Detection of Carrageenan in Meat Products Using Lectin Histochemistry

Abstract

Carrageenan is a polysaccharide that is widely used in the food industry. Due to its water holding capacity, there is a higher risk of adulteration for economic reasons related to it. A verifiable method for detecting carrageenan is still missing in the food inspection sector. The detection of carrageenan in meat products is not well described. Our study describes lectin histochemistry as a novel approach for carrageenan detection. Within this study, the detection of carrageenan in meat products by lectin histochemistry is validated. Lectins of Arachis hypogaea (PNA) and Bandeiraea simlicifolia (BSA), specific for galactose units of carrageenan, were used. The samples included model meat products (ground chicken-meat products) and meat products from retail markets (chicken and pork hams, sausages, salami, and dried sausages). The limit of determination (LoD) of this method was set at 0.01 g kg−1. The method sensitivity for lectin PNA reached 1, and, for lectin BSA, it reached 0.96. Method specificity for lectin PNA was 1, and, for lectin BSA, it was 1.33. Cross-reactivity with other hydrocolloids tested was not confirmed. The results confirm that lectin histochemistry is suitable for detecting carrageenan in meat products.

Detection of Carrageenan in Cheese Using Lectin Histochemistry

“…Detecting carrageenan in food is very problematic. Thus, there is no general method for its analysis yet [17,47]. Several methods for detecting carrageenan in food have been described in the literature.…”

“…Lectin histochemistry is performed based on the methods by Bartlová et al [17]. Biotinylated Arachis hypogaea lectin (peanut agglutinin, PNA) (Sigma-Aldrich, St. Louis, MO, USA) at a concentration of 2 µg mL −1 was used to detect carrageenan.…”

“…Biotinylated Arachis hypogaea lectin (peanut agglutinin, PNA) (Sigma-Aldrich, St. Louis, MO, USA) at a concentration of 2 µg mL −1 was used to detect carrageenan. Lectin of Arachis hypogaea binds specifically to sugars such as galactose and N-acetylgalactosamine by non-covalent bonds such as van der Walls and hydrogen bonds [12,[17][18][19].…”

“…B-Calleja solution was used for background staining which is prepared by mixing 1.0 mL of distilled water, 1.0 g of indigo carmine, and 200 mL of picric acid. Afterwards the solution was filtered [17].…”

“…The Arachis hypogaea lectin concentrations of 10 µg mL −1 , 2 µg mL −1 , and 1 µg mL −1 were tested on a sample of processed cheese from the retail market (Table 1) in this work. These concentrations were selected following previous work in which carrageenan was determined in meat products [17]. For the L* and a* parameters, a statistically significant difference was confirmed for the tested concentrations of 1 and 10 µg mL −1 (p < 0.05).…”