🍎 Sugar profile of fruit and vegetable juices — HPLC

Food Chemistry PN-EN 12630

Overview

STATUS (as of 03.11.2026). PN-EN 12630:2002 — Polish version (published on 18.10.2002), implements EN 12630:1999 [IDT]. The standard was WITHDRAWN on 09.04.2024 and the PKN catalogue card names no replacing standard; CEN withdrew EN 12630:1999 on 28.10.2026 (iTeh catalogue: stage 99.60, withdrawal effective), also without a successor. The description gives the content of the withdrawn standard, with its clause numbering.

SCOPE (clause 1). The standard applies to fruit and vegetable juices and related products, not to food in general. The method does not allow the determination of sucrose in the presence of maltose, because their peaks overlap.

PRINCIPLE (clause 4). The sugars and sorbitol are separated on a cation-exchange resin (sulfonated styrene–divinylbenzene copolymer in the Ca²⁺ form) by isocratic elution with an aqueous calcium disodium EDTA solution as the mobile phase, detected with a differential refractive index detector and quantified by the external standard method.

PROCEDURE (clause 7). The analysis is carried out on a volumetric basis and the result is expressed per litre of sample; concentrated products are analysed after dilution to a known relative density, which is reported. Based on a weighed sample and taking dilution into account, the result may be expressed per kilogram of product; for products with a high viscosity or a very high content of cells (e.g. pulp), a weighed test sample is the usual procedure. Cloudy samples are mixed well before dilution. Single-strength juice is diluted — 1 volume part of juice plus 4 volume parts of water — centrifuged for 15 min at 1400 g and filtered through the syringe filter. HPLC conditions: mobile phase — calcium disodium EDTA solution 0.1 mmol/l, flow rate 0.5 ml/min, column temperature 90 °C (or as defined in the column manufacturer's instructions), injection volume typically 10 µl; the refractive index detector is held at a constant temperature around ambient (25–35 °C). After equilibration of the system, the retention times are determined from solutions of the single compounds, checking at the same time that no inversion of sucrose occurs on the column; subsequent analysis may use a mixed standard, injected at regular intervals between samples (typically every fifth or seventh injection).

CALCULATION (clause 8). The concentrations are calculated by the external standard method from peak areas or peak heights: ρ = P / RF × F, where RF = Ps / ρs — a separate response factor for glucose, fructose, sorbitol and sucrose — and F is the dilution factor (5 for juices). The results are reported in g/l to one decimal place. In the collaborative study, enzymatic methods gave a better reproducibility for glucose and fructose, and the HPLC method for sucrose.

REGULATIONS. Regulation (EU) No 1169/2011 defines “sugars” as all monosaccharides and disaccharides present in food, excluding polyols (Annex I point 8); the amount of sugars is part of the mandatory nutrition declaration (Article 30(1)).

WHAT WE DO NOT GIVE HERE. Precision data — repeatability and reproducibility from the interlaboratory test (clause 9, Annex B) — and the example chromatogram (Annex C): they are outside the available text of the standard. Limit of detection and measuring range — the available text of the standard does not give them.

Method principle

The juice is diluted with water, centrifuged and filtered through a syringe filter. Glucose, fructose, sorbitol and sucrose are separated on a cation exchanger in the calcium form by isocratic elution with a calcium disodium EDTA solution and detected with a differential refractive index detector. The concentrations are calculated by the external standard method from response factors determined for each compound from a standard solution of 10 g/l.

Applications

• Fruit and vegetable juices and related products — glucose, fructose, sorbitol and sucrose (clause 1)
• Concentrated products — after dilution to a known relative density (7.1)
• Products with a high viscosity or a high pulp content — determination on a weighed sample, result per kilogram (7.1)
• Nutrition declaration — sugars as monosaccharides and disaccharides (Regulation (EU) No 1169/2011, Article 30(1), Annex I point 8)

Key parameters

Standard

Standard number

PN-EN 12630:2002

Title (PL)

Soki owocowe i warzywne — Oznaczanie zawartości glukozy, fruktozy, sorbitolu i sacharozy — Metoda wysokosprawnej chromatografii cieczowej

Title (EN)

Fruit and vegetable juices — Determination of glucose, fructose, sorbitol and sucrose contents — Method using high performance liquid chromatography

Step-by-step procedure

1. Sample preparation

   Mix cloudy samples well before dilution. Dilute single-strength juice: 1 volume part of juice and 4 parts of water; dilute concentrated products to a known relative density (7.1, 7.2).

2. Centrifugation and filtration

   Centrifuge for 15 min at 1400 g and filter through a 0.45 µm syringe filter — the solution is ready for HPLC analysis (7.2).

3. HPLC conditions

   Mobile phase: calcium disodium EDTA solution 0.1 mmol/l; flow rate 0.5 ml/min; column temperature 90 °C (or according to the column manufacturer); injection volume typically 10 µl; refractive index detector at a constant temperature of 25–35 °C (7.3).

4. Retention times and inversion check

   After equilibration of the system, determine the retention times from solutions of the single compounds and check that sucrose does not invert on the column under the chosen conditions (7.4).

5. Analysis

   Then use a mixed standard; inject the standard solutions at regular intervals between samples, typically every fifth or seventh injection (7.4).

6. Calculation

   For each compound determine the response factor RF = Ps / ρs and calculate ρ = P / RF × F (F = 5 for juices); report the result in g/l to one decimal place and, for a concentrated product diluted to single strength, report the relative density (clause 8).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The available text of the standard contains no safety requirements — health and safety rules for working with the chromatograph and reagents are set by the laboratory

Frequently asked questions