Foreword
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard was proposed by and is under the jurisdiction of National Committee of Biochemistry Products and Testing Technology (SAC/TC 387).
Examination methods of yeast extract powder
1 Scope
This standard specifies the quality examination method for yeast extract powder as a raw material of culture medium.
This standard is applicable to the quality examination of yeast extract powder in culture medium used for microbiological test of drugs, food, cosmetics, or other categories.
2 Normative references
The following referenced documents are indispensable for the application 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.
GB 4789.28 National food safety standard - Food microbiological examination - Quality requirements for medium and reagents
GB 5009.3 National food safety standard - Determination of moisture in foods
GB 5009.4 National food safety standard - Determination of ash in foods
GB 5009.11-2014 National food safety standard - Determination of total arsenic and abio-arsenic in foods
GB 5009.12 National food safety standard - Determination of lead in foods
GB 5009.15 National food safety standard - Determination of cadmium in foods
GB 5009.17 National food safety standard - Determination of total mercury and organic mercury in foods
GB 5009.44-2016 National food safety standard - Determination of chloride in foods
GB 5009.124 National food safety standard - Determination of amino acid in foods
GB/T 6682 Water for analytical laboratory use - Specification and test methods
GB/T 23530-2009 Yeast extract
Pharmacopoeia of the People's Republic of China (2015 Edition), Volume IV, Clarity test method (general chapter 0902)
Pharmacopoeia of the People's Republic of China (2015 Edition), Volume IV, Nitrogen determination method (general chapter 0704)
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3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
yeast extract powder
yellow or brownish yellow soluble powder refined from fresh yeast through autolysis and decomposition, rich in mixtures of peptides, amino acids, water-soluble vitamins, and carbohydrates, which may be used as a nutrient source for microbial growth in culture medium
3.2
count of heat resistant microorganisms
quantity of heat resistant microorganisms present in yeast extract powder, mainly heat resistant Bacillus. The count of heat resistant microorganisms in yeast extract powder refers to the colony forming units obtained by inoculating a 10% yeast extract powder solution in a boiling water bath for 30 min and inoculating it on a soybean-casein digest agar (TSA) plate, in CFU/g
4 Abbreviations
For the purposes of this document, the following abbreviations apply.
CFU: colony forming units
TSA: soybean-casein digest agar
TSB: soybean-casein digest broth
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Abbreviations
5 Standard strains
6 Reagents and solutions
7 Test methods
