Allergic reactions to emerging food allergens in Canadian children

Most Canadian food allergy data has focused on Health Canada’s priority food allergens. This study describes which non-priority (emerging) food allergens were most commonly reported by Canadian parents and categorized/confirmed by allergists. A secondary aim was to describe severity of allergic reactions to emerging allergens. Parents reported allergic reactions to emerging food allergens experienced by their child (< 18 years) which occurred in the past 12 months, and allergists categorized/confirmed them according to likelihood of IgE-mediated food allergy. Of 68 eligible patients completing the survey, the most commonly reported emerging allergens were fruits/vegetables (58.8%), seeds (22.1%), legumes (19.1%) and other (11.8%). Median allergist ranking for legumes was ‘probable’ IgE-mediated food allergy, ‘possible’ for seeds and fruits/vegetables, and ‘unlikely’ for other. Median reaction severity was mild for legumes, and moderate for seeds, fruits/vegetables, and other. Our study highlights that non-priority food allergens, namely legumes and seeds, can lead to probable/likely allergic reactions in Canadian children. These food allergens are increasing in popularity in the Canadian diet, which could lead to increasing reports of allergic reactions. More research is needed to confirm reports of reactions to emerging allergens, and to document their inclusion as ingredients in packaged foods.

Boiling and Pressure Cooking Impact on IgE Reactivity of Soybean Allergens

BACKGROUND

Soybean is one of the 8 foods that causes the most significant rate of food allergies in the USA and Europe. Thermal processing may impact on the allergenic potential of certain foods. We aimed to investigate modifications of the IgE-binding properties of soybean proteins due to processing methods that have been previously found to impact on the allergenicity of legumes such as peanut.

METHODS

Soybean seeds were subjected to different thermal processing treatments. To evaluate their impact on the IgE-binding capacity of soybean proteins, individual sera from 25 patients sensitized to soybean were used in in vitro immunoassays. Detection of specific soybean allergens in untreated and treated samples was carried out with specific monoclonal and polyclonal antibodies. In vivo studies of skin prick testing (SPT) were also performed.

RESULTS

The IgE reactivity of soybean was resistant to boiling up to 30 min, and this treatment had a higher impact when applied for 60 min. Treatment that combined heat and pressure produced a fragmentation of proteins in both soluble and insoluble fractions that went along with a decreased capacity to bind IgE and reduced the SPT wheal size. However, allergens such as 7S globulins survived this treatment.

CONCLUSIONS

Thermal-processing methods able to attenuate the capacity of soybean proteins to bind IgE may contribute to the improvement of food safety and could constitute a potential strategy for the induction of tolerance to soybean.