Tree nuts are primarily responsible for fatal allergic reactions. Thermal and non-thermal treatments are mainly carried out in industry to improve food quality. Food processing can modify the structure and function of food proteins and may alter their allergenic properties. We hypothesized that pressure and thermal treatment, could modify chestnut in vivo allergenicity.
An ambispective study was carried out, including patients evaluated between 2006 and 2016, with clinical allergy to chestnut, confirmed on the basis of either a convincing history of anaphylaxis with positive skin prick test and/or specific serum IgE levels to chestnut by the fluorescent enzyme immunoassay, or a positive double-blind placebo-controlled food challenge. The SPT were performed with the untreated and treated chestnut extracts (boiling 30 and 60 minutes, and heat/pressure treatment at 121º and 138º Celsius during 15 and 30 minutes).
16 patients were included. 68,7% were woman, median age was 42-years and 75% had an allergic respiratory disease. 31,2% were allergic to latex. 50% had allergies to other nuts (nut 75%, hazelnut 50% and almond 37,5%), showing sensitization to LTP (70%) and profiling (40%). The SPT median with untreated chestnut extract was 6.5mm.A consistent decrease in the SPT results size after boiling and heat/pressure treatments was observed. SPT results with heat and pressure treated chestnut extracts became negative.
The results of our study indicate that pressure and thermal treatments were able to significantly reduce the size of SPT in patients allergic to chestnut. It did not seem that any of these treatments increased chestnut allergenicity.