Hamit Köksel

Effects of industrial pasta drying temperatures on starch properties and pasta quality

Abstract Effects of industrial pasta drying temperatures on various starch properties and the quality of pasta were investigated. A short cut pasta (fusilli) was processed from durum semolina and dried by high temperature (HT) and very high temperature (VHT) drying cycles. Starch properties were examined by Rapid Visco Analyzer, differential scanning calorimeter, X-ray diffractometer and polarized light microscope. Cooking quality was evaluated by determining cooking loss (CL) into cooking water, total organic matter (TOM) in washing water after cooking, and sensory evaluation. The X-ray diffractograms of semolina samples showed typical A-type diffraction patterns. The diffractograms of pasta products using HT and VHT drying were similar. However, an additional small peak appeared at about 2θ=20° for both drying cycles, indicating the formation of a V-type X-ray diffraction pattern. All starch granules of semolina displayed a clear “Maltese cross” under polarized light, but approximately 20% of starch granules of HT- and VHT-dried pasta samples either partially or completely lost their birefringence. Starch from VHT-dried pasta had greater RVA peak viscosity and breakdown viscosity than HT-dried pasta. Both gelatinization enthalpy and peak temperature of HT-dried pasta were significantly lower than those of VHT-dried pasta. The HT-dried pasta had lower quality scores based on TOM and CL values and sensory evaluation as compared with the VHT-dried pasta. The present study indicated that the changes in starch during HT and VHT drying may affect the pasta cooking quality.

Phytochemical quantification and total antioxidant capacities of emmer (Triticum dicoccon Schrank) and einkorn (Triticum monococcum L.) wheat landraces.

In this study, samples of 18 ancient wheat (12 emmer, 6 einkorn) and 2 bread wheat varieties grown in different regions of Turkey were examined for their total phenolics and flavonoids, phenolic acids, lutein, total yellow pigment, and total radical scavenging capacities against ABTS cation. Results showed that health beneficial phytochemicals and total antioxidant capacities were generally significantly different in emmer and einkorn wheat groups. Remarkably higher total antioxidant activity (18.31 +/- 1.31 micromol Trolox equiv/g), total phenolics (6.33 +/- 0.98 micromol gallic acid equiv/g), ferulic acid (662.95 +/- 61.07 microg/g), and flavonoids (1.61 +/- 0.34 micromol catechin equiv/g) content were detected in emmer wheat samples (n = 12), suggesting that they may have high potential for utilization as a novel grain, rich in natural antioxidants. In addition, quite high levels of lutein (7.33 +/- 2.43 microg/g) of einkorn samples (n = 6) hold the potential of developing high-lutein bakery products to considerably raise the dietary intake of carotenoids. These findings for ancient wheat varieties are considered to be very useful in breeding programs for selecting and breeding wheat varieties for higher concentration and better composition of health-beneficial phytochemicals.

Effects of Transglutaminase Enzyme on Fundamental Rheological Properties of Sound and Bug-Damaged Wheat Flour Doughs

ABSTRACT Transglutaminase (TG) catalyzes the formation of nondisulfide covalent crosslinks between peptide-bound glutaminyl residues and e-amino groups of lysine residues in proteins. Crosslinks among wheat gluten proteins by TG are of particular interest because of their high glutamine content. Depolymerization of wheat gluten proteins by proteolytic enzymes associated with bug damage causes rapid deterioration of dough properties and bread quality. The aim of the present study was to investigate the possibility of using TG to regain gluten strength adversely affected by wheat bug proteases. A heavily bug-damaged (Eurygaster spp.) wheat flour was blended with sound cv. Augusta or cv. Sharpshooter flours. Dynamic rheological measurements, involving a frequency sweep at a fixed shear stress, were performed after 0, 30, and 60 min of incubation on doughs made from sound or blended flour samples. The complex moduli (G* values) of Augusta and Sharpshooter doughs blended with 10% bug-damaged flour decreased si...

Potential utilization of Mixolab for quality evaluation of bread wheat genotypes.

ABSTRACT The aim of this study was to determine the possibility of using Mixolab to assess the quality of different wheat genotypes. Mixolab data were compared with various flour quality characteristics and bread volume. The samples were chosen to represent a wide range in terms of grain and rheological properties and baking quality. There are eight paramaters used to evaluate a Mixolab curve. C1 and C2 are related to protein quality, whereas C3, C4 and C5 are related to the starch characteristics. Slopes α, β, γ are the indicators of protein weakening, starching speed, and enzymatic degradation. There were significant correlations between two Mixolab parameters (Stability and C2) and Zeleny sedimentation and Alveograph W values (P < 0.01). Some of the Mixolab parameters (C3, C4, C5) were correlated with Alveograph G and P/L value (P < 0.01). Mixolab values are generally in agreement with Farinograph values. There were significant negative correlations between most of the Mixolab parameters (Stability, C2...

Effects of Wheat Bug (Eurygaster maura) Protease on Glutenin Proteins

ABSTRACT Proteolytic degradation of 50% 1-propanol insoluble (50PI) glutenin of six common wheat cultivars by wheat bug (Eurygaster maura) protease was investigated using reversed-phase HPLC. Wheat at the milk-ripe stage was manually infested with adult bugs. After harvest, bug-damaged kernels were blended (2:1, kernel basis) with undamaged grain of the same cultivar. Samples of ground wheat were incubated in distilled water for different times (0, 30, 60, and 120 min). The incubated whole meal samples were subsequently freeze-dried and stored until analysis. The degree of proteolytic degradation of 50PI glutenin was determined based on the quantity of total glutenin subunits (GS), high molecular weight GS (HMW-GS), and low molecular weight GS (LMW-GS). For ground wheat samples incubated for ≥30 min, 50PI glutenin was substantially degraded as evidenced by a >80% decrease on average in total GS, HMW-GS, and LMW-GS. Some cultivars showed different patterns of glutenin proteolysis as revealed by differences...

Properties and composition of Turkish flat bread (bazlama) supplemented with barley flour and wheat bran

ABSTRACT In this study, effects of increasing levels of wheat bran and barley flour on dough properties and bazlama quality were investigated. Bazlama is a flat bread commonly consumed in Turkey. Flours of wheat cultivars Gun and Gerek, flour of barley cultivar Tokak, and Gerek bran mixture were used. Part of the wheat flours were replaced with barley flour at 10, 20, 30, and 40% levels and Gerek bran mixture at 5, 10, 15, and 20% levels. Farinogram properties of mixtures were determined. Bazlama samples were subjected to sensory analysis for external appearance, shape and symmetry, crust color, crumb color and structure, mouthfeel, taste and aroma. Increasing levels of bran and barley flour caused decreases in all sensory properties. The deteriorative effect of barley flour on bazlama properties was generally more obvious when compared to bran supplementation. However, all bazlama samples were considered acceptable. Penetrometer values of bazlama samples showed that increasing levels of barley flour crea...

Dissipation of organophosphorus pesticides in wheat during pasta processing

For investigating the carryover of some organophosphorus pesticide residues in the cereal food chain from grain to consumer, a study was set up on durum wheat, semolina and pasta. Pesticide-free durum wheat was placed into a small-scale model of a commercial storage vessel and treated with pesticides (malathion, fenitrothion, chlorpyrifos methyl, and pirimiphos methyl) according to the raw material legislation of Turkey. The residue levels of insecticides were determined in wheat, semolina, and spaghetti produced from stored wheat at various time intervals during five months of storage. A multiresidue analysis was performed using GC equipped with an NPD. The confirmation was performed by GC-MS. The residue levels of insecticides in wheat exceeded the maximum residue limits (MRLs) for wheat. The storage period was generally not effective enough to reduce the residues in wheat to levels below the MRLs. Although a considerable amount of the insecticides remained in the semolina, spaghetti processing significantly reduced residue concentrations in general. Pirimiphos methyl was the most persistent of the insecticides and comparatively less substantial loss occurred during milling and spaghetti processing due to its physicochemical properties.

Farinograph properties and bread quality of flours supplemented with resistant starch

Three different commercial starches (Hylon VII, Novelose 330 and CrystaLean) were incorporated into the bread formulation at different levels and their effects on the rheological and baking properties and resistant starch contents of breads were evaluated. Starch-supplemented doughs were weaker and absorbed more water than those of the base flour. Loaf volumes of the breads decreased above the 10% level for Novelose and above the 20% level for Hylon VII and CrystaLean supplementation. Commercial starches did not have a substantial deteriorative effect on crumb color, external appearance and symmetry of breads. Crust color values decreased at a 30% addition level in Novelose-supplemented and CrystaLean-supplemented breads and above a 10% addition level in Hylon VII-supplemented breads. Firmness of breads increased above the 10% level for Novelose and above the 20% level for Hylon VII and CrystaLean supplementation. Resistant starch contents of the breads (after 1 and 7 days storage) increased significantly as the addition level of commercial starches increased.

Effects of gamma-irradiation of wheat on gluten proteins

Abstract The effects of 60Co gamma-irradiation treatments (2·5, 5·0, 10·0 and 20·0 kGy) on the gluten proteins of two bread wheats and one durum wheat cultivar were investigated. Dough rheological properties of the flour processed from the irradiated wheat were also determined using a computerised micromixograph. Irradiation caused a significant deteriorating effect on all mixogram parameters. There was no observable effect of irradiation on gliadin proteins analysed by polyacrylamide gel electrophoresis. The 50% 1-propanol-insoluble (50 PI) glutenin fraction was highly affected by irradiation. By sodium dodecyl sulfate polyacrylamide gel electrophoresis, reduced 50 PI glutenin showed a noticeable reduction in band intensities of both high (HMW) and low molecular weight (LMW) glutenin subunits (GS) with increasing irradiation dosage greater than 5 kGy. The irradiation effect on 50 PI glutenin was further studied and quantified by reversed-phase high-performance liquid chromatography of glutenin subunits; there was a progressive decrease in the quantity of subunits with increasing irradiation dose level. Compared to non-irradiated wheat, the relative decline in total insoluble glutenin at the 20 kGy dosage level ranged from 34–49% depending on cultivar. Increasing levels of irradiation also progressively reduced the ratio of HMW:LMW-GS up to 13–15% at 20 kGy indicating that irradiation had a greater effect on the largest polymers of glutenin. The observed weakening of dough mixing properties and concomitant decline in the quantity of 50 PI glutenin with increasing levels of gamma-irradiation are consistent with a degradation of glutenin to a lower average molecular size by depolymerisation and/or disaggregation.

Comparison of physical properties of raw and roasted chickpeas (leblebi)

Abstract Physical properties of raw and roasted chickpeas (leblebi) were examined as a basis for evaluating the changes in structure and color that occur during leblebi production. Scanning electron microscopy (SEM) revealed that substantial structural changes occurred during processing. The raw chickpea was tightly packed while processing substantially increased the porosity of the chickpeas. The density measurement confirmed the SEM results. There were significant differences in the stiffness values of raw and roasted chickpea samples. The majority of the starch granules in the roasted chickpea sample retained strong birefringence. The roasted chickpea sample had a DSC endotherm at around 65°C comparable in size to that in raw chickpea, indicating that starch was not gelatinized during processing. Although there were slight differences in the X-ray diffraction patterns of the raw and roasted chickpea samples, they were both Ca type. The roasted chickpeas had lower L and higher a + and b + values compared to that of raw chickpeas. ©