Listeria and Listeriosis

Escrito por admin el . Posteado en pathogens

Listeria is a Gram-positive bacillus genus in which Listeria monocytogenes appears to be the only human foodborne pathogen specie. The infectious disease associated with Listeria monocytogenes is potentially mortal. Its riskiness is related to the ubiquitous presence of the bacteria in the environment and its growth capacity at low temperature and high salinity. Despite having listeriosis a low incidence (normally less that one in 100,000 people per year) the mortality rate appears to be around 20-30%.

According to the latest EFSA (European Food Safety Authority) report published in 2014 and referred to the 2012 year, there were 1,642 confirmed human cases of listeriosis in the European Union which corresponds to 10.5% increase compared with 2011. The highest notification rates were produced in Finland, Spain and Denmark with Romania representing the lowest notification rate. Almost all the cases were from domestic origin.

Antibiotics in food: responsibility of all

Escrito por admin el . Posteado en Antibiotics

antibiotics in food, zeulabBacterial infections have been controlled for decades thanks to the efficiency of antibiotics. Now different sectors are warning about the necessity of an appropriate use of these drugs in order to preserve its unrivaled capacity

The first studies using sulfonamides to treat infectious diseases began in the early 20th century. In just a few decades these drugs together with penicillin G help to decrease the rate of mortality caused by infections.

Time-out for the mouse bioassay

Escrito por admin el . Posteado en Marine biotoxins, Okatest

time-out-for-the-mouse-bioassay,-okatest,-zeulab,-Marine-toxins-analysis-in-bivalve-molluscs

Since July 2011 the liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the reference method for lipophilic toxins (Regulation (EU) No. 25/2011) Until then, the mouse bioassay was used as reference and it could have been applied for routine monitoring in official controls and own-checks until the 30th of December 2011. However, this biological assay is forbidden for routine monitoring of these toxins in Europe and in countries exporting products to the UE from the 1st of January 2015.

The European legislation (Regulations (EC) No. 2074/2005 and 15/2011) also allows other analytical methods to monitor lipophilic toxins, providing they fulfil the method performance criteria stipulated by the EU-RL (European Reference laboratory) and offer the same level of public health. Two other methods, a LC-MS/MS (H.J. Van den Top et al, Food & Contaminants 2011) and a phosphatase inhibition assay (Smienk et al, Toxins 2012) comply with these requisites.

The Van den Top’s LC-MS/MS uses 100% of methanol as extraction solvent and alkaline conditions and has been inter and intra laboratory validated in 2009 and 2011, respectively.

The phosphatase inhibition assay, OkaTest, is the only commercial kit that has been inter and intra-laboratory validated for quantification of Okadaic Acid group toxins (OA, DTX1, DTX2, DTX3 including their esters) in molluscs bivalves. The assay is performed in a 96-wells microtiter plate and includes five ready-to-use standards. A total of 43 samples can be tested in about 2.5 hours.

The combination of OkaTest and LC-MS/MS can be a good system to monitor lipophilic toxins in molluscs, as described below.

okatest-and-lc-ms-for-monitoring-lipophilic-toxins

Allergens on surfaces: A source of Cross-contacts control in allergen management

Escrito por admin el . Posteado en Allergens

The countdown to the coming into force of Regulation (EU) 1169/2011 starts. From 13th December of this year, all commercialized food has to highlight if any allergens of mandatory mention are present in their composition. Even unpackaged food and menus offering in catering or restaurants are included in this regulation.

Professionals along the chain from farm to folk must be aware of what ingredients are used in the different steps of manufacturing and handling to identify allergens correctly. In this way, final consumers can be informed correctly about allergens content, making this law useful. Hidden allergens will be one of the most dangerous enemies that workers must face to follow the law. But, where are allergens hidden? Unknown allergens have mainly two origins:

1) They can be part of the composition of a processed food as additive or preservative. For instance, egg can be added to clarification processing in wines. Also, soy lecithin is used like emulsifier to mix ingredients.

2) Cross-contacts (also known as cross contamination). When the ingredients are manipulated in powder form such flour, aerosols can appear. These particles remain in suspension in the air. Then, this powder flecks begins to deposit on the working surfaces, even on surrounding areas after cleaning.  Other hideous source of cross contacts is hard-to-reach areas in equipments and utensils which are difficult to clean properly. In these areas can remain rests of allergens that can be transferred to the next manufactured product.

new eu food allergy labelling regulations in food and menus offering in catering or restaurants How to avoid hidden allergens to appear in the food product sold to the consumer? Professionals have to work with a “Hazard analysis and critical control points” system, also known as HACCP. This systematic preventive approach helps to develop a risk management plan in a logical and efficient way. However, allergen analysis presence is needed to verify that the guidelines followed really work. Where can we analyze allergens? Ingredients used in manufactured food should be analyzed not only to confirm suppliers information, but also transport and storage are correct. Besides, working, equipment and utensils surfaces needs allergen analysis to verify manufacturing processes and cleaning systems avoid cross contact phenomenon.

How to analyzed allergens presence? Among all existing methodologies, ELISA tests and immunochromatographic strips are the ones that show better sensitivity vs cost. The Proteon line by ZEULAB offers several ELISA kits and rapid strips that allow analyzing allergens in a wide range of food. The first one provides quantitative results but small laboratory equipment is required to carry out the test. The strips tests results are qualitative but the testing time is just a few minutes with no need of trained personal or infrastructures. Besides, ZEULAB also supplies a specially design kit to analyze gluten, egg or milk in working surfaces. This kit integrates all components needed to control in an easy way without any additional material. This kind of tests permits to control the cleaning of facilities at the end of the workday or even during inspection and audit activities. Therefore it becomes a valuable tool for production and quality supervisors as well as for food industry and catering companies.

 
food allergen detector in surfaces proteon zeulab
SAMPLE PREPARATION
food allergen detector in surfaces rapid strips test proteon zeulab
IMMUNOCHROMATOGRAPHIC STRIPS TEST
 
food allergen detector in surfaces proteon zeulab Elisa test
ELISA TEST

Goat cheese? Sheep cheese? Is the label correct?

Escrito por admin el . Posteado en Milk adulteration, Uncategorized

The unknown mixture of milk from different species can be a common fraud in the cheese sector. Sheep milk is more expensive than goat´s or cow’s milk and tends to be adulterated with those of lower cost. Sheep´s and goat´s milk prices could however vary depending on the milk availability. Recent shortage of goat´s milk in the market made sheep´s milk prices double and therefore adulteration of goat´s milk with sheep´s milk should also be checked.

These adulterations are especially important for cheese makers, not only for economical reasons, but also because unknown milk mixtures produce changes in the final sensory properties and reduce the product quality. Besides, cheese producers need to assure that labelling details correct information about the milk species containing in the final product.

A recent study carried out by the British consumer rights group Which? revealed adulteration of goat´s cheese with sheep´s milk.  Out of 76 goat cheese samples tested, 3 contained more than 80% of sheep milk and 4 more samples up to 50%.

Greece, Spain, Italy, France and Romania are the main producers of sheep milk in the EU with about 92% of the total production (eurostat 2013). However cheese containing milk from sheep or goat is made in many other countries.

Cheese makers should check milk prior to production to assure correct labelling and expected quality. Cheese, yogurt and any other end products must also be checked to ensure consumers received the right information.

Milk species identification can be easily and quickly checked using rapid strip tests. ELISA and PCR methodologies are also available, but should be carried out at a laboratory.