Effects of pre-heating temperature and formulation on porosity,moisture content,and fat content of fried batters

The effect of pre-heating temperatures on moisture and fat contents, and porosity of fried batters was studied. Batter pre-heated at 60 °C showed higher moisture content, lower fat content and lower porosity than non-pre-heated batter and batters pre-heated at 70 and 80 °C. Moisture content, fat content, and porosity at 4 min frying for batters with different pre-heating treatments ranged from 35.08 to 39.37, 3.92 to 5.16, and 13.14 to 45.31 %, respectively. Because of significant reduction in fat content, 60 °C pre-heating temperature was chosen to study the effect of batter formulations on moisture and fat contents, and porosity. Different wheat to rice flour ratios were prepared, and then each batter was pre-heated at 60 °C. Batters with higher wheat flour content showed higher moisture content, and lower fat content and porosity than batters with higher rice flour.     

Effect of Process Parameters on Work Index, Milling Efficiency and Some Technological Properties of Yam Flour Using Attrition Mill

The effect of process parameters on work index, efficiency of milling, bulk density, swelling capacity and water absorption capacity of yam flour using attrition mill was studied. Independent variables were: moisture content (8, 12, 16, 20 and 24 % w.b.), speed (288, 346, 432, 576 and 864 rpm) and inlet opening (1,300, 2,600, 3,900, 5,200 and 6,500 mm²). The responses were work index, milling efficiency, bulk density, water absorption and swelling capacities of the flour. Work indexes for milling yam flour, meal and grit were found to be 0.25?±?0.13, 0.49?±?0.14 and 1.8?±?0.56, respectively. Flour fraction, bulk density, water absorption capacity and swelling capacity ranged from 42.2 to 56.6 %, 0.54 to 0.66 g/m³, 200 to 400 % and 13 to 23 ml, respectively. The treatments were found to influence the responses significantly (p?<?0.05). Optimum process condition was achieved at 12 % moisture content of feed, 506 rpm shaft speed and 5,200 mm² feed opening giving 19.1 % grit, 23.6 % meal and 54.2 % flour. The desirability of the optimisation process was 0.78. Validation of predicted optimal moisture content, worm shaft speed and feed inlet opening gave errors of 19, 14.4 and 6.1 % for grit, meal and flour, respectively.     

Karl Fischer Water Titration−Principal Component Analysis Approach on Wheat Flour

In this research, a new Karl Fischer water titration–principal component analysis (KFT–PCA) concept on wheat flour samples was introduced and studied. First, the evaluation of the performance of the determination of water content of wheat flour (Triticum aestivum L. subsp. aestivum) by using the KFT method was performed. The water content of white wheat flour, determined by KFT method, was in the range of 14.9–15.2 %, while for the whole-wheat and Graham flour samples, this concentration was lower (14.7 and 14.5 %, respectively) and was close to the limit of Romanian standards. The new approach on the KFT water reaction rates for wheat flour was performed. Thus, the “surface water” reaction rates of 1.2–2.1 mM/s and the “strongly bound water” reaction rates of 0.13–0.24 mM/s were obtained for flour samples. Further, these water reaction rates together with the primary KFT parameters (e.g., water concentration and normalized titration volume) were used in a multivariate statistical approach (PCA) in order to evaluate similarities–dissimilarities between samples. Among KFT parameters, the water content, the normalized titration volume, and the surface water reaction rate were important for a good classification of the flour products.     

Prediction of wheat quality parameters using near-infrared spectroscopy and artificial neural networks

In wheat and flour processing, the quality control needs quick analytical tools for predicting physical, rheological, and chemical properties. In this study, near infrared reflectance (NIR) spectroscopy combined with artificial neural network (ANN) was used to predict the flour quality parameters that are protein content, moisture content, Zeleny sedimentation, water absorption, dough development time, dough stability time, degree of dough softening, tenacity (P), extensibility (L), P/G, strength, and baking test (loaf volume and loaf weight). A total of 79 flour samples of different wheat varieties grown in different regions of Turkey were chemically analyzed, and the results of both NIR spectrum (400–2,498 nm) and chemical analysis were used to train/test the network by applying various ANN architectures. Prediction of protein, P, P/G, moisture content, Zeleny sedimentation, and water absorption in particular gave a very good accuracy with coefficient of determination (R ²) of 0.952, 0.948, 0.933, 0.920, 0.917, and 0.832, respectively. The results indicate that NIR combined with the ANN can successfully be used to predict the quality parameters of wheat flour.     

Evaluation of the TLC quantification method and occurrence of deoxynivalenol in wheat flour of southern Brazil

ABSTRACT

The study evaluated a QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction method for use with a TLC quantification procedure for deoxynivalenol (DON). It also surveyed DON occurrence in wheat flour from the southern region of Brazil. Forty-eight wheat flour samples were analysed, divided into 2 different harvest lots, each consisting of 24 different brands. The detection and quantification limits of the method were 30 and 100 ng of DON on the TLC plate. The various concentrations of DON presented high linearity (R² = 0.99). A negative matrix effect (?28%) of the wheat flour was verified, with suppression of the chromatographic signal of DON, and 80.2–105.4% recovery. The TLC method was reliable for DON evaluation, with a coefficient of variation of less than 10%. High-performance liquid chromatography of lot 2 samples confirmed the presence of DON in all samples identified DON-positive by the TLC technique. Of the 48 wheat flour samples in lots 1 and 2 analysed by TLC, 33.3 and 45.8% of the samples respectively were above the Brazilian legislation limit. Correlations were observed between the water activity and DON content, and between the fungal count and moisture content of the wheat flours.     

Microbial Enzymes as Substitutes of Chemical Additives in Baking Wheat Flour—Part II: Combined Effects of Nine Enzymes on Dough Rheology

In this work, the combined effects of nine commercial enzymes were studied on the rheological properties of dough wheat flour. Fungal (AMY-F), bacterial (AMY-B), and maltogenic (AMY-M) α-amylases; fungal (XYL-F) and bacterial (XYL-B) xylanases; glucose oxidase (GOX); laccase (LAC); lipase (LIP); and transglutaminase (TG) were tested in two types of flour: standard strong flour (flour A) and common weak flour (flour B). Falling number (FN), farinography, and alveography analysis were carried out through two sequential experimental designs, aiming to identify synergistic and antagonist effects between the enzymes and the optimal concentration of each one as substitutes of chemical additives. For flour A, the best combination of enzymes was AMY-B (166 U kg^?1), AMY-M (133 U kg^?1), XYL-B (150 U kg^?1), GOX (8 U kg^?1), and LIP (150 U kg^?1). It was identified as a synergistic effect between XYL-B and GOX to improvement of W value (10^?4 J) and the P/L ratio. For flour B, the best combination of enzymes was AMY-B (150 U kg^?1), LIP (150 U kg^?1), GOX (100 U kg^?1), and LAC (200 U kg^?1). GOX and LAC presented a cooperative effect, when they were used at opposite concentrations. The enzyme mixtures were compared with chemical oxidant azodicarbonamide, and, even at the maximum concentration allowed by Brazilian Health Surveillance Agency, the enzyme mixture was more effective. It was demonstrated that it is possible to perform the complete substitution of chemical oxidants by enzymes in order to adequately improve the rheological parameters of dough wheat flours, even for a weak flour, making it suitable for bakery.     

A Study on Staling Characteristics of Gluten-Free Breads Prepared with Chestnut and Rice Flours

The effects of chestnut flour and a xanthan–guar gum blend–DATEM mixture on staling of gluten-free rice breads baked in conventional and infrared–microwave combination ovens were studied. Staling properties of the bread were assessed using mechanical compression (TA), differential scanning calorimetry, X-ray diffraction, and fourier transform infrared spectroscopy (FT-IR). Hardness, moisture loss, and retrogradation enthalpy values for all bread samples increased significantly during storage. FT-IR spectra showed that the integrated area of peaks around 1,041 and 1,150 cm^?1 wave lengths, which are related to the structure of starch retrogradation, increased with storage time. The X-ray diffractograms of aged breads indicated a B-type structure with the appearance of peaks at around 17°, 19.5°, and 22°. An additional peak at 24° was observed in breads stored for longer periods. Higher values of hardness and lower moisture contents were obtained for breads baked in an infrared–microwave combination oven, but the use of infrared–microwave combination oven did not result in excessive hardness after storage. Retrogradation enthalpies and total crystallinity values of breads did not show significant differences with baking type.The replacement of rice flour with chestnut flour and addition of xanthan–guar gum blend–DATEM mixture in formulations significantly delayed staling of gluten-free breads by decreasing moisture loss, hardness, retrogradation enthalpy, and total mass crystallinity.     

Effect of Germination on the Functional and Moisture Sorption Properties of High–Pressure-Processed Foxtail Millet Grain Flour

Foxtail millet is one of the commonly cultivated, nutritionally competitive source of protein, fibre, phytochemicals and other micronutrients, as compared to major cereals like wheat and rice. Considering the potential of these grains, the high pressure processed flours of germinated (GFMF) and non-germinated foxtail millet (NGFMF) grains were studied for its functional, moisture sorption and thermodynamic properties. Germination and high-pressure processing of foxtail millet grains significantly improved the functional properties of the flour. Apart from this, the moisture sorption isotherms of both the flours were determined at 10, 25 and 40 °C and the sorption data was fitted to Guggenheim-Anderson-De Boer (GAB) sorption model. The monolayer moisture content for NGFMF and GFMF ranged between 3.235–2.364 and 2.987–2.063 g g^?1, respectively. The isosteric heat of sorption ranged between ? 76.35 to ? 38.23 kJ mol^?1 for NGFMF and 172.55 to ? 34.02 kJ mol^?1 for GFMF at a moisture range of 0 to 36%, whereas, the integral entropy of sorption for NGFMF ranged between ? 0.404 and ? 0.120 kJ mol^?1 K^?1 and for GFMF between ? 0.667 and ? 0.383 kJ mol^?1 K^?1. Along with the validation of the compensation theory, the values of spreading pressures lied in the range of 0–0.078 J m^?2 for NGFMF and 0– 0.124 J m^?2 for GFMF, while, the glass transition temperatures ranged between 82.25 and 28.67 °C for NGFMF and from 51.11 to 11.83 °C for GFMF at all three temperatures.     

Moisture Transfer Properties of Dry and Semimoist Foods

Equilibrium moisture content, mass diffusion coefficients, and densities were collected for wheat flour, shredded wheat, raisins, nonfat dry milk, and freeze-dried apple, turnip, and ground beef at 25 ± 1°C. Flour adsorbing to 0.75 a_w had the largest mass diffusion co-efficient, 1.15 × 10^?7 m²/hr and raisins had the smallest value of 0.015 × 10-⁷ m²/hr. Two of the food uroducts. flour desorbing to 0.11 a_w, and the freeze-dried turnip, exhibited diffusion coeffcients which were dependent on the moisture content. Most of the foods reached equilibrium within 1 wk based on an objective criterion of no more than a 0.5% dry basis moisture difference over three successive readings at 1 wk interval.     

A case study of characteristic bands selection in near-infrared spectroscopy: nondestructive detection of ash and moisture in wheat flour

Near-infrared (NIR) spectroscopy has been attempted to determine ash and moisture of wheat flour nondestructively combined with characteristic bands selection methods. Pearson product-moment correlation coefficients and interval partial least squares (iPLS) were performed comparatively to choose characteristic bands associated with ash and moisture distributions. Through comparing the performance of developed models with new samples, the optimal models of ash and moisture were obtained with the characteristic bands of 4000–5500, 6708–7304 and 4000–4896, 5504–6704 cm^?1, respectively. The root mean square errors of prediction were 0.019 and 0.088 % for ash and moisture, respectively. The results suggest that NIR technique combining with iPLS has significant potential to quantitatively analyze ash and moisture in wheat flour; moreover, it could indicate the related spectral contributions.     

Predicting the cookie quality of flours by using Mixolab<Superscript>®</Superscript>

The objective of this study was to determine the possibility of using Mixolab^® to predict the cookie baking quality of different wheat flours. Mixolab data was also compared with various flour quality characteristics. There were significant correlations (P < 0.001) between Mixolab stability and some of the flour quality characteristics (protein and wet gluten contents, Zeleny sedimentation value). Alveoconsistograph T value was negatively correlated with Mixolab C3, C4 and C5 values. The cookie diameter gave highly significant correlations with protein content, Zeleny sedimentation value and damaged starch content. Mixolab C3 and C4 values were highly correlated (P < 0.001) with both cookie diameter and spread ratio. A significant correlation coefficient (r = 0.556) was determined between the cookie diameter and C1–C2 value which is an indication of protein quality. The dependence of cookie diameter and spread ratio on Mixolab C3 value, damaged starch content and Zeleny sedimentation value were analyzed with multiple regression analysis and high multiple correlation coefficients were found between these parameters (r = 0.948 and 0.861, respectively).     

Dietary exposure to aluminium from wheat flour and puffed products of residents in Shanghai,China

A dietary survey of 3431 residents was conducted by a 24-h dietary recall method in Shanghai, China, quarterly from September 2013 to September 2014. A total of 400 food samples were tested for aluminium concentration, including wheat flour and puffed products from 2011 to 2013. Probabilistic analysis was used to estimate the dietary exposure to aluminium from wheat and puffed products. The means of dietary aluminium exposure for children (2–6 years old), juveniles (7–17 years old), adults (18–65 years old) and seniors (over 65 years old) were 1.88, 0.94, 0.44 and 0.42 mg kg^?1 body weight (bw) week^?1 respectively, with a population average of 0.51 mg kg^?1 bw week^?1. The proportions of those who had aluminium exposure from wheat and puffed products lower than the provisional tolerable weekly intake (PTWI) were 77%, 90%, 97%, and 97% respectively from children to seniors. We estimated that the proportions of people at risk would decrease by 13%, 6%, 2% and 2% respectively under the new China National Standards – GB 2760–2014 National Food Safety for Standards for using food additives. The results indicated that aluminium from wheat flour and puffed products is unlikely to cause adverse health effects in the general population in Shanghai; however, children were at a higher risk of excess aluminium exposure. Significant improvements in reducing the dietary exposure to aluminium are expected in the population, especially for children after the implementation of GB 2760–2014.     

Determination of benzoyl peroxide, as benzoic acid, in wheat flour by capillary electrophoresis compared with HPLC

BACKGROUND: In recent years, debate on the addition of benzoyl peroxide (BP) to wheat flour has increased in China. Medical studies have so far not confirmed that BP in wheat flour causes definite damage to the human body, but its main metabolite in the human body is benzoic acid. The addition of BP to wheat flour has been forbidden in China since 1 May 2011. It is therefore necessary to develop a suitable method to determine BP in wheat flour. RESULTS: A simple method using capillary electrophoresis (CE) was developed for determination of BP in wheat flour. BP was determined as benzoic acid after preceding reduction by potassium iodide. Separation was completed in less than 7 min with a running buffer of 10 mmol L^?1 sodium borate (pH 9.18), 4 s hydrodynamic injection, 25 kV separation voltage and UV detection at 228 nm. The method was validated in terms of linearity, sensitivity, detection limit, precision and accuracy. The detection limit was 0.29 µg mL^?1. The method was successfully applied to the determination of BP in wheat flour samples, with recoveries between 96.1% and 102.6%. CONCLUSION: The performance of the CE method was comparable, and the quantitative results were in good agreement with those using high‐performance liquid chromatography (HPLC). Meanwhile the proposed CE method has the advantages of better resolution, shorter analysis time and lower cost, and would be a good alternative to HPLC for routine monitoring of BP amount in wheat flour. Copyright © 2011 Society of Chemical Industry     

Determination of Deoxynivalenol in Wheat Bran and Whole-Wheat Flour by Fluorescence Polarization Immunoassay

A rapid and accurate fluorescence polarization (FP) immunoassay has been optimized for the determination of deoxynivalenol (DON) in wheat bran and whole-wheat flour. A preliminary treatment with activated charcoal was used to eliminate the strong matrix effect due to highly colored interfering compounds present in raw wheat bran extracts. In particular, matrix effect was removed by adding activated charcoal to the wheat bran extract (3.5 mg/mL) and mixing for 3 min of incubation time prior to the FP immunoassay analysis. No preliminary treatment was necessary for whole-wheat flour. Average recoveries from samples spiked with DON at levels of 500, 1,000, and 1,500 μg/kg were 95 % for wheat bran and 94 % for whole-wheat flour, with relative standard deviation generally lower than 13 %. Limits of quantification of the optimized FP immunoassay were 120 μg/kg for both matrices. The overall time of analysis was lower than 15 min for wheat bran and 10 min for whole-wheat flour. Good correlations (r?>?0.971) were observed between DON contents obtained by both FP immunoassay and high-performance liquid chromatography with immunoaffinity cleanup for 37 and 23 samples of naturally contaminated wheat bran and whole-wheat flour, respectively. These results show that the FP immunoassay is suitable for high-throughput screening as well as for quantitative determination of DON in wheat bran and whole-wheat flour.     

The relationship between moisture content and equilibrium relative humidity of five types of wheat flour

There was little difference at 5, 15 and 25°C between the moisture content-equilibrium relative humidity relationships of three types of bread flour and a biscuit flour made from wheat. A flour made from wheat a about 18% moisture content heated to 70°C for about 15 min, had a higher equilibrium relative humidity than the other types.     

Occurrence of beauvericin and enniatins in wheat flour and corn grits on the Japanese market,and their co-contamination with type B trichothecene mycotoxins

The contamination levels of beauvericin and four enniatins, A, A₁, B and B₁, in 207 samples of wheat flour and corn grits on the Japanese market were determined by an analytical method based on LC-MS/MS. The toxins were extracted from samples with acetonitrile–water (85:15, v/v) and then purified with C18 cartridges. The method was validated in a single laboratory using spiked samples at two levels; the recovery of the five toxins ranged from 91.1% to 113.8%. Enniatin B was frequently detected in imported wheat flour (81.8%) and domestic wheat flour (85.6%), and the highest concentration of enniatin B was present in a domestic wheat sample (633 μg kg^?1). In corn grits, beauvericin was found in 34% of the samples, but enniatins were not detected at all. The maximum concentration of beauvericin in corn grits was 26.1 μg kg^?1. Deoxynivalenol and nivalenol in the same samples were determined by a method using an immunoaffinity column. Co-contamination of deoxynivalenol and enniatins was observed in 61% of the imported wheat samples and in 58% of the domestic wheat samples. These results suggest the need for a risk assessment for cyclic depsipeptide mycotoxins in Japan and a study on the synergistic effect of deoxynivalenol and enniatins.     

Improving Carob Flour Performance for Making Gluten-Free Breads by Particle Size Fractionation and Jet Milling

Many different raw materials have been proposed for producing nutritious gluten-free breads, but rarely, there is a parallel analysis of the effect of physical treatment on those ingredients. The aim of this study was to incorporate carob flour fractions of varying particle size on rice gluten-free breads prepared with carob/rice (15:85) flour blends. Carob flour particle size was controlled by fractionation or jet milling application. Quality features of gluten-free breads containing carob flour and commercially available gluten-free breads were compared. Carob flour addition led to breads with improved colour parameters, crumb structure, retarded firming and lower moisture loss compared to rice bread. Further improvement in specific volume, crumb hardness, protein and ash content and estimated glycaemic index (eGI) could be obtained by a careful selection of the particle size distribution of the carob flour. Carob breads prepared either with the coarsest or the finest fraction prepared using jet milling led to end products with the highest specific volume (≈2.2 g/cm³) and the lowest crumb hardness (≈5.5 N), although they had lower specific volume and harder crumbs than breads from commercial blends (≈3–4 g/cm³, 0.6–3.8 N). Nevertheless, rice-based bread made with the finest carob flour was superior considering its slower firming, protein content and lower eGI. The incorporation of carob flour obtained by jet milling in rice-based gluten-free breads led to end products with quality characteristics and sensory acceptance resembling commercial breads and high nutritional value.     

The Effects of Extrusion Conditions on the Physical Properties of Wheat Flour Extrudates

The effects of extrusion conditions (feed moisture content and rate, process temperature, screw speed and geometry, and die diameter) on expansion ratio, bulk density, and breaking strength of wheat flour extrudates were investigated. Extrudate samples were prepared by using a Brabender single-screw extruder. Higher feed moisture content and process temperature were required for proper expansion. At 3.18mm die opening, the relationship between expansion and bulk density was positive. Feed rate was the most effective factor for increasing bulk density. Breaking strength was significantly decreased with increasing process temperature. Under extrusion conditions of 22% feed moisture, 110g/min feed rate, 160°C process temperature, and 130rpm screw speed with 5:1 CR, wheat flour was puffed with low bulk density and breaking strength.     

The conditioning of wheat. The influence of conditioning temperature on flour yield,moisture content and colour

Two UK wheats of similar protein content but differing in hardness have been conditioned at temperatures of 4, 10.5, 19 and 28°C to a moisture content of 15.5%, using lying times in the range 2 to 24h. The milling performance of the wheats has been assessed in terms of flour yield, moisture content and grade colour figure (GCF). Flour yield was expressed as straight-run milling yield (SR) and also as total yield (TE) which included flour from the impact finishing of by-products. The use of a conditioning temperature of 28°C increased TE and SR for the hard wheat and TE for the soft wheat, but decreased SR for the latter. Both types showed a reduction in flour yield when a lying time of 2h was employed. The use of temperatures above or below 19°C led to improved GCF results. The combination of low temperatures and short lying times brought about reductions in flour moisture content but these reductions were shown to be only partially responsible for the accompanying decreases in flour yield.     

Tempering–preservation treatment inactivated lipase in wheat bran and retained phenolic compounds

Wheat bran is rich in functional ingredients, but the high level of lipase limits its applications. Tempering–preservation treatment (at 70–90 °C with moisture of 20%–40% for 1–4 h) was exploited for stabilising wheat bran and its effect on polyphenols was investigated. The results showed that more lipase was inactivated at higher tempering moisture, temperature and longer time. The optimum condition for inactivation of wheat bran lipase was 30% moisture and 90 °C for 4 h. The inactivation rate reached 93.8% with a residual enzyme activity of 0.264 U g⁻¹. Under the optimum condition, the sum of free phenolic acids rose from 25.4 to 55.8 µg g⁻¹. As for bound phenolic acids, there was a slight increase of hydroxybenzoic acid derivatives but a slight decrease of hydroxycinnamic acid derivatives. The total contents of phenolic acids before and after stabilisation were not significantly different. This study showed the possibility of using tempering–preservation as an efficient method for inactivation of wheat bran lipase while maintaining its phenolic compounds, which could be used in the production of whole wheat flour.