NZQA Expiring unit standard
8972 version 5
Page 1 of 6
Title
Perform reference testing of the main milk components for
calibration of testing instruments
Level
4
Credits
10
Purpose
People credited with this unit standard are able to: explain the
importance of reference testing of the main components of milk
and factors which influence results; explain sampling of milk for
reference testing of milk components; explain gravimetric
testing of fat in milk and other dairy products; explain the
Kjeldahl method for determining protein in milk and other dairy
products; explain reference testing of lactose in milk; explain
the gravimetric method of testing the total solids of milk;
perform reference testing of milk components; check the
collation of milk component test results with total solids results
for four suppliers’ milk samples; and report on how the
application and quality assurance of reference testing of milk
could be improved in the individual’s own laboratory in the New
Zealand dairy industry.
Classification
Dairy Manufacturing > Dairy Laboratory Methodology
Available grade
Achieved
Entry information
Critical health and
safety prerequisites
Open.
Explanatory notes
1
Work must be carried out in accordance with organisational requirements.
2
Organisational requirements refers to instructions to staff on policy and procedures
(including the application of legislation to work situations) which are formally
documented or generally accepted at the work site. This may include legislation:
industry standards and methods, national and international standards and methods:
standards and methods published in internationally recognised reputable texts:
customer/organisation developed methods, standard operating procedures,
specifications, manuals, and manufacturer’s information.
3
The legislation and standards relevant to this unit standard may include but are not
limited to – Health and Safety in Employment Act 1992, Animal Products Act 1999,
Animal Products (Dairy) Regulations 2005, ISO/IEC 17025:1999 General
requirements for the competence of testing and calibration laboratories, NZFSA –
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
8972 version 5
Page 2 of 6
Approved Standards and Codes of Practice at
http://www.nzfsa.govt.nz/dairy/registers-lists.
Outcomes and evidence requirements
Outcome 1
Explain the importance of reference testing of the main components of milk and factors,
which influence results.
Evidence requirements
1.1
The importance of reference testing of the main components of milk is explained
in terms of the industry standard.
Range
1.2
Factors affecting milk composition are explained in terms of the industry
standard.
Range
1.3
official, reference or standard, routine, automated, modified, rapid
or screening.
Factors causing difficulty in reference testing of milk components are explained
in terms of the industry standard.
Range
1.6
colour, flavour, odour, milk density, freezing point, pH.
Types of testing methods for milk components are explained in terms of the
industry standard.
Range
1.5
genetic, environmental.
The physical and physio-chemical properties of milk are explained in terms of
the industry standard.
Range
1.4
payment for milk, measurement of milk as a raw material, final
product testing, research purposes, national milk composition,
genetic merit of national herd, truth of labelling for consumer milk
products.
milk as a complex biological fluid, lipid analysis, protein analysis,
ash analysis, total solids analysis.
Methods used to monitor laboratory performance of reference testing of milk
components are explained in terms of the industry standard.
Range
application of sampling and test methods, calibration procedures,
certified reference materials, quality assurance control material,
Inter Laboratory Comparison Programme (ILCP).
Outcome 2
Explain sampling of milk for reference testing of milk components.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
8972 version 5
Page 3 of 6
Evidence requirements
2.1
The factors affecting the taking and preparation of a representative sample for
reference testing are explained in terms of the industry standard.
Range
quality of sample, pre-transport storage of sample, transport of
sample, laboratory storage of sample, preparation of sample prior
to sampling for testing, identification of unsatisfactory samples.
Outcome 3
Explain gravimetric testing of fat in milk and other dairy products.
Evidence requirements
3.1
The relative efficiencies of the extraction of fat components and non fatty
substances and their implications are explained in terms of the industry
standard.
Range
Rose-Gottlieb (R-G), Schmid-Bonzynski-Ratzlaff (SBR).
3.2
The chemical and physical changes that occur in each stage of the R-G fat test
are explained in terms of the industry standard.
3.3
Pitfalls of the R-G test are explained in terms of the industry standard.
Range
3.4
reagent purity, technique, sampling.
Quality assurance of R-G testing is explained in terms of the industry standard.
Range
solvent blanks, reagent blanks, peroxide test, repeatability,
duplicates, reproducibility, oven temperature.
Outcome 4
Explain the Kjeldahl method for determining protein in milk and other dairy products.
Evidence requirements
4.1
The principle of the Kjeldahl method and its advantages and disadvantages are
explained in terms of the industry standard.
4.2
The chemical steps of the Kjeldahl process are explained in terms of the
industry standard.
Range
4.3
digestion, distillation, titration.
The make-up of nitrogen compounds in dairy products and the reason why a
conversion factor of 6.38 overestimates true protein are explained in terms of
the industry standard.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
Range
8972 version 5
Page 4 of 6
caseins, whey proteins, non-protein nitrogen.
4.4
The determination of casein and whey protein of milk is explained in terms of
the industry standard.
4.5
The critical factors in each stage of the manual and block-digestion Kjeldahl
methods are explained in terms of the industry standard.
Range
4.6
digestion, distillation, titration.
Quality assurance of Kjeldahl testing is explained in terms of the industry
standard.
Range
blanks, recovery checks, duplicates, ILCP.
Outcome 5
Explain reference testing of lactose in milk.
Evidence requirements
5.1
The classification and chemistry of carbohydrates are explained in terms of the
industry standard.
Range
5.2
The chemical stages of the Chloramine T test for lactose are explained in terms
of the industry standard.
Range
5.3
monosaccharides, disaccharides, polysaccharides.
sample clarification, addition of chloramine T, addition of
potassium iodide, titration with sodium thiosulphate.
Pitfalls in the Chloramine T test are explained in terms of the industry standard.
Range
reagent strength and stability, titration technique.
Outcome 6
Explain the gravimetric method of testing the total solids of milk.
Evidence requirements
6.1
Factors affecting repeatability and reproducibility are explained in terms of the
industry standard.
Range
6.2
sampling, chemical state of dried components, weight
determinations, non-availability of primary standards, oven
performance and loading, bound water, Maillard browning.
Pitfalls in the Total Solids test are explained in terms of the industry standard.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
Range
6.3
weighing, housekeeping, temperature distribution, drying time,
dish arrangement, laboratory environment.
Quality assurance of the Total Solids test is explained in terms of the industry
standard.
Range
6.4
8972 version 5
Page 5 of 6
temperature control of oven, duplicate analysis, ILCP.
The collation of the major milk component tests compared with the Total Solids
test is explained in terms of the industry standard.
Range
fat, protein, lactose, ash, total solids.
Outcome 7
Perform reference testing of UHT standard milk with established figures for fat, protein,
total solids, ash, and lactose.
Range
fat, protein, lactose, total solids.
Evidence requirements
7.1
Tests are performed in accordance with organisational requirements.
7.2
Test results are within repeatability limits in accordance with organisational
requirements.
Outcome 8
Check the collation of milk component test results with total solids results for four
suppliers’ milk samples.
Range
test results for one particular day.
Evidence requirements
8.1
The difference between the collation of the individual test results for protein, fat,
anhydrous lactose, ash, and the total solids is determined.
8.2
Results are stated as being within or outside acceptable limits in terms of the
industry standard.
8.3
Possible causes with supporting reasons are provided if collation results are
outside acceptable limits.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
8972 version 5
Page 6 of 6
Outcome 9
Report on how the application and quality assurance of reference testing of milk could be
improved in the individual’s own laboratory.
Evidence requirements
9.1
The five most important points relating theory to practice for improved quality
control are identified, with supporting reasons.
9.2
Recommendations, with supporting reasons, are provided on what changes
could be instituted to better meet organisatonal requirements.
This unit standard is expiring. Assessment against the standard must take place by
the last date for assessment set out below.
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
Registration
1
28 April 1997
31 December 2017
Revision
2
2 July 1999
31 December 2017
Revision
3
13 June 2003
31 December 2017
Rollover and
Revision
4
26 January 2007
31 December 2017
Review
5
15 October 2015
31 December 2017
Consent and Moderation Requirements (CMR) reference
0022
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA,
before they can report credits from assessment against unit standards or deliver courses
of study leading to that assessment.
Industry Training Organisations must be granted consent to assess against standards by
NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and
which are assessing against unit standards must engage with the moderation system that
applies to those standards.
Requirements for consent to assess and an outline of the moderation system that applies
to this standard are outlined in the Consent and Moderation Requirements (CMR). The
CMR also includes useful information about special requirements for organisations wishing
to develop education and training programmes, such as minimum qualifications for tutors
and assessors, and special resource requirements.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016