FUNCTIONS AND SCOPE OF THE LABORATORIES

Contacts

Deputy Director: National Analytical Services:

Ms Xoliswa Tlali

Tel: (021) 809 1643

Fax: (021) 887 0036

XoliswaT@Dalrrd.gov.za

CHEMICAL RESIDUE

The Chemical Residue laboratories in Pretoria and Stellenbosch render an analytical service in the monitoring of pesticide residue on the following

Fruit
Vegetables
Tea
Wine.

The fruit-, vegetable- and tea samples that are received come mainly from consignments that are destined for the export market and sampled by the Perishable Products Exporting Control Board (PPECB). Some samples come from the Agricultural Products Inspection Services (APIS) and the Department of Health and are drawn at local markets and shops.

Wine samples are screened on request from exporters and also screened daily to monitor locally produced wines from different areas. APIS also submit unfermented grape juice and raw wines from cellars to monitor organic classified wines.

TECHNICAL
All commodities have different spray programs for the protection against pests. These commodities are analysed for pesticide residues using Gas- and Liquid Chromatographs. The results are reported in milligram residue per kilogram of fruit, expressed as mg.kg-1 .

Each commodity has its own range of pesticide specifications. This differs from country to country.

The Chemical Residue Laboratory only report results and does not decide if a consignment is rejected or accepted.

WINE AND SPIRIT LABORATORY
INTRODUCTION AND SERVICES
The Division: Analytical Services (South) is mandated in terms of the Liquor Products Act 60 of 1989 to perform various analytical laboratory services pertaining to Liquor Products, that are presented for export, import and national trade control and as part of the departmental responsibility in ensuring the safety & quality of these products. The Wine & Spirit Laboratory tests for compositional characteristics in liquor products to ensure compliance to the Liquor Products Act. The Wine & Spirits laboratory works in conjuction with the Divisions: Liquor Products, APIS and SAWIS for the certification of the Wine of Origin Scheme.

The following tests are performed:

• Alcohol determination using pycnometer method
• Reducing sugar content determination using skalar auto analyzer which is based on segmented flow analysis.
• Volatile acidity determination using skalar auto analyzer
• Total acidity & pH determination using a Mettler autotitrator.
• Total sugar content using Fehlings A method.
• Sulphur dioxide content using a Flow Injection analyzer and Aspiration method which is the reference
• Gas pressure tests are performed on sparkling and perle wines.

Products analysed are the following::

• Wine
• Spirits
• Sparkling wines
• Perle wines & Fortified wine
• Port & Sherry.
• Grape juice
• Spirit Aperitif
• Spirit Coolers & Ciders
• Fortified apple and fortified pear beverages
• Reduced wine based drinks

MICRO- ADDITIVES LABORATORY

INTRODUCTION AND SERVICES

The Additives laboratory is mandated to analyze mostly liquor products for a range of regulated and illegal additives in accordance with the stipulations of the Liquor Products Act (Act 60, 1989). The activities of the Additives laboratory may be divided into routine and non-routine tests. Routine tests include:

• Determination of legal additives and regulated substances in liquor product. D
• Determination of Sorbic acid in export wines (HPLC).
• Ochratoxin A in local and export wines (HPLC).
• Artificial sweeteners in local products (HPLC).
• Methanol, Acetone and higher alcohols in local and exported wines and spirits (GC).
• Lead in export wines (AAS).
• Butterfat in cream liqueurs (Gravimetry).

Non-routine tests performed are of a periodic nature and mostly involve projects that are identified by Division: Liquor Products and other role-players in the Agricultural sector. These activities include:

• Determination of the authenticity of South African Sauvignon blanc wines (LC-MS),
• Occurrence of Ethyl Carbamate in South African wines and spirits (LC-MS),
• Occurrence of Natamycin in South African export wines to the EU (LC-MS),
• Determination of Terramycin in South African honey (LC-MS),
• Determination of Melamine in animal feed and agricultural fertilizer (HPLC),
• Determination of drugs of abuse in South African wines (LC-MS),
• Determination of the Sodium/Chloride ratio and levels of bromine in South African wines
• The Microbiology laboratory serves the Rooibos tea industry exclusively. Three tests are performed on export Rooibos tea
• Determination of Salmonella,
• E-coli and Total bacterial count.

PROCESSED AND DAIRY LABORATORY

INTRODUCTION AND SERVICES

The commodities that are being tested in Processed Food section is the following: honey, vinegar, dried fruit and fruit juices.
The following TESTS are performed:

Different techniques are used for the different analyses. The act that is employed is Agriculture Product standards Act, ACT 119 OF 1990. These standards are in line with the CODEX standards.

The Dairy division performs a routine function of dairy commodities under the Agricultural Product Standards Act, 1990 (Act 119 of 1990) for the local market.

Commodities include, but are not limited to milk, cheese, butter, yoghurt, cream and mayonnaise. The latter is not a dairy product, but it still forms part of the scope. Types of analyses that are performed are: fat, moisture, salt and fatty acids as well as analysis on the Lactoscan which include the following parameters: fat, moisture, total solids, added water, protein and lactose.