Quality assurance:
trade classes,
vitamin content and preservatives

In order to clas­sify food, espe­cially fruit and vegeta­bles, into trade classes, sensory tests are carried out. When deter­mining the sensory prop­er­ties of fruits and vegeta­bles, there are three different commer­cial classes. These classes are as follows:

  • Extra class (H. Extra): fruits and vegeta­bles are of perfect quality, without defects in their texture, shape, coloration and size
  • Commer­cial class I (H. I): the fruit or vegetable has slight devi­a­tions in shape, color or firm­ness. The product may have some bruises or scratches
  • Commer­cial class II (H. II): the fruit or vegetable has slight devi­a­tions in shape, color or firm­ness: the fruit or vegetable has obvious defects. Almost all organic prod­ucts fall into this category

Tentamus Group labo­ra­to­ries also perform tests to deter­mine the vitamin content of a food product. This is done with an HPLC device or by LC-MS/MS. According to the recom­men­da­tions of the German Chem­ical Society (GDCh), vita­mins A, D, E, B12, biotin and folic acid can deviate by 30% of the stated content. The toler­ance for vita­mins B1, B2, B66, C, pantothenic acid and niacin may deviate by 20% of the stated content.

LC-MS/MS can also be used to check for preser­v­a­tives in foods and agri­cul­tural commodi­ties. Preser­v­a­tives include, but are not limited to, benzoates, nitrites, sulfites, and sorbates. Preser­v­a­tives are used to extend shelf life or increase the sensory desir­ability of a product.

Isotope analysis for
origin verification

Veri­fi­ca­tion of origin by the method of isotope analysis is carried out on prod­ucts whose origin is frequently misrep­re­sented. Since food­stuffs consist largely of biolog­ical elements such as oxygen, carbon, hydrogen, nitrogen and sulfur, their stable isotopes can be compared with those of known refer­ence samples.

In an isotopic analysis, the isotopic ratios of the biolog­ical elements are measured and compared with the ratios of samples of known origin. This results in detectable and specific isotopic patterns that allow veri­fi­ca­tion of origin, thus reducing consumer decep­tion due to erro­neous origin labeling.

Article 26 (2) of Regu­la­tion (EU) No. 1169/2011 spec­i­fies the labeling require­ments related to the decla­ra­tion of origin or country of origin of a product.

Foods that are frequently adul­ter­ated have their own guide­lines, such as honey. The decla­ra­tion of origin infor­ma­tion for honey are regu­lated in Direc­tive 2001/110/EC.

Other food prod­ucts frequently affected by adul­ter­ation and false origin decla­ra­tions are:

  • Coffee
  • Tea
  • Edible oils
  • Herbs/​spices
  • Tree nuts
  • Fruits
  • Vegeta­bles
  • Fish
  • Meat
  • Wine

Isotope analysis also helps to ensure product trace­ability and develop appro­priate trace­ability systems to provide consumers with high quality food.

What is an isotopic analysis and how is it used to verify origin?

Isotopes are atoms whose nuclei contain the same number of protons but differ in neutron number. Isotopes of an element behave chem­i­cally the same, but can differ in their mass number, which in turn leads to mole­c­ular vari­a­tions. Almost every element has more than one isotope.

Example: Carbon-12, for example, would contain 6 protons and 6 neutrons, while carbon-13 contains 6 protons and 7 neutrons. Although carbon-12 is the lighter of the two isotopes, both are still consid­ered carbon.

Because these vari­a­tions occur due to product prove­nance, the product of a partic­ular origin has a unique isotopic finger­print.” The patterns of product origin can be iden­ti­fied using isotope ratio mass spec­trom­etry (IR-MS).

The isotopes analyzed in this process come from ecolog­ical ecosys­tems that form the basis of food webs. The most commonly analyzed isotopes in foods are carbon-13 (δ13C), sulfur-34 (δ 34S), and nitrogen-15 (δ15N), as well as deuterium (δ2H) and oxygen (δ18O).

Isotope ratios refer to the ratio of neutron imbal­ances within an element, i.e., the ratio between, for example, oxygen-18 and oxygen-16 (δ18O value) against inter­na­tional refer­ences (for oxygen, this is VSMOW). First, the sample is burned or pyrolyzed to convert the elements to the gas phase, e.g., sulfur becomes SO2 with the isotopic ratio of the sample. This ratio is analyzed using a mass spec­trom­eter, which shoots a beam of elec­trons at the gas mole­cules, ionizing them. The mass spec­trom­eter then uses elec­tric and magnetic fields to direct the ions onto the detec­tors. Thus, the atoms of the bioele­ments can give the tester an indi­ca­tion of the product’s origin.

Food products with
protected geographical origin

The Euro­pean Union has quality regu­la­tions to protect the repu­ta­tion of regional prod­ucts in order to promote tradi­tional and agri­cul­tural activities.

For example, one food product that requires origin veri­fi­ca­tion is Scotch whisky, as whisky cannot be sold as Scotch” if it is not produced in Scot­land. Another example is Noord-Hollandse Gouda cheese, which also has protected geograph­ical indi­ca­tion status because its produc­tion is limited to Gouda in the Nether­lands. Beelitz asparagus is also a protected product in the EU.

These and other prod­ucts are tested in an isotope labo­ra­tory using mass spec­trom­etry to ensure that the isotopes in the sample match isotopes in refer­ence samples from the correct region.

Correct indi­ca­tion of origin on a food product’s label builds consumer confi­dence in the brand. Geograph­ical indi­ca­tions of prod­ucts are listed in Annex III of Regu­la­tion (EC) No. 110/2008.

What does the consumer asso­ciate with regionality?

A region has both spatial and socio-cultural bound­aries. These can be geograph­i­cally smaller than a nation state but larger than a munic­i­pality. In most cases, natural areas such as the Alte Land,” Lake Constance and the Spree­wald” give a region its name.

How does Tentamus contribute to
ensuring the product quality of food?

The Tentamus Group has special­ized labo­ra­to­ries around the world that perform isotopic analysis for origin veri­fi­ca­tion. This reduces consumer decep­tion by offering organic and origin verification.

The following analyses are performed within the Tentamus network to verify and ensure the quality of your food:

  • Deter­mi­na­tion of origin by isotopic analysis
  • Pollen analysis of honey (deter­mi­na­tion of origin)
  • Veri­fi­ca­tion of the desig­nated classes of table pota­toes and fruits and vegetables
  • Deter­mi­na­tion of vitamin content (with LC-MS/MS)
  • Qual­i­ta­tive & quan­ti­ta­tive deter­mi­na­tion of preservatives
  • Deter­mi­na­tion of morpho­line and the other 7 amino alcohols
  • Pre-market Testing (6 – 24h)
  • Quality assur­ance in rela­tion to honey and tobacco products

Food Fraud –
False Indications of Origin

Tentamus has also launched the Tentamus Center for Food Fraud (TCF²), which provides consulting services and analyt­ical support in the detec­tion of fraud­u­lent activ­i­ties in the food sector. The TCF² has state-of-the-art equip­ment that provides the most accu­rate test results and methods. This equip­ment consists of:

  • R‑MS (isotope ratio mass spec­trom­etry): deter­mining the origin of a product by iden­ti­fying its isotopic fingerprint.
  • LC-IRMS (liquid chro­matog­raphy coupled with isotope ratio mass spec­trom­etry): analyzes indi­vidual ingre­di­ents found in a food product to deter­mine its unique origin.
  • LC-HRMS (liquid chro­matog­raphy coupled with high-reso­lu­tion mass spec­trom­etry): often used to analyze honey for adul­ter­ants and other means of food fraud.
  • NMR (nuclear magnetic reso­nance spec­troscopy): used to deter­mine the struc­tures of e.g. proteins, amino acids, lipid frac­tions and the mobility of water in food.
  • LC-MS/MS (liquid chro­matog­raphy coupled with mass spec­trom­etry): modern analyt­ical method for iden­ti­fying trace substances in food, e.g. aller­gens or pesti­cide residues.
  • NGS (next gener­a­tion sequencing): exam­ines the DNA and RNA struc­ture of foods to deter­mine genetic alterations.
    ICP-MS (Induc­tively Coupled Plasma Mass Spec­trom­etry): Iden­ti­fies cont­a­m­i­nants and toxic elements in food, e.g. heavy metals.

Worldwide network for
product quality assurance

Tentamus has a large number of sites with isotope labo­ra­to­ries that have a proven track record of accu­rate trace­ability. These labo­ra­to­ries are part of the industry of instru­mental analysis, testing poten­tially harmful substances in food for compliance.

An example of one of these toxins is pyrrolizide alka­loids, the content of which is often too high in dried and frozen herbs.

Overview of
Laboratories for the Food Verification of Origin of the Tentamus Group

The following labo­ra­to­ries of the Tentamus Group offer isotope analysis:

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