GB/T 24534.4-2009
Cereals and pulses.Determination of hidden insect infestaion.Part 4:Rapid methods (English Version)

Standard No.

GB/T 24534.4-2009

Language

Chinese, Available in English version

Release Date

2009

Published By

General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China

Latest

GB/T 24534.4-2009

Scope

This part of GB/T 25434 specifies 5 rapid methods for estimating the degree of cryptic insect infection in cereals and beans, or the presence or absence of infection. Method 1: Carbon Dioxide Method This method is suitable for the determination of whole grains and grains that have been coarsely ground or rolled and sieved to remove fine grains and live insects. This method is not suitable for the determination of: a) finely ground processed grain products, because their particles may absorb moisture in the air; b) grain products with a moisture content greater than 15%. Because the food itself and microorganisms may produce carbon dioxide and affect the results. In addition, this method is not suitable for the rapid detection of grain products that have absorbed a large amount of carbon dioxide. Such as grain stored in controlled atmosphere or grain infested by serious pests. This method may be applied to coarse-grained or kibble-ground grain products, using inspection sieves to distinguish sound grains from exposed pests. This method does not allow the determination of dead adults, pupae, larvae and eggs. Method 2: Ninhydrin method This method is suitable for the determination of insect infestation inside any dry grain, especially wheat, sorghum, rice and grains of similar size. Large grains, such as corn, should be partially broken (crushed) before measurement. However, these treatments of large-grain grains may result in the reduction or fragmentation of some insects and make the result description unreliable. This method may underestimate eggs and young larvae, but in this respect it is no worse than any other method. Method 3: Whole Grain Flotation Method This method is applicable to the determination of most of the occult infections of grains and beans, but only limited to qualitative ones. Method 4: Sound measurement method This method is applicable to the determination of active insect adults and larvae that feed on grains, and is not applicable to the determination of dead adults, larvae, or live eggs and pupae (non-feeding insect state). Method 5: X-ray method This method is suitable for determining live and dead larvae and adults in grains. Freshly killed insects (such as those caused by fumigation) may be difficult to distinguish from insects that are still alive.

GB/T 24534.4-2009 Referenced Document

• GB 5491 Inspection of grain and oilseeds--Methods for sampling and sample reduction
• GB/T 12620 Round and elongated apertures with round and square plate screens
• GB/T 21305 Cereals and cereal products.Determination of moisture content.Routine reference method
• GB/T 24534.2 Cereals and pulses.Determination of hidden insect infestation.Part 2:Sampling
• GB/T 5519 Cereals and pulses—Determination of the mass of 1000 grains*， 2018-02-06 Update

GB/T 24534.4-2009 history

• 2009 GB/T 24534.4-2009 Cereals and pulses.Determination of hidden insect infestaion.Part 4:Rapid methods

GB/T 24534.4-2009 -All Parts