Microbiology

• Determining the microbiological status of foods and detection of pathogenic germs such as Salmonella, Listeria monocytogenes and Campylobacter
• Verification of the best-before date
• Rapid methods (Vidas) for salmonella and Listeria monocytogenes
• Sensory evaluation
• Conducting follow-up studies to determine or monitor compliance with best before or the use by date
• Implementation of the mandatory microbiological tests according to Regulation (EG) no. 2073/2005 on the microbiological criteria for food
• Microbiological monitoring of incoming goods for plant and animal raw materials and/or semi-finished products
• Microbiological analysis of the cleanliness and disinfection level of equipment and surfaces
• Sampling of drinking water for microbiological analysis
• Microbiological analysis of drinking water in accordance with current potable water regulations
• Verification of the designated commercial classes for fresh and frozen poultry and eggs
• Testing of eggs for their degree of freshness (air chamber height, yolk index, Haugh units
• Challenge testing

According to the Food Information Regulation (FIC), a best-before date (BBD) must be indicated for foods that are marketed, and a use-by date must be indicated for perishable foods. Exceptions to this are listed in appendix X of the FIC.

The best-before date indicates the date until which the food retains at least its specific properties under compliance with the specified storage conditions. While products with an exceeded best-before date can still be consumed, products with a stated use-by date may no longer be consumed after this date.

Establishing the best-before and use-by dates

The determination of the best-before date or the use-by date is the responsibility of the person marketing the product. Various influencing factors, e.g. ingredients, manufacturing process, packaging, must be taken into account.  If empirical values or studies on comparable products are already available, these can be used as a basis for determining the best before date. However, it is not always possible to use existing data.  In such cases, it is recommended to carry out a storage test to determine the best before/use by date. This test is also suitable for checking an already determined best before date.

In a storage test, the considered food is stored in real time under real conditions until the possible/ determined best before date. At previously determined dates, a microbiological, sensory and chemical examination of the samples is carried out for possible changes during storage. This procedure is suitable for foods with a relatively short shelf life.

Influencing factors on the best-before date

Composition of the food:

• Water content: High water content can promote the growth of microorganisms and shorten the shelf life.
• pH value: Acidic foods (low pH value) generally have a longer shelf life, as most microorganisms do not grow well in acidic environments.
• Nutrient content: Certain nutrients such as sugars and proteins can promote microorganism growth.
• Preservatives: The use of preservatives can extend shelf life.
• Packaging: Packaging materials and methods

Thermal preservation:

• Pasteurization: temperature and time: typically temperatures below 100°C for seconds to minutes. The aim is to kill pathogenic microorganisms and reduce the total bacterial count without significantly altering the food.
• Sterilization: Temperature and time: Higher temperatures (over 100°C) for longer periods of time. The aim is to kill all microorganisms including spores.
• Blanching: Temperature and time: Short-term treatment with hot water or steam. The main aim is to inactivate enzymes and reduce the bacterial count before further processing.Storage conditions:

Temperature:

• Cool temperatures slow down chemical reactions and the growth of microorganisms.
• Humidity: High humidity can promote the growth of mold and bacteria.
• Light: UV light can accelerate chemical reactions that lead to spoilage.
• Oxygen in the air: Oxygen can promote oxidation reactions and the growth of aerobic microorganisms.

To determine the best-before date of a foodstuff, the samples can be stored under the storage conditions at the desired date after production and analyzed accordingly. Thermal preservation plays a decisive role in the shelf life of food. Determining the best-before date requires careful validation of the thermal processes, microbiological tests, chemical and sensory analyses and storage tests.

Determination of the degree of freshness (determination of the Haugh units)

The Haugh unit (HU) is used to determine the degree of freshness of eggs. This method is used to determine the egg white quality and is based on the relationship between egg weight and the height of the egg white. For this, the egg is first weighed, then broken on a flat glass plate and the egg white height is determined by using a height gauge at a distance of about 1cm from the yolk edge. The Haugh unit can then be calculated from the egg white height and weight.

Determination of the yolk color (raw and cooked)

On the basis of the yolk color, it is possible to make statements about the feeding or possibly the state of health of the laying hens. The yolk color is determined with a yolk color fan.

Determination of the weight class

Eggs are divided into the weight classes S, M, L and XL depending on their weight. For this purpose, the eggs are weighed one by one and the weight must correspond to one of the following weight ranges:

XL: ≥ 73g

L: 63 bis < 73g

M: 53 bis < 63g

S: < 53g

Checking for roll marks

By using UV light, it is checked whether rolling marks are visible on the shell of the eggs. In this way it can be possibly proven whether the eggs originate from cage rearing.

Air chamber height

The height of the air chamber can be used to make conclusions about the freshness of the eggs.

Measurement of eggshell thickness and strength

With this measurement, possible shell defects can be detected.

Complete range of services for eggs

bilacon supports you in all analyses related to your eggs in the course of in-house inspections or inspections ordered by the authorities. This includes:

In the past, there were more and more public recalls of food, especially meat and sausage products. The reason for this was a so-called zoonosis, such as the qualitative detection of Listeria monocytogenes. Challenge testing offers effective protection against such contamination.
Regulation (EC) No. 2073/2005 lays down microbiological criteria for food. These are obligatory for food producers.
According to the regulation, food business operators must set up and regularly implement one or more procedures based on checkpoint analysis (HACCP principles). These procedures must be constantly monitored and verified. The entire manufacturing process must be suitable to inhibit or prevent the spread of pathogenic germs. Thus, in order to meet the strict criteria of the regulation, it is not only the quality of the final product that is considered, but the entire production route.
Challenge tests are used to critically examine the manufacturing process of a product. This is the only way to ensure that the measures taken to protect hygiene during production are sufficient and meet the requirements of Regulation (EC) No. 2073/2005.

The equipment of bilacon GmbH is always state of the art. This enables us to guarantee precise and fast analyses at all times.

In microbiology, for example, we work with spiral platers so that processes are automated, simplified and accelerated.

Tobias Stapper
Head of Microbiology bilacon GmbH
tobias.stapper@tentamus.com
+49 30 206 038 370