Soybean allergen detection methods – A comparison study

Abstract

Soybean containing products are widely consumed, thus reliable methods for detection of soy in foods are needed in order to make appropriate risk assessment studies to adequately protect soy allergic patients. Six methods were compared using eight food products with a declared content of soy: a direct sandwich ELISA based on polyclonal rabbit antibody (ab) to raw soy flakes, a commercial and an in-house competitive ELISA both based on ab to denatured, 'renatured' soy protein, an enzyme-allergosorbent test (EAST) inhibition based on two sera from soy allergic patients, histamine release (HR) using basophils passively sensitized with patient serum and a PCR method detecting soy DNA. Eight food products were selected as model foods to test the performance of the methods. There was an overall good agreement between the methods in terms of ranks of soy content but not the quantity. The sandwich ELISA aimed at native soy proteins had the lowest detection limit of 0.05 ppm, but only identified soy in 5/8 products, and generally in lower amounts compared to other methods. The competitive ELISA had a higher detection limit of 21 ppm, but seemed more successful in detecting processed soy. Only HR, EAST inhibition and PCR detected soy in all eight products. In spite of a general good correlation in terms of ranks of soy content, more than a single method may be necessary to confirm the presence of soy in foods.

Tüketime Hazır Dönerlerde PCR ile Soya Proteininin Aranması

“…It brings economical disadvantages because of replacement of an expensive  İletişim (Correspondence)  +90 532 6250060  karlomrt@istanbul.edu.tr PCR Detection of Soy ... ingredient like meat with a cheaper ingredient like soy. Besides soy is an important allergy source for sensitive consumers [3][4][5] . Because of these reasons, use of soy in food products are limited or banned in various countries [4,5] .…”

“…Besides soy is an important allergy source for sensitive consumers [3][4][5] . Because of these reasons, use of soy in food products are limited or banned in various countries [4,5] . In our country presence of soy in a food product has to be declared in the label.…”

“…Several methods have been used for detection of soy in food products so far [3,4,7] . However, most reliable methods are based on detection of soy protein or DNA.…”

“…However, most reliable methods are based on detection of soy protein or DNA. Protein based methods includes, electrophoretic or serologic (ELISA) methods [7][8][9] while PCR is most widely used as DNA based methods [4,10] . Because DNA is more stable to processing conditions than protein, PCR methods are shown to be more reliable when used in processed foods [10] .…”

Food safety and label claims for hazelnut allergy traces: evaluation of two PCR assays

“…The implementation of immune enzymatic methods like ELISA, and the applica-tion of genetic mechanics (PCR and Real-time PCR) under this context represent a special challenge (Yeung & Collins 1996;Koppelman et al1999;Holzhauser et al 2000;Poms et al 2004;Schoringhumer et al 2007;Pedersen et al 2008). Several papers reported on the development of ELISAs to detect traces of hazelnut in food with the target molecule for the first main distinction being either a protein or DNA Rejeb et al 2003).…”