ISO 1842-1991 PDF

Full title and description

ISO 1842:1991 — Fruit and vegetable products — Determination of pH. Specifies a potentiometric method for measuring the pH of fruit- and vegetable-derived products, including the principle, sample preparation, test procedure, expression of results and required contents of the test report.

Abstract

This second edition (1991) of ISO 1842 describes a laboratory potentiometric method for pH determination in fruit and vegetable products. It covers sample preparation (including dilution or homogenization where required), electrode and equipment considerations, stepwise test procedure, calculation and reporting of results, and quality/accuracy considerations. This edition cancels and replaces ISO 1842:1975.

General information

• Status: Published (confirmed standard; second edition).
• Publication date: 28 November 1991.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 67.080.01 — Fruits, vegetables and derived products (general).
• Edition / version: 2nd edition (1991), replaces ISO 1842:1975.
• Number of pages: 2 (catalogues list 2–3 pages depending on formatting).

Scope

Specifies a potentiometric method for determining the pH of fruit and vegetable products and their derivatives. The standard defines required apparatus and electrodes, details on sample preparation (including representative sampling and any necessary dilution), the measurement procedure, how to express and report results, and notes on precision and reporting. It is intended for routine testing and quality control in food laboratories.

Key topics and requirements

• Potentiometric measurement principle using pH electrodes and meters.
• Guidance on representative sampling and preparation of fruit and vegetable product samples (homogenization/dilution where applicable).
• Instructions for calibration, electrode conditioning and measurement procedure.
• Calculation and expression of pH results; recommended reporting elements for test reports.
• Notes on accuracy, repeatability and factors affecting measurement (temperature, ionic strength, electrode type).
• Replacement of the 1975 edition with updated procedural and reporting guidance.

Typical use and users

Used by food testing laboratories, quality control teams in fruit and vegetable processing, research laboratories working on food composition, regulatory agencies performing food safety and labeling checks, and standards bodies harmonizing analytical methods across jurisdictions.

Related standards

Standards commonly used alongside ISO 1842 include ISO methods for related compositional analyses such as ISO 750 (Determination of titratable acidity), ISO 2173 (Determination of soluble solids — refractometric method) and other ISO/IDF methods for food chemical analysis. National adoptions and identical versions exist (e.g., NF ISO 1842).

Keywords

pH; potentiometric; fruit and vegetable products; food analysis; sample preparation; analytical method; ISO 1842; test report.

FAQ

Q: What is this standard?

A: ISO 1842:1991 is an ISO international standard that specifies a potentiometric method for determining the pH of fruit and vegetable products.

Q: What does it cover?

A: It covers the principle of the potentiometric measurement, required apparatus and electrodes, sample preparation, the step‑by‑step measurement procedure, result calculation and how results and related information should be reported.

Q: Who typically uses it?

A: Food and beverage laboratories, processors of fruit and vegetable products, regulatory testing authorities, and research institutions performing compositional or quality analyses. (See "Typical use and users" above.)

Q: Is it current or superseded?

A: ISO 1842:1991 is the second edition (published 28 November 1991) and replaced the 1975 edition; catalogues and national bodies list it as the published/confirmed edition (standard monitoring records indicate confirmation activity in later years). Users should check their national standards body or ISO for any newer revisions or withdrawals before use.

Q: Is it part of a series?

A: It is part of the body of ISO standards for food analysis and specifically within the ISO/TC 34 committee work on food products (fruit and vegetables). Related ISO methods for acidity, soluble solids and other compositional tests are commonly used together.

Q: What are the key keywords?

A: pH, potentiometric, fruit and vegetable products, food testing, analytical method, sample preparation, ISO 1842.