Current Challenges in Detecting Food Allergens by Shotgun and Targeted Proteomic Approaches: A Case Study on Traces of Peanut Allergens in Baked Cookies

Abstract

There is a need for selective and sensitive methods to detect the presence of food allergens at trace levels in highly processed food products. In this work, a combination of non-targeted and targeted proteomics approaches are used to illustrate the difficulties encountered in the detection of the major peanut allergens Ara h 1, Ara h 2 and Ara h 3 from a representative processed food matrix. Shotgun proteomics was employed for selection of the proteotypic peptides for targeted approaches via selective reaction monitoring. Peanut presence through detection of the proteotypic Ara h 3/4 peptides AHVQVVDSNGNR (m/z 432.5, 3+) and SPDIYNPQAGSLK (m/z 695.4, 2+) was confirmed and the developed method was able to detect peanut presence at trace levels (≥10 μg peanut g−1 matrix) in baked cookies.

A multiple reaction monitoring method for determining peanut (Arachis hypogea) allergens in serum using quadrupole and time-of-flight mass spectrometry

“…An alternative method, which could provide sequence-level confirmation of the presence of food allergens in the circulation, is targeted liquid chromatography mass spectrometry (LC-MS). Target peptides have previously been identified for major peanut allergens and used to develop LC-MS methods for detection of peanut in food [16][17][18][19][20][21], a set of which were used to develop a triple quadrupole multiple reaction monitoring (QQQ-MRM) method which had a greater sensitivity when a microfluidic separation was used for analysis of a chocolate-containing dessert matrix [22]. This method has now been adapted to the analysis of peanut allergen peptide targets in serum and compared with a quadrupole-time-of-flight (Q-TOF) MS approach for analysis of biomarkers in undepleted plasma [23], which had a superior sensitivity when analysing tissues [24].…”

Advanced DNA- and Protein-based Methods for the Detection and Investigation of Food Allergens

“…SIM of whole proteins has also performed well for the detection of milk in fruit juices (LOD 1 µg/mL) (Monaci et van Hengel, 2008). When the m/z of the precursor ion and of some of the product ions are known, the specific m/z pair precursor ion/product ion (termed transition) can be followed using the highly sensitive LC-MS/MS targeted acquisition mode, which is called (Shefcheck et al, 2006;Careri et al, 2007;Pedreschi et al, 2012) with an LOD as low as 1 ppm, and of milk in dairy as well as other complex products (Mollé et al, 2005;Lutter et al, 2011;Ansari et al, 2011) with LODs ranging between 1 and 20 ppm. The LC-MS/MS approach has the additional advantage of being a multi-allergen screen, unlike ELISA where individual allergens must be detected by separate kits.…”

“…The MALDI-TOF analysis of whole proteins, which is termed protein profiling, was used for the evaluation of milk proteins in infant formulas (Sabbadin et al, 1999). PFF, using LC-MS/MS, has also been used for the characterization of allergenic food proteins, such as several allergens from peanut (Shefcheck et al, 2006;Pedreschi et al, 2012), fish (Carrera et al, 2010) and crustaceans (Ortea et al, 2009a, Rahman et al, 2010.…”

Making Progress in Plant Proteomics for Improved Food Safety

“…Most compelling examples are the work performed on Hevea brasiliensis exudates (rubber material source) (88) on Cupressus sempervirens pollen extracts (29) and Arachis hypogea nut extracts (89). Most compelling examples are the work performed on Hevea brasiliensis exudates (rubber material source) (88) on Cupressus sempervirens pollen extracts (29) and Arachis hypogea nut extracts (89).…”