Birthe Jespersen
University of Copenhagen, Department of Food Science, Department Member
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Cyclodextrins (CDs) are cyclic oligosaccharides that have found widespread application in numerous fields. CDs have revealed a number of various health benefits, making them potentially useful food supplements and nutraceuticals. In this... more
Cyclodextrins (CDs) are cyclic oligosaccharides that have found widespread application in numerous fields. CDs have revealed a number of various health benefits, making them potentially useful food supplements and nutraceuticals. In this study, the impact of α-, β-, and γ-CD at different concentrations (up to 8% of the flour weight) on the wheat dough and bread properties were investigated. The impact on dough properties was assessed by alveograph analysis, and it was found that especially β-CD affected the viscoelastic properties. This behavior correlates well with a direct interaction of the CDs with the proteins of the gluten network. The impact on bread volume and bread staling was also assessed. The bread volume was in general not significantly affected by the addition of up to 4% CD, except for 4% α-CD, which slightly increased the bread volume. Larger concentrations of CDs lead to decreasing bread volumes. Bread staling was investigated by texture analysis and low field nucle...
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Research Interests: Engineering, Chemistry, Principal Component Analysis, Multivariate Data Analysis, Medicine, and 12 moreMolecular modeling, Agricultural, Enzyme, CHEMICAL SCIENCES, Phenols, Phenolic compound, Beta-Glucans, Functional Group, Agricultural and Food Chemistry, Molecular Interactions, glucan, and Partial least square regression
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Near Infrared hyperspectral imaging (HSI) offers a fast and non-destructive method for seed quality assessment through combining spectroscopy and imaging. Recently, convolutional neural networks (CNN) have shown to be promising tools for... more
Near Infrared hyperspectral imaging (HSI) offers a fast and non-destructive method for seed quality assessment through combining spectroscopy and imaging. Recently, convolutional neural networks (CNN) have shown to be promising tools for red-green-blue (RGB) image or spectral cereal classification. This paper describes the design and implementation of deep CNN models capable of utilizing both the spatial and spectral dimension of HSI data simultaneously for analysis of bulk grain samples with densely packed kernels. Classification of eight grain samples, including six different wheat varieties, were used as a test case. The study shows that the CNN architecture ResNet, originally designed for RGB images, can be adapted to use the full spatio-spectral dimension of the HSI data through adding a linear down sample layer prior to the conventional ResNet architecture. Using traditional spectral pre-processing methods before passing the data to the CNN does not improve the classification ...
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QY Shu (ed.), Induced Plant Mutations in the Genomics Era. Food and Agriculture Organization of the United Nations, Rome, 2009, 182-186 Abstract This paper describes, with examples, how biochemical seed mutations can be used not only to... more
QY Shu (ed.), Induced Plant Mutations in the Genomics Era. Food and Agriculture Organization of the United Nations, Rome, 2009, 182-186 Abstract This paper describes, with examples, how biochemical seed mutations can be used not only to improve quality in cereals, but also to ...
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As documented by eight IAEA/FAO symposia (1968-82) on nutritionally improved seeds, a wide range of high lysine endosperm mutants were isolated in maize, sorghum and barley. These mutants observed by new spectroscopic screening methods... more
As documented by eight IAEA/FAO symposia (1968-82) on nutritionally improved seeds, a wide range of high lysine endosperm mutants were isolated in maize, sorghum and barley. These mutants observed by new spectroscopic screening methods can now be exploited to advance basic biological research and theory. Since 1982, effective methods to overview the physiochemical composition of seeds by Near Infrared Spectroscopy evaluated by chemometric data analysis have developed. Spectroscopic analyses by calibration have now substituted the wet analyses in the industry. In genetics there has traditionally been a differentiation between major genes for qualitative and minor ”polygenes” for quantitative traits. This view has been coupled with an incomplete understanding of pleiotropy. It is shown that seed spectra from isogenic barley endosperm mutants represent a coarse-grained physiochemical overview of the phenome that can be classified by chemometrics. Pleiotropy expressed by a gene is quant...
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Mixed-linkage (1→3),(1→4)-β-d-glucans (BG) reduce cholesterol level and insulin response in humans. Despite this, their role in human metabolism and a mode of action remains largely unknown. To investigate the effects of three... more
Mixed-linkage (1→3),(1→4)-β-d-glucans (BG) reduce cholesterol level and insulin response in humans. Despite this, their role in human metabolism and a mode of action remains largely unknown. To investigate the effects of three structurally different BG on human fecal metabolome in a full cross-over intervention using GC-MS metabolomics. Over three weeks of intervention, young healthy adults received food supplemented with BG from oat, two different BG from barley or a non-fiber control in a full cross-over design. Untargeted metabolomics and short chain fatty acid analysis was performed on day three fecal samples. ANOVA-simultaneous component analysis was applied to partition the data variation according to the study design, and PLS-DA was used to select most discriminative metabolite markers. Univariate and multivariate data analysis revealed a dominating effect of inter-individual variances followed by a gender effect. Weak effects of BG intake were identified including an increas...
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The development of crop varieties tolerant to growth temperature fluctuations and improved nutritional value is crucial due to climate change and global population growth. This study investigated the metabolite patterns of developing... more
The development of crop varieties tolerant to growth temperature fluctuations and improved nutritional value is crucial due to climate change and global population growth. This study investigated the metabolite patterns of developing barley seed as a function of genotype and growth temperature for ideal vegetable protein production and for augmented β-glucan production. Seeds from three barley lines (Bomi, lys3.a and lys5.f) were sampled eight times during grain filling and analysed for metabolites using gas chromatography-mass spectrometry (GC-MS). The lys3.a mutation disrupts a regulator gene, causing an increase in proteins rich in the essential amino acid lysine, while lys5.f carries a mutation in an ADP-glucose transporter gene leading to a significant increase in production of mixed-linkage β-glucan at the expense of α-glucan. Unique metabolic patterns associated with the tricarboxylic acid cycle, shikimate-phenylpropanoid pathway, mevalonate, lipid and carbohydrate metabolism...
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The supercontinuum laser is a new type of light source, which combines the collimation and intensity of a laser with the broad spectral region of a lamp. Using such a source therefore makes it possible to focus the light onto small sample... more
The supercontinuum laser is a new type of light source, which combines the collimation and intensity of a laser with the broad spectral region of a lamp. Using such a source therefore makes it possible to focus the light onto small sample areas without losing intensity and thus facilitate either rapid or high-intensity measurements. Single seed transmission analysis in the long wavelength (LW) near-infrared (NIR) region is one area that might benefit from a brighter light source such as the supercontinuum laser. This study is aimed at building an experimental spectrometer consisting of a supercontinuum laser source and a dispersive monochromator in order to investigate its capability to measure the barley endosperm using transmission experiments in the LW NIR region. So far, barley and wheat seeds have only been studied using NIR transmission in the short wavelength region up to 1100 nm. However, the region in the range of 2260-2380 nm has previously shown to be particularly useful ...
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ABSTRACT This article was submitted without an abstract, please refer to the full-text PDF file.
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... The two mutants of unknown origin, w1 (1201) and w2 (841878), were included with a note that they were selected for the waxy trait (high amy-lopectin starch). They are located in the C and the N cluster, respectively, in Fig. 18.1 g.... more
... The two mutants of unknown origin, w1 (1201) and w2 (841878), were included with a note that they were selected for the waxy trait (high amy-lopectin starch). They are located in the C and the N cluster, respectively, in Fig. 18.1 g. ...
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This study investigates the release of selected strawberry flavor compounds from aqueous solutions of two barley and oat beta-glucan products at concentrations of 5, 10, and 15% (w/w). The flavor release of 12 esters and 3 alcohols was... more
This study investigates the release of selected strawberry flavor compounds from aqueous solutions of two barley and oat beta-glucan products at concentrations of 5, 10, and 15% (w/w). The flavor release of 12 esters and 3 alcohols was measured by dynamic headspace GC-MS. For each compound the ratio of the flavor release from the beta-glucan solution to the release from aqueous solution, A(rel), was recorded. In general, esters were retained in the beta-glucan matrices in a mass-dependent manner where heavier molecules were retained more. A(rel) for alcohols was found to be significantly larger than for the esters. Whereas A(rel) values for esters were always below unity, this parameter was above unity for alcohols in some preparations of beta-glucan. This implies that relative to esters, alcohols were rejected from some matrices. An increase in the concentration of the beta-glucan products was associated with an increased retention of alcohols and esters. For solutions of oat and b...
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Barley (Hordeum vulgare) is an important cereal that has many applications; as a human food, in malt products and as livestock feed. The content of soluble health-promoting fibers, beta-glucans, varies substantially among barley... more
Barley (Hordeum vulgare) is an important cereal that has many applications; as a human food, in malt products and as livestock feed. The content of soluble health-promoting fibers, beta-glucans, varies substantially among barley varieties. In the present study, the content of secondary metabolites with potential positive health effects in different high- and low-beta-glucan barley varieties was studied. Five different flavanols were isolated and identified: (2R,3S)-catechin-7-O-beta-D-glucopyranoside (1), prodelphinidin B3 (2), procyanidin B3 (3), (+)-catechin (4) and procyanidin B1 (5). Procyanidin B1 has never been reported in barley grains before. The compounds were identified using 1H NMR and quadrupolar time-of-flight mass spectrometry. A quantitative analytical method was developed for prodelphinidin B3, procyanidin B3 and (+)-catechin in liquid chromatography triple quadrupole-linear ion trap mass spectrometry and these compounds were quantified in all varieties, together wit...
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This study investigates the release of selected strawberry flavor compounds from aqueous solutions of two barley and oat beta-glucan products at concentrations of 5, 10, and 15% (w/w). The flavor release of 12 esters and 3 alcohols was... more
This study investigates the release of selected strawberry flavor compounds from aqueous solutions of two barley and oat beta-glucan products at concentrations of 5, 10, and 15% (w/w). The flavor release of 12 esters and 3 alcohols was measured by dynamic headspace GC-MS. For each compound the ratio of the flavor release from the beta-glucan solution to the release from aqueous solution, A(rel), was recorded. In general, esters were retained in the beta-glucan matrices in a mass-dependent manner where heavier molecules were retained more. A(rel) for alcohols was found to be significantly larger than for the esters. Whereas A(rel) values for esters were always below unity, this parameter was above unity for alcohols in some preparations of beta-glucan. This implies that relative to esters, alcohols were rejected from some matrices. An increase in the concentration of the beta-glucan products was associated with an increased retention of alcohols and esters. For solutions of oat and b...
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ABSTRACT Cereals are the most efficient human food source, in terms of both energy supply and nutrition. People of all races rely on cereals as their main staple diet, with more than half of the world's population eating rice as... more
ABSTRACT Cereals are the most efficient human food source, in terms of both energy supply and nutrition. People of all races rely on cereals as their main staple diet, with more than half of the world's population eating rice as their principal food. Therefore, producers, processors, the public and governmental authorities need to be aware of the spoilage, adulteration, and public health problems of these basic foods. This chapter covers only the major grains in commercial production, with less emphasis on small-scale farming and processing (Iizuka, 1957, 1958). For reviews of the microbiology of fermented Oriental and Indian cereal products see Hesseltine (1965, 1979) and Beuchat (1987). Cereals are also the basis for many animal feeds (see Chapter 4), but this chapter covers only human foods.
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Two barley materials (III) are utilised, the results of which are published elsewhere22,24 but are here recalcu-lated and presented in a completely new form to support our case. The materials were: I. The 17 samples of the malting barley... more
Two barley materials (III) are utilised, the results of which are published elsewhere22,24 but are here recalcu-lated and presented in a completely new form to support our case. The materials were: I. The 17 samples of the malting barley Alexis24 grown in different places in Europe ...
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ABSTRACT J. Inst. Brew. 110(1), 18-33, 2004 The physiological and physical-chemical basis of barley germi- nation was studied. Vigour was defined as germination percent- age after 24 h and viability as that of 72 h. The barley samples... more
ABSTRACT J. Inst. Brew. 110(1), 18-33, 2004 The physiological and physical-chemical basis of barley germi- nation was studied. Vigour was defined as germination percent- age after 24 h and viability as that of 72 h. The barley samples were analysed under germination capacity and energy conditions after harvest and after long time cold storage at 7°C three-six years. These parameters were each correlated by Partial Least Squares Regression (PLSR) to two separate multivariate data sets: a set of ten physical-chemical parameters and to Near Infra- red Transmission (NIT) spectra (850-1050 nm). Surprisingly high correlation coefficients for each of these two data sets were obtained especially with vigour, extract (%) and -glucan in wort (mg/L) when outliers with viability below 92% were re- moved. Hard, slowly germinating seeds were more resistant to decay in vigour and viability storage than soft seeds. This change could be predicted by PLSR correlations to the two physical- chemical multivariate methods. Vigour was a more sensitive indicator for the ability to store than viability. The steep criterion was also found to have a physical-chemical basis. The results indicate that NIT calibrations can be used to predict vigour in malting grade barley.
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The vigour loss model based on normal distribution after artificially ageing by heat treatment of barley seeds developed by Ellis and Roberts and further developed at Carlsberg by Aastrup et al. introducing vigour potential (VP), does not... more
The vigour loss model based on normal distribution after artificially ageing by heat treatment of barley seeds developed by Ellis and Roberts and further developed at Carlsberg by Aastrup et al. introducing vigour potential (VP), does not adequately describe seed vigour for all ...
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In earlier studies concerning vigour, where subsamples are heat-treated before germination there was found heat-sensitive as well as heat-resistant barley samples. The vigour model developed by Ellis and Roberts and further developed at... more
In earlier studies concerning vigour, where subsamples are heat-treated before germination there was found heat-sensitive as well as heat-resistant barley samples. The vigour model developed by Ellis and Roberts and further developed at Carlsberg, could only describe the heat-...
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Near Infrared Reflectance spectroscopy was tested as a screening method to characterise high lysine mutants from a barley collection by classification through Principal Component Analysis (PCA). Mean spectra of the samples within each... more
Near Infrared Reflectance spectroscopy was tested as a screening method to characterise high lysine mutants from a barley collection by classification through Principal Component Analysis (PCA). Mean spectra of the samples within each cluster identified gene-specific patterns ...
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This study investigates the release of selected strawberry flavor compounds from aqueous solutions of two barley and oat beta-glucan products at concentrations of 5, 10, and 15% (w/w). The flavor release of 12 esters and 3 alcohols was... more
This study investigates the release of selected strawberry flavor compounds from aqueous solutions of two barley and oat beta-glucan products at concentrations of 5, 10, and 15% (w/w). The flavor release of 12 esters and 3 alcohols was measured by dynamic headspace GC-MS. For each compound the ratio of the flavor release from the beta-glucan solution to the release from aqueous solution, A(rel), was recorded. In general, esters were retained in the beta-glucan matrices in a mass-dependent manner where heavier molecules were retained more. A(rel) for alcohols was found to be significantly larger than for the esters. Whereas A(rel) values for esters were always below unity, this parameter was above unity for alcohols in some preparations of beta-glucan. This implies that relative to esters, alcohols were rejected from some matrices. An increase in the concentration of the beta-glucan products was associated with an increased retention of alcohols and esters. For solutions of oat and b...
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Influence of malt roasting on the oxidative stability of sweet wort was evaluated based on radical intensity, volatile profile, content of transition metals (Fe and Cu) and thiols. Malt roasting had a large influence on the oxidative... more
Influence of malt roasting on the oxidative stability of sweet wort was evaluated based on radical intensity, volatile profile, content of transition metals (Fe and Cu) and thiols. Malt roasting had a large influence on the oxidative stability of sweet wort. Light sweet worts were more stable with low radical intensity, low Fe content, and ability to retain volatile compounds when heated. At mild roasting, the Fe content in the wort increased but remained close to constant with further roasting. Dark sweet worts were less stable with high radical intensities, high Fe content, and a decreased ability to retain volatiles. Results suggested that the Maillard reaction compounds formed during the roasting of malt are prooxidants in sweet wort. A thiol-removing capacity was observed in sweet wort, and it was gradually inhibited by malt roasting. It is possibly caused by thiol oxidizing enzymes present in the fresh malt.
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Research Interests: Engineering, Multivariate Data Analysis, Agricultural, Water Absorption, CHEMICAL SCIENCES, and 15 moreGenotype, Seeds, Analysis of Variance, Time Factors, Dietary fiber, Agricultural and Food Chemistry, Seasons, Chemical Composition, Rye, Ferulic Acid, PLANT PROTEINS, Plant Height, Functional Properties, Secale cereale, and Protein content
Wort from the barley varieties (Hordeum vulgare) Pallas, Fero, and Archer grown on the same location were investigated for their influence on oxidative stability and volatile profile during wort processing. Barley varieties had a small... more
Wort from the barley varieties (Hordeum vulgare) Pallas, Fero, and Archer grown on the same location were investigated for their influence on oxidative stability and volatile profile during wort processing. Barley varieties had a small influence on radical formation, thiol-removing capacity, and volatile profile. Wort boiling with and without hops had a large influence on these same parameters. Potentially antioxidative thiols were oxidized in sweet wort, but reduction of thiols using tris(2-carboxyethyl)phosphine hydrochloride revealed that Archer wort had a significantly larger content of total thiols than Pallas and Fero. Oxidized thiols resulted in gel proteins and longer filtration time for Archer wort. Our study shows that wort processing to a large extent will eliminate variations in volatile profile and thiol levels in wort which otherwise might arise from different barley varieties.
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ABSTRACT This study investigates the plasma metabolic effectiveness from 3.3 g mixed linkage barley or oat β-glucan fibre per day by 1H NMR spectroscopy on plasma samples and multivariate data analysis. Three large-scale extracted,... more
ABSTRACT This study investigates the plasma metabolic effectiveness from 3.3 g mixed linkage barley or oat β-glucan fibre per day by 1H NMR spectroscopy on plasma samples and multivariate data analysis. Three large-scale extracted, equally sized but structurally different β-glucans, were tested in a blinded randomised cross-over design using young healthy adults, where the β-glucans were compared to a non-fibre control during a 21 day dietary intervention period. Subject variance was found to dominate the metabolomics data although the variations in subject age and BMI was very small. The second most influential variation was found to be due to gender as characteristic lipoprotein profiles were found for male and female samples. The 3.3 g/d did not perturb the blood homeostasis in healthy adults as no systematic differences between 3-week β-glucan treatments and control was found. The present study constitutes the first metabolomic β-glucan human intervention study which proves complementary and confirmatory with respect to previous nutritional investigations evaluating traditional cardiovascular disease risk markers.
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Health effects of β-glucan are typically related to dose, size and viscosity without taking the specific molecular structure into account. High β-glucan mutant barley, mother barley and oat β-glucans were large-scale extracted by... more
Health effects of β-glucan are typically related to dose, size and viscosity without taking the specific molecular structure into account. High β-glucan mutant barley, mother barley and oat β-glucans were large-scale extracted by comparable protocols using hot water, enzyme assisted hydrolysis and ethanol precipitation leading to similar molecular masses (200-300kDa). Multivariate data analysis on all compositional, structural and functional features demonstrated that the main variance among the samples was primarily explained by block structural differences as determined by HPSEC-PAD. In particular the barley high β-glucan mutant proved to exhibit a unique block structure with DP3 and DP4 contributions of: 78.9% and 16.7% as compared to the barley mother (72.1% and 21.4%) and oat (66.1% and 29.1%). This unique block structure was further confirmed by the (1)H NMR determination of the β-1,4 to β-1,3 linkage ratio. Low solubility of the barley samples was potentially an effect of substructures consisting of longer repetitive cellotriosyl sequences. FT-Raman and NMR spectroscopy were useful in measuring sample impurities of α-glucans and prediction of β-linkage characteristics.
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The present study is aimed at evaluating the possibility to predict bread specifications, for an industrial bread-making process, on the basis of the properties of flour employed in production. The flour delivered at the production plant,... more
The present study is aimed at evaluating the possibility to predict bread specifications, for an industrial bread-making process, on the basis of the properties of flour employed in production. The flour delivered at the production plant, of which rheological and chemical properties were available, were analysed by means of Near Infrared Spectroscopy (NIRS). Based on the flour properties and NIR signals, multivariate control charts were constructed in order to detect flour batches leading to a bread with non-optimal behaviour. The results show that it is possible to distinguish flour batches leading to a product with a particularly negative performance, by modelling the properties commonly measured on flours and the acquired Near Infrared signals. In spite of the absence of monitoring of process variables, which could have offered a more sound basis for the interpretation, especially when false positives and negatives are detected, these results are of particular interest from the point of view of raw material evaluation in process monitoring. Also, the potentiality of Near Infrared Spectroscopy allows considering this approach for an on-line implementation in the control of incoming raw materials in this industrial process.