ISO 15214 pdf download

ISO 15214 pdf download.Microbiology of food and animal feeding stuffs — Horizontal method for the emumeration of mesophilic lactic acid bacteria — Colony-count technique at 30 °C 1 Scope This International Standard specifies a horizontal method for the enumeration of viable mesophilic lactic acid bacteria by counting the colonies growing in a solid medium after incubation at 30 °C for 3 days. NOTE In some food products, there exist psychotrophic or thermophilic lactic acid bacteria necessitating culture temperatures different from 30 °C. Moreover, not all lactic acid bacteria grow on MRS agar at pH 5,7 and some grow only weakly. Subject to the limitations discussed in the introduction and in the note above, this International Standard is applicable to products intended for human consumption or animal foodstuffs. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of the publication, the editions indicated were valid. All standards are subject to revision, and parties to agreement based on the International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards inidicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 6887-1 :— 1 ) , Microbiology of food and animal feeding stuffs — Preparation of test samples, initial suspension and decimal dilutions for microbiological examination — Part 1 : General rules for the preparation of the intial suspension and decimal dilutions. ISO 721 8:1 996, Microbiology of food and animal feeding stuffs — General rules for microbiological examinations. 3 Definitions For the purposes of this International Standard, the following definition applies. 3.1 mesophilic lactic acid bacteria bacteria which form colonies at 30 °C in a solid selective medium (MRS at pH 5,7) under the test conditions specified in this International Standard. 4 Principle 4.1 Preparation of two dishes using MRS agar at pH 5,7 contained in Petri dishes. Poured-plate or possibly surface 2) inoculation of the dishes with a specified quantity of the test sample if the initial product is liquid, or with a specified quantity of the initial suspension in the case of other products. 4.2 Inoculation of other pairs of dishes, under the same conditions, using decimal dilutions of the test sample or of the initial suspension. Incubation of the dishes at 30 °C for 72 h. 4.3 Calculation of the number of mesophilic lactic...