Effects of the incorporation of ß-glucans in chicken breast during storage.

ß-glucans are cereal-derived soluble fiber compounds that elicit health benefits when consumed in amounts of 0.75 g/serving. The use of ß-glucans in whole muscle meat products, such as chicken breast, is unexplored and needs clarification at a discovery level. The objective of this study was to evaluate the incorporation of ß-glucan in the whole muscle chicken breast and identify changes in physical, chemical, textural, microbiological, and thermal properties during 9 D of aerobic storage at refrigeration temperatures. Treatments were 1) control (no salt or ß-glucan added; CON), 2) salt solution (2% NaCl and 0.2% phosphate curing solution; SALT), 3) ß-glucan solution (1.5% ß-glucan; ßG), and 4) combination of salt and ß-glucan solutions (2% NaCl, 0.2% phosphate, and 1.5% ß-glucan; SALT+ßG). The target injection level was 20%, however the average uptake level was 8.15%. Color, pH, shear force, and bacteria count were minimally affected by treatment during the 9 D of aerobic storage at 4°C. Cooking loss (P < 0.01) was greater in CON samples compared to all other treatments indicating the presence of salt or fiber or both improved water retention. The ß-glucan concentration in uncooked chicken following injection was 0.125 g/100 g product and 0.133 g/100g product in ßG and SALT+ßG treatments, respectively. Following cooking, the ß-glucan concentration was 0.010 g/100g product and 0.004 g/100g product in ßG and SALT+ßG treatments, respectively. There was no storage day effect (P = 0.42) for the ß-glucan concentration in cooked product, therefore it was assumed that during cooking, ß-glucan concentration in whole muscle injected products was lost. Finally, thermal behavior measured with a differential scanning calorimeter indicated that there were only minimal differences, although some significant, among treatments in this study. Overall, the application of ß-glucan injection in whole chicken breast was not detrimental to product quality and actually improved water retention levels. However, new methods need to be developed for the incorporation of ß-glucan in injected whole muscle meat product so that ß-glucan can be retained during and after cooking.

Effect of extrusion temperature and screw speed on properties of oat and rice flour extrudates.

BACKGROUND: Whole oat and rice flours were mixed to develop instant flours by a high pressure and low mechanical shear extrusion process. The screw profile was designed aiming to obtain an infant food with gelatinized starch and high hydration ability. Response surface methodology was selected to study the impact of operating parameters such as temperature and screw speed (73-186 °C; 109-391 rpm) on physicochemical and pasting properties of the final extruded product. The main challenge of this study was to process high oats content, since they are characterized by high lipid and fiber content, which impact on material processing. RESULTS: The optimal response was achieved at 170 °C and 350 rpm. The optimal expansion ratio, bulk density, water absorption index, and water solubility index were 2.24, 289.65 kg m-3 , 6.42 g g-1 , and 4.75 g g-1 respectively. Overall, both temperature and screw speed affected the responses studied, except for water absorption index (only screw speed affected this response). Although lipids from oats reduce the expansion ratio of extrudates compared with samples containing higher starch proportions, their lipids protect the starch granules from mechanical degradation when higher screw speed values are used. As a result, both ungelatinized and gelatinized starches may be found in extrudates, which was confirmed by pasting property analyses. CONCLUSION: High oat content may be efficiently processed by optimizing the extruder conditions (temperature, screw speed, and profile), improving the nutritional properties of the final product. © 2017 Society of Chemical Industry.