Mobility and oxidative stability in plasticised food matrices the role of water

The importance of water in food structure and stability is well known, and the role of water as a plasticiser for biopolymers has been extensively studied during the last 25 years. Recently, understanding of the mechanisms of water plasticisation of glassy carbohydrate matrices at the molecular level has increased and its relevance to the rate of mass transfer has been emphasized. There appears to be a lack of such studies with food proteins, although the water factor is similarly recognised for example in protein-based edible films. Furthermore, food stability is currently evaluated on the basis of water activity and the physical state of the matrix. Therefore, it would be important to consider whether the major food polymers, starch-based carbohydrates and proteins, really act similarly with respect to water. In the present work, the role of water in system stability and biopolymer interactions was studied in two different systems: cast films with and without plasticiser and spray-dried particles with a dispersed lipid phase. Plasticisation of amylose films by glycerol and water was studied by proton NMR relaxometry. In glassy amylose the proximity of Tg did not strongly affect the amylose mobility. The second moment M2, which is a measure of strong dipolar interactions and decreases with increasing distance between the protons contributing to it, decreased slightly with increasing water content. It was thus suggested that glassy state swelling occurred in amylose film. Swelling behaviour is probably important when mass transfer in the matrix is considered. In rubbery state, high concentration (30%) of glycerol increased the mobility of amylose despite the phase separation that occurs in these systems already at much lower plasticiser content. The data on mobility of plasticised amylose was combined with results presented earlier on oxygen permeability of these films. Although increasing mobility generally resulted in increased permeability, conditions were found in which the plasticiser induced segmental motions in amorphous amylose without appreciable loss in oxygen barrier properties. In powder particles, the stability of embedded lipid phase was studied in traditional carbohydrate carriers, i.e. hydrolysed (maltodextrin with gum Arabic as an emulsifier) and modified (octenyl succinate derivative) starches, and in whey protein isolate. Powders with oils rich in volatile flavour or in polyunsaturated fatty acids were prepared by spray-drying and characterised by laser diffraction and scanning electron microscopy for oil distribution and by differential scanning calorimetry for their glass transition temperatures (Tg). The powders were stored under controlled conditions, and the effect of relative humidity on the rate of oxidation was studied by following the increase in peroxide value during storage. Formation of hydroperoxides is linked with oxygen transfer in the system, as it is the oxygen consuming step of the reaction. In the case of powders with embedded oil rich in volatiles, the release of limonene and carvone was studied as a function of time and temperature. The starting hypothesis of this work was that a higher water vapour sorption at higher humidity would increase oxygen permeation in the matrices and lead to an increased rate of oxidation. This was in fact found to be the case in carbohydrate matrices during storage at 20°C, at which temperature the rate of oxidation in matrices was higher at RH 54% than at RH 11%. An opposite behaviour was found for bulk oil, suggesting that the effect of water in matrix-dispersed oil was due to matrix properties. At elevated temperatures, a difference was found between hydrolysed and modified starches. The stability of oil in modified starch still correlated with the proximity of Tg, whereas the hydrolysed starch completely lost its barrier properties at 50°C, which could not be explained by the Tg of the matrix. When volatiles release was studied at elevated temperature (70°C), little release from dry matrices was found. Intense release was found in the proximity of the glass transition temperature in all the systems. In whey protein isolate matrix, oxidation of matrix-embedded oil was retarded compared to that of bulk oil at all humidities, but followed almost the same pattern as bulk oil with respect to humidity. The rate of oxidation was high at low humidities (RH 0% and RH 11%), was retarded at intermediate humidities (RH 50% and RH 75%) and again increased at high humidity (RH 90%), at which caking of the powder was observed as an indication of physical instability. Thus, it appeared that water did not have a similar role in the matrix formed of globular proteins as it had in a glassy carbohydrate matrix. The importance of storage conditions and matrix properties for relating oxygen transfer to the rate of oxidation was demonstrated. Furthermore, it was proposed that the high solubility of the volatiles in non-volatile triglyceride phase was the reason for the retention of limonene and carvone in the matrices at elevated temperatures

The Impact of Vanilla and Lemon Aromas on Sensory Perception in Plant-Based Yogurts Measured with Static and Dynamic Methods

The application of cross-modal interaction is a potential strategy to tackle the challenges related to poor sensory properties, such as thin mouthfeel, in plant-based yogurts. Thus, we aim to study the influence of aroma compounds possibly congruent with sweetness on the perceived sensory profile. Descriptive analysis and temporal dominance of sensations (n = 10 × 4) with a trained panel were conducted with and without a nose clip. One unflavored sample and samples flavored with either lemon or vanilla aromas were included (vanilla; 0.05%; 0.1%; lemon: 0.025%; 0.05%). Odor intensity, thick, sticky, and melting sensation, sweetness, and grain-like flavor were evaluated on an unstructured 10-cm line scale with anchors and reference samples. The results demonstrate how vanilla and lemon aromas suppressed grain-like flavor and enhanced odor intensity and sweetness. The following order was detected among samples in perceived sweetness intensity: unflavored < lemon < vanilla. The two sessions with and without nose clip differed statistically in sweetness, highlighting that the aromas impacted the perceived sweetness but not the mouthfeel in vanilla samples. The study suggests that congruent aromas could modify the perceived sweetness in plant-based yogurts; however, aroma or perceived sweetness does not impact the mouthfeel in plant-based yogurts. While the odor–taste interaction in such products is evident, the study highlights that aroma compounds alone do not modify mouthfeel

The Impact of Vanilla and Lemon Aromas on Sensory Perception in Plant-Based Yogurts Measured with Static and Dynamic Methods

The application of cross-modal interaction is a potential strategy to tackle the challenges related to poor sensory properties, such as thin mouthfeel, in plant-based yogurts. Thus, we aim to study the influence of aroma compounds possibly congruent with sweetness on the perceived sensory profile. Descriptive analysis and temporal dominance of sensations (n = 10 × 4) with a trained panel were conducted with and without a nose clip. One unflavored sample and samples flavored with either lemon or vanilla aromas were included (vanilla; 0.05%; 0.1%; lemon: 0.025%; 0.05%). Odor intensity, thick, sticky, and melting sensation, sweetness, and grain-like flavor were evaluated on an unstructured 10-cm line scale with anchors and reference samples. The results demonstrate how vanilla and lemon aromas suppressed grain-like flavor and enhanced odor intensity and sweetness. The following order was detected among samples in perceived sweetness intensity: unflavored < lemon < vanilla. The two sessions with and without nose clip differed statistically in sweetness, highlighting that the aromas impacted the perceived sweetness but not the mouthfeel in vanilla samples. The study suggests that congruent aromas could modify the perceived sweetness in plant-based yogurts; however, aroma or perceived sweetness does not impact the mouthfeel in plant-based yogurts. While the odor–taste interaction in such products is evident, the study highlights that aroma compounds alone do not modify mouthfeel

The effect of deamidation and lipids on the interfacial and foaming properties of ultrafiltered oat protein concentrates

The aim of this study was to investigate the air-water interfacial and foaming properties of oat protein concentrates produced by an enzyme-aided ultrafiltration method with and without deamidation. A further aim was to determine the role of polar and non-polar lipids at the air-water interface and in foams. The deamidated and ultrafiltered oat protein concentrate (DE-UF-OPC) exhibited higher surface tension compared to the ultrafiltered oat protein concentrate (UF-OPC). DE-UF-OPC had a significantly higher negative zeta potential value (−50 mV) compared to the UF-OPC (−38 mV) at pH 7.0. The higher net charge of the DE-UF-OPC may have decreased the equilibrium concentration of oat proteins at the interfacial layer due to higher repulsion between them. Both of the ethanol extracted OPCs exhibited higher surface tension values most likely due to the partial denaturation of albumins and/or globulins. Removal of the majority of non-polar lipids had no effect on the equilibrium surface tension of OPCs. DE-UF-OPC and UF-OPC exhibited some, but limited foaming ability. The removal of non-polar lipids significantly improved the foamability and stability of DE-UF-OPC and UF-OPC, but the removal of polar lipids only improved the foamability of DE-UF-OPC.Peer reviewe

Dynamic texture perception in plant-based yogurt alternatives: Identifying temporal drivers of liking by TDS

As texture properties in novel food categories have a crucial role in consumer acceptance, mouthfeel profile of different plant-based yogurt-like semi-solid products were studied and compared to dairy yogurts. Mouthfeel properties of five plant-based yogurt-like products and two dairy yogurts were analyzed using temporal dominance of sensations (TDS) with consumers (n = 87). The attributes evaluated were thick, thin, creamy, watery, sticky, and foamy. Following TDS, overall liking and mouthfeel liking were evaluated using a 7-point hedonic scale. Temporal drivers of mouthfeel liking were studied using correspondence analysis and penalty-lift analysis with different time points during mastication. For penalty-lift analysis TDS data was analyzed as check-all-that-apply (CATA) data. Results from the present work show that mouthfeel perception in non-dairy yogurt alternatives is a dynamic process. Attributes typically used to describe dairy yogurts are also relevant for describing non-dairy yogurt alternatives. Yogurt alternatives and dairy yogurts can be similar and equally liked by their mouthfeel profile. Temporal drivers of liking in plant-based products are thickness and creaminess and temporal drivers of disliking are thinness and wateriness. In this study, the first dominant attributes were found to have a stronger impact on mouthfeel liking than the dominant attributes perceived later during mastication

Genetic polymorphism related to monocyte-macrophage function is associated with graft-versus-host disease

Despite detailed human leukocyte antigen (HLA) matching and modern immunosuppressive therapy, severe graft-versus-host disease (GvHD) remains a major hurdle for successful allogeneic hematopoietic stem cell transplantation (HSCT). As the genetic diversity in GvHD complicates the systematic discovery of associated variants across populations, we studied 122 GvHD-associated single nucleotide polymorphisms (SNPs) in 492 HLA-matched sibling HSCT donor-recipient pairs from Finland and Spain. The association between these candidate SNPs and grade III-IV acute GvHD and extensive chronic GvHD was assessed. The functional effects of the variants were determined using expression and cytokine quantitative trait loci (QTL) database analyses. Clear heterogeneity was observed in the associated markers between the two populations. Interestingly, the majority of markers, such as those annotated to IL1, IL23R, TLR9, TNF, and NOD2 genes, are related to the immunological response by monocytes-macrophages to microbes, a step that precedes GvHD as a result of intestinal lesions. Furthermore, cytokine QTL analysis showed that the GvHD-associated markers regulate IL1 beta, IFN gamma, and IL6 responses. These results support a crucial role for the anti-microbial response in GvHD risk. Furthermore, despite apparent heterogeneity in the genetic markers associated with GvHD, it was possible to identify a biological pathway shared by most markers in both populations.Peer reviewe

Physicochemical Properties and Mouthfeel in Commercial Plant-Based Yogurts

There is a growing need for plant-based yogurts that meet consumer demands in terms of texture. However, more research is needed to understand the relationship between physicochemical and mouthfeel properties in plant-based yogurts. The purpose of the study was to determine the physicochemical properties of five commercial plant-based yogurt alternatives with different chemical compositions, making comparisons to dairy yogurts and mouthfeel sensations such as thick, creamy, thin, and watery. The physicochemical parameters studied included large and small deformation rheology, particle size, soluble solids, acidity, and chemical composition. Significant differences in flow behavior and small deformation rheology were found between dairy and plant-based yogurts. Among plant-based yogurts, mouthfeel sensations such as thick, creamy, thin, and watery were strongly associated with steady shear rates and apparent viscosity. The results highlight the importance of large deformation rheology in advancing the use of plant-based ingredients in the development of yogurt alternatives. Furthermore, the study demonstrates that dairy and plant-based yogurts with a similar mouthfeel profile may have different viscoelastic properties, which indicates that instrumental and sensory methods should not be considered substitutes but complementary methods when developing plant-based yogurts in a cost-effective and timely manner

Hidden genomic MHC disparity between HLA-matched sibling pairs in hematopoietic stem cell transplantation

Matching classical HLA alleles between donor and recipient is an important factor in avoiding adverse immunological effects in HSCT. Siblings with no differences in HLA alleles, either due to identical-by-state or identical-by-descent status, are considered to be optimal donors. We carried out a retrospective genomic sequence and SNP analysis of 336 fully HLA-A, -B, -DRB1 matched and 14 partially HLA-matched sibling HSCT pairs to determine the level of undetected mismatching within the MHC segment as well as to map their recombination sites. The genomic sequence of 34 genes locating in the MHC region revealed allelic mismatching at 1 to 8 additional genes in partially HLA-matched pairs. Also, fully matched pairs were found to have mismatching either at HLA-DPB1 or at non-HLA region within the MHC segment. Altogether, 3.9% of fully HLA-matched HSCT pairs had large genomic mismatching in the MHC segment. Recombination sites mapped to certain restricted locations. The number of mismatched nucleotides correlated with the risk of GvHD supporting the central role of full HLA matching in HSCT. High-density genome analysis revealed that fully HLA-matched siblings may not have identical MHC segments and even single allelic mismatching at any classical HLA gene often implies larger genomic differences along MHC.Peer reviewe

Varautumisen kehitystarpeet turvallisessa yhteiskunnassa

Varautumisen kehitystarpeet turvallisessa yhteiskunnassa -hanke vastaa Valtioneuvoston päätöksentekoa tukevan selvitys- ja tutkimustoiminnan kärkiteemaan Turvallinen yhteiskunta menestyksen ja hyvinvoinnin mahdollistajana (VNK/471/48/2014). Hankkeessa selvitetään, miten yhteiskunnan turvallisuusstrategiassa määritettyjen yhteiskunnan elintärkeitä toimintoja ja niiden tavoitetilaa vaarantavien uhkamallien ja häiriötilanteiden hallinta on kehittynyt viime vuosien aikana, miten sitä käytännössä toteutetaan, ja miten siihen liittyvät turvallisuussidonnaiset palvelut ovat kehittyneet. Tutkimuksen kohteena on kolme häiriötilannetta: sähkönjakelun häiriöt, kuljetusten häiriintyminen ja pandemia. Hankkeen tulosten mukaan häiriötilanteita ja toimintaympäristön muutoksia on tarkasteltava riittävän laajasti hyödyntäen eri toimijoiden osaamista. Yhtä aikaa tapahtuvat muutokset voivat olla yhteisvaikutuksiltaan yllättäviä, joten asioiden ja ilmiöiden riippuvuuksien tunnistaminen ja analysointi on keskeistä organisaation toiminnan turvaamiseksi. Alueelliset ja paikalliset erityispiirteet on otettava huomioon varautumissuunnitelmissa. Suunnitelmien on oltava riittävän joustavia vastatakseen erilaisten häiriötilanteiden vaatimuksiin. Suunnitelmia laadittaessa on niitä tarkasteltava yhdessä muiden toimijoiden kanssa, jotta suunnitelmista tulee riittävän yhteensopivia. Varautumisen tason seurantaan on kehitettävä sopivat mittarit. Käytännön toimintaa harjoiteltaessa on harjoitusten oltava riittävän laajoja ja kaikkien tarpeellisten osapuolten tulee olla mukana, jotta harjoituksissa saatava oppi ja tieto toisten osapuolten resursseista ja käytännöistä leviäisi mahdollisimman laajasti. Kolmas sektori ja yksityiset kansalaiset tulee ottaa tiiviimmin mukaan varautumissuunnitteluun niin alueellisella kuin paikallisella tasolla. Yritysten omatoimista varautumista tulee edistää esimerkiksi hyvien mallien ja työkalujen avulla sekä palvelun ostajan vaatimuksilla ja painotuksilla. Toiminta ja varautuminen häiriötilanteisiin tulee sisällyttää palvelusopimuksiin. Häiriötilanteessa toimiminen vaatii nopeaa ja luotettavaa tilannekuvan muodostamista ja tilannetietoisuuden ylläpitoa. Digitalisaatio antaa mahdollisuuksia rakentaa monipuolisempia tapoja viestiä häiriötilanteista. Käynnissä oleva valtionhallinnon uudistus voi olla mahdollisuus ratkaista epäselviä vastuukysymyksiä ja helpottaa yhteistoimintaa yhtenäistämällä eri toimijoiden maantieteellisiä ja substanssiin liittyviä vastuualueita