2014 Annual Meeting Abstract - Effects of ozone pretreatment on the molecular properties of wheat grain proteins

Poster Presentation
Protein & Gluten

115-P

Effects of ozone pretreatment on the molecular properties of wheat grain proteins
T. Aussenac (1), L. RHAZI (2), P. GOSE (2)
(1) Inst Polytechnique LaSalle Beauvais, Beauvais, France; (2) LaSalle Beauvais, beauvais, France

In this study, we report the effects of ozone pretreatment of different bread wheat grains on the alveograph properties of the dough obtained and on the molecular distribution of the storage proteins. Experiments have been realized to evaluate the influence of a range of ozonation conditions (humidification rate, ozonation time and ozone concentration in the inlet flow). Two wheat cultivars differing on their HMW-GS composition and technological properties were used. Results showed that the rheological properties of the dough can be largely modified by the ozone pretreatment of the grain whatever the cultivar used. The P/L of the dough was significantly increased (from 0.83 to 4.22 and from 1.89 to 5.67 for Rubisko and Diamento, respectively) by the ozone pretreatment, revealing a large modification of the tenacity/extensibility ratio in the dough protein networks. Protein solubility evaluated by the Extractable Protein/Total Protein ratio (EP/TP) significantly decreased with the ozone pretreatment and remarkable protein polymers/aggregates were observed in both reduced and non-reduced SDS-PAGE patterns. In addition, ozonized samples displayed increased molecular weight distribution as determined by an A-FFFF method. Protein oxidation by ozone (via disulfide-sulfhydryl interchange reactions and formation of tyrosine bonds) is the main suggested phenomenon which could explain these modifications.