ISO 4134-2021 PDF

Full title and description

Meat and meat products — Determination of L-(+)-glutamic acid content — Reference method. This International Standard specifies reference analytical procedures for measuring the free L-(+)-glutamic acid content of meat and meat products (including livestock and poultry products), using spectrophotometer and light-absorption microplate reader techniques.

Abstract

The standard defines two validated analytical approaches — a spectrophotometric method and a microplate reader (light absorption) method — for the determination of free L-(+)-glutamic acid in meat and meat products. It covers sample preparation, reagents, instrument settings, calibration, calculation of results and method performance considerations applicable to routine testing and reference laboratories.

General information

• Status: Published.
• Publication date: July 2021 (2021-07).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 67.120.10 (Meat and meat products).
• Edition / version: Edition 3 (2021).
• Number of pages: 15 pages (English original).

Scope

This standard is applicable to meat and meat products (including poultry) and specifies procedures for the determination of free L-(+)-glutamic acid content by spectrophotometric and microplate-reader techniques. It is intended as a reference method suitable for implementation in national or reference laboratories and for use where accurate measurement of free glutamic acid is required for quality, labeling, research or regulatory purposes.

Key topics and requirements

• Defined analytical principles: spectrophotometer method and light-absorption microplate reader method for free L-(+)-glutamic acid.
• Detailed sample preparation and extraction procedures to isolate free amino acids from meat matrices.
• Specified reagents, calibration standards and preparation of calibration curves.
• Instrument settings, measurement wavelengths and microplate reader parameters required for reproducible results.
• Calculation methods for expressing results (mass per unit mass), including correction factors and reporting conventions.
• Performance characteristics and validation guidance (precision, repeatability, limit of detection/quantification and potential interferences).
• Applicability statements for different meat product types (fresh, processed, cured, poultry) and notes on matrix effects.

Typical use and users

Adopted primarily by national reference laboratories, commercial food testing laboratories, meat processors' quality-control teams, research institutions studying meat composition or flavor precursors, and regulatory authorities requiring standardized, comparable measurements of free L-(+)-glutamic acid in meat and meat products.

Related standards

Standards from ISO/TC 34/SC 6 covering meat analysis and laboratory methods are commonly used alongside ISO 4134:2021. Examples include ISO standards for meat moisture determination and protein/nitrogen measurement (e.g., ISO 1442 — determination of moisture content; ISO 937 — determination of nitrogen content by Kjeldahl) and general Kjeldahl guidance (ISO 1871). These related methods are often referenced for sample preparation, compositional context and reporting.

Keywords

Free L-(+)-glutamic acid; glutamate; meat analysis; meat products; reference method; spectrophotometry; microplate reader; ISO 4134; food laboratory; amino acids; method validation.

FAQ

Q: What is this standard?

A: ISO 4134:2021 is an International Standard that provides a reference analytical method for determining the free L-(+)-glutamic acid content in meat and meat products.

Q: What does it cover?

A: It covers two analytical techniques (spectrophotometer and microplate light-absorption methods), including sample extraction, reagents, calibration, instrument settings, calculations and performance requirements for accurate measurement of free L-(+)-glutamic acid in various meat matrices.

Q: Who typically uses it?

A: Reference and commercial food-testing laboratories, quality-control teams in meat processing, research groups analyzing amino-acid profiles, and regulatory bodies that require standardized, comparable results for labeling, safety or quality purposes.

Q: Is it current or superseded?

A: ISO 4134:2021 is the current published edition (third edition, 2021). It supersedes and replaces earlier editions, including ISO 4134:1999 (which is withdrawn).

Q: Is it part of a series?

A: Not a numeric series in the sense of consecutively titled parts, but it is part of the body of ISO standards developed by ISO/TC 34/SC 6 covering methods of analysis for meat and meat products; users commonly apply it together with other ISO reference methods for moisture, protein/nitrogen and related compositional tests.

Q: What are the key keywords?

A: Glutamic acid, glutamate, meat analysis, spectrophotometry, microplate reader, reference method, ISO 4134, amino acids, food laboratory, method validation.