Specific Detection of Soybean Residues in Processed Foods by the Polymerase Chain Reaction

Investigation of undeclared food allergens in commercial Thai food products

“…In order to ensure avoidance of the offending food allergen, a labeling system to provide information regarding food allergens used in food products has been adopted globally (Mills et al, 2004;Yamakawa et al, 2007). Thailand, however, has not participated in this program.…”

Detection of Food Allergens

“…There are a few studies comparing enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) for the detection of the same allergen, showing a generally good correlation for different food matrices (Meyer et al, 1996;Holzhauser et al, 2000Holzhauser et al, , 2002Dahinden et al, 2001;Hirao et al, 2006;Yamakawa et al, 2007;Bettazzi et al, 2008;Demmel et al, 2008;Piknova et al, 2008). Some PCR assays have been reported to be more sensitive than ELISA (Koppel et al, 1998).…”

“…DNA of soy protein isolates and soy concentrates has been shown to be degraded to fragment sizes ranging from 100 to 400 bp (Meyer et al, 1996). PCR designed to detect soybean in processed foods failed to detect soy residue in highly processed foods, including tofu and seasoning containing hydrolyzed soy protein (Yamakawa et al, 2007). The average DNA size extracted from bread is around 300 bp (Allmann et al, 1992).…”

“…To ensure the extraction of DNA from foods, mainly from highly processed products and the presence or absence of PCR inhibitors, many assays for food allergens include a universal eukaryotic primer pair (Brezna et al, 2006a, b;Brezna and Kuchta, 2008) or plant-specific primer pair used to amplify the noncoding region of chloroplast (Rossi et al, 2006;Watanabe et al, 2007;Yamakawa et al, 2007;Yano et al, 2007).…”

Detection of Walnut Residues in Processed Foods by Polymerase Chain Reaction

“…PCR methods for detecting wheat, peanuts, soybeans, and kiwifruit have already been established using conventional PCR and electrophoresis. [8][9][10][11][12] In the present study, we developed a detection method for walnuts with sensitivity and specificity using conventional PCR. We show that the method established can be applied to processed food products, and that even trace amounts of walnut contained in a commercial food product can easily be detected by it.…”