Analysis of protein structures and interactions in complex food by near-infrared spectroscopy. 1. Gluten powder

The potential of near-infrared (NIR) spectroscopy in detailed food analysis was tested in a model system consisting of gluten powder treated with moisture and heat. Second-derivative transformation and extended multiplicative signal correction were applied for improving the band resolution and removing physical and quantitative spectral variations. Subsequent chemometric analyses gave loading spectra, which were interpreted as spectral effects of altered protein structures, induced by the treatments. Moistening of the gluten powder resulted in shifts and intensity changes in the protein bands, which could be explained by a combination of minor secondary structure changes, water binding, and changed microenvironments of the amino acid side chains. Heat denaturation induced increases at 2209 nm and decreases at 2167-2182 nm, indicating an alpha-helix to beta-sheet transformation, in agreement with the expectations.     

Structural analogues of homoeriodictyol as flavor modifiers. Part III: short chain gingerdione derivatives

In order to find new flavor modifiers, various short chain gingerdione derivatives were synthesized as structural analogues of the known bitter masker homoeriodictyol and evaluated by a sensory panel for masking and sweetness enhancing activities. 1-(4-Hydroxy-3-methoxyphenyl)hexa-3,5-dione ([2]-gingerdione) and the homologue 1-(4-hydroxy-3-methoxyphenyl)hepta-3,5-dione ([3]-gingerdione) at concentration ranges 50-500 mg kg (-1) showed the most promising masking activity of 20-30% against bitterness of a 500 mg kg (-1) aqueous caffeine solution. Additionally, both compounds were able to reduce the bitterness of a 5 mg kg (-1) quinine solution by about 20%; however, the bitter tastes of salicine, the model peptide H-Leu-Trp-OH, and KCl solutions were not reduced. Whereas for bitter masking activity a vanillyl moiety seems to be important, some of the tested isovanillyl isomers showed an interesting sweet enhancing effect without exhibiting a significant intrinsic sweetness. The isomer 1-(3-hydroxy-4-methoxyphenyl)hexa-3,5-dione ([2]-isogingerdione) at 100 mg kg (-1) caused a significant and synergistic increase of 27% of sweet taste of a 5% sucrose solution.     

Sediment as a dynamic natural resource—from catchment to open sea

Journal of Soils and Sediments -     

Evaluation of the Effects of Fucoidans from Fucus Species and Laminaria hyperborea against Oxidative Stress and Iron-Dependent Cell Death

Fucoidans are algal polysaccharides that exhibit protective properties against oxidative stress. The aim of this study was to investigate different fucoidans from brown seaweeds for their ability to protect against iron-dependent oxidative stress (ferroptosis), a main hallmark of retinal and brain diseases, including hemorrhage. We investigated five new high-molecular weight fucoidan extracts from Fucus vesiculosus, F. serratus, and F. distichus subsp. evanescens, a previously published Laminaria hyperborean extract, and commercially available extracts from F. vesiculosus and Undaria pinnatifida. We induced oxidative stress by glutathione depletion (erastin) and H₂O₂ in four retinal and neuronal cell lines as well as primary cortical neurons. Only extracts from F. serratus, F. distichus subsp. evanescens, and Laminaria hyperborea were partially protective against erastin-induced cell death in ARPE-19 and OMM-1 cells, while none of the extracts showed beneficial effects in neuronal cells. Protective fucoidans also attenuated the decrease in protein levels of the antioxidant enzyme GPX4, a key regulator of ferroptosis. This comprehensive analysis demonstrates that the antioxidant abilities of fucoidans may be cell type-specific, besides depending on the algal species and extraction method. Future studies are needed to further characterize the health-benefiting effects of fucoidans and to determine the exact mechanism underlying their antioxidative abilities.     

Response of amidohydrolases in soils to chloroform fumigation

An ongoing challenge in enzymology is the differentiation between the various pools of enzymes in soils, i.e. between accumulated (extracellular) enzymes and enzymes associated with the microbial biomass (intracellular enzymes). In order to solve this problem, 10 surface soils representing a wide range of physico‐chemical properties and purified reference enzyme proteins were fumigated for 24 h at 25 °C. The activities of L‐asparaginase, L‐glutaminase, amidase, and L‐aspartase were assayed in chloroform fumigated soils, in reference enzyme proteins and in their nonfumigated counterparts in the presence and absence of toluene. Chloroform fumigation decreased the activities of L‐asparaginase, L‐glutaminase, and L‐aspartase in soils, on average, by 41, 78, and 78 %, respectively. The response of amidase activity towards chloroform fumigation of soils varied within the 10 soils studied. In five soils increases in activity values up to 40 % were observed. A loss of amidase activity, varying between 7 and 17 %, was found in four soils, whereas in one soil no effect of chloroform fumigation was determined. Enzyme activities of the four purified reference proteins were decreased by fumigation, with L‐glutaminase showing a nearly complete inhibition of 99 %, followed by amidase, L‐aspartase, and L‐asparaginase with an inhibition of 29, 18, and 7 %, respectively. Toluene treatment of the nonfumigated soils resulted in increases in the activity values of L‐asparaginase, L‐glutaminase, and L‐aspartase of 21 to 213 % (average of 10 soils). In contrast, amidase activity of soils was decreased in the presence of toluene by a mean of 32 %. Enzyme protein concentrations, calculated for the 10 soils, based on the specific activities of the purified enzymes (i.e., activity values per mg protein) and the activity values obtained in the soils, were, on average, 0.73, 0.50, 3.38, and 2.61 mg protein (kg soil)^—1 for L‐asparaginase, L‐glutaminase, amidase, and L‐aspartase, respectively. Comparison of activity values of soil amidohydrolases with the protein concentrations present in soils indicates that catalytic efficiency can vary greatly among different soil enzymes.     

Evaluation of a Brown Seaweed Extract from Dictyosiphon foeniculaceus as a Potential Therapeutic Agent for the Treatment of Glioblastoma and Uveal Melanoma

Ingredients of brown seaweed like fucoidans are often described for their beneficial biological effects, that might be interesting for a medical application. In this study, we tested an extract from Dictyosiphon foeniculaceus (DF) to evaluate the effects in glioblastoma and uveal melanoma, looking for a possible anti-cancer treatment. We investigated toxicity, VEGF (vascular endothelial growth factor) secretion and gene expression of tumor and non-tumor cells. SVGA (human fetal astrocytes), the human RPE (retinal pigment epithelium) cell line ARPE-19, the tumor cell line OMM-1 (human uveal melanoma), and two different human primary glioblastoma cultures (116-14 and 118-14) were used. Tests for cell viability were conducted with MTS-Assay (3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium), and the proliferation rate was determined with cell counting. VEGF secretion was assessed with ELISA (enzyme-linked immunosorbent assay). The gene expression of VEGF receptor 1 (VEGFR1), VEGF receptor 2 (VEGFR2) and VEGF-A was determined with real-time qPCR (quantitative polymerase chain reaction). DF lowered the cell viability of OMM-1. Proliferation rates of ARPE-19 and OMM-1 were decreased. The VEGF secretion was inhibited in ARPE-19 and OMM-1, whereas it was increased in SVGA and 116-14. The expression of VEGFR1 was absent and not influenced in OMM-1 and ARPE-19. VEGFR2 expression was lowered in 116-14 after 24 h, whereas VEGF-A was increased in 118-14 after 72 h. The extract lowered cell viability slightly and was anti-proliferative depending on the cell type investigated. VEGF was heterogeneously affected. The results in glioblastoma were not promising, but the anti-tumor properties in OMM-1 could make them interesting for further research concerning cancer diseases in the human eye.     

Determination of Pea Proteinase Inhibitors Using ELISA Based on Monoclonal Antibodies

Abstract

An immunoassay method for analysis of trypsin and chymotrypsin inhibitor activity in seeds from different pea cultivars has been developed. This method is fast, cheap and well suited for screening of large numbers of seed samples. The technique is based on enzyme linked immunoassay (ELISA) using monoclonal antibodies produced against pea (Pisum sativum L.) proteintype trypsin inhibitors (PPI). The results obtained by ELISA have been compared with results achieved by using traditional enzymatic analyses for determination of both trypsin and chymotrypsin inhibitor contents, and these methods showed good agreement. Great differences in PPI levels have been found between various pea cultivars grown in Finland and Denmark, and these differences comprised both the total amount of PPI and the relative composition of individual PPI. Several proteins occurring in pea exhibited inhibitor activity, and at least 10 PPI inhibitors with p/ values 4.9–7.8 were detected. Pea cultivars with low PPI levels had a PPI composition different from the PPI composition found in cultivars with high PPI levels.     

Consequences of specialized breeding in the Swedish Warmblood horse population

In many European warmblood studbooks, clear specialization toward either jumping or dressage horses is evident. The Swedish Warmblood (SWB) is also undergoing such specialization, creating a possible need for separate breeding programs and a discipline-specific Young Horse Test (YHT). This study investigated how far specialization of the SWB breed has proceeded and the potential consequences. Individuals in a population of 122,054 SWB horses born between 1980 and 2020 were categorized according to pedigree as jumping (J), dressage (D), allround (AR), or thoroughbred (Th). Data on 8,713 J horses and 6,477 D horses assessed for eight traits in YHT 1999–2020 were used to estimate genetic parameters within and between J and D horses and between different periods. Future scenarios in which young horses are assessed for either jumping or dressage traits at YHT were also analyzed. More than 80% of horses born in 1980–1985 were found to be AR horses, while 92% of horses born in 2016–2020 belonged to a specialized category. The average relationship within J or D category was found to increase during the past decade, whereas the relationship between these categories decreased. Heritability estimates for gait traits were 0.42–0.56 for D horses and 0.25–0.38 for J horses. For jumping traits, heritability estimates were 0.17–0.26 for J horses and 0.10–0.18 for D horses. Genetic correlations between corresponding traits assessed in J and D horses were within the range 0.48–0.81, with a tendency to be lower in the late study period. In the future scenarios, heritability and genetic variance both decreased for traits that were not assessed in all horses, indicating that estimation of breeding value and genetic progress for these traits could be affected by a specialized YHT. However, ranking of sires based on estimated breeding values (EBVs) and accuracy of EBVs was only slightly altered for discipline-specific traits. With continued specialization in SWB, specialization of the YHT should thus be considered.     

Dam Mycobacterium avium subspecies paratuberculosis (MAP) infection status does not predetermine calves for future shedding when raised in a contaminated environment: a cohort study

Uptake of Mycobacterium avium subsp. paratuberculosis (MAP) by calves in the first days of life from colostrum, milk and faeces is regarded an important moment of transmission. The objective of this study was to quantify the association between the MAP status of dams as determined by the presence of MAP DNA and antibody in colostrum and that of DNA in faeces and the environment with subsequent MAP shedding of their daughters. A cohort of 117 dam-daughter pairs giving birth/being born on eight commercial dairy farms with endemic paratuberculosis was followed where colostrum, faecal and environmental samples (dust) were analysed for the presence of MAP using an IS900 real-time PCR. Antibodies in colostrum were measured by ELISA. Analysis of dust samples showed that on all farms environmental MAP exposure occurred continuously. In significantly more colostrum samples (48%) MAP DNA was detected compared to faecal samples (37%). MAP specific antibodies were present in 34% of the colostrum samples. In total MAP DNA was present in faecal samples of 41% of the daughters at least once during the sampling period. The association between faecal shedding in the offspring and the dam MAP status defined by MAP PCR on colostrum, MAP PCR on faeces or ELISA on colostrum was determined by an exact cox regression analysis for discrete data. The model indicated that the hazard for faecal shedding in daughters born to MAP positive dams was not significantly different compared to daughters born to MAP negative dams. When born to a dam with DNA positive faeces the HR was 1.05 (CI 0.6; 1.8) and with DNA positive colostrum the HR was 1.17 (CI 0.6; 2.3). When dam status was defined by a combination of both PCR outcomes (faeces and colostrum) and the ELISA outcome the HR was 1.26 (CI 0.9; 1.9). Therefore, this study indicates that neither the presence of MAP DNA in colostrum, MAP DNA in faeces nor the presence of MAP antibodies in colostrum of the dam significantly influences the hazard of MAP shedding in their subsequent daughters up to the age of two years when raised in a contaminated environment.