BS EN 15787:2021 pdf free download – Animal feeding stuffs: Methods of sampling and analysis一Detection and enumeration of Lactobacillus spp. used as feed additive.
6.14 Microscope, capable of phase-contrast microscopy at a magnification of 600x to 1 000x.
6.15 pH meter, having an accuracy of calibration of± 0,1 pH unit at 20°C to 25 °C.
6.16 Equipment for anaerobic incubation.
Appropriate anaerobic jars or chambers with a system for the generation of anaerobic conditions.
7 Sampling
Carry out the sampling procedure in accordance with the specific standard appropriate to the product concerned. If such a specific standard is not available, it is recommended that agreement be reached on this subject among the parties concerned. Apply community rules [1] for official control sampling of animal feeds.
NOTE Sampling can be done according to EN ISO 6497 [61. Although EN ISO 6497 is not specifically applicable for microorganisms, due to the lack of other references it seems to be the most suitable protocol to be taken into account for microorganisms as feed additives.
Take precautions to avoid potential cross-contamination of samples with microorganisms, particularly after sampling additives and premixtures supplemented with microorganisms. Where required, clean and disinfect the sampling equipment between each sample, particularly after sampling additives and prem ixtu res.
Put the sample in a sterile container.
8 Preparation of test sample
The test sample preparation shall be done in accordance with EN ISO 6498 and the congruent product standard.
NOTE EN ISO 6498 gives general guidelines on test sample preparation.
9 Procedure
9.1 Samples with a single or multi-component added microflora
Weigh the recommended quantity of the sample according to Table 4 into an aseptic blender bowl, beaker or plastic bag. Add the corresponding amount of tempered tPBS (5.1.1) according to Table 4. If encapsulated lactobacilli are analysed, an adequate amount of sample material depending on the size of the capsules shall be used for the preparation of the initial suspension. The number of capsules should be greater than 25, to obtain a standard deviation in repeated analysis of less than 20 % for a good repeat of analysis.
It is recommended to examine the copper content of the initial suspension in a pre-test. Copper contents exceeding 20 mg/I in the initial suspension require the application of a chelating agent e.g. iminodiacetic acid in an appropriate concentration with regard to the pH value (see A.2).
If a significantly lower value than expected is obtained in a first analysis, it is recommended to repeat the analysis with a wider ratio of sample mass to diluent volume (5.1.1) for initial suspension or to blend the sample with low-germ grain bran or any other neutral carrier to reduce the influence of interfering substances.
For compound feed it is strongly recommended to perform the analysis in duplicate to minimize variation. The result will be the average of both samples. For pelleted compound feeds, a low speed dry grinding for 30 s is recommended to obtain an unrefined powder. Avoid excessive heating that can damage the microorganisms.
According to specific procedures for dehydrated products and products with low water activity in EN ISO 6887-471 it is recommended to weigh out the sample accurately into a pre-dispensed volume of tempered tPI3S (5.1.1) to minimize osmotic shock to the microflora.