Comparison of commercial DNA kits for allergen detection of celery in food matrices

Abstract

For correct allergen risk management by industry, retail and food safety authorities, sensitive and reliable fast allergen detection methods are required, even more when precautionary allergen labelling based on reference doses will be implemented in legislation. This study aimed to perform a comparative assessment of three commercially available quantitative or qualitative test kits, for DNA analysis of celery in food products. Five product groups, representing different sectors of the AOAC food-matrix triangle, being (plant-based) meat products, snacks, sauces, dried herbs and spices, and smoothies, were identified to potentially contain celery. From each group, blank and incurred (labelled to contain celery) food products were selected, of which the blank food products were additionally spiked with low protein levels of celery prior to qPCR assessment. Results show that the assessed test kits perform according to their specifications, however, a clear influence of the matrix on the detection ability of celery was observed. In addition, quantification of the amount of celery in the different food products showed to be challenging in all food product groups using the two quantification kits.

Fig. 1

Determined quantities of celery spiked in the different blank materials. Data presented as mean ± SEM. Asterixes (*, P < 0.05) are is used to represent a comparative statistically significant result, based on a one-way ANOVA, Bonferroni's Multiple Comparison Test. R = r-Biopharm, B = Biotecon. On the x-axis the different matrices are given (details in Table 3). 1, 3 and 10 represent spiked levels of mg total celery protein per kg food product.

Fig. 2

Determined celery quantities in incurred samples. Data presented as mean ± SEM. Asterixes (*, P < 0.05) are is used to represent a comparative statistically significant result, based on a One-way ANOVA, Bonferroni's Multiple Comparison Test. R = r-Biopharm, B = Biotecon. On the x-axis the different matrices are given (details in Table 3).

Fig. 3

Determined protein quantities of celery spiked in the different blank materials, 1,3 and 10 ppm indicate mg total celery protein per kg food product. N = 4, data presented as mean ± SEM. Asterixes (*, P < 0.05) are is used to represent a comparative statistically significant result, based on a One-way ANOVA, Bonferroni's Multiple Comparison Test.