Physicochemical Evaluation and Optimization of Enriched Expanded Pellets with Milk Protein Concentrate

The objective of this work was to study the effect of addition of milk protein concentrate (MPC, 0–10%) and feed moisture (FM, 20–30%) in a blend of corn starch (CS, 80%) and quality protein maize (QPM, 20%) on different physicochemical characteristics of third‐generation (3G) snack foods using extrusion technology. A laboratory single‐extruder with a 3:1 compression ratio, a rectangular die, and a central composite nonroutable model with two variables were used. The physicochemical characteristics evaluated were expansion index (EI), bulk density (BD), penetration force (PF), and color parameters L*a*b*. EI decreased with the increase of MPC and FM, whereas BD and color parameters (a* and b*) increased; PF showed a minimum point (MPC = 5% and FM = 25%). EI, BD, and PF were selected for the optimization process in an area of superposition of 1.5–4.1% of MPC and 20.0–24.1% of FM. A validation of the optimal area was performed on samples with average values of 4.64 (±0.28) for EI, 141.02 (±7.29) kg m^–3 for BD, and 0.0033 (±0.00065) for N m PF. It is feasible to obtain a functional 3G snack food with good expansion characteristics using a microwave oven, and this snack has health benefits due to the addition of MPC and QPM.     

Development and Characterization of Extruded Pellets of Whole Potato (Solanum tuberosum L.) Flour Expanded by Microwave Heating

In various Latin American countries, large volumes of potato are classified as unsuitable for use as food and destined for use as feed. This raw material has a high starch and fiber content that could be used in the production of different kinds of food. The objective of this research was the preparation and characterization of extruded whole potato pellets expanded by microwave heating. A 3³ central composite routable experimental design and response surface methodology were used. The barrel temperature (BT, 93–127°C), feed moisture (FM, 19–29%), and corn starch concentration (CS, 3–37%) in the blends were evaluated. CS was the most important variable affecting the functional properties of the expanded pellets. Adding CS to the blends increased the expansion index and viscosity and improved luminosity, decreasing the apparent density and breaking force of the products. Low BT and especially high FM increased the luminosity of the expanded pellets. Increasing FM content increased the viscosity of the expanded pellets. The best functional characteristics for the expanded pellets were obtained using a blend of 63% potato flour and 37% CS, extruded at 110°C BT with 24% FM content. Nonfood-grade whole potato flour showed good potential for use in the production of expanded pellets with acceptable functional properties.     

Association of Barley Kernel Hardness with Physical Grain Traits and Food Processing Parameters

Kernel hardness is not a well‐characterized food quality trait in barley. Unlike wheat, not much is known about the effect of barley kernel hardness on food processing. Ten barley genotypes differing in single kernel characterization system hardness index (SKCS‐HI) (30.1–91.2) of dehulled kernels were used to determine the association of barley HI with other physical grain traits and food processing parameters. Thousand kernel weight (TKW) values of 10 genotypes were 29.7–38.1 g. Values for bulk density of grains were 721.1–758.9 kg/m³. Crease width and depth values were 0.9–1.3 mm and 0.4–0.7 mm, respectively. Barley HI showed no significant association with TKW, bulk density, or kernel crease dimensions. Kernel loss due to pearling after 325 sec of abrasion was 28.8–38.4% and showed significant negative correlation with HI (r = –0.87, P < 0.01). Proportion of barley flour particles >106 μm had values of 34.5–42.0%, and starch damage values were 1.8–4.5% among those 10 barley genotypes. HI showed significant positive correlations with both proportion of barley flour particles >106 μm (r = 0.93, P < 0.01) and starch damage (r = 0.93, P < 0.01). Water imbibition of barley kernels and cooked kernel hardness did not show significant correlation with HI.     

Effects of Steeping Temperatures and Periods of Waxy Rice on Expansion Properties of Gangjung (a traditional Korean oil‐puffed rice snack)

This study was conducted to investigate the effect of steeping conditions of waxy rice, temperatures (15, 25, and 35°C) and time periods (1, 11, and 21 days) on the expansion ratio of gangjung (a traditional Korean oil‐puffed rice snack). Physicochemical properties of waxy rice flour steeped under various conditions and expansion properties of gangjung made of the steeped waxy rice flour were investigated, and multiple regression analyses were applied between those properties to identify major physicochemical factors that optimally predict the expansion ratio of gangjung. As steeping temperature and time periods of waxy rice changed from the lowest to the highest, the expansion ratio of gangjung markedly increased (from 1,022 to 2,533%). Yet, the expansion ratio of the waxy rice sample steeped for 11–21 days at 35°C was not significantly different from the sample steeped for 21 days at 25°C, indicating that the lengthy steeping process for gangjung making can be shortened by increasing the steeping temperature. Physicochemical properties include moisture (γ = 0.85), protein (γ = –0.91), ash (γ = –0.84), potassium (γ = –0.89), magnesium (γ = –0.88), phosphorous (γ = –0.91), peak viscosity (γ = 0.77), and breakdown (γ = 0.94) of steeped waxy rice flour. These properties were highly correlated with expansion ratio (P < 0.01). Multiple regression analysis showed that the expansion ratio of gangjung was predicted successfully by the phosphorous content and breakdown value of steeped waxy rice flour.     

Effect of Barley Flour on Development of Rice‐Based Extruded Snacks

This study was conducted to develop a ready‐to‐eat extruded food using a single‐screw laboratory extruder. Blends of Indian barley and rice were used as the ingredients for extrusion. The effect of extrusion variables and barley‐to‐rice ratio on properties like expansion ratio, bulk density, water absorption index, hardness, β‐glucan, L*, a*, b* values, and pasting characteristics of extruded products were studied. A central composite rotatable design was used to evaluate the effects of operating variables: die temperature (150–200°C), initial feed moisture content (20–40%), screw speed (90–110 rpm), and barley flour (10–30%) on properties like expansion ratio, bulk density, water absorption index (WAI), hardness, β‐glucan, L*, a*, b* values, and sensory and pasting characteristics of extruded products. Die temperature >175°C and feed moisture <30% resulted in a steep increase in expansion ratio and a decrease in bulk density. Barley flour content of 10% and feed moisture content of <20% resulted in an increased hardness value. When barley flour content was 30–40% and feed moisture content was <20%, a steep increase in the WAI was noticed. Viscosity values of extruded products were far less than those of corresponding unprocessed counterparts as evaluated. Rapid visco analysis indicated that the extruded blend starches were partially pregelatinized as a result of the extrusion process. Sensory scores indicated that barley flour content at 20%, feed moisture content at 30%, and die temperature at 175°C resulted in an acceptable product. The prepared product was roasted in oil using a particular spice mix and its sensory and nutritional properties were studied.     

Technological and Nutritional Properties of Flours and Tortillas from Nixtamalized and Extruded Quality Protein Maize (Zea mays L.)

Nixtamalized and extruded flours from quality protein maize (QPM, V‐537C) and tortillas made from them were evaluated for some technological and nutritional properties and compared with the commercial brand MASECA. Both QPM flours showed higher (P < 0.05) protein content, total color difference, pH, available lysine, and lower (P < 0.05) total starch content, Hunter L value, water absorption index, gelatinization enthalpy, resistant starch, and retrograded resistant starch than nixtamalized MASECA flour. Tortillas from nixtamalized and extruded QPM flours had higher contents of essential amino acids than tortillas from MASECA flour, except for leucine. Tortillas from processed QPM flours also showed higher (P < 0.05) values of the nutritional indicators calculated protein efficiency ratio (C‐PER 1.80–1.85 vs. 1.04), apparent and true in vivo protein digestibility (78.4‐79.1 vs. 75.6% and 76.4–77.4 vs. 74.2%, respectively), PER (2.30–2.43 vs. 1.31), net protein retention (NPR; 2.88–2.89 vs. 2.11), and protein digestibility corrected amino acid score (PDCAAS; 54–55 vs. 29% based on preschool children and 100 vs. 85% based on adults) than MASECA flour. The use of QPM for flour and tortilla preparation may have a positive effect on the nutritional status of people from countries where these products are widely consumed.     

Solvent Retention Capacity Values in Relation to Hard Winter Wheat and Flour Properties and Straight‐Dough Breadmaking Quality

Solvent retention capacity (SRC) was investigated in assessing the end use quality of hard winter wheat (HWW). The four SRC values of 116 HWW flours were determined using 5% lactic acid, 50% sucrose, 5% sodium carbonate, and distilled water. The SRC values were greatly affected by wheat and flour protein contents, and showed significant linear correlations with 1,000‐kernel weight and single kernel weight, size, and hardness. The 5% lactic acid SRC value showed the highest correlation (r = 0.83, P < 0.0001) with straight‐dough bread volume, followed by 50% sucrose, and least by distilled water. We found that the 5% lactic acid SRC value differentiated the quality of protein relating to loaf volume. When we selected a set of flours that had a narrow range of protein content of 12–13% (n = 37) from the 116 flours, flour protein content was not significantly correlated with loaf volume. The 5% lactic acid SRC value, however, showed a significant correlation (r = 0.84, P < 0.0001) with loaf volume. The 5% lactic acid SRC value was significantly correlated with SDS‐sedimentation volume (r = 0.83, P < 0.0001). The SDS‐sedimentation test showed a similar capability to 5% lactic acid SRC, correlating significantly with loaf volume for flours with similar protein content (r = 0.72, P < 0.0001). Prediction models for loaf volume were derived from a series of wheat and flour quality parameters. The inclusion of 5% lactic acid SRC values in the prediction model improved R² = 0.778 and root mean square error (RMSE) of 57.2 from R² = 0.609 and RMSE = 75.6, respectively, from the prediction model developed with the single kernel characterization system (SKCS) and near‐infrared reflectance (NIR) spectroscopy data. The prediction models were tested with three validation sets with different protein ranges and confirmed that the 5% lactic acid SRC test is valuable in predicting the loaf volume of bread from a HWW flour, especially for flours with similar protein contents.     

The Impact of Oat Quality on White Salted Noodles Containing Oat Flour

This research compared the physicochemical properties of six milling oat cultivars from Western Australia over two growing seasons (2011 and 2012). Variations among the cultivars in physicochemical properties, particularly β‐glucan content, were assessed to determine their suitability for incorporation into white salted noodles at a level of 30% of the flour component. The average across six oat cultivars grown in 2012 was significantly higher (P < 0.05) for protein content, lipid content, and volume of smaller sized particles (<100 µm) and significantly lower for ash content, starch damage, and volume of larger particles (>100 µm) in comparison with the average across the same oat cultivars grown in 2011. The year of cultivation by cultivar interaction was significant (P < 0.05) for ash content, protein content, β‐glucan content, starch damage, and particle size. Oat cultivar Mitika had the highest peak viscosity for 100% oat flour (whole groat) and 30% oat–wheat (OW) flour blend, which may be owing to lower amylose percentage, high protein content, and greater volume of smaller particles. The effect of growing season had greater impact on OW noodle firmness than the genetic effect of cultivars. The eating and cooking quality attributes of OW noodles, such as color, color stability, firmness, and cooking solid loss were superior for those incorporated with 2012 oat flour (whole groat) compared with 2011 oat flour. Among the six oat cultivars, Williams produced noodles with poor cooking and eating quality, and Mitika was easier to handle during processing and produced noodles with superior brightness and color stability in comparison with other oat cultivars evaluated.     

Chemical and Physical Characteristics of Proso Millet (Panicum miliaceum)‐Based Products

Celiac disease and gluten sensitivities, as well as obesity and overweight‐related disorders, have led to the investigation of gluten‐free grains and development of new food products. To address this, refined proso millet and refined corn (control), both gluten‐free grains, were used to produce four different product types (muffin, couscous, extruded snack, and porridge). The products contained four different grain combinations (100% proso millet, 75% proso millet/25% corn, 25% proso millet/75% corn, and 100% corn). All products were evaluated for their nutritional composition, in vitro starch digestibility, and expected glycemic index (eGI). Products made with refined proso millet had increased protein (7.6–11.3%), lipid (1.2–6.1%), fiber (7.0–8.8%), and phenolic content (323.5–425 μg/g) compared with those incorporating corn flour (2.5–9.0%, 0.8–4.0%, 2.1–4.1%, and 213–315 μg/g, respectively). As the proso millet content increased, the eGI decreased significantly (P < 0.05). Products made from refined proso millet appear to be good candidates for producing low‐GI, gluten‐free foods.     

Effect of Milling and Particle Size on Functionality and Physicochemical Properties of Cowpea Flour

Cowpeas (Vigna unguiculata) were milled through 0.5‐, 1.0‐, and 2.0‐ mm screens, and the flour was subsequently separated into different particle‐size ranges. Such procedures caused only minimal changes in moisture, fat, protein, ash, and total carbohydrate. The amount of extractable starch, however, varied from 34.5 to 52%. The effects of both mill screen and sieve mesh size were significant (P < 0.05). Differences in milling and separation procedures resulted in significant variations in water absorption (0.41–2.81 g of water/g of flour), solids lost (0.34–1.17 g/g of flour), and protein solubility (21.2–37.4%) (P < 0.05). Finely milled flours (91% moisture) had lower initial gelatinization temperatures (70–73°C), as measured by differential scanning calorimetry (DSC) (P < 0.01). Gelatinization peaks in high‐moisture flour were similar to that of pure starch. At lower moisture, a second peak was observed indicative of protein. Light‐scattering analysis showed that different conditions produced a bimodal particle‐size distribution when samples were suspended in water. The small size had relatively constant diameters (19–21 μm) and was associated with starch granules. The latter had a large size distribution and varying peak size and was associated with aggregated flour particles. These results indicate that changes in processing produces cowpea flours with differing chemical and physical properties.     

Significance of Wheat Flour Particle Size on Sponge Cake Baking Quality

We evaluated the effect and magnitude of flour particle size on sponge cake (SC) baking quality. Two different sets of wheat flours, including flours of reduced particle size obtained by regrinding and flour fractions of different particle size separated by sieving, were tested for batter properties and SC baking quality. The proportion of small particles (<55 μm) of flour was increased by 11.6–26.9% by regrinding. Despite the increased sodium carbonate solvent retention capacity, which was probably a result of the increased starch damage and particle size reduction, reground flour exhibited little change in density and viscosity of flour‐water batter and produced SC of improved volume by 0.8–15.0%. The volume of SC baked from flour fractions of small (<55 μm), intermediate (55–88 μm), and large (>88 μm) particles of soft and club wheat was in the range of 1,353–1,450, 1,040–1,195, and 955–1,130 mL, respectively. Even with comparable or higher protein content, flour fractions of intermediate particle size produced larger volume of SC than flour fractions of large particle size. The flour fractions of small particle size in soft white and club wheat exhibited lower flour‐water batter density (102.6–105.9 g/100 mL) than did those of large and intermediate particle fractions (105.2–108.2 g/100 mL). The viscosity of flour‐water batter was lowest in flour fractions of small particle size, higher in intermediate particles, and highest in large particles. Flour particle size exerted a considerable influence on batter density and viscosity and subsequently on SC volume and crumb structure. Fine particle size of flour overpowered the negative effects of elevated starch damage, water absorption, and protein content in SC baking.     

Evapotranspiration model selection for estimation of actual evaporation from bare soil,as required in annual potential groundwater recharge studies of a semi-arid foothill region

Improved evapotranspiration estimation is instrumental in annual potential recharge (Re) evaluations of semi-arid regions, in the context of the water balance approach. Complementary relationship areal evapotranspiration (CRAE) and advection–aridity (AA) and a general combination equation proposed by Granger and Gray (GG) were evaluated for the estimation of actual evaporation (E_a) from bare soil under occurrence of Re. Model capability was evaluated by utilizing data from lysimeter measurements during the hydrological years [(2011–2012) and (2012–2013)]. Measured parameters included soil moisture (SM), rainfall and related meteorological data and Re (lysimeter output). All models with original parameters performed poorly during 2011–2012 and 2012–2013, underestimating annual Re values. The 2011–2012 data were used for model calibration, considering annual E_a [criterion (I)] and cumulative E_a during the occurrence period of Re [criterion(II)]. The calibrated CRAE model [criterion (II)] produced the best simulation for E_a (NRMSE < 30%). The 2012–2013 data were used to validate the models, and the calibrated CRAE model produced acceptable results (NRMSE < 10%) in SM simulation (both criteria). But calibrated CRAE under criterion (II) provided the best estimation of annual Re (ΔQ < 6%). According to the results, CR models can produce acceptable estimation of annual Re, if initially calibrated utilizing criterion (II).     

Functional Characteristics of Extruded Blends of Whey Protein Concentrate and Corn Starch

The aim of this work was to study the effects of extrusion barrel temperature (70–180°C), feed moisture (18–30%), pH (3–8), different proportions of corn starch (75–95%), and whey protein concentrate (WPC, 80% protein concentration) (25–5%) on the preparation of functional blends. Expansion index (EI), bulk density (BD), compression force (CF), color, water absorption index (WAI), water solubility index (WSI), gel strength (GS), syneresis of the gel, and in vitro digestibility were evaluated. Barrel temperature and the proportion of WPC had significant effects on BD; at higher temperatures, BD was lower. Feed moisture and pH had significant effects on EI; with lower moisture and higher pH, the EI increased. An interaction of barrel temperature and feed moisture had an effect on WAI; at lower moisture content, the temperature effect was nonexistent, whereas at higher temperatures and feed moisture content, the WAI increased. The pH level had a significant effect on WSI, showing high WSI when lower pH levels were used. Color analysis showed that higher protein content and pH generated higher δE values; low feed moisture and low pH resulted in gel syneresis. Higher in vitro digestibility was obtained when a higher WPC proportion and pH were used. Extruded WPC-CS blends under alkaline and acidic conditions were affected by the preparation of diverse formulations that potentially can be used in foods to improve some functional and protein content.     

Gluten‐Free Bread from Sorghum: Quality Differences Among Hybrids

Gluten‐free breadmaking quality of 10 sorghum flours was compared using (relative basis) decorticated sorghum flour (70), corn starch (30), water (105), salt (1.75), sugar (1), and dried yeast (2). Batter consistency was standardized by varying water levels to achieve the same force during extrusion. Crumb properties were evaluated by digital image analysis and texture profile analysis (TPA). Significant differences (P < 0.001) in crumb grain were found among the hybrids with mean cell area ranging from 1.3 to 3.3 mm² and total number of cells ranging from 13.5 to 27.8/cm². TPA hardness values of the crumb also varied significantly (P < 0.001). Based on significant correlations (P < 0.01), starch damage, influenced by kernel hardness, was identified as a key element for these differences. Breads differed little in volume, height, bake loss, and water activity. Investigation of added ingredients on bread quality was conducted using response surface methodology (RSM) with two sorghum hybrids of opposite quality. Addition of xanthan gum (0.3–1.2% flour weight basis [fwb]) and skim milk powder (1.2–4.8% fwb) and varying water levels (100–115% fwb) were tested using a central composite design. Increasing water levels increased loaf specific volume, while increasing xanthan gum levels decreased the volume. As skim milk powder levels increased, loaf height decreased. Quality differences between the hybrids were maintained throughout the RSM.     

Network Formation in Gluten‐Free Bread with Application of Transglutaminase

One of the main problems associated with gluten‐free bread is obtaining a good structure. Transglutaminase (TGase), an enzyme that catalyzes acyl‐transfer reactions through which proteins can be cross‐linked could be a way to improve the structure of gluten‐free breads. The objective of this study was to evaluate the impact of TGase at different levels (0, 0.1, 1, and 10 U of TGase/g of protein) on the quality of gluten‐free bread. The recipe consisted of white rice flour (relative amount: 35), potato starch (30), corn flour (22.5), xanthan gum (1), and various protein sources (skim milk powder [SMP] [12.5], soya flour, and egg powder). The influence of the various proteins in combination with the different addition levels of TGase on bread quality (% bake loss, specific volume, color, texture, image characteristics, and total moisture) was determined. Confocal laser‐scanning microscopy (CLSM) was used to evaluate the influence of TGase on the microstructure of the bread. Baking tests showed that TGase had an effect on the specific volume of the bread. For instance, the SMP bread with 10 U of enzyme contained the most compact structure, which was reflected in the crumb texture profile analysis results (highest values) (P < 0.05), digital image analysis (highest level of cells/cm²) (P < 0.05), and CLSM micrographs (network formation). Finally, it can be concluded that it is possible to form a protein network in gluten‐free bread with the addition of TGase. However the efficiency of the enzyme is dependent on both the protein source and the level of enzyme concentration.     

Effects of Fortification and Enrichment of Maize Tortillas on Growth and Brain Development of Rats Throughout Two Generations

The growth and brain development of laboratory rats fed typical indigenous tortilla‐based diets were determined throughout two generations. The experiment compared three different types of tortilla‐based diets: regular tortillas produced from dry masa flour (RDMF), tortillas obtained from fresh masa (FM), and tortillas produced from dry masa flour fortified with 6% defatted soybean and enriched with vitamins B₁, B₂, niacin, and folic acid and microminerals iron and zinc (FEDMF). Female rats were mated 58 days postweaning with males belonging to the same treatment with the objective of obtaining second generation pups that were further subjected to regular lactation and 28 day postweaned growth. A comparison between growth of first and second generation rats was determined. In addition, representative animals of each physiological stage were first exsanguineted for hematocrit determination and then slaughtered with the aim of obtaining femur and brain tissues. Cerebral DNA and number of neurons were determined in each of the brains sampled. Growth of rats fed FEDMF was significantly higher (P < 0.05) in both generations than counterparts fed RDMF or FM. The difference among treatments was more evident in second generation rats. Pregnancy rate, number of newborns per litter, litter weight, and pup's survival rate was higher for the control and FEDMF treatments. Femur growth was also higher (P < 0.05) for first‐generation male adult rats fed control and FEDMF. The concentration and total content of cerebral DNA and number of neurons in males and females belonging to the first generation was similar. However, for second generation rats, these values were lower for animals fed regular tortilla diets. This data clearly demonstrates that the negative effects of malnutrition on brain development of pups occurred during gestation and lactation.     

Relationship Between Soft Wheat Flour Physicochemical Composition and Cookie‐Making Performance

Nowadays in Argentina, cookies, crackers, and cakes are made of flour obtained from bread wheat with additives or enzymes that decrease the gluten strength but increase production costs. The present research work aims to study the relationship between flour physicochemical composition (particle size average [PSA], protein, damaged starch [DS], water soluble pentosans [WSP], total pentosans [TP], and gluten), alkaline water retention capacities behavior, solvent retention capacities profile (SRC) and cookie‐making performance in a set of 51 adapted soft wheat lines with diverse origin to identify better flour parameters for predicting cookie quality. Cookie factor (CF) values were 5.06–7.56. High and significant negative correlations between sucrose SRC (–0.68), water SRC (–0.65), carbonate SRC (–0.59), and CF were found, followed by lactic SRC that presented a low negative but significant correlation (r = –0.35). The flour components DS (r = –0.67), WSP (r = –0.49), and TP (r = –0.4) were negatively associated to CF. PSA showed a negative correlation with CF (r = –0.43). Protein and gluten were the flour components that affected cookie hardness, but no significant correlation were found with pentosan or DS content. A prediction equation for CF was developed. Sucrose SRC, PSA, and DS could be used to predict 68% of the variation in cookie diameter. The cluster analysis was conducted to assess differences in flour quality parameters among genotypes based on CF. Clusters 1 and 4 were typified by lower CF (5.70 and 5.23, respectively), higher DS, pentosan content, and SRC values. Cluster 2 with a relative good CF (6.47) and Cluster 3 with the best cookie quality, high CF (7.32) and low firmness, and the lowest DS, TP, WSP content, and sucrose SRC values.     

Effect of Stabilized Rice Bran Fractions on the Formation of Rice Flour Pasting Properties

Rice flour composition played a key role in determining the changes in pasting properties of rice flour. The influence of incorporating defatted rice bran (DFRB), rice bran fiber (RBF), rice bran protein (RBP), and stabilized rice bran (SRB) fractions on the mechanism of rice flour pasting viscosities was investigated. Pasting properties of long‐ and medium‐grain rice flour substituted with 5, 10, 15, 20, and 100% bran fractions resulted in a significant decrease (P < 0.05) in rice flour pasting property values. Flour substituted with RBP had the lowest pasting property measurements compared with other fractions, and the greater the percentage substituted, the lower the pasting property values. DFRB and RBF were least affected properties when used as a replacement. Results were attributed to the contribution of rice starch in the mechanism of rice paste formation, in which decreasing starch in a rice flour sample, as a result of substituting with fractions of SRB, may have resulted in faster swelling of starch granules to the maximum extent and increased their susceptibility to be disrupted by shear, resulting in low paste viscosities. Results also suggested that protein structural integrity and the nature of starch–protein bonding affected rice flour pasting mechanism formation.     

End Use Quality of Waxy Wheat Flour in Various Grain‐Based Foods

The practical applications of flour from waxy (amylose‐free) hexaploid wheat (Triticum aestivum L.) were assessed. The applications evaluated were bread, cakes, white salted noodles, and pasta for gyoza. An excessive addition of waxy hexaploid wheat flour to total wheat flour (>20%) resulted in poorer functional properties (sticky, lumpy, or less crispy textures) in almost every end use product. However, incorporation of <20% waxy hexaploid wheat flour, produced considerable improvement in shelf‐life characteristics. After one day of storage, the bread from flour including waxy hexaploid wheat flour maintained moistness, softness, and stickiness. This application of waxy hexaploid wheat flour as an antistaling ingredient was also confirmed in cake products. Tests were also conducted on alimentary pasta products. In alimentary pasta, waxy hexaploid wheat flour was most effective when utilized for frozen fried dumplings (gyoza). By using flour including 30 or 50% waxy hexaploid wheat flour, the problem of firmness was solved without other ingredients. In conclusion, flour from waxy hexaploid wheat may be useful in developing more increased staling‐ and freezing‐tolerant grain‐based foods. Starch properties could be responsible for these improved characteristics.     

Effect of l‐Cysteine on the Rheological Properties of Wheat Flour

Extrudate expansion of cereal‐based products is largely dependent on the molecular interactions and structural transformations that proteins undergo during extrusion processing. Such changes strongly influence the characteristic rheological properties of the melt. It is possible to modify rheological properties of wheat flour during extrusion processing, in particular shear viscosity, with cysteine. The objective of this work was to further develop an understanding of the molecular interactions and structural transformations of wheat flour from dynamic oscillatory rheological measurements. Temperature and frequency sweeps were conducted in the linear viscoelastic range of the material. Changes in the storage modulus (G′), the loss modulus (G″) and the loss tangent (tan δ) of 25% moisture wheat flour disks as a function of cysteine concentration (0–0.75%) were monitored. Molecular weight between cross‐links (M_c) and the number of cross‐links (N_c) per glutenin molecule were determined from frequency sweep data. Increasing cysteine concentration broke cross‐links by decreasing G′ maximum and increasing tan δ values. Molecular weight between cross‐links increased and the number of cross‐links decreased. G′ values from temperature sweeps showed a similar trend. This information leads to a better understanding of the viscoelastic behavior of wheat flour doughs during extrusion cooking and elucidation of protein‐protein reaction mechanisms and other interactions in extruded cereal‐based snack foods.