Marzipan under the microscope
15 Dec 2011 by Evoluted New Media
Is that real or fake marzipan on your Christmas cake?
December is the peak season for indulging in marzipan – a rich almondy paste found in stollen and Christmas cakes but it can be adulterated with ground soy, peas and other ingredients.
Ilka Haase and Markus Fischer from the Hamburg School of Food Science turned food detectives and adapted the polymerase chain reaction (PCR) to test various marzipan concoctions with different amounts of apricot seeds – since apricots are closely related to almonds – peach seeds, peas, beans, soy, lupine, chickpeas, cashews and pistachios.
“We chose the PCR as this method detects the DNA of an organism. The DNA is very specific for each individual and allows the differentiation of even closely related species like almonds and apricots,” Hasse told Laboratory News. “PCR is already very commonly used also in food analysis.”
PCR enabled researchers to detect even small amounts – as little as 0.1% – of an almond substitute.
“Classical analytical methods for the identification/differentiation often fail or are not sensitive enough to quantify apricot concentrations below 1%. Polymerase chain reaction-based methods have been shown to enable the differentiation of closely related plant species in the past. These methods are characterized by high specificity and low detection limits,” the research said.
The researchers say PCR could serve as a perfect tool for routine screening of marzipan pastes for contaminants. The research was published in the Journal of Agricultural and Food Chemistry and funded by the German Ministry of Economics and Technology, the FEI and the Association of the German Confectionary Industry.
Marzipan: Polymerase chain reaction-driven methods for authenticity control
