Pastry Flour Research Articles

A green miniaturized QuEChERS based on an electrospun nanofibrous polymeric deep eutectic solvent coupled to gas chromatography-mass spectrometry for analysis of multiclass pesticide residues in cereal flour samples

A new polymeric deep eutectic solvent (DES) composed of poly (2-hydroxyethyl methacrylate):1-tetradecanol ([PHEMA]:[TD]) was prepared through thermally-induced free-radical polymerization using azobisisobutyronitrile (AIBN) as initiator. The [PHEMA]:[TD] DES was mixed with polyamide 6 (PA6) and electrospun into a composite fibrous scaffold for the first time. The PA6/[HEMA]:[TD] nanofibers were characterized by ATR-FTIR, SEM, BET, and BJH techniques and applied as a sorbent in the micro-solid phase extraction (µSPE) step of pesticide residues from cereal flour samples. The analyses were carried out with the GC–MS technique. The effect of sorbent mass, desorption solvent (kind and volume), pH, and ionic strength was investigated to establish the optimal conditions. Besides, the factors influencing the performance of the electrospinning process, such as electrospinning voltage, polymer solution feed rate, syringe needle tip-to-collector distance, and electrospinning duration, were also optimized. Matrix-matched calibration curves showed good linearity (r2 = 0.9803–0.9984) in the concentration range of 0.016–250 μg kg−1. The obtained limits of quantification (0.016–1.805 μg kg−1) were lower than the maximum residue levels (MRLs) established by the European Union and the Food and Agriculture Organization (0.01–0.05 mg kg−1) for the pesticide residues in cereal samples. The intra-day and inter-day precision based on relative standard deviation (RSD) were obtained as 1.1–5.8% and 2.4–8.5%, respectively. The method was applied to the detection of multiclass pesticide residues in maize, rice, wheat, and pastry flour samples, and the obtained relative recoveries were in the range of 71–118% (RSD%<7.5). Finally, the procedure greenness was evaluated based on Complex Green Analytical Procedure Index (Complex GAPI) and the Analytical Eco-Scale (AEC) approaches. This paper also suggests the first application of green hydrophobic PA6/[PHEMA]:[TD] electrospun nanofibers as sorbent for analyzing pesticides in different cereal samples.

Impact of water and flour components in dough investigated through low-field nuclear magnetic resonance

Bound and free water within dough strongly affect its rheological behavior and processability, as well as its gluten network. Depending on its total content and on the characteristics of flour constituents, water can be both bound to components and free in the dough. The equilibrium between bound and free water directly impacts the elasticity and extensibility of dough and therefore controls the texture of final products. In this study, Nuclear Magnetic Resonance (NMR) was used to assess the relaxation behavior with the focus on water. The proton spin-spin relaxation measurements were carried out at 20 MHz with a Bruker Minispec mq20 NMR spectrometer (Bruker, Rheinstetten, Germany). The transverse relaxation time in a spin locking field (T1?) was determined at 25°C following the Carr–Purcell–Meiboom–Gill (CPMG) sequence. The data were analyzed by the continuous distribution model. The dough was prepared with commercial semolina, which was mixed with water in a Brabender Mixer 350 (Brabender® GmbH, Duisburg, Germany) to reach three different levels of water content (30, 50, and 70%, based on semolina weight) and to study the water distribution as a function of the water total content. The dough characterization was carried out also comparing the T1? distribution of semolina dough with that of starch-water and gluten-water mixtures and also of pure starch and gluten to assess the role of each flour component. Additionally, the semolina dough sample was compared with a sample prepared with pastry flour, with a lower content of proteins, to investigate the different behavior as a function of the gluten amount. It was found that the dough presents three relaxation processes: one, very fast, is related to crystalline starch, while the other two are characteristic of two water populations, water in intragranular and in extragranular regions of starch, respectively. The comparison with pastry flour showed that the dough prepared with the latter one was less homogenous than the semolina one, with a clear distinction between free and bound water, while the semolina dough seemed to contain several water populations differently bounded, that were responsible for a broader peak at medium water content (around 50%).

Validation of a Simulated Commercial Frying Process to Control Salmonella in Donuts.

This study validated a typical commercial donut frying process as an effective kill-step against a 7-serovar Salmonella cocktail (Newport, Typhimurium, Senftenberg, Tennessee, and three dry food isolates) when contamination was introduced through inoculated flour. The bread and pastry flour mix (3:1) was inoculated with the Salmonella cocktail, and subsequently dried back to original preinoculation moisture content, achieving a Salmonella population of 7.6 log CFU/g. Inoculated flour was used to prepare a typical commercial donut batter, which was fried using 375°F (190.6°C) oil temperature. No viable Salmonella was detected using an enrichment plating protocol in the donuts after 2 min of frying, resulting in >7-log reduction in Salmonella population. The internal donut temperature increased from ∼30°C to ∼119°C at the end of 2 min of frying. The water activities of the donut crumb and crust after 2 min of frying, followed by 30 min of ambient air cooling, were 0.944 and 0.852, respectively. The donut pH after ambient-air cooling was 5.51. The D- and z-values of the Salmonella cocktail in donut dough were determined using thermal-death-time disks and temperature-controlled water baths. The D-values of the cocktail were 8.6, 2.9, and 2.1 min at 55°C, 58°C, and 61°C, respectively, whereas the z-value was 10°C. This study validated that >7-log reduction could be achieved if donuts are fried for at least 2 min in the oil at 190.6°C, and calculated D- and z-values present the heat resistance of Salmonella in donut dough at the start of the frying processes. However, results from this study should not be extrapolated when donut composition and frying parameters are changed significantly.

Effects of Cooking Temperatures and Starch Source on the Gelatinization and Thickening Power of Roux

Roux made from three wheat flours and cornstarch and cooked to six different temperatures were tested for gelatinization onset temperatures and thickening power. All roux showed an increase in thickening power on moderate heating. Cooking to higher temperatures greatly reduced thickening power. Bread flour and all-purpose flour showed increasing gelatinization onset temperatures on heating, whereas pastry flour and cornstarch showed the opposite trend. Only roux made with wheat flours developed color during cooking. These results suggest that the browning during roux cooking is due to Maillard reactions and that caramelization is only a minor contributor to color change.

Acidulant and oven type affect total anthocyanin content of blue corn cookies

Anthocyanins, pink to purple water-soluble flavonoids, are naturally occurring pigments with claimed health benefits. However, they are sensitive to degradation by high pH, light and temperature. Blue corn (maize) contains high levels of anthocyanins. Cookies are popular snacks and might serve as a vehicle to deliver antioxidants. A cookie formula with a high level of blue corn was developed with added acidulents and baked in ovens with different heat transfer coefficients. The best whole-grain blue corn flour/wheat pastry flour ratio (80:20 w/w), guar gum level (10 g kg(-1), flour weight basis) and water level (215 g kg(-1), flour weight basis) were determined based on response surface methodology analysis. The interactions of citric and lactic acids and glucono-δ-lactone with three oven types having different heat transfer coefficients (impingement oven 179 °C/4 min, reel oven 204 °C/10 min and convection oven 182 °C/4 min) influenced the total anthocyanin content (TAC) remaining in blue corn-containing cookies after baking. Cookies baked with citric acid in the convection oven retained the maximum TAC (227 ± 3 mg kg(-1)). By baking rapidly at lower temperatures and adding acidulents, it may be possible to increase residual natural source antioxidants in baked foods.

Inverse Method to Estimate Kinetic Degradation Parameters of Grape Anthocyanins in Wheat Flour Under Simultaneously Changing Temperature and Moisture

Thermal and moisture effects on grape anthocyanin degradation were investigated using solid media to simulate processing at temperatures above 100 degrees C. Grape pomace (anthocyanin source) mixed with wheat pastry flour (1: 3, w/w dry basis) was used in both isothermal and nonisothermal experiments by heating the same mixture at 43% (db) initial moisture in steel cells in an oil bath at 80, 105, and 145 degrees C. To determine the effect of moisture on anthocyanin degradation, the grape pomace-wheat flour mixture was heated isothermally at 80 degrees C at constant moisture contents of 10%, 20%, and 43% (db). Anthocyanin degradation followed a pseudo first-order reaction with moisture. Anthocyanins degraded more rapidly with increasing temperature and moisture. The effects of temperature and moisture on the rate constant were modeled according to the Arrhenius and an exponential relationship, respectively. The nonisothermal reaction rate constant and activation energy (mean +/- standard error) were k(80 degrees C, 43% (db) moisture) = 2.81 x 10(-4)+/- 1.1 x 10(-6) s(-1) and DeltaE = 75273 +/- 197 J/g mol, respectively. The moisture parameter for the exponential model was 4.28 (dry basis moisture content)(-1). One possible application of this study is as a tool to predict the loss of anthocyanins in nutraceutical products containing grape pomace. For example, if the process temperature history and moisture history in an extruded snack fortified with grape pomace is known, the percentage anthocyanin loss can be predicted.

Effects of phenolic acids and transglutaminase on soft wheat flour dough and baked products

AbstractBACKGROUND: The effects of phenolic acids on the physical properties of soft wheat flour dough and baked soft wheat flour products were investigated. Transglutaminase (TG) was added to observe the effects of non‐disulfide crosslinks on phenolic acid treated dough. Ferulic acid, p‐coumaric acid or fumaric acid was blended with pastry flour at a level of 250, 500 or 1000 ppm of flour dry weight, respectively.RESULTS: The addition of phenolic acids, TG or a mixture of phenolic acids and TG to flour had no effect on the mixing properties of the doughs but significantly affected 90 min rested dough. The addition of phenolic acids decreased the maximum resistance and increased the extensibility of 90 min rested dough, and TG reversed the effects of phenolic acids on the rested dough. The physical characteristics of cookies blended with each phenolic acid plus TG were not significantly different (P &gt; 0.01) from those of the control cookies. However, TG with and without phenolic acids had significant effects on the moisture content, weight and volume of crackers.CONCLUSION: These results suggest that the addition of phenolic acids and TG in the absence of a fermentation process do not affect the physical properties of soft wheat flour products. The fermentation process allows the chemical reaction of the phenolic acids and TG to occur before the soft wheat flour products are baked. Copyright © 2008 Society of Chemical Industry

Response of irrigated soft white spring wheat to seeding date, seeding rate and fertilization

Irrigated production of soft white spring wheat (Triticum aestivum L. Em Thell.) (SWSW) for pastry flour or ethanol production is feasible if the high yield potential of recently released cultivars can be realized. Field studies were conducted at three locations over a 3-yr period to determine the response of irrigated SWSW to seeding date, seeding rate and fertilization (N, P and K) in southern Alberta. The highest yield was obtained for the first seeding date (Apr. 20 to 24). Seeding 2 wk later reduced ave rage grain yield by 3%, while seeding 4 wk later reduced average grain yield by 15%. The optimum seeding rate was 200 to 240 viable seeds m-2 (84 to 101 kg ha-1). Maximum yields were achieved when total available N (fertilizer + residual soil NO3-N + mineralized N) was greater than 26 kg N Mg-1 of potential yield. Mineralized N ranged from 45 to 183 kg N ha-1 (mean 125 kg N ha-1). Grain protein concentration did not exceed the maximum allowed for protein premiums (99 g kg-1) when total available N was less than 27 kg N Mg-1 of potential yield. The optimum P fertilizer rate was approximately 13 kg P ha-1 unless extractable soil P was very high. No response to K fertilizer was observed. Maximum grain yields of 7.3 to 10.6 Mg ha-1 were achieved by seeding early with a minimum of 200 viable seeds m-2 and application of sufficient N and P fertilizer. Key words: Triticum aestivum, nitrogen fertilizer, N mineralization, grain protein concentration, phosphorus

Effects of Wheat Protein Fractions on Flour Tortilla Quality

ABSTRACTCommercial wheat protein fractions (10) were evaluated during processing for quality of tortillas prepared using pastry, tortilla, and bread flours. Protein fractions that separately modify dough resistance and extensibility were evaluated in tortillas to determine whether the proteins could increase diameter, opacity, and shelf stability. Tortillas were prepared using laboratory‐scale, commercial equipment with fixed processing parameters. Dough and tortilla properties were evaluated using analytical methods, a texture analyzer, and subjective methods. Tortillas were stored in plastic bags at 22°C for up to 20 days. Adjustments in water absorption and level of reducing agent were made to normalize differences in functionality of 3% added proteins on dough properties. Tortilla weight, moisture, pH, opacity, and specific volume were not affected by added proteins, except for glutenin and vital wheat gluten treatments, which had decreased opacity in tortillas prepared from pastry flour. Increased insoluble polymeric protein content corresponded to decreased tortilla diameter and improved shelf stability. Treatments yielding tortillas with improved shelf stability and similar tortilla properties were produced when commercially processed vital wheat gluten products, FP600, FP6000, FP5000, or gliadin were added to pastry or tortilla flour. These wheat protein fractions improved processing and tortilla quality of wheat flours, especially pastry flour, by modifying protein content and quality.

Effects of Soil‐Moisture Stress on the Yield and Quality of Flour from Wheat (Triticum aestivum L.)1

AbstractEffects of soil‐moisture stress at different periods during the growth of spring wheat planted in December on yield and quality of flour were studied under field conditions at Tucson, Arizona. Moisture stress at any stage of growth lowered wheat pastry flour quality. Moistures stress at the jointing stage resulted in a decrease in flour yield and an increase in flour protein, viscosity, and mixing curve area. Moisture stress at flowering resulted in an increase in flour protein, viscosity, and mixing curve area. Moisture stress at the dough stage decreased flour yield and increased flour protein, mixing curve peak, and mixing curve area. Increases in viscosities and mixing curve areas of flour from grain from stressed plants were due to the increases in flour protein content. Changes in the alkaline water retention capacity and mixing curve peak values were not related to changes in protein content and must be due to other factors resulting from moisture stress.

SEPARATION OF STARCH AND GLUTEN: IV. APPLICATION OF A RAPID PROCESS TO FLOURS FROM VARIOUS GRADES AND TYPES OF WHEAT

A rapid process for separating starch and gluten from hard wheat patent flour (consisting of dispersal of a soft dough in water followed by screening) has been applied to pastry flour, whole wheat flour, and patent flours from the following wheats: No. 1 Northern, Hard Red Spring of high protein content; No. 2 Northern, Hard Red Spring of low protein content; No. 4 Northern, Hard Red Spring, severely damaged by frost; No. 2 C. W. Garnet; No.: C. W. Amber Durum; and No. 1 Alberta Red Winter. The original separation procedure required only minor modifications in spite of varying quantities and characteristics of the glutens of these flours. Whole wheat flour required a substantially greater amount of mixing water for the preparation of a satisfactory dough. Approximately 90% of the starch present in each flour was recovered. Starches from the patent flours had protein contents ranging from 0.49 to 0.64% while that from whole wheat flour contained 1.06% of protein. Recoveries of gluten from all flours were practically complete. Crude dry gluten prepared from patent flours contained 20 to 30% of starch while the bran–gluten fraction from whole wheat flour contained 9.9%.