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Sprouting is a simple technique for improving the nutritional and quality characteristics of cereal grains. The purpose of this study was to examine ultrasonic pretreatment and drying methods (hot-air and infrared) on microbial population (total bacterial counts, molds, and yeasts), physicochemical properties (ash content, moisture, acidity, pH, lightness, redness, and yellowness), and total phenolic content of sprouted wheat powder (SWP). The results confirmed that the sonication decreased the total bacterial count of SWP. In this study, drying sprouted wheat with the hot-air and infrared radiation killed all molds and yeasts in the powders, and no molds or yeasts grew on the microbial plates. Moisture content, redness, yellowness, and phenolic content of SWP dried by the infrared dryer were higher than those by the hot-air dryer. The acidity and lightness of SWP dried by the hot-air dryer were higher than those by the infrared dryer. Applying ultrasonic pretreatment to sprouted wheat increased the amount of phenolic compounds in the powders, but this increase was not significant (p>0.05). In general, ultrasonic pretreatment and the use of infrared dryers are promising techniques for production of SWP with high phenolic content and low microbial population. [ABSTRACT FROM AUTHOR]

Harnessing previously unused farm inventories and corn books, we provide data on wheat storage and sales by English farmers, 1750–1850. Wheat was predominantly stored outdoors in thatched stacks (or 'ricks')—often for more than a year, sometimes for multiple years—although carryover volumes were generally small. Farm stocks tended to be threshed and sold evenly across the year to meet demand. Storage costs were low, and carried over wheat sold at a premium as the natural drying process raised its quality. Wheat was frequently sold directly to millers, bypassing the open market, but private sale prices tracked market prices closely. [ABSTRACT FROM AUTHOR]

The characteristics of moisture diffusion during wheat drying were determined through low-field nuclear magnetic resonance. The feasibility of variable temperature drying was validated by identifying the variation in the characteristics of evaporable water (EW) and each water component in wheat. During drying, chemically bound water in wheat was converted into EW, which comprised physically bound water and free water components that can evaporate and gasify directly. EW was removed from wheat through diffusion. The analysis of the average rate of the reduction in EW and the variation in the characteristics of weakly chemically bound water ( T 22 ) at different wheat drying stages showed that EW was rapidly removed from wheat at the drying temperature was set at 80 °C during the early stage of drying. The highest average drying rate of T 22 was observed during the later stage of drying at the drying temperature of 70 °C. As inferred from the behavior of chemically bound water during conversion and the behavior of EW during diffusion in wheat, the activation energy required for the removal of EW from wheat comprises the activation energy of the diffusion of EW from wheat ( E a − EW ∗ ) and the activation energy of the conversion of chemically bound water to EW ( E a − c ). Calculations showed that E a − c and E a − EW ∗ fell within the ranges of 25.72–53.75 and 1.09–24.17 kJ/mol, respectively. The maximum value of E a − EW ∗ was less than the minimum value of E a − c . This result confirmed that the energy consumption of removal of chemically bound water is bigger than that of EW. A method for calculating the drying activation energy of wheat ( E a ) was developed in reference to the characteristics of the stable component contents of mature wheat. The relationship between E a and the moisture content of biomass was revealed. [ABSTRACT FROM AUTHOR]

A small, novel wheat drying oven was designed, and tested in order to validate the possibility of recovering diesel engine waste heat as thermal energy. Prior to experiments, the theoretical probability was conducted, and it was confirmed that the thermal energy required for drying wheat could be satisfied by reusing the diesel engine waste heat. Three different experiment parameters, including air temperature, baffle angle, and drying time, were controlled to optimize the results. Based on the experiment data, the optimum temperature for drying wheat was 55°C, and the optimum baffle angle was 23.25°. The drying efficiency decreased as the drying temperature and drying time increased. The moisture content of wheat decreased from 26.0% to 20.0% with 55°C hot air when the proposed wheat drying oven was used. The test results demonstrated that the proposed oven could be made to work.

Background and aims: Although phosphorus (P) application is known to affect the zinc (Zn) nutrition of crops, the underlying mechanisms and effects of soil type are unclear.Methods: A greenhouse pot experiment was conducted with wheat, two soils (calcareous and acid), and nine P fertilizer rates (0, 50, 100, 200, 400, 1000, 2000, 3000, and 5000 mg P2O5 kg−1 soil).Results: The effects of P application on the Zn content of shoots and roots in wheat and on the levels of available Zn in soil differed on the two soils. The wheat dry weight on both soils was highest with 2000 mg P2O5 kg−1. Total Zn accumulation was reduced above 2000 mg P2O5 kg−1 on the acid soil and above 100 mg P2O5 kg−1 on the calcareous soil. Available soil Zn declined when the Bray-P concentration reached about 34 mg kg−1 in the acid soil and when the Olsen-P concentration exceeded 200 mg kg−1 in the calcareous soil. Shoot Zn concentrations were negatively related to available soil P on the two soils.Conclusion: The negative effects of increasing P application rates on Zn accumulation by wheat differed between the two soils. The effects showed no close relationship to available soil Zn. [ABSTRACT FROM AUTHOR]

A small, novel wheat drying oven was designed, and tested in order to validate the possibility of recovering diesel engine waste heat as thermal energy. Prior to experiments, the theoretical probability was conducted, and it was confirmed that the thermal energy required for drying wheat could be satisfied by reusing the diesel engine waste heat. Three different experiment parameters, including air temperature, baffle angle, and drying time, were controlled to optimize the results. Based on the experiment data, the optimum temperature for drying wheat was 55°C, and the optimum baffle angle was 23.25°. The drying efficiency decreased as the drying temperature and drying time increased. The moisture content of wheat decreased from 26.0% to 20.0% with 55°C hot air when the proposed wheat drying oven was used. The test results demonstrated that the proposed oven could be made to work. [ABSTRACT FROM AUTHOR]

The effect of four soaking regimes: 5 °C/20 °C with/without changing of soaking water followed by oven-drying at 40 °C–70 °C on various characteristics of buckwheat-based products was evaluated. Soaking buckwheat groats, hazelnuts and prunes at 5 °C was more favourable to total phenolic content, quercetin level and significantly decreased Escherichia coli counts in comparison with those obtained at 20 °C. The highest contents of phenolic, flavonoid and antioxidant capacity were observed upon drying at 40 °C followed by its decrease with the increase in drying temperature. While quercetin content seemed to be unaffected by drying temperature, rutin content increased. A small but gradual increase of Maillard products was observed at 40 °C–60 °C followed by a steep rise at 70 °C. Total coliforms and E. coli counts increased to >6.0 log cfu/g in products dried at 40 °C but decreased below 1.0 log cfu/g when dried at 50 °C–70 °C. [ABSTRACT FROM AUTHOR]

Ozone application in postharvest grains has a potential reduction of insects, contaminating micro-organisms and a minimal or no effect on grain quality, in addition to being able to be used during the drying process. Thus, this study was evaluated the ozone exposure time applied with the drying air to wheat seeds at different temperatures, under levels of total fungal count, germination, vigor and electrical conductivity. The evaluations occurred shortly after the drying and ozonation process and in 45 days of storage. The achieved data showed that fungal reduction significantly improved with increased ozone exposure time and drying air temperature. The maximum reduction of fungal count was 92.86%, with reduction from 1.87 cfu/g to 0.13 cfu/g, when the wheat seeds was treated with ozone for 45 min and dried with air temperature at 50 °C. Results also showed that germination, vigor and electrical conductivity were not significantly affected by ozone exposure time and drying air temperature. Therefore, the gaseous ozonation applied at the initial instants of the drying process can be considered an effective and rapid way to reduce contamination by filamentous fungi in wheat seeds, not influencing their physiological quality. This method also showed efficacy after storage for 45 days. [ABSTRACT FROM AUTHOR]

The influence of temperature and dryer types on kinetics, thermodynamic properties of parboiled wheat (bulgur) in Turkey was studied during drying. Durum wheat (local name in Turkey, Burgos) was cooked under atmospheric conditions and then it was dried at 50, 60 and 70 °C. Six semitheoretical and Fick's diffusivity models with Arrhenius and Eyring-Polanyi approaches were employed to predict drying kinetics and thermodynamic properties. Among all the models, Midilli model was found to have the best fit as suggested average R2 value of 0.9987 and corresponding RMSE value of 0.010. Effective diffusion coefficient (Deff) increased significantly (P⩽ 0.05) from 2.38x10-11 to 5.84x10-11 (59% increase), 4.65x10-11 to 8.51x10-11 (45% increase) and 8.70x10-11 to 14.10x10-11 (38% increase) for natural convective air, forced convective air and vacuum drying systems with temperature increase from 50 to 70 °C. The activation energy values of the samples of natural convective air drying (NCAD) (41.46 kJ mol-1) compared with that of forced convective air drying (FCAD) (27.71 kJ mol-1) and vacuum drying (VD) (22.28 kJ mol-1) show a decrease trend which suggests more effective drying. The enthalpy and entropy decreased with increasing temperature for all dryers. The Gibbs free energy increased with increasing temperature. For each dryer, also, general equations to describe the moisture ratio of parboiled wheat as a function of time and temperature were developed. It was concluded that vacuum dryer has provided more effective drying than the other dryers. [ABSTRACT FROM AUTHOR]

BACKGROUND The influence of cooking (traditional, microwave, autoclave) and drying techniques (microwave and hot air) on bioactive compounds in the production of einkorn and durum bulgur were investigated. Total phenolic content ( TPC), total yellow pigment ( TYP), total antioxidant capacity ( DPPH•, ABTS•+, FRAP), soluble free ( SF), soluble conjugated ( SC) and insoluble bound ( IB) phenolic acid contents of the samples were determined. RESULTS For both wheats, a significant amount of antioxidant capacity was preserved after bulgur production. TPC was found to be higher in einkorn but it was exposed to greater loss during bulgur production than durum. The amount of TYP was found to be two-fold higher in einkorn than in durum. Ferulic acid was recorded as the most phenolic acid, and chlorogenic was the least phenolic acid in both wheats. The maximum loss during bulgur production was determined in the SC fraction for einkorn and in the SF fraction for durum. CONCLUSION In respect of the results of the analysis, microwave cooking + hot air drying treatment could be favourable for bulgur production for both wheats. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Wheat Distillers’ Dried Grains with Solubles (DDGS) and in-process samples were used for protein extraction. Prolamins were the predominant protein components in the samples. The absence of extractable α - and γ -gliadins in DDGS indicated protein aggregation during the drum drying processing stage. Prolamin extraction was performed using 70% (v/v) ethanol or alkaline–ethanol solution in the presence of reducing agent. DDGS extracts had relatively low protein contents (14–44.9%, w/w), regardless of the condition applied. The wet solids were the most suitable raw material for protein extraction, with recovery yields of ∼55% (w/w) and protein content of ∼58% (w/w) in 70% (v/v) ethanol. Protein extracts from wet solids were significantly rich in glutamic acid and proline. Mass balance calculations demonstrated the high carbohydrate content (∼50%, w/w) of solid residues. Overall, the feasibility of utilising in-process samples of DDGS for protein extraction with commercial potential was demonstrated. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the airflow distribution in a mixed-flow dryer (MFD) and to study the effect of different bed materials and air duct arrangements. The results were used to validate the numerical model developed in a previous work based on Computational Fluid Dynamics (CFD). A series of experiments have been conducted at a semi-technical MFD test dryer with horizontal and diagonal air duct arrangement. Wheat and rapeseed were used as bed materials. The experiments were performed under isothermal conditions. Two experimental methods were selected and adapted to the measuring problem—the measurement of the isobar distribution within the grain bed and the residence time analysis using the tracer gas pulse method. As could be shown, the isobar distributions measured for wheat and rapeseed agreed well with the model predictions. The numerical model could calculate the influence of the bed material with its different particle characteristics (e.g., particle shape, particle size, bed porosity). The results obtained from the residence time analysis confirmed the known quartering of the air stream flowing from one inlet air duct to the four surrounding outlet air ducts for the horizontal air duct arrangement; in the diagonal air duct arrangement, the air stream from one inlet air duct was nearly halved flowing to the two adjacent diagonal outlet air ducts. These results were confirmed by investigations of the air velocity distribution within the grain bulk. Further experiments are necessary to refine the model. The residence time and isobar measurements will be extended to study the influence of different air properties under real drying conditions, the effect of structural elements, and dryer designs. [ABSTRACT FROM PUBLISHER]

This study investigates the electrohydrodynamic drying characteristics of wheat and its effect on the conformation of wheat protein using Fourier Transform Infrared Spectroscopy (FT-IR). A single wire electrode EHD system was used with a set electrode gap of 1.5 cm, applied voltages of 10 kV, 12.5 kV and 15 kV in combination with air cross-flow of velocities 1 m/s, 1.5 m/s and 2 m/s. It was observed that the drying rate of wheat sample was significantly affected by applied voltage and air velocity. The drying rate increased with an increase in air velocity and applied voltage. This study also showed that wheat protein conformation was significantly affected by EHD drying. In the analysis of the Amide I region (1720–1580 cm −1 ) of wheat protein, FT-IR spectra showed distinct valleys at 1682–1686 cm −1 (β-sheets), 1674 cm −1 (β-sheets), 1664–1667 cm −1 (turns), 1654–1657 cm −1 (α-helices), 1651 cm −1 (α-helices), 1645–1647 cm −1 (Random coils) and 1633–1634 cm −1 (β-sheets). Peak fitting using Gaussian band shapes suggested that exposure to electric field influenced the hydrogen bonding pattern of wheat protein resulting in shifts between low and high frequency bands which further supported these results. [ABSTRACT FROM AUTHOR]

A new coupled mathematical modeling to predict heat and moisture (liquid and vapor) transfer in capillary-porous bodies with particular reference to wheat kernel is presented. The mathematical model is based on the non-equilibrium thermodynamics by considering the wheat as prolate spheroid, variable transport coefficients and equilibrium boundary conditions at the surface of the solid. All the partial differential equations presented in the model have been written in prolate spheroidal coordinates. The finite-volume method has been used to obtain the numerical solution of the governing equations. Results of the average moisture content, average temperature, heat flux, liquid flux, vapor flux, and moisture content and temperature distributions inside a wheat kernel during drying process (T=87.8 oC, RH=5.6% and v=1.71 m/s) are presented and analyzed. [ABSTRACT FROM AUTHOR]

A mathematical model of temperature and wheat moisture content distribution inside a triangular spouted bed dryer was developed. The model is based on analysis of heat and mass transfer inside the dryer. In addition to that, an empirical bulk density model has been developed for wheat and included in the drying simulation. A laboratory-scale triangular spouted bed (TSB) dryer was used to dry wheat grain to validate the model. The dryer was divided into three sections, namely spouting, downcomer, and fountain. A series of drying runs were conducted to record moisture and temperature profile. There were two distinct regions observed during wheat drying. A constant rate period was observed during the initial drying stage and the falling rate period took place at the later drying stage. Initial moisture content and operating drying temperature governed the timing of transition from constant rate period to falling rate period. The model can be used to accurately predict the moisture content of wheat during drying. The temperature prediction inside the TSB dryer was less accurate, especially at high temperatures due to heat losses in the experimental dryer. Further studies are needed to improve the accuracy of this model, especially with regard to the temperature prediction. [ABSTRACT FROM AUTHOR]

In this study, temperature rise and non-uniformity of heating of grain with different moisture contents after microwave treatment were investigated. The temperature anomalies after microwave treatment were measured for barley and wheat at four moisture levels (12, 15, 18, and 21% wet basis) and for canola at five moisture levels (8, 12, 15, 18, and 21% wet basis). Fifty grams of grain samples were heated in a laboratory scale, continuous-type, industrial microwave dryer (2450 MHz) at five power levels (100, 200, 300, 400, and 500 W) and two exposure times (28 and 56 s). Grain samples were thermally imaged using an infrared thermal camera as soon as they came out from the microwave chamber. Average, maximum, and minimum temperatures were extracted from each thermal image and the difference between maximum and minimum temperatures (ΔT) was calculated. The grain type had significant effect on the surface temperatures after microwave treatment. The surface temperatures increased with microwave powers and exposure times but decreased with moisture content. The average surface temperatures after microwave treatment were between 72.5 and 117.5°C, 65.9 and 97.5°C, and 73.4 and 108.8°C for barley, canola and wheat, respectively, when the applied microwave power was 500 W. At the same power level, the maximum surface temperature was between 100.3 and 140.0°C, 77.8 and 117.7°C, and 98.3 and 130.9°C for barley, canola, and wheat, respectively. Non-uniform heating patterns were observed for all three grain types at all moisture contents, power levels, and exposure times. The ΔT was in the range of 7.2 to 78.9°C, 3.4 to 59.2°C, and 9.7 to 72.8°C for barley, canola, and wheat, respectively. The location of hot and cold spots may vary in different dryers based on the position of magnetron and other components, but almost similar non-uniform heating pattern is expected in all microwave dryers. Therefore, this non-uniformity must be taken into consideration while developing microwave processing systems for grains. [ABSTRACT FROM AUTHOR]