Assessment of the efficiency of allergenicity-reducing processes in whey

AMBROSI, VANINA; BRUNO MARIELA A.; GONZALEZ, CLAUDIA; POLENTA, GUSTAVO

Córdoba

Congreso; V Congreso Internacional de Ciencia y Tecnología de Alimentos; 2014

Ministerio de Industria,Comercio, Minería y Desarrollo Científico

Dairy products are included in the group of foods known as the ¡°Big 8¡±, which are responsible for the majority of food allergies. Infants suffering from Milk Allergy should consume hypoallergenic infant formulas (HIF), which are usually made of extensively hydrolyzed proteins. It have been stated that in a sensitive population fed with HIF, it must not cause allergy symptoms in 90% of infants . However, the assessment of this requirement constitutes a challenge from the analytical point of view. We have recently developed a competitive ELISA which was adapted to measuring the remaining antigenicity of whey proteins without the need of diluting samples at high levels. In the present work, we tested the performance of the method by monitoring remaining antigenicity of whey proteins subjected to technologies such as high pressure treatment (HPT) combined with hydrolysis. For monitoring purposes, we choose ¥â-lactoglobulin (BLG) considering that it constitutes the main whey allergen. With that purpose, 1% solutions of whey protein concentrate (WPC 80 1%) were processed combining HPT (5 min, 300MPa, 45¨¬C) and enzymatic hydrolysis (45¨¬C, E:S ratio 1:10 of bromelain from pineapple stem with an activity of 10 caseinolytic units/ml). Samples were subjected to: a) 30 min hydrolysis followed by HPT + 5 min 100¨¬C to inactivate de enzyme; b) 30 min hydrolysis followed by 5 min 100¨¬C to inactivate the enzyme and then HPT; c) hydrolysis concomitantly with HPT (5 min, 45¨¬C) followed by 5 min at 100¨¬C to inactivate de enzyme. Untreated WPC 80 1% was used as a control. Regarding the efficiency of the treatments, the combination c) was the most effective to reduce BLG antigenicity, rendering a 72% reduction of antigenicity. Contrarily, treatment a) and b) increased by 214 and 174% BLG antigenicity compared to the control sample. These results suggest a synergic effect when hydrolytic treatments and HPT are applied simultaneously (treatment c). It can be speculated that hydrolysis was not completed in treatments a) and b), probably because of steric hindrance, which made the enzyme unable to cleave the antigenic epitopes of BLG. The increased antigenicity may be due to exposure of hidden linear epitopes by the combined effect of heat treatment + HPT (treatment b). Although further studies should be conducted, preliminary results are highly promising. Thus, the monitoring method can be regarded as a powerful tool: its application in quality control activities can lead to the production of high quality analytically certified HIF.