| 1. |
- Börjesson, T., et al.
(författare)
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Adsorption of volatile fungal metabolites to wheat grains and subsequent desorption
- 1994
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Ingår i: Cereal Chemistry. - : American Association of Cereal Chemists. - 0009-0352 .- 1943-3638. ; 71:1, s. 16-20
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Tidskriftsartikel (refereegranskat)abstract
- Adsorption of the volatile fungal metabolites 2-methylfuran, 3-methyl-1-butanol, and 1-octen-3-ol to wheat grains, and their subsequent desorption, were investigated. Adsorption was performed both dynamically and statically. In the dynamic system, volatile compounds in a N2 flow were led through 400 g of wheat in a glass column. In the static system, 400 g of wheat was stored in an airtight glass vessel containing the volatile compounds in the atmosphere. Three desorption procedures were compared: an N2 flow at 20-degrees-C, an N2 flow at 50-degrees-C, and extraction with supercritical CO2. 3-Methyl-1-butanol and 1-octen-3-ol were efficiently adsorbed and could also readily be desorbed to considerably higher extents at 50-degrees-C than at 20-degrees-C. The supercritical CO2 extraction was more efficient than N2 desorption in extracting volatile compounds, but because of the smaller sample sizes (1 g), the amounts extracted per gram of grain were lower than the amounts extracted with N2 desorption at 50-degrees-C. The adsorbed amount of each volatile compound was calculated as the difference between content in the N2 stream before passage through the wheat and its content after passage. Desorption by means of a N2 stream led to the recovery of about 5% of 2-methylfuran, 35% of 3-methyl-1-butanol, and 100% of 1-octen-3-ol.
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| 2. |
- Börjesson, T., et al.
(författare)
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Electronic nose for odor classification of grains
- 1996
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Ingår i: Cereal Chemistry. - : American Association of Cereal Chemists. - 0009-0352 .- 1943-3638. ; 73:4, s. 457-461
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Tidskriftsartikel (refereegranskat)abstract
- An electronic nose was used to classify grain samples based on their smell and to predict the degree of moldy/musty odor. A total of 235 samples of wheat, barley and oats, which had been odor classified by at least two grain inspectors, were used. Headspace samples from heated grain were pumped through chambers containing metal oxide semiconductor field effect transistor (MOSFET) sensors, SnO2 semiconductors and an infrared detector monitoring CO2. The sensor signals were evaluated with a pattern-recognition software program based on artificial neural networks. The samples were divided into either the four classes moldy/musty, acid/sour, burnt, or normal or the two classes good and bad according to the inspectors descriptions. They were also assigned a score describing their intensity of moldy/musty odor. The electronic nose correctly classified approximate to 75% of the samples when using the four-class system and approximate to 90% when using the two-class system. These values exceeded the corresponding percentages of agreement between two grain inspectors classifying the grain.
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| 3. |
- Börjesson, T., et al.
(författare)
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Near-infrared spectroscopy for estimation of ergosterol content in barley : A comparison between reflectance and transmittance techniques
- 2007
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Ingår i: Cereal Chemistry. - St. Paul, USA : AACC International. - 0009-0352 .- 1943-3638. ; 84:3, s. 231-236
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Tidskriftsartikel (refereegranskat)abstract
- The fungal-specific lipid ergosterol correlates with fungal biomass and often also with the degree of mycotoxin contamination of cereals. We compared the ability of a near-infrared reflectance (NIR) instrument with a broad wavelength range (400-2500 nm) and a near-infrared transmittance (NIT) instrument with a narrower wavelength range (850-1050 nm) to predict the ergosterol content of naturally infected barley samples. The two instruments were equally good at predicting ergosterol content in Swedish samples (r(2) = 0.81 and 0.83 for NIT and NIR, respectively). The NIT instrument was then used for samples from three countries (Sweden, Ireland, UK). This model had about the same root mean-squared error (approximate to 5 mg of ergosterol/kg, db, of grain) as the dataset with only Swedish samples, although the r(2) value was lower (0.58). The investigation has shown that it is possible to predict ergosterol content in whole barley samples using NIR or NIT instrumentation, and acceptable models can be obtained using different barley cultivars and samples from different countries and harvest years. This should make it possible to routinely predict the fungal biomass at grain terminals.
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| 4. |
- Cárdenas-Castro, Alicia P., et al.
(författare)
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Bioaccessibility of phenolic compounds in common beans (Phaseolus vulgaris L.) after in vitro gastrointestinal digestion : A comparison of two cooking procedures
- 2020
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Ingår i: Cereal Chemistry. - : Wiley. - 0009-0352 .- 1943-3638. ; 97:3, s. 670-680
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Tidskriftsartikel (refereegranskat)abstract
- Background and objectives: Beans (Phaseolus vulgaris L.) are widely consumed, but the bioaccessibility of their phenolic compounds (PCs) may be affected by different factors. Within this framework, an in vitro gastrointestinal digestion of two bean varieties: “Azufrado” and “Negro Jamapa,” was performed and the bioaccessibility and in vitro release kinetics of PC was evaluated. Mashed beans were prepared by two common culinary procedures in Mexico: pressure cooking followed by mashing, and pressure cooking and mashing, followed by frying. Findings: The bioaccessibility of PC was about 50% in the cooked samples and 30% in cooked-fried samples. The cooking condition did not modify the PC release kinetics during the first 60 min in any of the bean preparations. Three PCs were identified by HPLC-DAD-MS: kaempferol-3-O-glucoside, quercetin-3-O-glucoside, and chlorogenic acid, which was the main PC released from all samples. Conclusions: Simulated gastrointestinal digestion revealed processing-related differences in the PC bioaccessibility in these two bean varieties, which should be further considered and evaluated in nutritional studies. Significance and novelty: The study is in line with current approaches for assessing PC bioaccessibility during the gastrointestinal digestion, providing knowledge on the types and quantities of PC released from the food matrix of beans as eaten.
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| 5. |
- Johansson, Eva, et al.
(författare)
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Wheat gluten polymer structures : The impact of genotype, environment, and processing on their functionality in various applications
- 2013
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Ingår i: Cereal Chemistry. - 0009-0352 .- 1943-3638. ; 90:4, s. 367-376
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Tidskriftsartikel (refereegranskat)abstract
- For a number of applications, gluten protein polymer structures are of the highest importance in determining end-use properties. The present article focuses on gluten protein structures in the wheat grain, genotype- and environment-related changes, protein structures in various applications, and their impact on quality. Protein structures in mature wheat grain or flour are strongly related to end-use properties, although influenced by genetic and environment interactions. Nitrogen availability during wheat development and genetically determined plant development rhythm are the most important parameters determining the gluten protein polymer structure, although temperature during plant development interacts with the impact of the mentioned parameters. Glutenin subunits are the main proteins incorporated in the gluten protein polymer in extracted wheat flour. During dough mixing, gliadins are also incorporated through disulfide-sulfhydryl exchange reactions. Gluten protein polymer size and complexity in the mature grain and changes during dough formation are important for breadmaking quality. When using the gluten proteins to produce plastics, additional proteins are incorporated in the polymer through disulfide-sulfhydryl exchange, sulfhydryl oxidation, β-eliminations with lanthionine formation, and isopeptide formation. In promising materials, the protein polymer structure is changed toward β-sheet structures of both intermolecular and extended type and a hexagonal close-packed structure is found. Increased understanding of gluten protein polymer structures is extremely important to improve functionality and end-use quality of wheat- and gluten-based products.
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| 6. |
- Mira, Isabel, et al.
(författare)
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Effect of surfactant structure on the pasting properties of wheat flour and starch suspensions
- 2005
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Ingår i: Cereal Chemistry. - 0009-0352 .- 1943-3638. ; 82:1, s. 44-52
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Tidskriftsartikel (refereegranskat)abstract
- Systematic studies were performed on the effect of the surfactant alkyl chain length (10-16 carbon atoms) and the head group charge/structure (anionic, cationic, nonionic) on the pasting properties of wheat flour and starch aqueous suspensions by means of a Rapid Visco Analyser (RVA). An excellent agreement was observed between the effect of surfactants on the onset temperature of the pasting process (PT) and the time to reach peak viscosity (t(peak)) of wheat flour and wheat starch suspensions. Moreover, a correlation was found between the effect of different surfactants on these two parameters. With the exception of the cationic surfactants (alkyl trimethyl ammonium bromides), the effect of surfactants (alkyl sulfates, maltosides, monoglycerides, and sucrose esters) was found to be strongly dependent on the surfactant chain length. Shorter chain surfactants (C10-C12) induced an earlier pasting, while longer chain surfactants (C14-C16) had the opposite effect. The effect of surfactants on PT and t(peak) of flour suspensions was enlarged when the surfactant concentration was increased from approximate to1% to 15% (w/w) on a dry starch basis.
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| 7. |
- Monti, Carlo, et al.
(författare)
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Determining the geographical origin of durum wheat samples by combining strontium isotope ratio and multielemental analyses
- 2023
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Ingår i: Cereal Chemistry. - : John Wiley & Sons. - 0009-0352 .- 1943-3638. ; 100:2, s. 522-531
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Tidskriftsartikel (refereegranskat)abstract
- Background and objectives: Determining the geographical origin of durum wheat is an important and emerging challenge because consumers perceive added value of final products (e.g., pasta) depending on the origin. Declaration of geographical origin is also an emerging requirement of specific national regulations. Among analytical strategies for determining geographical origins of samples, isotopic techniques based on both light and radiogenic isotope targets stand out, despite limitations of applicability, validation and assessment of interyear variability.Findings: In this study, 87Sr/86Sr isotopic analysis was successfully used to discriminate Italian (ITA) samples versus rest-of-the world (RoW) samples and subsequently integrated with an elemental analysis (ICP‒MS) on 75 elements. A tiered approach was finally adopted in which the results of the 87Sr/86Sr analysis were input to a second step of support vector machine classification modeling (SVMC) based on the Al, Mn, Mo, P, S, Ti, Y, and Zn percentages in each sample. This model was tested against a blind group of samples with overall satisfactory performance.Conclusion: Valuable information from multielemental and stable isotope ratio analyses was collected for authentic samples from different Italian, European, and non-European regions harvested during different years.Significance and novelty: This study demonstrates the potential and validity of an innovative combined multielemental and strontium isotope ratio approach for the geographic discrimination of durum wheat on a global scale: the developed predictive model has already been routinely employed to control industrial lots.
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| 8. |
- Regnér, S., et al.
(författare)
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Ergosterol content in relation to grain kernel weight
- 1994
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Ingår i: Cereal Chemistry. - : American Association of Cereal Chemists. - 0009-0352 .- 1943-3638. ; 71:1, s. 55-58
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Tidskriftsartikel (refereegranskat)abstract
- The relation between fungal biomass content and grain kernel weight was investigated in five lots of grain: three wheat, one rye, and one triticale. Fungal biomass was quantified as ergosterol content. Samples were fractionated on the basis of grain kernel weight using an automatic sorter. In all lots, ergosterol concentrations increased as kernel weight decreased. In four of the five lots, the absolute amount of ergosterol per kernel also increased with decreasing kernel weight. Within-cultivar variation in ergosterol levels could not be explained solely by differences in surface-to-volume ratio. Ergosterol concentrations in the impurities (material not classified as whole, sound kernels) were generally several times higher than those in the original lots. Although concentrations of ergosterol were relatively high in small kernels and impurities, removal of these fractions did not significantly influence the average ergosterol levels of the lots, due to the low relative weight of these fractions. Separation during handling of the grain might, however, lead to extreme ergosterol concentrations in certain locations of the storage bins. These locations can serve as potential starting points for mold growth.
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| 9. |
- Richardson, G., et al.
(författare)
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Microstructure of ?-crystalline emulsifiers and their influence on air incorporation in cake batter
- 2002
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Ingår i: Cereal Chemistry. - 0009-0352 .- 1943-3638. ; 79:4, s. 546-552
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Tidskriftsartikel (refereegranskat)abstract
- The microstructure of ?-gel and ?-crystalline emulsifiers and their effects on cake batter foam have been studied with polarized light microscopy, confocal laser scanning microscopy (CLSM) and image analysis, freeze-etching, and transmission electron microscopy (TEM). The emulsifiers Colco and Aroplus, which are commercial ?-gels, and the monoglyceride Dimodan P in its ?-gel and ?-crystalline forms were added to the batter in concentrations of 0.8, 2.0, 3.1, and 4.2%. Dimodan P ?-gel was also prepared with three NaCl concentrations (0.05, 0.67, and 1.35%c). The distribution of air in the foam was evaluated with density measurements and with image analysis of bubbles in optically sectioned batter. In the cake batter, all the ?-gel emulsifiers decreased the density, thereby increasing the incorporation of air, more than the ?-crystalline emulsifier, which did not have any effect on the density. There were noticeable differences in microstructure between the different ?-crystalline emulsifiers. Large, regular ?-structures seemed to increase the batter volume and interfacial area more than smaller aggregates. Adding salt in the emulsifier gel changed the structure, probably into ?-lamellar liposomes, which impaired the aerating effect at lower concentrations.
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| 10. |
- Rutgersson, A., et al.
(författare)
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Influence of hydrothermal treatment on lipid oxidation in barley
- 2000
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Ingår i: Cereal Chemistry. - 0009-0352 .- 1943-3638. ; 77:4, s. 407-413
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Tidskriftsartikel (refereegranskat)abstract
- A steeping process of barley grains was evaluated regarding lipid oxidation. The steeping process was evaluated with respect to the temperature during the first steep and second steep, and the lactic acid concentration of the steep solutions. The study was conducted using a central composition circumscribed design, and response surface models were estimated with the use of partial least square. The change in the concentration of hexanal was used to monitor the oxidation during processing and subsequent storage at 30°C. In all samples there was hexanal development during processing and the hexanal concentration increased considerably during storage. The results show that it is possible to optimize the process to get a lower oxidation during the subsequent storage. The temperature during the second steep in the hydrothermal process and the level of lactic acid addition were the most important factors. Both of them should be kept low to favor the oxidative stability.
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