it is still easily found. Since the activity of insects, insect activity at least such a state, the insect can move in the heap of grain Dynamic and tends to focus on the most suitable for their feeding, breeding grain bulk part. These insects are not necessarily stationary activity centers, because they can be very Many complex reasons diffusion, shrink or move, one of the most important reason is that the physical condition of the food (such as temperature, moisture) and insects rapid change Population density propagation speed caused by too large. Thus, the insect food distribution within the stack is rarely random check found that they require specialized knowledge and technology.

4 Sampling

ISO 950 and ISO 951 sampling provisions do not apply to cereals and legumes hidden insect infestation sampling, it is because Non-random distribution of insect populations, especially after long-term storage or transportation.

And ISO 950, grain quality testing for the purpose of the provisions is not the same method ISO 951, hidden insect infestation of specialized sampling techniques Surgery, including internal and external heap Liangdai top or in bags of grain in the stack sampling, and sampling from surface and bulk grain bulk grain temperature higher areas.

These positions are often most vulnerable to insect infestation site of occurrence, so contrary to the fundamental principle of representative sampling. Nevertheless, most Under points, the same man with the same operation, the same equipment acquired samples, both for food quality measurement, can also be used for concealment GB/T 24534.1-2009/ISO 6639-1. 1986