Introduction. Food allergies are hypersensitivity reactions mediated by immune mechanisms triggered by the presence of antigens –generally proteins- in food, such as those found in cows‘ milk. International guidelines recommend the use of extensively hydrolyzed formulas as alternative for children with Cow milk allergy. Strategies to reduce allergenicity of food proteins comprise treatments such as heating and hydrolysis. Non-thermal treatments are able to induce protein modifications similarly to thermal treatments; however less damage is produced by these innovative processing methods. Thus, high intensity pulsed light (HIPL) technology can be proposed alternatively to thermal treatments to assist on the reduction of food allergenicity.
The aim of this work was to assess the effect of the use of HIPL treatment previous to enzymatic hydrolysis, applied to modify the antigenicity of target proteins, such as whey proteins.
Materials and Methods. Experiments were carried out to verify the effectiveness of HIPL technology to accelerate protein hydrolysis reaction with a selected enzyme. The combined treatments are an alternative to induce further modification of proteins structure in order to affect their allergenic power. For this purpose, samples of whey solution were submitted to different HIPL-energy doses (0, 1, 3, 5, 8 and 12 J/cm2) at a fixed distance from the light source. Untreated sample was used as control. For the combined treatment, bromelain was added to HIPL pre-treated samples at an enzyme/ substrate ratio of 1/10 (w/w). Hydrolysis was carried out for 0, 5, 10, 20, or 30 min.
Results. Concerning the efficiency of HIPL treatment to induce protein unfolding, the highest exposure of free SH groups took place upon the highest energy doses. When HIPL treatment was combined with enzymatic hydrolysis, a raise in the degree of hydrolysis was observed, particularly at the highest energy levels tested.
Conclusions. Results obtained in the present work suggest that, even if an increased antigenicity potentially occurs due to the exposure of hidden linear epitopes upon the unfolding induced by the non-thermal treatment assayed, further peptide bonds cleavage also take place after hydrolysis. This effect could change whey proteins antigens, and thus its antigenic power. Although further studies are required these preliminary result is promising
