ISO/DIS 25163:2026(en)

ISO/TC 34/SC 3

Secretariat: TSE

Date: 2025-12-09

Black garlic — Specification and test methods

© ISO 2026

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Contents

Foreword iv

Introduction v

1 Scope 1

2 Normative references 1

3 Terms and definitions 1

4 Description 2

5 Classification and requirements 2

5.1 Classification 2

5.2 Requirements 2

6 Test method 3

6.1 Sensory inspection 3

6.2 Determination of moisture content 3

6.3 Determination of Brix 4

6.4 Determination of pH 4

6.5 Determination of coliforms 4

6.6 Determination of total plate count 4

6.7 Determination of Escherichia coli 4

6.8 Determination of Salmonella 4

6.9 Determination of lead 4

7 Packaging and labelling 4

7.1 Packaging 4

7.2 Labelling 5

8 Storage and transport 5

8.1 Storage 5

8.2 Transport 5

Foreword

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This document was prepared by Technical Committee ISO/TC34, [Food products], Subcommittee SC 3, [Fruits and vegetables and their derived products].

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Introduction

The history of cultivating and consumption of garlic is more than 2 000 years. One of the most important deeply processed garlic products is black garlic. After maturing in an incubator under high temperature and humidity, fresh garlic will turn black and is called black garlic due to its colour.

Black garlic is rich in sugar, fructan, protein, amino acids, phenols, cellulose, vitamin and minerals. Besides, the content of superoxide dismutase in black garlic is more than that of other ordinary plant-derived foodstuffs. The bioactivity is also enhanced during the heating process. And there is more sweetness and less irritating odour in the product. Due to its good taste and strong bioactivity, it is popular among consumers as a new type of health food, and recently it has become increasingly popular as a food ingredient in Europe and elsewhere.

There are many countries producing black garlic including the People's Republic of China, Japan and the Republic of Korea. The United States of America, the Europe union, Southeast Asia and Australia also has a large consumption of black garlic. However, there is no unified and clear global product quality and specification requirements for black garlic. Therefore, this document has been developed to reduce the barriers to international trade and promote the circulation of black garlic.

Black garlic — Specification and test methods

This document specifies requirements and test methods for black garlic.

It is applicable to black garlic only.

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 1026, Fruit and vegetable products — Determination of dry matter content by drying under reduced pressure and of water content by azeotropic distillation

ISO 1842, Fruit and vegetable products — Determination of pH

ISO 2173, Fruit and vegetable products — Determination of soluble solids — Refractometric method

ISO 4832, Microbiology of food and animal feeding stuffs — Horizontal method for the enumeration of coliforms — Colony-count technique

ISO 4833‑1, Microbiology of the food chain — Horizontal method for the enumeration of microorganisms — Part 1: Colony count at 30 °C by the pour plate technique

ISO 6579‑1, Microbiology of the food chain — Horizontal method for the detection, enumeration and serotyping of Salmonella — Part 1: Detection of Salmonella spp.

ISO 6633, Fruits, vegetables and derived products — Determination of lead content — Flameless atomic absorption spectrometric method

ISO 16649‑1, Microbiology of the food chain — Horizontal method for the enumeration of beta-glucuronidase-positive Escherichia coli — Part 1: Colony-count technique at 44 degrees C using membranes and 5-bromo-4-chloro-3-indolyl beta-D-glucuronide

CXS 1-1985, General Standard for the Labelling of Prepacked Foods

CXS 337-2020, Standard for fresh garlic

For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp

— IEC Electropedia: available at https://www.electropedia.org/

Black garlic shall be produced from raw garlic through a process of pre-treatment, high temperature and humidity processing, and drying when applicable.

Black garlic is divided into two groups according to the number of cloves:

— solo black garlic: garlic with only one clove;

— multiple-clove black garlic: garlic with more than one clove.

The requirements of raw material shall comply with CXS 337-2020.

Appearance

The black garlic and the black garlic clove shall be sound, without splitting or mould, and non-sticky.

Color

The black garlic peel shall be taupe or white, the color of black garlic clove shall be black and uniform.

Odour, taste and texture

The odour and taste shall be sweet and sour and it shall have a soft texture, as the characteristic of the black garlic product; it should not possess the pungent, spicy taste and hard texture typical of raw garlic, nor any other foreign odour, taste, or texture.

Impurity

No visible impurities shall be seen with the naked eye.

Physical and chemical properties of black garlic shall be in accordance with Table 2.

Table 2 — Physical and chemical requirements

The microbial limits of black garlic shall be in accordance with Table 3.

Table 3 — Microbial limits requirements

Black garlic shall be free from living insects, mites or other parasites and moulds. They shall be practically free from dead insects, insect fragments and rodent contamination visible to the naked eye (corrected, if necessary, for abnormal vision) or with such magnification as may be necessary in any particular case. If the magnification exceeds ×10, this fact shall be stated in the test report.

The limit of lead in black garlic shall be 0,3 mg/kg.

Take a moderate amount of samples, place them in clean white disks (porcelain plate or similar container), cut the samples with stainless steel knife horizontally, observe the colour and status with the naked eye under sufficient natural light, check out for foreign matters, smell the odour, gargle with warm water and taste them.

The moisture content value of the samples shall be determined in accordance with ISO 1026.

The Brix value of the samples shall be determined in accordance with ISO 2173. In clause 7.1.3, it need to be mixed thoroughly by homogenizer.

The pH value shall be determined in accordance with the method in ISO 1842.

The Coliforms shall be determined in accordance with the method in ISO 4832.

The total plate count shall be determined in accordance with the method in ISO 4833-1.

The Escherichia coli shall be determined in accordance with the method in ISO 16649-1.

The Salmonella shall be determined in accordance with the method in ISO 6579-1.

The lead content shall be determined in accordance with the method in ISO 6633.

Black garlic shall be packed in such a way as to protect the product properly. The product shall be packaged in clean and food-grade packaging materials that of such a quality as to avoid causing any external or internal damage to it. The packaging materials and process shall not contaminate the product or otherwise affect its technological, nutritional or sensory quality.

The containers shall be clean, sound and dry, and be made of materials that are safe and suitable for their intended use. They shall not impart any toxic substance or undesirable odour or flavour to the product.

The size of the packages and the number of small packages packed in a container shall be subject to agreement between the purchaser and vendor.

Packages shall be free of all kinds of foreign matter.

Glue, ink or paint used for marking shall be of food grade.

There are two ways of packaging:

— quantitative packaging;

— weigh sales packaging.

In addition to the requirements of CXS 1-1985, the container and case shall be marked or labelled with the following:

a) the name of the product or variety, and the trademark or brand name, if any;

b) the name and address of the manufacturer or packer;

c) the code or batch number;

d) the net mass or gross mass (according to the request of the importing country);

e) the producing country;

f) the class of product;

g) any other marking required by the purchaser, such as the year of harvest and date of packing (if known);

h) the expiry date;

i) the storage conditions.

8.1.1 The products shall be stored in a cool, dry, well-ventilated indoor place, and shall not be peeled in the open or be exposed to sunshine and rain.

8.1.2 The products shall not be stored with goods that are toxic, harmful, odorous, volatile or corrosive.

8.2.1 The transport vehicles shall be clean and free from foreign odour.

8.2.2 The products shall not be mixed with goods that are toxic, harmful, odorous or corrosive.

8.2.3 The products shall not be squeezed, collided, frozen, sun-drenched or drenched in the rain during the transport process.