Defining the Overall Quality of Cowpea‐Enriched Rice‐Based Breakfast Cereals

The development of innovative legume‐enriched rice products is a promising way to exploit rice varieties with a low sensory grade. In this work, a multidisciplinary approach was applied to the characterization of extruded breakfast cereals prepared from African‐grown Oryza glaberrima (cv. Viwonor) or Oryza sativa (cv. Jasmine 85) enriched with 30% cowpea flour, obtained from sprouted or nonsprouted cowpea. Regardless of the rice species, addition of sprouted cowpea flour conferred a peculiar volatiles profile, rich in sour, bitter, and astringent taste. Protein structural indices provided molecular insights about the macroscopic differences among samples. Extruded products from O. glaberrima were characterized by lower expansion rates with respect to those obtained from O. sativa , regardless of the type of cowpea flour. Sprouting time had a positive influence on the hardness of extruded glaberrima‐based products, facilitating formation of a more compact matrix, but it did not influence sativa‐ based products. Therefore, the breakdown of protein during sprouting appeared fundamental for the incorporation of legume proteins in more compact matrices, such as the one from sativa rice. In the glaberrima‐based products, addition of sprouted cowpea resulted in further loosening of the structure, and this was more evident at increased sprouting times.     

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.     

Temporal Variation of Hydro‐Physical Properties of Paddy Clay Soil under Different Rice‐Based Cropping Systems

Spatial variability of hydro‐physical properties has long been observed, whereas temporal variation is much less documented and considered in studies and applications, particularly of paddy clay soils under different cropping systems. The objective of this study was therefore to assess the seasonal‐ and inter‐seasonal variation of selected hydro‐physical properties of a paddy clay soil under different rice‐based cropping systems with contrasting tillage. In a long‐term experiment, plots were arranged in a randomized complete block design with four treatments and four replications: (i) rice–rice–rice; (ii) rice–maize–rice; (iii) rice–mung bean–rice; and (iv) rice–mung bean–maize. Soil samples were collected at three depths (0–10, 10–20 and 20–30 cm) at three times during two cropping seasons, i.e., 15 days after soil preparation (DASP), 45 DASP and 90 DASP during the winter–spring and spring–summer seasons. Results show that temporal variability of soil bulk density, macro‐porosity (MacP) and matrix‐porosity within both seasons and between seasons was limited for cropping systems with upland crop rotations, whereas within season variation was significant for rice monoculture system. Observed variation in bulk density, matrix‐porosity and MacP was mainly associated with cropping system and soil depth. Field saturated hydraulic conductivity of topsoil showed great temporal variability, both seasonal and inter‐seasonal, in correspondence with MacP (r  = 0·58). These results highlight the need of depth differentiated soil sampling and time consideration when evaluating management practices on soil physical properties and modeling the hydrological behavior of paddy soil. Copyright © 2017 John Wiley & Sons, Ltd.     

Single‐Screw Extrusion Processing of Distillers Dried Grains with Solubles (DDGS)‐Based Yellow Perch (Perca flavescens) Feeds

This study was conducted to investigate the production of balanced diets for juvenile yellow perch (Perca flavescens) feeds. Six isocaloric (≈3.21 kcal/g), isonitrogenous (30.1 ± 0.4% db) ingredient blends were formulated with 0, 10, 20, 30, 40, and 50% distillers dried grains with solubles (DDGS), and appropriate amounts of soybean meal, fish meal, vitamins, and minerals. Extrusion cooking was performed using a laboratory‐scale single‐screw extruder at a constant barrel temperature profile of 40–90–100°C, and a constant screw speed of 230 rpm (24.1 rad/sec). The mass flow rate was determined during processing; it generally increased with progressively higher DDGS content. Additionally, moisture content, water activity, unit density, expansion ratio, compressive strength, compressive modulus, pellet durability index, water stability, and color were extensively analyzed to quantify the effects of DDGS content on the physical properties of the resulting extrudates. Significant differences (P < 0.05) between blends were observed for color and water activity for both the raw material and extrudates, respectively, and for the unit density of the extrudates. There were significant changes in brightness (L), redness (a), and yellowness (b) among the final products when increasing the DDGS content of the blends. Expansion ratio and compressive strength of the extrudates were low. On the other hand, all blends showed high pellet durability (PDI ≥ 96.18%). Overall, it was ascertained that DDGS could be successfully included at rates of <50%, and that each of the ingredient blends resulted in viable, high quality extrudates.     

Twin‐Screw Extrusion Processing of Rainbow Trout (Oncorhynchus mykiss) Feeds Using Various Levels of Corn‐Based Distillers Dried Grains with Solubles (DDGS)

Increasing demand for seafood products and rising demand for fish meal for commercial fish feeds is driving the search for effective alternative protein sources. Twin‐screw extrusion trials were conducted to study the production of nutritionally balanced feeds for rainbow trout fingerlings (Oncorhynchus mykiss). Six isocaloric (≈4.61 kcal/g) ingredient blends with a target protein content of >45% db were formulated with 0, 10, 20, 30, 40, and 50% distillers dried grains with solubles (DDGS) and other feed ingredients. The moisture contents of the diets were initially adjusted to 5–7% db, and then extruded at 250 rpm using dual 1.9 mm dies with varying amounts of steam (7.2–7.7 kg/hr) injected into the conditioner and water (4.3–6.5 kg/hr) into the extruder. Mass flow rates, moisture contents, and temperatures were measured during processing and moisture content, water activity, unit density, bulk density, expansion ratio, compressive strength, compressive modulus, pellet durability index, water stability, and color were analyzed to quantify the effects of varying DDGS content on the extrudate physical properties. Significant differences (P < 0.05) among the blends were observed for color and bulk density for both the raw and extruded materials, respectively, and for the unit density and pellet durability index of the extruded products. There were also significant changes in redness and yellowness, but only minor changes in brightness, among the final products with increasing DDGS content. The compressive strength of the extrudates increased significantly with increasing DDGS. Expansion ratio of all pellets was low. All extruded diets achieved very good water stability.     

Separation of Water‐Soluble Proteins from Cereals by High‐Performance Capillary Electrophoresis (HPCE)

Most research concerning grain proteins has concentrated on the gluten storage proteins. The albumins and globulins are the water‐ and salt‐soluble proteins that contain biologically active enzymes and enzyme inhibitors. A free‐zone capillary electrophoresis method was developed to separate these proteins. Optimization included sample extraction method, capillary temperature, buffer composition, and additives. The optimal conditions for separation of these proteins was 50 μm i.d. × 27 cm (20 cm to detector) capillary at 10 kV (with a 0.17 min ramp‐up time) and 25°C. The optimum buffer was 50 mM sodium phosphate, pH 2.5 + 20% acetonitrile (v/v) (ACN) + 0.05% (w/v) hydroxypropylmethyl‐cellulose (HPMC) + 50 mM hexane sulfonic acid (HSA). Sample stability was an issue that was addressed by lyophilizing fresh extracts and redissolving in aqueous 50% ethylene glycol and 10% separation buffer. This method was successfully used in both wheat flour and whole meal samples. Comparisons were made of several wheats of different classes as well as several cereal grains. This methodology could be useful in screening cereal grains for important enzymes and their impact on end‐use quality such as food functionality, food coloration, and malting quality.     

Policosanol Contents and Compositions in Wax‐Like Materials Extracted from Selected Cereals of Korean Origin

Policosanols, long‐chained alcohols, have been reported to have beneficial physiological activities. Content and composition of policosanols in wax‐like materials extracted from selected cereals of Korean origin were determined. Wax‐like materials were extracted using hot hexane. Yields of wax‐like materials from unpolished grain sorghum, polished grain sorghum, brown rice, purple rice, wheat, and maize were 223, 37, 33, 61, 10, and 10 mg/100 g of dry kernels, respectively. Policosanol contents, as determined using HPLC, in the wax‐like materials from the cereals were 33, 29, 6, 0, and 2% (w/w, db), respectively. Major alcohols in the policosanols from grain sorghum were octacosanol and triacontanol. Docosanol was the major alcohol in the policosanols from brown rice, purple rice, wheat, and maize.     

Characterization of Extruded Plant Protein and Petroleum‐Based Packaging Sheets

Extruded packaging sheets (EPS) were manufactured from wheat gluten (WG) or sorghum flour (SF) in combination with (10, 25, 50, 75, and 100%) low density polyethylene (LDPE) or metallocene‐catalyzed ethylene‐butene copolymer (MCEBC), and plasticized successfully with sorbitol at a weight ratio of 1:1. Physical analyses were used to characterize the extruded packaging materials. Tensile strengths and elongations of the sheets significantly decreased as the WG or SF increased. Sheets formulated with ≈1:1:2 wheat gluten, sorbitol, and MCEBC exhibited similar elastic properties compared with a 100% MCEBC sheet. Young's modulus and percent elongation at break values decreased as WG‐sorbitol or SF‐sorbitol level increased in the EPS.     

Dry‐Grind Processing of Corn with Endogenous Liquefaction Enzymes

An amylase corn has been developed that produces an α‐amylase enzyme that is activated in the presence of water at elevated temperatures (>70°C). Amylase corn in the dry‐grind process was evaluated and compared with the performance of exogenous amylases used in dry‐grind processing. Amylase corn (1–10% by weight) was added to dent corn (of the same genetic background as the amylase corn) as treatments and resulting samples were evaluated for dry‐grind ethanol fermentation using 150‐g and 3‐kg laboratory procedures. Ethanol concentrations during fermentation were compared with the control treatment (0% amylase corn addition or 100% dent corn) which was processed with a conventional amount of exogenous α‐amylase enzymes used in the dry‐grind corn process. The 1% amylase corn treatment (adding 1% amylase corn to dent corn) was sufficient to liquefy starch into dextrins. Following fermentation, ethanol concentrations from the 1% amylase corn treatment were similar to that of the control. Peak and breakdown viscosities of liquefied slurries for all amylase corn treatments were significantly higher than the control treatment. In contrast, final viscosities of liquefied slurries for all amylase corn treatments were lower than those of the control. Protein, fat, ash, and crude fiber contents of DDGS samples from the 3% amylase corn treatment and control were similar.     

Effect of Cooking on Lignans Content in Whole‐Grain Pasta Made with Different Cereals and Other Seeds

Lignans are of increasing interest because of their potential anticarcinogenic, antioxidant, estrogenic, and antiestrogenic activities. In this work, mixed‐cereal pastas manufactured by adding 60% whole‐grain flours of different cereals (wheat, oat, rye, barley, and rice) to durum wheat semolina, a multigrain pasta with different grains (cereals, legumes, and flaxseed), and a traditional industrial durum wheat semolina were analyzed for their lignans content both in the raw and in the cooked state, ready for consumption. For raw mixed‐cereal pastas, total lignans were within the range 94.91–485.62 μg/100 g d.w. After cooking, total lignans losses of about 35.5, 18.31, and 5.46% were observed respectively in oat‐, rye‐, and rice‐added pastas, whereas increases of 5.74 and 13.62% were observed in barley‐added and whole durum wheat pastas. Interesting results were obtained for the multigrain pasta: the raw product exhibited a total lignans content of 9,686.17 ± 287.03 μg/100 g d.w., and the major contribution was given by secoisolariciresinol. This highest total lignans value resulted from its rich and varied composition in seeds of different origin, legumes, and flaxseed in particular. Our findings showed that mixed‐cereal and multigrain pastas can be considered a good source of lignans. The effect of cooking was not the same for each product, and it depended on the different lignans profile of each grain, on the different chemical structure of each lignan, and on the nature of the food matrix.     

Use of Phytases in Ethanol Production from E‐Mill Corn Processing

Effects of phytase addition, germ, and pericarp fiber recovery were evaluated for the E‐Mill dry grind corn process. In the E‐Mill process, corn was soaked in water followed by incubation with starch hydrolyzing enzymes. For each phytase treatment, an additional phytase incubation step was performed before incubation with starch hydrolyzing enzymes. Germ and pericarp fiber were recovered after incubation with starch hydrolyzing enzymes. Preliminary studies on phytase addition resulted in germ with higher oil (40.9%), protein (20.0%), and lower residual starch (12.2%) contents compared to oil (39.1%), protein (19.2%), and starch (18.1%) in germ from the E‐Mill process without phytase addition. Phytase treatment resulted in lower residual starch contents in pericarp fiber (19.9%) compared to pericarp fiber without phytase addition (27.4%). Results obtained led to further investigation of effects of phytase on final ethanol concentrations, germ, pericarp fiber, and DDGS recovery. Final ethanol concentrations were higher in E‐Mill processing with phytase addition (17.4% v/v) than without addition of phytase (16.6% v/v). Incubation with phytases resulted in germ with 4.3% higher oil and 2.5% lower residual starch content compared to control process. Phytase treatment also resulted in lower residual starch and higher protein contents (6.58 and 36.5%, respectively) in DDGS compared to DDGS without phytase incubations (8.14 and 34.2%, respectively). Phytase incubation in E‐Mill processing may assist in increasing coproduct values as well as lead to increased ethanol concentrations.     

Plant availability and leaching of (heavy) metals from ammonium‐, calcium‐, carbohydrate‐, and citric acid‐treated uranium‐mine‐dump soil

Remediation of an uranium‐mine soil from Settendorf (East Germany) includes phytoextraction under conditions which make its heavy metals more plant‐available but less leachable. A second way is active inhibition of heavy metal uptake by the plant. In a pot trial with Chinese cabbage (Brassica chinensis L.), planted and unplanted soil samples were daily irrigated with deionized water or aqueous solutions with a total of (g (kg soil)^–1) CaCl₂ (0.26 Ca), NH₄Cl (1.39), casein, sucrose, citric acid (13), and an extract of rape (B. napus L.) shoots (13 DW) in a phytotron for 26 d. Water‐irrigated plants were also treated with a 50 mM citric acid solution (10.5 g (kg soil)^–1) 6 and 7 d prior to harvesting. Total elements in plant tissue and soluble elements in aqueous extracts from control and postharvest soils were determined by ICP‐AES. Supplements of NH , and the NH ‐generating casein and rape extract reduced soil pH during nitrification, and increased plant uptake of Cd, Cu, Ni, and Zn. Citric acid at 50 mM adjusted soil to pH 4.5–6.0 and enhanced uptake of all elements. Long‐term application of sucrose and citric acid increased pH and inhibited uptake of Cd, Cr, Cu, Ni, and Zn. Contemporarily, leaching of heavy metals and humic substances was lowest with Ca and NH and highest with sucrose and citric acid amendments. It is concluded that Chinese cabbage grown for chelate‐assisted phytoextraction should be supplied with Ca and NH to obtain a high plant biomass on soil with a low hazard of leaching. Metal uptake should be stimulated by application of chelator 7 d prior to harvesting. Undesired uptake of heavy metals by Chinese cabbage determined as food should be inhibited with carbohydrate amendments. Long‐term application of NH or chelator, which reduces the solubility of certain elements but increases their uptake moderately, is recommended as a tool for continuous phytoextraction technologies.     

Study on the Parameters of Extrusion Pretreatment of Corn Germ with Semi‐Wet Milling in Solvent Oil Extraction

Efficiency of oil extraction from corn germ was improved by the extrusion pretreatment, and residual oil was taken as the index of this oil extraction process. An orthogonal rotation combination test design of five levels and four factors, consisting of the moisture of material, screw speed, barrel temperature, and die nozzle diameter, was employed to optimize the model and reaction condition. The optimum parameters of extrusion were as follows: moisture of material, W = 12%; extrusion temperature, T = 105°C; screw speed, n = 185 rpm; die nozzle diameter, Φ = 9 mm × 3. Under these optimum conditions, residual oil of this process was 0.61–0.66%, which was lower than residual oil by pressing alone (residual oil of 5–6%) or by a combination of prepressing and hexane extraction (residual oil of nearly 2%). The corn oil obtained by the optimum extrusion parameters was analyzed, and iodine value, acid value, peroxide value, and saponification value were 1,250 g/kg, 400 mg/kg, 5.1 mmol/kg, and 189%, respectively.     

Processing Affects the Physicochemical Properties of Fiber from Wheat and Flax in Ready‐to‐Eat (RTE) Flaked Cereal

Fiber from wheat and flax is mostly insoluble, making addition in high amounts to a food difficult without adversely affecting product attributes. One approach to increasing the level of these fibers in food is to hydrolyze fiber to more soluble forms through processing. This study was designed to evaluate the impact of a steam pressure cooking process on physicochemical properties of ready‐to‐eat (RTE) cereal with 17.7% added unhydrolyzed flax fiber (a combination of arabinoxylans, rhamnogalacturonans, and pectins) or 15.4% added hydrolyzed wheat fiber (a purified arabinoxylan extract). Peak molecular weights of unhydrolyzed and hydrolyzed fibers were ∼2.9 × 10⁶ and ∼800 g/mol, respectively, with a ∼400‐fold higher viscosity for unhydrolyzed fiber. Molecular weight of the unhydrolyzed fiber ingredient was reduced to approximately the molecular weight of the hydrolyzed fiber as a result of the low‐shear steam pressure cooking process used, and consistent with molecular weight results, there was only a twofold difference in viscosity of the cereal remaining. The low‐fiber control RTE cereal had the highest viscosity owing to starch content.     

Effect of Extrusion Cooking on the Primary Structure and Water Solubility of β‐Glucans from Regular and Waxy Barley

Water‐soluble β‐glucan from native and extrusion‐cooked barley flours of two barley cultivars, Candle (a waxy starch barley) and Phoenix (a regular starch barley), was isolated and purified. The purity of β‐glucan samples was 85–93% (w/w, dry weight basis) for Candle and 77–86% (w/w, dry weight basis) for Phoenix. The water solubility of β‐glucan (at room temperature, 25°C) in the native and extruded flours (primary solubility) was different from that of the purified β‐glucan samples (secondary solubility). The solubility of β‐glucan in the native and extruded Candle flour was substantially higher than that of β‐glucan in Phoenix. For both cultivars, β‐glucan in the extruded flours had solubility (primary solubility) values higher than in their native counterparts. The solubility of β‐glucan in the purified β‐glucan samples differed depending on the barley cultivar and the extrusion conditions employed. The glycosidic linkage profiles of purified soluble β‐glucan from native and extruded barley flours were determined in order to understand the changes in the primary structure of β‐glucan and the effect of extrusion on the β‐glucan structure‐solubility relationship.     

Valorization of Wet Okara,a Value‐Added Functional Ingredient,in a Coconut‐Based Baked Snack

Wet okara (soy milk residue), as a functional ingredient, was evaluated to be added to a coconut‐based snack at 10, 20, 30, 40, and 50% levels to replace dry coconut in the formula. Certain physicochemical, nutritional, and sensory properties of the samples were evaluated. A coconut‐based, soft, baked snack with incorporated okara showed higher total fiber and much lower fat content than the control, which significantly improved the nutritional profile of the samples. Samples 3 and 4 (which had 30 and 40% replacement of coconut with wet okara, respectively) received the highest overall sensory score (8.4), which was significantly higher than the score of a control sample (7.5). Sample 3 also had a significantly improved nutritional profile per serving size, such as an increased fiber content of 6.11 ± 0.04 g/100 g and a decreased fat content of 17.57 ± 0.02 g/100 g, and sample 4 had an increased fiber content of 6.19 ± 0.03 g/100 g and a decreased fat content of 15.64 ± 0.03 g/100 g compared with the control sample. The appearance, color, flavor, physical measurements (instrumental texture profile analysis), and water activity of samples 3 and 4 were not significantly different from the control sample and demonstrated potential application of this formulation in the baking industry, proving that the wet okara can be successfully used as a value‐added functional ingredient.     

Estimation of soil texture from permanent wilting point measured with a chilled‐mirror dewpoint technique

Soil texture is an important factor governing a range of physical properties and processes in soil. The clay and fine fractions of soil are particularly important in controlling soil water retention, hydraulic properties, water flow and transport. Modern soil texture analysis techniques (x‐ray attenuation, laser diffraction and particle counting) are very laborious with expensive instrumentation. Chilled‐mirror dewpoint potentiameters allows for the rapid measurement of the permanent wilting point (PWP) of soil. As the PWP is strongly dictated by soil texture, we tested the applicability of PWP measured by a dewpoint potentiameter in predicting the clay, silt and sand content of humid tropical soils. The clay, silt, and sand content, organic matter and PWP were determined for 21 soils. Three regression models were developed to estimate the fine fractions and validated using independent soil data. While the first model showed reasonable accuracy (RMSE 16.4%; MAE 13.5%) in estimating the clay, incorporating the organic matter into the equation improved the predictions of the second model (RMSE 17.3%; MAE 10.9%). When used on all soil data, the accuracy of the third model in predicting the fine fraction was poor (RMSE 31.9%; MAE 24.5%). However, for soils with silt content greater than 30%, the model prediction was quite accurate (RMSE 7–12%; MAE 7–9%). The models were used to estimate the sand content and soil textures of soils, which proved relatively accurate. The dewpoint potentiometer can serve a dual purpose of rapidly estimating the PWP and the clay, fine fraction, and soil texture of soils in a cost efficient way.     

Plant‐growth‐promoting rhizobacteria isolated from a Calcisol in a semi‐arid region of Uzbekistan: biochemical characterization and effectiveness

Bacteria were isolated from the rhizosphere of cotton, wheat, alfalfa, and tomato grown in field locations within a semi‐arid region of Uzbekistan. Strains were identified as Pseudomonas denitrificans, P. rathonis, Bacillus laevolacticus, Bacillus amyloliquefaciens, and Arthrobacter simplex. The isolated strains produced different enzymes, phytohormone auxin and were antagonists against specific plant‐pathogenic fungi. Most of the strains are tolerant with respect to salt and temperature. All of the bacterial strains isolated in this study have been found to increase plant growth of wheat and maize in pot experiments.     

Impact of Chickpea‐ and Raw Plantain‐Based Gluten‐Free Snacks on Weight Gain,Serum Lipid Profile,and Insulin Resistance of Rats Fed with a High‐Fructose Diet

Two gluten‐free snacks containing chickpea, plantain, and maize flours at different concentrations were prepared. The impact of chickpea or plantain flour level on weight gain, insulin resistance, and serum lipid profile of rats fed a high‐fructose diet was evaluated. A dose of 0.93 g/kg was used in the experiments to simulate the snack consumption level by humans (average content of a small package, which is twice the portion recommended by the U.S. Department of Agriculture). Compared with a high‐fructose reference diet, consumption of both snacks decreased weight gain, fasting serum glucose, and triglycerides. The effect was more pronounced for snack B, with higher chickpea content. Consumption of these snacks may also have beneficial effects against obesity and cardiometabolic complications. Chickpea flour is a promising functional ingredient for the development of antiobesity foods.