Cereal Chem. 80(5):587-595The rheological properties of dough and gluten are important for enduse quality of flour but there is a lack of knowledge of the relationships between fundamental and empirical tests and how they relate to flour composition and gluten quality. Dough and gluten from six breadmaking wheat qualities were subjected to a range of rheological tests. Fundamental (small-deformation) rheological characterizations (dynamic oscillatory shear and creep recovery) were performed on gluten to avoid the nonlinear influence of the starch component, whereas large deformation tests were conducted on both dough and gluten. A number of variables from the various curves were considered and subjected to a principal component analysis (PCA) to get an overview of relationships between the various variables. The first component represented variability in protein quality, associated with elasticity and tenacity in large deformation (large positive loadings for resistance to extension and initial slope of dough and gluten extension curves recorded by the SMS/Kieffer dough and gluten extensibility rig, and the tenacity and strain hardening index of dough measured by the Dobraszczyk/Roberts dough inflation system), the elastic character of the hydrated gluten proteins (large positive loading for elastic modulus [G], large negative loadings for tan d and steady state compliance [J e 0 ]), the presence of high molecular weight glutenin subunits (HMW-GS) 5+10 vs. 2+12, and a size distribution of glutenin polymers shifted toward the high-end range. The second principal component was associated with flour protein content. Certain rheological data were influenced by protein content in addition to protein quality (area under dough extension curves and dough inflation curves [W]). The approach made it possible to bridge the gap between fundamental rheological properties, empirical measurements of physical properties, protein composition, and size distribution. The interpretation of this study gave indications of the molecular basis for differences in breadmaking performance.

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Industrially blanched/frozen vegetables should preferably be cooked by pouch technology, rather than conventional cooking in water. Including cooking water or exuded liquid into the final dish will increase the level of nutrients in a meal. Warm-holding of vegetables after cooking should be avoided.

Blanched and nonblanched potato rods (var. Beate) were fermented with Lactobacillus plantarum strain NC8 (10 9 colony-forming units [CFU]/mL) at 37 °C for 45 and 120 min. Potato rods were pre-fried at 170 °C for 3 min, cooled, and subsequently deep-fried for 2 min 15 s. Potato juice (var. Beate) was fermented with the same strain (10 8 CFU/mL) at 30 °C for 1 to 5 h. Lactic acid fermentation of nonblanched potato rods for 45 min reduced acrylamide level in French fries with 48%, and with 71% after 120 min. By blanching potato rods before fermentation, reductions in acrylamide after 45 min and 120 min were 79% and 94%, respectively. Blanching, and especially fermentation, reduced visually judged browning of the French fries. Fermentation of potato juice reduced pH from 5.70 to 4.05 after 3 h. Simultaneously, glucose declined from 610.8 mg/100 mL to 7.9 mg/100 mL, fructose from 457.8 mg/100 mL to 0.0 mg/100 mL, and sucrose from 132.0 mg/100 mL to 29.2 mg/100 mL. Asparagine content remained largely unaffected between 0 h (1217.5 mol/100 mL) and 4 h (1175.6 mol/100 mL) and increased slightly (1470.3 mol/100 mL) after 5 h fermentation. Levels of several other amino acids involved in Maillard reactions, that is, alanine, arginine, phenylalanine, and serine, decreased during fermentation. It is concluded that acrylamide formation during production of French fries can be effectively lowered by lactic acid fermentation of potato rods before deep-frying. The reduction is due to reduced levels of reducing sugars rather than reduction of available asparagine.