Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO document should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 34, Food products.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

This document provides characteristics for both:

fresh baker’s yeast: block yeast, granulated yeast and liquid yeast;
dry baker’s yeast: active dry yeast and instant dry yeast.

COFALEC, the European confederation of yeast producers, first established information on the characteristics of fresh baker’s yeast and dry baker’s yeast as early as 2006, which serves as the basis for this document.^[ 12 ^]

Although both fresh and dry baker’s yeast are living products with a very long history, no real definition of either currently exists. The yeast mentioned in the Food Chemicals Codex^[ 14 ^] is “inactivated yeast” and the description is not relevant for either fresh or dry baker’s yeast.

This document includes the following information:

product characteristics (see Clause 4);
application characteristics (see Clause 5);
physico-chemical characteristics (see Clause 6);
microbiology (see Clause 7);
nutritional data (see Clause A.2).

Within each clause, several parameters are mentioned with their value and typical values; those which can be of interest for the consumer are given in Annex A. This number is the value which is most prevalent; however, baker’s yeast can be adapted to local characteristics and customs. For that reason, some parameters have a rather large range indicated.

It is important to note that baker’s yeast is a living organism, which delivers its functionalities such as carbon dioxide formation, alcohol formation and the production of aromatic compounds, among other functionalities, out of a living cell by making use of its intrinsic enzymatic activities in contrast to the addition of isolated enzymes.

This document is intended for use by the baking industry but is also aimed at laboratory and food testers.

The described product displays and formats represent today’s status. Future deviations in shipping and packing formats and parameters are possible and do not conflict with this document.

1 Scope

This document specifies characteristics of living fresh and dry baker’s yeast, particularly those relating to general product properties, application performance, physical and chemical properties, microbiology and nutritional value information.

This document does not apply to any kind of processed products made out of baker’s yeast.

2 Normative references

3 Terms and definitions

4 Product characteristics

4.1 General

4.2 Product use

4.3 Conservation

4.4 Mass of the package

4.5 Traceability

5 Application characteristics

5.1 Fermentation activity in case of fresh baker’s yeast application

5.2 Fermentation activity in case of dry baker’s yeast application

6 Physico-chemical characteristics

6.1 Dry matter

6.2 Nitrogen

6.3 pH

7 Microbiology

7.1 General

7.2 Total count

7.3 Coliforms

7.4 Escherichia coli

7.5 Salmonella

7.6 Listeria monocytogenes

7.7 Coagulase positive staphylococci (including Staphylococcus aureus)

Bibliography