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Content Methods for fat determination in milk powders and ingredients Gerhardt fast protein analysis for starch and low level N “Without good sample preparation we are wasting our time” ISO 17025 conformity using Ger- hardt equipment Gerhardt INFO Posters Contact C. Gerhardt UK Ltd. Unit 5, Avonbury Court County Road, Brackley Northamptonshire NN13 7AX Tel 01280 706772 Fax 01280 706088 [email protected] www.gerhardtuk.com 3 Methods for fat determination in milk powders and ingredients. A comparison of methods was done by Gerhardt in the determination of fat content of milk powders and milk based ingredients. This included Röse-Gottlieb, Schmid-Bondzyn- ski-Ratzlaff and Weibull-Berntrop. The Weibull-Berntrop method can accommodate almost all sample types and involves the acid hydrol- ysis of the sample prior to filtration and subsequent Soxhlet extraction. The overall manual method is shown to be as accurate as other methods however, it is prone to technician errors and requires fume cupboards and safety gloves for handling the acid. These errors, including poor washing of the filter, have been removed by automating the entire hydrolysis procedure. Hydrotherm automated hydrolysis and filtration runs 6 samples at a time without any manual intervention. Hydrotherm presents a filtered sample on a stand- ard filter paper ready for drying and Soxhlet extraction. The Soxtherm au- tomated Soxhlet extraction also with minimal manual intervention is a great combination for the Hy drotherm, allowing the 6 filters to be quickly extracted for final weighing of the extracted fat. As well as improving overall ac- curacy by removing errors the Hydrotherm and Soxtherm combi- nation minimises hands on time, keeps consumable costs low and shows excellent reproducibility of results between technicians. If you would like to see our full presentation of results or have more information on Hydrotherm/ Soxtherm, please contact Tim by e-mail: [email protected]. 1 C. Gehardt Newsletter UK newsletter 08 / 2016 NEWSLETTER Issue 08 / 2016 1 2 4 2

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ContentMethods for fat determination in milk powders and ingredients

Gerhardt fast protein analysis for starch and low level N

“Without good sample preparation we are wasting our time”

ISO 17025 conformity using Ger-hardt equipment

Gerhardt INFO Posters

Contact

C. Gerhardt UK Ltd.Unit 5, Avonbury CourtCounty Road, BrackleyNorthamptonshire NN13 7AX

Tel 01280 706772Fax 01280 [email protected]

3

Methods for fat determination in milk powders and ingredients.

A comparison of methods was done by Gerhardt in the determination of fat content of milk powders and milk based ingredients. This included Röse-Gottlieb, Schmid-Bondzyn-ski-Ratzlaff and Weibull-Berntrop. The Weibull-Berntrop method can accommodate almost all sample types and involves the acid hydrol-ysis of the sample prior to filtration and subsequent Soxhlet extraction. The overall manual method is shown to be as accurate as other methods however, it is prone to technician errors and requires fume cupboards and safety gloves for handling the acid. These errors, including poor washing of the filter, have been removed by automating the entire hydrolysis procedure. Hydrotherm automated hydrolysis and filtration runs 6 samples at a time without any manual intervention. Hydrotherm presents a filtered sample on a stand-ard filter paper ready for drying and Soxhlet extraction. The Soxtherm au-tomated Soxhlet extraction also with minimal manual intervention is a great combination for the Hy

drotherm, allowing the 6 filters to be quickly extracted for final weighing of the extracted fat.

As well as improving overall ac-curacy by removing errors the Hydrotherm and Soxtherm combi-nation minimises hands on time, keeps consumable costs low and shows excellent reproducibility of results between technicians.

If you would like to see our full presentation of results or have more information on Hydrotherm/ Soxtherm, please contact Tim by e-mail: [email protected].

1 C. Gehardt Newsletter UK newsletter 08 / 2016

NEWSLETTERIssue 08 / 2016

1

2

4

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Page 2: Methods for fat determination Content in milk …gerhardtuk.com/newsletter-2016.pdf · Content Methods for fat determination in milk powders and ingredients Gerhardt fast protein

Gerhardt have produced a case study document on the analysis of protein in Starch. This can also be used as a reference for the analysis of samples with very low levels of N. The case study looks at a comparison of Kjeldahl and Dumas combustion using high and low sample weights respectively.

In summary the Dumas method is shown to be a credible alternative to Kjeldahl despite using low sample weights in the region of 100 – 200mg. The document discusses Dumas

combustion and the methods for re-ducing atmospheric and combustion gases along with the sensitivity of analysis using various carrier gases.

The Gerhardt Dumatherm is now supplied with a 64 (+8) position au-to-sampler. Samples are weighed into foils and placed into the au-to-sampler tray at the balance. The tray is simply slotted onto the Dumatherm and the bottom plate removed to load the samples. This guarantees accurate loading of samples into the correct position.

The Dumatherm can also be supplied with a camera to confirm individu-al sample entry into the furnace.

For a copy of the case study document contact Paul Campbell by e-mail; [email protected]

Gerhardt fast protein analysis for starch and low level N.

This statement should be used in every training session for food testing laboratory staff. Sample preparation is the most important laboratory activity of all. Yet whenever it is necessary to investigate anoma-lous results, all too often the cause is simply poor sample preparation.

Generally speaking, poorly homog-enised sample material will affect analytical data in two ways. Either the test result will be directly af-fected because a non-representative test portion has been taken, or the test material may interfere with the analytical process and thereby give rise to an anomalous result. In food analysis this can be illustrated

by reference to determinations of total nitrogen and total dietary fibre.The determination of nitrogen is often performed with combustion Dumas instruments. The most reli-able of these instruments tend to be gravity fed units operating with a test portion up to 0.5g. If the test portion is not representative then widely differing results for the same sample may be obtained. This is not resolved by taking a larger test portion, but by initial satisfactory homogenisation of the test material.

Total dietary fibre analysis is a complex procedure. Challenges can arise with what might otherwise be considered homogenous samples

- nuts, grains, beans and seeds - which can require specialised milling equipment. Full dispersion within buffered medium to allow for serial enzyme digestions is essential to successful method performance. Therefore, finely homogenised test material is crucial as larger particles remain untouched by this process. Such undigested material usually causes inappropriately high final results. However, in some cases,if these larger particles are then also included in the analysis for protein correction, incorrect neg-ative values can also be achieved.

Author: Antony Bagshaw - AB Consulting

2 C. Gehardt Newsletter UK newsletter 08 / 2016

“Without good sample preparation we are wasting our time”

Page 3: Methods for fat determination Content in milk …gerhardtuk.com/newsletter-2016.pdf · Content Methods for fat determination in milk powders and ingredients Gerhardt fast protein

ISO 17025 conformity using Gerhardt equipment.

ISO 17025 details the general requirements for the competence of testing and calibration laboratories. Gerhardt equipment is generally used in only testing laboratories so this is what we will focus on. The ISO describes the requirement for laboratories to use different test methods, record the data, authorise personnel to use certain test methods and issue test reports. Documentation is also key to ISO 17025 and laboratories must have control of documents relating to regulations, test methods, soft-ware, specifications, instructions and manuals. The laboratory must retain records of original observations, calibration records, staff records and a copy of each test report issued. Managers must ensure suppliers provide quality reagents and consumables to guarantee the quality of the tests.

Gerhardt equipment can help with ISO17025 as follows:

Equipment Built in Records Paper/LIMS Records

Dumatherm User, methods, results, time Complete customised printout, csv export

Vapodest 200 - 450 User, methods, time Results - manual recording. Printing or csv export of user data, methods and errors.

Vapodest 50s/sc User, methods, results, time Complete customised printout, csv export.

Hydrotherm User, methods, time No results. Printing or export of user data, methods and errors.

Soxtherm/PC User, methods, time Printout, csv export. Printing or export of user data, methods and errors

To enable staff to use the equipment according to the manufacturer and the method, Gerhardt can provide training and meth-odology. This can be provided on-site and at a time of convenience to the user. Certification of training can also be provided.

For details of how Gerhardt can support you in ISO 17025 contact Paul by e-mail; [email protected].

3 C. Gehardt Newsletter UK newsletter 08 / 2016

Page 4: Methods for fat determination Content in milk …gerhardtuk.com/newsletter-2016.pdf · Content Methods for fat determination in milk powders and ingredients Gerhardt fast protein

Gerhardt INFO Posters.We have introduced a poster range to explain and educate the methods behind our equipment. Available to all our equipment users the posters are useful tools in the class room, for projects or for explaining to lab visitors the chemistry behind our equipment. The range of posters includes:

4 C. Gehardt Newsletter UK newsletter 08 / 2016

Kjeldahl N and protein analysis Dumas N and protein analysis using Gerhardt Dumatherm

Nitrogen Cycle

Rapid distillation and titration using Gerhardt Vapodest 50s

Soxhlet extraction using Gerhardt Soxtherm

Acid hydrolysis using Gerhardt Hydrotherm

Crude fibre analysis using Gerhardt Fibretherm

Posters are available in A1 size, however we are happy to supply smaller sizes if required. E-mail or Telephone Tim Haigh at [email protected] or 01280 706772 and specify which equipment you have and the poster(s) you require.