Development of gluten-free fresh egg pasta analogues containing buckwheat

To improve the use of common buckwheat (Fagopyrum esculentum), characterized by interesting nutritional properties, it could be used in pasta formulations. In particular, as buckwheat is devoid of the gluten-forming proteins, it might be an ingredient for celiac patient food. The aim of this study was to develop both fresh egg pastas integrated with buckwheat and fresh egg pasta analogues classifiable as gluten-free, based on buckwheat and rice flours. Matter loss in the cooking water and weight increase during cooking of buckwheat pasta were higher than those of a reference sample made of common wheat flour. As buckwheat integration increased, sample break strain was significantly lower, as a result of the progressive reduction in gluten content. In the production of gluten-free pasta analogues, wheat flour was substituted with rice flour, precooked rice flour or pregelatinized rice starch. Since samples containing precooked rice flour gave the best results, in terms of workability, break strain and weight increase during cooking, they were also produced on an industrial scale. Industrial gluten-free fresh egg pasta analogues were tougher and less deformable in comparison with the laboratory-produced samples. These results were determined by the presence of the double thermal pasteurisation treatment, which allows to obtain a better structure of the product, showing also a lower matter loss during cooking.     

Gluten-free pasta production from banana and cassava flours with egg white protein and soy protein addition

Egg white protein and soy protein were incorporated into a banana and cassava flour blend (75:25) to produce gluten-free pasta. The objectives of study were to investigate the effects of the different protein sources on the physico-chemical properties of gluten-free pasta. The levels of protein inclusion were 0%, 5%, 10% and 15% of composite flour (w/w) for each type of protein. Pasta made from 100% durum wheat semolina was used as controls. The protein fortification affected the total starch, resistant starch and protein content of gluten-free pasta compared to semolina pasta. No significant effects of soy/egg white protein addition were found in either insoluble or soluble dietary fibre content. Cooking properties of pasta (optimum cooking time, swelling index, water adsorption index and cooking loss) and texture properties (firmness and extensibility) were affected by the level of protein addition and the type of protein. Results showed the utilisation of 25% cassava flour and protein inclusion have a promising application in gluten-free pasta production.     

Effect of semolina replacement with a raw:popped amaranth flour blend on cooking quality and texture of pasta

The replacement of semolina (SEM) with raw:popped (90:10) amaranth flour blend (AFB) in pasta making at 25, 50, 75, and 100 g/100 g levels (flour basis, 14 g of water/100 g) was carried out to evaluate the effects on cooking quality and texture of the supplemented pasta samples. Significant differences on cooking quality characteristics and texture of the pasta samples were observed. The pasta solid loss increased, weight gain and firmness decreased as the AFB level increased. The semolina pasta showed the lowest solid loss (7 g/100 g) and the highest weight gain (188.3 g/100 g) and firmness (1.49 N), whereas the amaranth blend pasta was the softer (around half of the firmness of semolina pasta) and lost the higher amount of solids (11.5 g/100 g). The raw and popped AFB was suitable for increasing the nutritional quality through dietary fiber and high quality protein and even to obtain gluten-free pasta with acceptable cooking quality (solid loss of 3.5 g/100 g higher than that considered as acceptable for semolina pasta). The amaranth blend used in this study enables the partial or total replacement of wheat semolina in pastas with acceptable cooking quality and texture.     

Optimisation of resistant starch II and III levels in durum wheat pasta to reduce in vitro digestibility while maintaining processing and sensory characteristics

Foods with elevated levels of resistant starch (RS) may have beneficial effects on human health. Pasta was enriched with commercial resistant starches (RSII, Hi Maize™ 1043; RSIII, Novelose 330™) at 10%, 20% and 50% substitution of semolina for RSII and 10% and 20% for RSIII and compared with pasta made from 100% durum wheat semolina to investigate technological, sensory, in vitro starch digestibility and structural properties. The resultant RS content of pasta increased from 1.9% to ∼21% and was not reduced on cooking. Significantly, the results indicate that 10% and 20% RSII and RSIII substitution of semolina had no significant effects on pasta cooking loss, texture and sensory properties, with only a minimal reduction in pasta yellowness. Both RS types lowered the extent of in vitro starch hydrolysis compared to that of control pasta. X-ray diffraction and small-angle scattering verified the incorporation of RS and, compared to the control sample, identified enhanced crystallinity and a changed molecular arrangement following digestion. These results can be contrasted with the negative impact on pasta resulting from substitution with equivalent amounts of more traditional dietary fibre such as bran. The study suggests that these RS-containing formulations may be ideal sources for the preparation of pasta with reduced starch digestibility.     

Effect of semolina and absorption level on extrusion of spaghetti containing non‐traditional ingredients

Specific mechanical energy (SME), mechanical energy, extrusion rate and temperature of extruded spaghetti were monitored to determine the effects of semolina, hydration level and non‐traditional ingredients on pasta extrusion using a semi‐commercial pasta press with a fixed screw speed of 25 rpm. SME transferred to the dough during extrusion and the temperature of extruded spaghetti were greater with strong than with weak gluten semolina and at low than at high absorption levels. When compared with semolina hydrated to 300 g kg^?1 absorption, SME transferred to the dough was 13 kJ kg^?1 lower for semolina mixed with buckwheat (Fagopyrum esculentum Moench.) bran flour, 47 kJ kg^?1 lower for semolina mixed with flaxseed (Linum usitativissimum L.) flour and 7 kJ kg^?1 lower for semolina mixed with wheat (Triticum turgidum var. durum L.) bran. Weak gluten semolina, high absorption levels and non‐traditional ingredients reduced the mechanical energy required for extrusion more than they reduced extrusion rate. The target temperature for extruded spaghetti was 45 °C. The temperature of extruded spaghetti containing flaxseed flour was below 45 °C whereas the temperature of spaghetti containing wheat bran was above 45 °C, regardless of semolina type or absorption level. Copyright © 2006 Society of Chemical Industry     

Quality characteristics of dried pasta enriched with buckwheat flour

The addition of pseudocereal flours to semolina is becoming more and more popular to improve the nutritional quality of the resultant pasta. The aim of this study was the evaluation of several properties of commercial pasta made from a mixture of buckwheat flour and durum wheat semolina. The characterisation of products, belonging to different producers, focused on the evaluation of chemical and physical properties, such as water uptake and mechanical properties before and after cooking and surface characteristics. A sensory analysis was also performed in order to evaluate firmness, resistance to breaking and overall acceptability. The results highlighted high heterogeneity of the mechanical properties, solid loss and water absorption among the samples. The great variability could be explained by the different processing conditions adopted by each producer, particularly by the procedure used to form and shape the dough into the final product.     

Influence of commodity on the population growth of the larger grain borer,Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae)

In this study, we compared different amylaceous commodities for their suitability for population growth of the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae), which is an important pest of stored maize in the tropics. In this context, we conducted three different series of tests. In the first test, we compared whole grains: whole barley, peeled barley, maize, whole oats, peeled oats, peeled rice, rough rice, rye, triticale, and wheat. Only maize was found suitable for P. trunctatus to reproduce and significantly increase its population, but there were certain commodities where surviving adults were found. In the second series of tests, we evaluated the percentage of cracked maize kernels on P. truncatus population growth. In this test, we found that the numbers of alive P. truncatus adults in the vials that contained 100% cracked kernels was higher than these with lower percentages of cracked kernels (5–50%) or no cracked kernels (0%). Finally, in the third series of tests, we compared eleven different types of amylaceous commodities with maize. These commodities were: whole maize (whole kernels), whole oat flakes, maize flour, whole barley flour, pasta, white soft wheat flour, whole soft wheat flour, white hard wheat flour, whole hard wheat flour, whole rye flour, and semolina. The results indicated that only whole maize and maize flour were suitable for P. truncatus population growth. Nevertheless, in some of the other commodities tested, there was a low number of adults and immatures that were able to survive 60 days after the incorporation of the parental adults. The results of the present study indicate that from the commodity range tested here, only maize was suitable for P. truncatus population growth. Nevertheless, the marginal numbers of surviving individuals in the non-maize commodities and the role of these substrates as potential “non-preferred food vehicles” that may contribute to further spread of this species should be tested in more detail.     

Gluten contamination of cereal foods in Canada

Persons suffering from celiac disease (CD) must avoid foods containing gluten or those contaminated with wheat, barley, or rye. This study was designed to estimate gluten contamination of cereal-based foods available in Canada, whether labelled gluten-free or not. About half of the 148 foods sampled were labelled as gluten-free. According to R5-enzyme-linked immunosorbent assay (ELISA), twenty-three cereal-based foods (or 15%) contained more than 20 mg of gluten per kg, including sixteen regular and seven gluten-free foods, the latter being the least contaminated. When used in combination with R5-ELISA, AOAC-ELISA (not detecting barley) was a simple and efficient tool to roughly estimate the nature of the gluten contamination, which was later confirmed by real-time polymerase chain reaction for barley, and wheat/barley/rice. Rice-, corn- or quinoa-based foods were the safest for celiac patients. In addition to misleading food labelling for both gluten-rich and gluten-free foods, critical issues for persons with CD included foods made with oats or buckwheat (contaminated with wheat and barley gluten) in addition to those, such as breakfast cereals, specifically enriched with barley malt ingredients.     

Chemical,biological and sensory evaluation of pasta products supplemented with α‐galactoside‐free lupin flours

α‐Galactoside‐free lupin flour has been used to supplement durum wheat semolina flour in order to increase the nutritive value of pasta products. Supplemented pasta products had a shorter cooking time, higher cooking water absorption, cooking loss and protein loss in water than control pasta prepared with only semolina. Sensory evaluation of cooked pastas showed that products supplemented with 80 g kg^?1 of α‐galactoside‐free Lupinus angustifolius var. Emir flour or with 100 g kg^?1 of α‐galactoside‐free Lupinus angustifolius var. Troll flour showed the same acceptability by panellists as the semolina pasta. These levels of supplementation were selected for further studies. The cooked α‐galactoside‐free lupin/semolina pastas showed higher amounts of protein, dietary fibre, calcium, phosphorus, magnesium, zinc and antioxidant capacity than control pasta and a reasonable level of vitamin B₁, vitamin B₂ and vitamin E. Biological assessment of cooked pastas indicated that the true protein digestibility did not change after the fortification of semolina but protein efficiency ratio increased sharply in the pasta supplemented with α‐galactoside‐free lupin flours (2.07 and 1.92 for Emir and Troll lupin varieties, respectively) in comparison with the control pasta (1.11). It is concluded that the α‐galactoside‐free lupin flours are an adequate ingredient to improve the nutritional quality of pasta products without adding flatulent oligosaccharides. Copyright © 2006 Society of Chemical Industry     

Is the calculation of the gluten content by multiplying the prolamin content by a factor of 2 valid?

Presently, the only essential therapy of celiac disease (CD) is the permanent strict withdrawal of gluten from the diet. With respect to gluten containing foods from wheat, rye, barley, and oats, CD patients have to consume surrogates that must be gluten-free according to the “Codex Alimentarius Standard for Gluten-Free Foods”. The recent “Draft Revised Standard” proposes a gluten threshold of 20 mg per kg gluten-free product. For gluten quantitation, the alcohol-soluble prolamins should be extracted and analyzed by an immunochemical method; the amount of gluten is calculated by multiplying the prolamin content by the factor of 2. To investigate, whether this calculation is valid in any case of contamination of gluten-free products by wheat, rye, barley, and oats, wholemeal or white flours from common wheat, spelt, durum wheat, kamut, emmer, einkorn, rye, barley and oats were analyzed for the ratio of prolamins to glutenins (PROL/GLUT) by a combination of extraction and reversed-phase HPLC procedures. Additionally, different industrial wheat starches were analyzed for their prolamin and total gluten content using different extraction and concentration steps followed by gel permeation HPLC. The results for the cereal flours revealed that the ratio PROL/GLUT was generally higher than 1.0 as proposed by the “Draft Revised Standard” and strongly influenced by cereal species and variety. Common wheat showed the lowest ratio (1.5–3.1), followed by oats and spelt (1.7–3.3), barley (1.4–5.0), durum wheat and kamut (3.1–3.4), emmer (3.5–7.6), rye (6.3–8.2), and einkorn (4.0–13.9). In any case, the gluten content of gluten-free products contaminated with CD activating cereals was generally overestimated, when the prolamin content was multiplied by the factor of 2. In extreme cases, e.g., contamination with rye, the overestimation amounted to 72–79%. Completely different PROL/GLUT ratios were found in ten commercial wheat starches ranging from 0.2 to 4.9. Obviously, the quality of wheat cultivars used for starch production and/or different process parameters, e.g., washing steps, influenced the composition of gluten proteins adherent to starch granules. For wheat starch, the calculation of the gluten content by 2 × PROL may either lead to underestimation (−71% at most) or overestimation (+66% at most). In conclusion, this calculation is invalid; therefore, a future task will be the development of immunoassays with antibodies against all types of storage proteins from wheat, rye, barley, and oats.     

Evolution of porosity, shrinkage and density of pasta fortified with pea protein concentrate during drying

The aim of this work was to study the impact of fortification with commercial pea protein concentrate on the evolution of the moisture content, density, shrinkage and porosity of pasta made from durum wheat semolina during drying. Pasta were processed from durum wheat semolina enriched with pea protein concentrate at 0, 5, 10 and 15 g 100-g-dry matter⁻¹ and dried at low (40 °C) and high (80 °C) temperature. Moisture content, density, shrinkage and porosity and effective moisture diffusivity coefficients were linked through theoretical development. It enabled to study the behaviour of the properties as a function of drying time. The results showed that drying temperature has a greater effect on the studied properties than enrichment with pea protein concentrate. Drying at 80 °C increased radial and total shrinkage compared to drying at 40 °C, but no differences were observed for longitudinal shrinkage. Pasta dried at 80 °C were denser and overall less porous, but had greater internal porosity. The volumetric percentage of water lost during drying replaced by air within the pasta matrix was lower at 80 °C. Scanning electron microscopy analysis showed that the gluten network of pasta dried at 80 °C seems denser and more continuous. Effective moisture diffusivity coefficients of pasta dried at 80 °C were higher at 5 and 10 g 100-g-dry matter⁻¹ enrichment level compared to the control.     

Developmental and reproductive biology of Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) on seven commodities

This study examines the effect of semolina, cracked wheat, maize flour, cracked maize, whole oat flakes, whole barley flour and cracked barley on the developmental and reproductive biology of the saw-toothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae). The pest completed its development at all tested commodities except semolina and cracked wheat, while females did not produce eggs on maize flour and cracked barley. The developmental time of larvae was significantly longer when O. surinamensis fed on whole oat flakes (20.3 days) and whole barley flour (19.2 days) compared with maize flour (16.6 days) or cracked maize (17.2 days). The developmental duration of larvae fed on cracked barley (18.3 days) did not differ significantly when fed on cracked maize or whole barley flour, but it was significantly longer compared to maize flour and significantly shorter compared to whole oat flakes. The tested commodities did not affect the pupal development, which ranged between 4.6 and 4.7 days. The highest fecundity was recorded when O. surinamensis fed on cracked maize (4.8 eggs/female) and whole oat flakes (0.3 eggs/female). The tested commodities also affected the risk of death of O. surinamensis and its mean survival time. The shortest survival time was recorded on cracked wheat (11.1 days) while the longest was on cracked maize and whole oat flakes (37.8 and 42.2 days, respectively). The calculation of demographic parameters was feasible only on cracked maize. The net reproductive rate, the intrinsic rate of increase, the finite rate of increase and the mean generation time were 1.48 females/female, 0.01 females/female/day, 1.01 and 37.1 days, respectively. These results may be useful for improving the knowledge on the biology of this species and its potential spread.     

Phenolic profile and carbohydrate digestibility of durum spaghetti enriched with buckwheat flour and bran

The potential of common buckwheat flour (Supreme) and bran (Farinetta) in improving upon the phenolic and antioxidant properties of durum spaghetti was investigated. The cooking quality and carbohydrate digestibility of products were also studied. Significantly large increments of between 114 and 522% for total phenolic content (TPC), 50 and 242% for total flavonoids content (TFC), and over 359% for 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity were recorded for uncooked experimental spaghetti samples over the control. Farinetta contributed more phenolic and antioxidant compounds than Supreme flour. Processing and cooking resulted in decreases in phenolic content and antioxidant activity. Cooking losses of up to 8.8% were recorded for the experimental samples and were higher in Farinetta-substituted products. These were generally higher than that of the control (6.3%). The introduction of buckwheat increased carbohydrate digestibility of products, but at the same time, resulted in an overall lower amount of reducing sugars after 120 min of in vitro hydrolysis. Results show that the phenolic and antioxidant properties of durum spaghetti fortified with buckwheat milling fractions can compare favourably with those of 100% whole buckwheat soba pasta, and at the same time, maintain a higher cooking quality due to the presence of semolina.     

How the inclusion of mushroom powder can affect the physicochemical characteristics of pasta

In this study, a partial substitution of durum wheat semolina with three different species of mushrooms (white button, shitake and porcini) was undertaken to increase the nutritional value of the pasta. The cooking properties and textural characteristics of the pasta produced were also determined. The results showed that the addition of mushroom powder increased the cooking loss, as well as firmness and resistance of the uniaxial tension of the pasta. Porcini mushroom incorporation significantly decreased the swelling index, water absorption index and moisture content values of the cooked pasta, while, for the white button and shiitake mushrooms, there was no noticeable effect on either index compared with the control sample (containing exclusively durum wheat semolina). The addition of shiitake mushroom powder resulted in pasta with the highest firmness and tensile strength.     

Effect of Pleurotus eryngii Mushroom β‐Glucan on Quality Characteristics of Common Wheat Pasta

The objective of this study was to evaluate the effect of β‐glucan‐rich fractions (BGRFs) from Pleurotus eryngii mushroom powder on the quality, textural properties, and sensory evaluation of common wheat pasta. Pasta was prepared from semolina flour and common wheat flour by replacing common wheat flour at 2%, 4%, and 6% with BGRFs. Semolina flour showed significantly higher viscosities than common wheat flour samples. However, all viscosities, except the breakdown viscosity, were reduced with increasing percentages of BGRFs. Replacement of the common wheat flour with BGRFs resulted in a reddish brown colored pasta with a lower L* value and a higher a* value. The common wheat pastas containing up to 4% BGRFs were not significantly different from semolina pasta with regard to cooking loss. Addition of up to 2% BGRFs had no significant impact on swelling index and water absorption. The addition of BGRFs in common wheat flour had a positive effect on the quality of common wheat pasta and resulted in hardness values similar to those of semolina pasta. In a sensory evaluation, cooked pasta with 2% BGRFs had the highest overall acceptability score. In summary, the results showed that common wheat flour containing 4% BGRFs could be used to produce pasta with an improved quality and texture properties similar to semolina pasta.     

Germinated Cajanus cajan seeds as ingredients in pasta products: Chemical,biological and sensory evaluation

Pigeon peas (Cajanus cajan) seeds were germinated for 4 days at 20 °C in darkness in order to improve the nutritional quality of seeds. Germination brought about a sharp reduction of α-galactosides, phytic acid and trypsin inhibitor activity (83%, 61% and 36%, respectively) and an increment of vitamin B₂ (145%), vitamin C (from negligible amounts to 14 mg/100 g d.m.), vitamin E (108%) and total antioxidant capacity (28%). These flours were used as ingredients to produce pasta products in a proportion of 5%, 8% and 10%. The supplemented pasta products had shorter cooking time and higher water absorption, cooking and protein losses in water than had control pasta (100% semolina). From sensory evaluation, fortified pasta generally had acceptability similar to control pasta. Cooked pasta with the highest level of substitution (semolina:germinated pigeon pea flour at 10%) was chemically and biologically evaluated and results showed that protein, fat, dietary fibre and mineral contents were improved. Fortified pasta provided more vitamin B₁, B₂, E and antioxidant capacity than did control pasta. Biological assessment of fortified, cooked pasta indicated that true TD and PER value increased by 12% and 64%, respectively, in comparison with control. The germinated pigeon pea flour can be an excellent ingredient to increase the nutritional value of semolina pasta without affecting the sensory properties.     

Quality assessment of gluten-free crackers based on buckwheat flour

Formulation and characterization of new products - gluten-free crackers based on two types of buckwheat flour (refined and wholegrain) are presented in this study. Their proximate composition, content of main antioxidant compounds (polyphenols and tocopherols), antioxidant activity (radical scavenging activity on 1,1-diphenyl-2-picrylhydrazyl radicals - DPPH) and sensory quality were analyzed and compared with those of wheat crackers made from refined and wholegrain wheat flours.Protocatechuic acid and ferulic acid were quantified in buckwheat and wheat crackers, while two flavonoids, rutin and quercetin, were quantified only in buckwheat crackers. Content of total phenolics and tocopherols was significantly higher (P < 0.05) in buckwheat crackers in comparison to wheat crackers. Tocopherols in crackers were present in the following order: α- ? γ- > δ-tocopherol. Buckwheat crackers exhibited significantly higher (P < 0.05) radical scavenging activity on DPPH according to their IC₅₀ values.No significant differences were observed in sensory quality of wholegrain buckwheat crackers in comparison to wheat ones. Crackers made from buckwheat flours can broaden the utilization of buckwheat, increase supply of gluten-free products on the market and may be regarded as health-promoting functional foods, especially for celiac disease patients.     

Population growth of the khapra beetle,Trogoderma granarium Everts (Coleoptera: Dermestidae) on different commodities

We evaluated the population growth of the khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae) on different grains, cracked wheat containment categories and amylaceous materials by conducting three series of laboratory bioassays. In the first series, peeled barley, whole (raw) barley, peeled oats, whole (raw) oats, peeled rice, rough rice, rye, triticale and hard wheat were tested. In the second series, six cracked wheat containment categories were tested: wheat containing intact kernels only (0% cracked kernels), wheat containing 5% cracked kernels and 95% intact kernels, wheat containing 10% cracked kernels and 90% intact kernels, wheat containing 25% cracked kernels and 75% intact kernels, wheat containing 50% cracked kernels and 50% intact kernels and wheat containing 100% cracked kernels. In the third series, the following amylaceous commodities were tested: hard wheat (intact kernels), whole oat flakes, maize flour, whole barley flour, pasta, white soft wheat flour, whole soft wheat flour, white hard wheat flour, whole hard wheat flour, whole rye flour and semolina. Significantly more dead adults were found on wheat than on peeled barley, maize, whole oats, rough rice and rye. Significantly more larvae alive were found on wheat and triticale, than on the other grains, with the exception of oats, both whole and peeled. The increase of the percentage of cracked wheat kernels increased population growth, except in the case of 10% cracked wheat kernels. In vials that contained 100% cracked wheat kernels, 584.1 individuals per vial were found, which was 3.7 times more than the respective number of larvae alive in vials with intact wheat kernels only. Significantly more dead adults were found on whole barley flour than on the other commodities. More than 1213 larvae per vial were recorded on whole barley flour, which was 1.3–15 times higher than the other commodities. The lowest number of larvae alive was found on pasta, followed by the white soft wheat flour. The findings of the present work show that some commodities are more prone to spread T. granarium than others, a fact which should be seriously taken into account in international trade of grains and related amylaceous products.     

Varied Composition of Tocochromanols in Different Types of Bran: Rye,Wheat, Oat,Spelt, Buckwheat,Corn, and Rice

The profiles of tocopherol (T) and tocotrienol (T3) homologues in 37 samples of seven different types of bran (rye, wheat, oat, spelt, buckwheat, rice, and corn), available on the Polish market, were studied. Tocochromanols were identified and quantified by reverse phase-high-performance liquid chromatograph/fluorescence detector and reverse phase-ultra performance liquid chromatography-electrospray ionization/mass spectrometry. Only rice bran contained all eight tocochromanol types. Corn bran lacked β-T3; rye, wheat, oat, and spelt bran lacked γ-T3 and δ-T3; and buckwheat bran lacked β-T3, γ-T3, and δ-T3. In buckwheat and corn bran tocopherols predominated (98 and 78%, respectively); whereas rye, wheat, oat, spelt, and rice bran were rich in tocotrienols (78, 76, 66, 87, and 66%, respectively). The average total tocochromanol contents in the oat, corn, spelt, buckwheat, wheat, rye, and rice bran were 5.5, 16.2, 15.8, 14.7, 12.8, 10.7, and 9.1 mg/100 g of dry weight, respectively. Tocochromanol concentrations in samples of the same type bran from different sources varied considerably. Better labeling of bran products to reflect this variation would assist with control of vitamin E daily dietary requirements.     

Microstructure and water distribution of commercial pasta studied by microscopy and 3D magnetic resonance imaging

Manufacturing pasta is a rather well known process, but it is still challenging to tailor pasta products with new raw materials. In this study, we evaluated the effects of raw materials on the microstructure and water distribution in cooked pasta using ¹H magnetic resonance imaging (MRI) as well as bright field and polarized light microscopy. The MRI parameters initial intensity (I₀) and transverse dephasing time (T₂^⁎) serve as indicators of the local water concentration and water–macromolecule interactions through chemical exchange, respectively. These parameters were mapped throughout the whole pasta volume with a spatial resolution of 78 μm in all three dimensions. MRI was combined with light microscopy to link I₀ and T₂^⁎ to microstructure components such as fiber particles and the extent of starch gelatinization. Four commercial spaghetti samples were analyzed which were made of durum wheat flour, both plain and enriched with wheat fiber, as well as with wholegrain and soft wheat flour. Although all pasta samples showed similar macroscopic water absorption as measured by weight increase, the sample structures differed at the microscopic scale. Compared to durum wheat spaghetti, the presence of fiber particles decreased T₂^⁎, while spaghetti enriched with soft wheat flour increased T₂^⁎. In addition, light microscopy showed that large fiber particles partly acted as barriers against water migration and protected starch granules from swelling. Smaller wheat fiber particles did not affect local starch swelling. Thus, the combination of light microscopy and MRI is a powerful tool to study the microstructure and water distribution in pasta.