ORIGINAL ARTICLE Functional, physiological, and rheological properties of oat b-glucan oxidized with hydrogen peroxide under soft conditions Nelisa Lamas de Souza 1 | Josiane Bartz 1 | Elessandra da Rosa Zavareze 1 | Patrícia Diaz de Oliveira 2 | Angelita da Silveira Moreira 2 | Wagner Schellin Vieira da Silva 1 | Alvaro Renato Guerra Dias 1 1 Departamento de Ci^ encia e Tecnologia Agroindustrial, Universidade Federal de Pelotas, Pelotas, 96010-900, Brazil 2 Centro de Desenvolvimento Tecnol ogico- Biotecnologia, Universidade Federal de Pelotas, Pelotas, 96010-900, Brazil Correspondence Wagner Schellin Vieira da Silva, Departamento de Ci^ encia e Tecnologia Agroindustrial, Universidade Federal de Pelotas, Pelotas, 96010-900, Brazil. Email: wagnersvsilva@yahoo.com Funding information FAPERGS; CAPES; CNPq; SCT-RS; Pole of Technological Modernization of the Southern Region Food Abstract The b-glucan fiber has been used to change the consistency, water activity, and fat binding capacity (FB), promoting viscosity, gelification or emulsification, in foods. Its properties are related to their structure, which can be modified chemically, enzymatically, and physically. The objective of this study was to evaluate the effect of oxidation under soft conditions (0.05 mL 100 g 21 and 0.10 mL 100 g 21 H 2 O 2 for 10 and 20 min) on the functional, thermal, and rheological properties of oat b-glucan. The soft oxidation of b-glucan at higher levels of oxidant increased the power of swelling and bile acids binding capacity, resulting in a higher hypocholesterolemic effect. In the same levels, the texture profile of oxidized b-glucans gels showed a reduction in hardness and lack of adhesiveness, as well as an increase in springiness and gumminess. The viscosity of b-glucan decreased after oxidation and showed pseudoplastic behavior. Practical applications b-glucan solutions can easily suffer molecular breakdown due to different processes, which may alter the effectiveness of health benefits due to their relationship with the viscosity. Among the possible modifications to which polysaccharides like b-glucan may be submitted, oxidation stands out. Studies on oxidation of b-glucan has been carried out using hydrogen peroxide as an oxidizing agent and iron ions as a catalyst, under conditions of concentration and temperature variables. However, there are no studies of oxidation of b-glucan under soft reaction conditions, with the purpose of improving physiological properties. KEYWORDS bile acids binding, oat b-glucan, oxidation, texture, viscosity 1 | INTRODUCTION The b-glucan is an important dietary fiber present in grains such as oats and barley, which has been studied for health claims such as reduced incidence of heart disease, lower cholesterol, and blood glucose, pre- vention and treatment of type 2 diabetes, and control of obesity (Brennan & Cleary, 2005). Oat b-glucan is a linear polysaccharide con- stituted by units of b-D-glucopyranosyl joined by links of the type b (1 ! 3) and b (1 ! 4) (Wood, 1994). The units, 3-O-b-D-glucose celo- biosil (DP3) and 3-O-b-D-glucose celotriosil (DP4), explain about 90% of its structure (Lazaridou, Biliaderis, Micha-Screttas, & Steele, 2004). The ability to form high viscosity solutions depends directly on the concentration and molecular weight of b-glucan, which is related with their functional properties, such as solubility or thermal and rheological properties (Wood, 2007). b-glucan solutions can easily suffer molecular breakdown due to different processes, which may alter the effective- ness of health benefits due to their relationship with the viscosity (Faure, Andersen, & Nystr€ om, 2012). Among the possible modifications to which polysaccharides like b-glucan may be submitted, oxidation stands out. Studies on oxidation of b-glucan has been carried out using hydrogen peroxide as an oxidizing agent and iron ions as a catalyst, under conditions of concentration and temperature variables (Faure, Andersen, & Nystr€ om, 2012; Faure, et al., 2014; Kivel€ a, Gates, & Sontag-Strohm, 2009; Kivel€ a, Henniges, Sontag-Strohma, & Potthast, 2012; Kivel€ a, Nystr€ om, Salovaara, & Sontag-Strohm, 2009; Kivel€ a, Sontag-Strohm, Loponen, Tuomainen, & Nystr€ om, 2011; Moura et al. J Food Process Preserv 2017; e13169; DOI: 10.1111/jfpp.13169 wileyonlinelibrary.com/journal/jfpp V C 2017 Wiley Periodicals, Inc. | 1 of 9 Received: 11 April 2016 | Revised: 17 June 2016 | Accepted: 22 July 2016 DOI 10.1111/jfpp.13169