Overview
ISO 605:1991 is an international standard developed by the International Organization for Standardization (ISO) under Technical Committee ISO/TC 34, focused on agricultural food products. This second edition, published in 1991, specifies standardized test methods for determining the quality of pulses. It covers procedures for sampling, sample preparation, and tests to identify impurities, pulse size, foreign odours, insect infestation, and the species and variety of pulses. The standard replaces the original 1977 edition, refining testing approaches and enhancing clarity.
This standard applies to unprocessed pulses intended for human consumption or animal feed, ensuring consistent quality control methods globally in pulse production and trade.
Key Topics
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Sampling and Sample Preparation
Laboratory samples should be taken in accordance with ISO 951:1979 to ensure representative test portions. Samples must be thoroughly mixed and reduced to specified test portion weights (usually 200-300 g).
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Impurities Determination
Separation of test portions into five groups for analysis:
- Seeds typical of the species and variety
- Seeds of the species but of another variety
- Defective seeds (broken, insect damaged, rotten)
- Organic impurities (seed coats, stems, other seeds)
- Inorganic impurities (stones, soil, dust)
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Pulse Size Measurement
Use of sieves with appropriately sized round or elongated holes depending on pulse type (e.g., peas vs. beans) to determine size distribution and express results as percentage mass per sieve fraction.
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Detection of Foreign Odours
A stepwise olfactory test is performed including smelling the sample initially, after 24 hours, and on ground and heated samples to detect abnormal odours that may indicate spoilage or contamination.
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Insect Infestation Tests
Visual inspection for live or dead insects, larvae, or webbing is essential. Chemical and physical methods determine hidden infestations, especially targeting pests like Bruchid beetles and house moth larvae. Tests include warming samples under bell jars and chemical exposure.
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Species and Variety Identification
Morphological, chemical, and ultraviolet light tests allow differentiation of seed varieties and detection of impurities such as rogues in peas, lentil vetch contamination, and bitter versus sweet lupin seeds.
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Test Reporting
Reports must detail methods used, results obtained, and any deviations, providing full identification of the sample and contextual information about testing conditions.
Applications
ISO 605:1991 is valuable for a broad range of stakeholders in the pulse industry, including:
- Agricultural producers and processors performing quality control to meet market specifications.
- Breeders and seed certification agencies to authenticate pulse species and varieties, and detect impurities or agricultural pests.
- Food and feed industries to ensure raw materials meet safety, purity, and quality standards.
- Regulatory authorities and import/export inspectors standardizing inspections to ensure compliance with international pulse quality requirements.
- Research organizations conducting studies on pulse quality, contamination, and pest management.
By providing reliable methods for assessing impurities, size, odour, and pests, ISO 605 helps maintain the integrity and safety of pulse supplies, supporting trade consistency and consumer confidence.
Related Standards
- ISO 951:1979 – Pulses in bags: Sampling
- ISO 6639 series (Parts 1-4) – Cereals and pulses: Determination of hidden insect infestation, including general principles, rapid methods, and sampling
- Additional standards relating to food safety, pest detection, and seed certification complement ISO 605 to form a comprehensive framework for quality assurance in leguminous grains.
Keywords: ISO 605:1991, pulses testing, pulse impurities, pulse size determination, foreign odour detection, insect infestation test, species identification, variety determination, agricultural product standards, legume quality control, pulse sampling methods.
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