Types of Raw Materials or samples received are:

Heavy Metal-    Fresh fish, salted bilis, powder, rice vermicelli, ice-cream, cutter fish, canned food.

Additive- Fresh fruits (longan, lynches, delima, coconut), dried fruits, preserver, sweetener without nutrient, rice vermicelli, powder, instant noddle, fresh fish, noodle.

Pesticide- Fresh vegetables(cabbage, baby corn, kalian, salad), groundnut, fruits (papaya, banana, longan, apple, orange, pear), imported and local herbs.

Microbiology- Processed Food(canned food), cooked foods, food poisoning  sample, swab.

Receiving of Raw materials

Raw materials are received from the customers usually by Authority Officer according to the procedure in Food Act and Regulation 1985, which means Health Inspector. All the raw materials are received at the “Sample Receiving Counter”. The analyst is responsible to receive the materials. The materials are then delivered to the laboratory with least practicable delay. The request for analysis of food samples is made in Request Form. All samples received by the laboratory is registered and given the laboratory number. Registration of samples can be made by individual sample or by batch of samples and to be recorded in the samples custodium form. The analyst will identify and label the raw materials with laboratory number. The laboratory number, sample reference number and date received are recorded by the analyst in the logbook or sample receiving record. The raw materials together with the form are sent to sub-sampling area or to respective unit. In situation where sample are received by analyst that do not perform the test, the sample is then handling over to specific analyst and this is recorded.

Sub-sampling should be done accordingly to each sample type. This is obtained a representative portion for each type of analysis to determine the level of residues and contaminants. Analyst will do the sample sub-sampling of the raw materials and store the raw material accordingly as some raw material need a sub-sampling before analysis before analysis done. The raw materials package or container is labeled before storage. The label consists of laboratory number, raw material name, receiving date and storage identification.
Analysts are responsible to check the sample and determine the type of analysis to be conducted for each sample. Analyst must identify the sample type to determine the procedure for sample preparation before analysis because each type of food needs different ways of preparation. The sub-sampling is divided into microbiology and chemical analysis.

1.    Microbiology Analysis
For microbiology analysis, the whole sample will be used in analysis. The quality of samples to be taken is determined by the analysis method. The preparation of sample and first dilution are carried out as described in the relevant method of microbiology analysis (Australia Standard and Part 3 Section 1-Preparation of Food Homogenate and Dilution in MMEF). Preparation of further dilution- Refer to AS 1766.1.2-1991

2.    Chemical Analysis
Frequently the sample received is in larger size than is required for laboratory sample, it should be divided to provide representative portion. The size of analytical portion is determined by analytical method, so the sample portion must be kept enough for replicate and confirmatory analysis as required. For sample that requested for different type analysis, the portion should be kept separately for each analysis. Each sample portion should be placed in a clean, chemically inert container and sealed to avoid any contamination. Each sample must be correctly identified by record and labeled accordingly by the respective analyst before storage.


All raw materials will be stored in the sample storage area. Fresh materials are kept in the chiller or freezer while un-fresh materials are kept at room temperature. The analyst should store the sample accordingly to the type of sample before and after sub-sampling, so that it will not affect the level of residues and contaminants. This storage technique is suitable for chemical analysis method only.
Occasionally, the microbiology sample will be proceed with the analysis as soon as it received, but sometimes, there is unexpected event occur and the analyst have to store it for awhile. Storage of microbiology sample must be stored accordingly as below:-

1.    Before Analysis
a.    Frozen sample or deep frozen sample
This sample will be kept in chiller for thawing process with temperature between 0-4°C overnight(less than 24hours). If the thawing period is not enough, it can be prolonged for about 15 minutes at 45°C.
b.    Fresh sample
This sample temperature must be maintained between 0-4°C in refrigerator before analysis.
c.    Un-fresh sample or shelf stable packaged products or dry food
This sample can be stored at room temperature before analysis.
d.    Canned food or process food
For “good condition” canned food, directly incubate at 30°C for 14 days whereas for “bad condition” canned food can be stored at refrigerator (0-4°C) before analysis.

2.    During Analysis
Prepared sample can be temporarily stored in refrigerator at 0-4°C less than 18hours and cannot be exposed to room temperature for more than 15 minutes.

3.    After Analysis
The retained sample should be packed in another sterile packaging or container and tightly sealed. The stored condition of retained sample according to their types as follows:-
a.    Frozen sample or deep frozen sample
The retained sample must be kept in freezer at -18°C to -20°C.
e.    Fresh sample
This sample temperature must be maintained between 0-4°C.
f.    Un-fresh sample or shelf stable packaged products or dry food
This sample can be stored in store cabinet at room temperature.
g.    Canned food or process food
This sample temperature must be maintained between 0-4°C.

Analysis will be done according to parameter or analysis requested by customers. Extraction and Instrumentation for raw materials are carried out according to the method specified in the documented test method in each unit, by authorized personnel. For contravene sample, the analysis need to be repeated up to 3 replicates (minimum 2 replicates). All the data for instrument performance check, calibration curve, worksheet and result generated from this analysis are attached together and will be compiled and kept. Result of the analysis will be sent to the respective customers.

Negative sample will be disposed at least 2 weeks after issuance of test report, while for contravened samples to be disposed after 150 days from the date of sample received. Retained samples from microbiology analysis will be disposed within one week of analysis and to be autoclaves before being disposed. Retained chemical analysis samples can be directly disposed or send back to the customer upon request.