E. Souza

Effect of Tempering Conditions on Milling Performance and Flour Functionality

ABSTRACT Tempering conditions of wheat grain change the quality of the flour, yet most experimental milling systems use a standard tempering without optimization. The effect of tempering condition on milling performance and flour functionality for soft red winter (SRW) wheat grain was tested by measuring flour yield, ash, polyphenol oxidase (PPO), and solvent retention capacity (SRC) in grain samples from three SRW cultivars (Roane, Cyrus, and Severn). Tempering was conducted with a full factorial design of initial wheat moisture, tempered wheat moisture, tempering temperature, and tempering time at two levels. Tempered wheat moisture had the largest effect on milling performance and flour functionality. Flour yield was more reduced for all samples tempered at 15% moisture than for samples tempered to 12% moisture. Flour quality of the 15% tempered sample was better than the 12% tempered samples due to less bran contamination as measured by flour ash and PPO. Increasing the tempering moisture increased fl...

Effects of Extent of Chlorination, Extraction Rate, and Particle Size Reduction on Flour and Gluten Functionality Explored by Solvent Retention Capacity (SRC) and Mixograph

The effects of extraction rate, extent of chlorination, and particle size distribution on flour and gluten functionality were explored using solvent retention capacity and mixograph for the soft wheat cultivar, Croplan 594W. The SRC results showed dramatic effects of milling extraction and chlorination extent, but less significant effects of additional milling to reduce particle size. With increasing extent of chlorination, SRC analysis showed increases in water, sodium carbonate and sucrose SRC values, but a decrease in lactic acid SRC values. The ratio LA/(NaC + Suc) SRC values decreased significantly with increasing extent of chlorination and the effect was greater when the milling yield decreased from 74 to 55%.

Application of RVA and Time-Lapse Photography to Explore Effects of Extent of Chlorination, Milling Extraction Rate, and Particle-Size Reduction of Flour on Cake-Baking Functionality

ABSTRACT Three factors (extent of chlorination, milling extraction rate, and particle-size reduction) in cake-baking functionality of Croplan 594W flour were explored using a Rapid Visco-Analyser (RVA) and time-lapse photography. The extent of chlorination and milling extraction rate showed dramatic effects, but postmilling to reduce flour particle size was a less significant factor. RVA results showed that starch pasting was accelerated, and both peak and set-back viscosities were enhanced, with increasing extent of chlorination. These effects were exaggerated by the high sugar concentration relevant to cake baking, compared to the same effects in water. Cake baking with chlorinated flours, in a formulation with 50% sugar (%S) and 275 parts total solvent (TS), showed that, as the extent of chlorination increased, cake moisture content and edge height decreased. Cake center height and shape factor were curvilinear, with maxima near flour with pH 4.6. Dramatic collapse occurred for cakes baked with unchlor...

Evaluation of α-amylase activity and falling number around maturity for soft white and soft red wheat varieties in Michigan

White wheat is, categorically, more susceptible to pre-harvest sprouting (PHS) than red wheat. Physiological maturity (PM), defined as when the seeds reach their maximum dry weight, is a critical time before harvesting. The objective of this study was to determine a reference level of α-amylase activity and the corresponding Falling Number (FN) value near the time of PM of selected red and white cultivars in the absence of PHS inducing conditions. Twenty-four soft winter wheat genotypes (12 red and 12 white) adapted to Michigan with varying historic levels of susceptibility to PHS were planted in an α-lattice design in two locations from 2008 to 2010. Spikes were collected three days before PM, at PM, and three days post PM. Samples were freeze-dried, threshed, milled and evaluated for α-amylase activity and FN value using high throughput method. Within genotype, clear trends were observed in the reduction of α-amylase activity and the increase of FN value during the physiological maturation. A nonlinear relationship between α-amylase activity and FN value was fit with an r2 of 0.801. Significant differences were observed for genotype for both α-amylase activity and FN value for all collection time points. No significant differences were found between red and white wheat, categorically, at any of the three time-points in the absence of PHS. The evaluation results provide a critical reference prior to induction of PHS. The α-amylase activity and FN tests show different advantages in analyzing PHS samples as the relationship between α-amylase activity and FN value is not linear over wide-ranging results.

Nutritional Profile of Whole-Grain Soft Wheat Flour

ABSTRACT Whole-grain wheat flour is used in baking to increase fiber content and to provide vitamins from the bran layers of the kernel. We surveyed whole-grain soft flour samples from North America to determine the nutritional profile using recently revised fiber quantification protocols, Codex 2009.1. Standard compositional and vitamin analyses were also included in the survey. Three separate studies were included in the survey: sampling of commercial whole-grain soft wheat flour, a controlled study of two cultivars across three years and two locations, and a regional study of soft white and soft red grain from commercial grain production. The Codex method for fiber measurement estimated total fiber concentration in the commercial sampling at 15.1 g/100 g, dry weight basis (dwb). In the controlled research trial, the largest source of variation in total fiber concentration was attributed to year effects, followed by genotype effects. For the two locations used in this study, location effects on fiber co...

Water-Extractable Nonstarch Polysaccharide Distribution in Pilot Milling Analysis of Soft Winter Wheat

ABSTRACT Commercial wheat (Triticum aestivum em. Thell) flour milling produces flour streams that differ in water absorption levels because of variability in protein concentration, starch damaged by milling, and nonstarch polysaccharides. This study characterized the distribution of water-extractable (WE) nonstarch polysaccharides (NSP) in long-flow pilot-milling streams of soft wheat to model flour quality and genetic differences among cultivars. Existing reports of millstream analysis focus on hard wheat, which breaks and reduces differently from soft wheat. Seven soft winter wheat genotypes were milled on a pilot-scale mill that yields three break flour streams, five reduction streams, and two resifted streams. Protein concentration increased linearly through the break streams. WENSP concentration was low and similar in the first two break streams, which are the largest break streams. Flour recovery decreased exponentially through the reduction streams; flour ash and water-extractable glucose and galac...