Effects of Processing on Physicochemical Properties and Efficacy of β-Glucan from Oat and Barley

Abstract

Effects of Processing on Oat β-Glucan PropertiesKilning and Flaking. Most of the oats used by the food industry are processed into groats, flakes, flour, or bran prior to incorporation in other food products or cooking by the enduser (e.g., porridge). Initial processing involves a heat-moisture treatment called kilning-the primary purpose of which is to inactivate lipase activity that leads to fat rancidity and decreased shelf life. In kilning and subsequent steaming and flaking processes other enzymes such as b-glucanase are also inactivated. As a result, kiln-dried oat groats, flakes, bran, and flour have virtually no endogenous enzyme activity (6). In our lab tests we found the b-glucan viscosity and MW of untreated oats (or "raw oats") to be dramatically lower than in the corresponding kilned material, which is consistent with inactivation of b-glucanase enzymes during the kilning process and suggests that this process is critical to the maintenance of b-glucan physicochemical properties. Table I shows how b-glucan viscosity increased with each subsequent heat-treatment step during primary oat processing (38). In his thesis study, Wang (38) also found variation between oat genotypes with respect to b-glucan physicochemical properties (Table I).Baking and Freezing. Studies testing the effects of baking and frozen storage on oat b-glucan properties have shown that both types of processing can cause a decrease in the MW, soluhttp://dx.

The Mutual Correlation of Glucose, Starch, and Beta-Glucan Release During Microwave Heating and Antioxidant Activity of Oat Water Extracts

“…The antioxidant activity of oat fractions, confirmed both in vitro and in vivo (Masisi et al 2016), turns them into a valuable resource of antioxidants which can impact the total antioxidant activity of human plasma (Harasym and Oledzki 2014). Some study revealed that different processing of oat products can affect its bioactivity assessed as a content of antioxidants and beta-glucan (Ames et al 2015); therefore, a thorough study is needed to evaluate the best possible treatment for each oat-containing product. Microwave radiation heating differs significantly from conventional cooking which is based on conduction and convection currents transporting heat from external sources.…”

Effect of Heat Treatments on Microbial Load and Associated Changes to β‐Glucan Physicochemical Properties in Whole Grain Barley

“…Barley products containing BG with a high viscosity, MW, and solubility are more successful at cholesterol lowering (Ames and Rhymer 2008;Theuwissen and Mensink 2008;Wang et al 2013;Ames et al 2015). However, other physicochemical properties of BG also influence its nutritional functionality and health benefits.…”

“…The mean BG in vitro digest extract viscosity, MW, and solubility of the commercial barley end-products are summarized in Table III. Typically, higher MW chains of BG are harder to solubilize and, therefore, are negatively correlated to solubility (Klamczynski et al 2004;Ames et al 2015). BG in vitro digest extract viscosity was measured by the RVA and described the viscosity of the BG extract in the flour slurry (Gamel et al 2015).…”

“…Health claims have been approved in the United States (U.S. Food and Drug Administration 2006) and Canada (Health Canada 2012) for the cholesterol-lowering properties of barley b-glucan (BG). Furthermore, clinical trials have shown barley to be effective at lowering postprandial glycemic response (Behall et al 2006;Ames et al 2015). Furthermore, clinical trials have shown barley to be effective at lowering postprandial glycemic response (Behall et al 2006;Ames et al 2015).…”

Effect of Processing on Viscosity and Molecular Weight of (1,3)(1,4)‐β‐Glucan in Western Australian Oat Cultivars

“…The amount, M w , solubility, and viscosity in the upper gastrointestinal tract are thought to be important (Rimsten et al 2003;Regand et al 2009;Wang and Ellis 2014;Ames et al 2015). The amount, M w , solubility, and viscosity in the upper gastrointestinal tract are thought to be important (Rimsten et al 2003;Regand et al 2009;Wang and Ellis 2014;Ames et al 2015).…”