Amount of damaged starch in laboratory and production grinding flour

2.50 - Development of FIA Biosensor System for the Determination of Starch in Flour

The feasibility of near-infrared (NIR) diffuse reflectance spectroscopy scanning from 1100 to 2500 nm in the analyses of the amounts of moisture, protein, starch, amylose, and tannin in buckwheat flours was examined. Fifty ground samples comprised of 27 different cultivars harvested in 12 different countries were divided into two sets: 35 samples as a calibration set and 15 samples as a prediction set. The multiple regression equations (MREs) established between the second derivative NIR spectra data and the reference data, which were obtained by chemical analyses of the calibration set, gave multiple correlation coefficients of higher than 0.93 for moisture, protein, and starch, and workable standard error of predictions (SEPs) in relation to the reference standard deviation data. In contrast, the MREs for amylose and tannin were judged as unstable because the SEPs had no difference with their reference standard deviation data. The influential wavelengths were 1925 nm for water (assigned to the combination of the stretching and bending vibrations of hydroxyl [OH]), 2057 nm for protein (assigned to the combination of NH and amide II or III), and 2100 nm for starch (assigned to the combination of OH and CO). The obtained results indicated that the NIR procedure can be used as a nondestructive analysis method for rapid and simple measurement of the amounts of moisture, protein, and starch in buckwheat flours.

The aim of this study was to clarify the change in the powder properties of rice flour depending on the milling process. Rice flour samples, which have gradual mechanical shock properties, were prepared using different milling methods. Furthermore, the correlation between the starch damage, owing to mechanical shock, and powder properties of rice flour was investigated. The particle size was changed gradually through each milling process; however, the change did not clearly correlate with starch damage. The results of the X-ray diffraction (XRD) pattern of nongelatinized samples showed the typical A-type structure of starch. The crystal structure of starch in rice flour may change to a disorder state with the progress of milling; thus, in this study, instead of crystallinity, we considered the disorder index (DI) calculated from the XRD intensity of samples. Relationship between DI and starch damage was confirmed with R2 = 0.923. Therefore, the mechanical shock caused by the milling process contributes to the crystal state of starch. The parameter qm calculated from the Guggenheim-Anderson-de Boer (GAB) equation of each sample corresponded to the DI. This result suggested that the sorption site of rice flour decreased, and a positive correlation was observed between the parameter K and DI. Thus, the interaction between the rice flour and water molecules weakened because of the mechanical shock. In addition, the use of a SEM image supports the insight that the change in parameter K may reflect the structural change in the solid phase. These results demonstrated that the change in powder properties of rice flour caused by mechanical shock of the milling could evaluate quantitatively.

Background and objectivesParticle size distribution and damaged starch content have a major impact on flour quality because they influence the behavior of flour during hydration in processing. Particle size distribution and starch damage of legume flours and their relationship during grinding have not been evaluated. The standard enzymatic method for the measurement of damaged starch content (AACC 76‐31) was used to find a new calibration equation for the rapid amperometric method (SDmatic, AACC 76‐33.01) for legume flours. Changes in particle size distribution and starch damage during regrinding in a commercial pea flour were compared with those in a commercial wheat flour.FindingsLegume flours had a smaller damaged starch content (0.8–4.7 SD%) than wheat flours (2.2–7.0 SD%). The bimodal particle size distribution of flours was linked to structural elements as confirmed by environmental scanning electron microscopy and laser granulometry. Particle size distribution and starch damage varied concomitantly during regrinding in the commercial pea flour as in the commercial wheat flour. The main factor responsible for the increase in damaged starch content was an increase in the proportion of the fine fraction in the flour. Fine fractions contained higher damaged starch contents than coarse fractions.ConclusionsHypotheses concerning differences in fragmentation mechanisms in the two flours were formulated, suggesting that pea flour has a higher likelihood for fracture but less tendency to produce damaged starch than wheat flour.Significance and noveltyThe amperometric method (AACC 76‐33.01) can be used for a rapid estimation of the damaged starch content in legume flours. Furthermore, the results suggest a lower hardness of pea flour material compared to wheat flour material that would have a significant impact on milling strategies.

Calcium fortification is usually achieved by employing wheat flour as the most frequently used vehicle. In this study, potential of calcium extraction from chicken eggshell and its utilization as a bread fortificant in straight grade flour (SGF) is investigated. In addition, the fortified and unfortified (control) flour samples were evaluated for nutrient composition and rheological properties. Results showed that addition of fortificant at different concentrations significantly (p<0.05) enhanced calcium content of fortified flour and it was considerably increased from 115.80 mg/kg (To) to 1135.1 mg/kg (T3). Nutrient composition data of fortified flour have shown a significant (p<0.05) reduction in moisture content of flour from 12.7% (To) to 11.76% (T3) and protein content from 9.89% (To) to 9.79% (T3). However, a significant increase in ash content was observed by increasing fortificant level from 0.54% (To) to 1.04% (T3). Rheological properties indicated a significant increase in water absorption from 63.60 to 67.527%, dough development time (DDT) from 7.38 to 11.37 min and dough stability from 13.79 to 17.37 min. Textural characteristics of fortified bread revealed a significant reduction for hardness values from 11.40 N (control) to 6.50 N (T3) in response to fortificant addition. Quality assessment of bread indicated that bread quality was significantly affected with corresponding rises in fortificant addition levels.

(1) Background: The general use of food-processing facilities in the agro-food industry has increased the risk of unexpected material contamination. For instance, grain flours have similar colors and shapes, making their detection and isolation from each other difficult. Therefore, this study is aimed at verifying the feasibility of detecting and isolating grain flours by using hyperspectral imaging technology and developing a classification model of grain flours. (2) Methods: Multiple hyperspectral images were acquired through line scanning methods from reflectance of visible and near-infrared wavelength (400–1000 nm), reflectance of shortwave infrared wavelength (900–1700 nm), and fluorescence (400–700 nm) by 365 nm ultraviolet (UV) excitation. Eight varieties of grain flours were prepared (rice: 4, starch: 4), and the particle size and starch damage content were measured. To develop the classification model, four multivariate analysis methods (linear discriminant analysis (LDA), partial least-square discriminant analysis, support vector machine, and classification and regression tree) were implemented with several pre-processing methods, and their classification results were compared with respect to accuracy and Cohen’s kappa coefficient obtained from confusion matrices. (3) Results: The highest accuracy was achieved as 97.43% through short-wavelength infrared with normalization in the spectral domain. The submission of the developed classification model to the hyperspectral images showed that the fluorescence method achieves the highest accuracy of 81% using LDA. (4) Conclusions: In this study, the potential of non-destructive classification of rice and starch flours using multiple hyperspectral modalities and chemometric methods were demonstrated.

Effect of adding wheat (Triticum aestivum L.) farina with varied integrity of endosperm cell wall on dough characteristics, dried noodles quality and starch digestibility

Plant-based dietary fibers play a fundamental role in improving human health. The objective of this study is to determine the effect of incorporating black plum powders (pulp and peel) on the thermal and rheological properties of wheat dough. The test dough cake samples were prepared with 0% (control), 3%, 5% and 7% replacement of wheat flour with black plum pulp and peel powders. Thermal and rheological properties of these doughs were determined using Differential Scanning Calorimetry (DSC) and rheometer, respectively. Thermal analysis showed a decrease and an increase in the peak temperature (Tp) (65.90 ± 0.01 - 65.22 ± 0.03℃) and gelatinization enthalpy (ΔH) (5.54 ± 0.33 – 6.71 ± 0.45 SI) of the wheat flour-black plum pulp or peel powder mixture, respectively. However, the gelatinization temperature range (TF –Ti) of the wheat flour starch did not significantly (P&gt;0.05) vary. The doughs exhibited shear thinning (pseudo-plastic) behavior and a typical solid-elastic behavior. Both powders (pulp and peel) did not have significant effects (P&gt;0.05) on the rheological properties (flow and viscoelasticity) of the dough. Black plum pulp (FVPu) and peel (FVPe) powders can be partially incorporated into wheat flour in the preparation of cakes without significant modifications to the properties of wheat dough.

The study of chemical composition and dough rheology changes in sieve-classified two fractions (up to 60 and 60-240 microm particles) of wheat flour was the subject of this study. The straight grade flours were obtained by the milling of three Polish varieties of spring wheat, differing in particle size index (PSI) values. The flours were separated with the use of an SZ-1 laboratory sifter. The yield of fine fraction was in the range 50.0-55.7%. The obtained fractions were assayed for the content and composition of free lipids, gluten proteins, damaged starch, ash, water absorption and amylograph viscosity. Dough rheology (extrusion in OTMS cell, alveograph and farinograph tests) and baking trials were also performed. The content of free lipids, including the non-polar and phospholipids was lower and the content of glycolipids was higher in fine flours. Those fractions were more rich in linoleic acid but the lower content of oleic and linolenic acids resulted in a higher oxidizability index of free lipids. Fine flours contained less ash and significantly more damaged starch. At the same time, they were characterized by a higher content of wet gluten, water absorption, amylograph viscosity and better dough parameters. This was reflected in the bread volume, which was higher by 6.3-10.7%. The influence of the changes in composition and the content of free lipids upon the rheology of the dough after the 90 days flour storage has not been defined unambiguously and requires further research.

Characterization of sorghum grain and evaluation of sorghum flour in a Chinese egg noodle system

Whole buckwheat flour (WBF) was used in leavened flat bread (bazlama) and unleavened flat bread (yufka) formulations to improve the nutritional status of flat breads. WBF replaced wheat flour at 10, 15, 20, 25 and 30% levels in both flat breads. The effects of WBF on some rheological properties of dough and some physical, chemical and sensory properties of flat breads were studied. The effects of some additives (gluten and sodium stearoyl-2-lactylate; SSL) for improving dough rheology and bread properties were also investigated. For this purpose WBF replaced wheat flour at 20, 30 and 40% levels in flat bread formulation with the aid of additives. WBF increased water absorption and development time values of dough up to 93.3% and 14.4 min, respectively. While dough stability, energy and resistance values were adversely affected by an increasing level of WBF, usage of gluten and SSL improved those parameters significantly. Ash, protein and crude fibre content of both flat breads were found at the highest ratio in 30-40% level of WBF with additive combination. Phytic acid content ranged between 163.03 and 651.04 mg/100 g in bazlama and between 220.01 and 772.34 mg/100 g in yufka samples. Fe, K, Mg and P contents of both flat breads increased with an increasing amount of WBF in formulation. Mineral content of bazlama samples increased from 0.96 to 1.72 mg/100 g for Fe, 165.92 to 272.71 mg/100 g for K, 36.21 to 109.01 mg/100 g for Mg and 131.13 to 264.72 mg/100 g for P with 40% WBF usage. WBF content above 10% caused an increment in darkness, yellowness and redness of the flat bread samples. A sensory analysis revealed that the taste and odour score decreased above the 20% WBF level for bazlama and 30% WBF level for yufka compared to control bazlama/yufka.

The effect of α-amylases from cereal and fungal sources on dough rheological properties was studied. Increasing the enzyme addition level to 160 SKB units (c. 1.1%, fwb) decreased dough stability and increased mixing tolerance indexes. Gas production rates with cereal α-amylase were higher than that with fungal α-amylases, indicating more activity during fermentation. A higher adsorption rate occurred with cereal α-amylase. Dough stability is very important for Turkish hearth bread production, as it is for other hearth breads. Spread ratio tests on fermented doughs showed significant changes in dough rheological properties as a function of α-amylases. The spread test is a reliable tool for observing rheological changes during fermentation. As a guide, the dough spread ratio should not be more than 2 for desirable bread.

Eight tests designed to screen early generations of wheat, Triticum aestivum L. em Thell., for breadmaking quality were evaluated. Sedimentation value, mixograph development time, centrifuge absorption and nitrogen content (in that order) were the most repeatable of the eight tests. Flour yield and starch damage were least repeatable. The heritability of mixograph development time was low because of a significant cultivar by year interaction. Nitrogen content, sedimentation value and centrifuge absorption were shown to contain all the information about loaf volume and farinograph absorption that was available in the set of eight tests. It was therefore concluded that nitrogen content, sedimentation value and centrifuge absorption are the most useful of the eight tests for purposes of plant breeding programs.

The gliadin/glutenin ratio of 15 diverse wheat varieties ranged from 0.75 to 1.16, whereas the high molecular weight glutenin subunits (HMW‐GS) to low molecular weight glutenin subunits (LMW‐GS) ratio of these varieties ranged from 0.31 to 0.93. Gliadin/glutenin ratio showed a significant negative relationship with specific loaf volume (r = −0.73), dough development time (DDT; r = −0.73), dough stability (r = −0.79) and positive associations with LMW quantity (r = 0.72). Mixolab classified the wheat varieties into two groups on the basis of HMW‐GS located at Glu‐A1 and Glu‐D1. Wheat varieties HI 977 and DBW 16 with subunits 2* and 5 +10 at Glu‐A1 and Glu‐D1, respectively, exhibited the characteristics of “extra strong” doughs with longer DDT of 8.3 and 7.2 min, and higher dough stability values of 9.1 and 8.6 min, respectively. Wheat varieties C 306, HW 2004 with null allele at Glu‐A1 and 2 + 12 at Glu‐D1, in contrast, were weak as they developed quickly, with low dough stability (≤4 min).Practical ApplicationsBread has been one of the principal forms of food for man from the earliest times. Bread quality is determined by the composition and molecular structure of gluten which in turn controls the interactions of gluten subfractions during processing. Rheological properties, microstructure of gluten, gliadin/glutenin ratio and HMW‐GS/LMW‐GS ratio have been found to be associated with bread‐making quality of wheat varieties. The research implications may be utilized both by industry personnel as well as researchers to assess the bread‐making quality of wheat varieties.

Utilization of Highly Deoxynivalenol-Contaminated Wheat Via Extrusion Processing