An International Laboratory Comparison Study of Volumetric and Gravimetric Hydrogen Adsorption Measurements

In order to determine a material’s hydrogen storage potential, capacity measurements must be robust, reproducible and accurate. Commonly, research reports focus on the gravimetric capacity, and often times the volumetric capacity is not reported. Determining volumetric capacities is not as straight‐forward, especially for amorphous materials. This is the first study to compare measurement reproducibly across laboratories for excess and total volumetric hydrogen sorption capacities based on the packing volume. The use of consistent measurement protocols, common analysis, and figure of merits for reporting data in this study, enable the comparison of the results for two different materials. Importantly, the results show good agreement for excess gravimetric capacities amongst the laboratories. Irreproducibility for excess and total volumetric capacities is attributed to real differences in the measured packing volume of the material

Investigating sodium reduction in the UK diet through salt particle design and understanding contributions of food oral processing on perception

The global food industry urgently requires effective sodium reduction solutions to increase health credentials and align with changing salt reduction targets. Previously investigated strategies for sodium reduction in potato crisps (e.g. salt enhancers, replacers and direct salt removal) have proven limitations and challenges. Therefore, studies presented in this thesis focused on redesigning salt particles to deliver optimum saltiness in snacks by developing and validating a range of physicochemical design rules to achieve effective salt reduction. It is also important to consider variations in consumer perception due to inter-individual differences in oral processing parameters and their impact on dietary intake. Therefore, the relationship between salivary parameters, saltiness perception and dietary intake, and the impact of mouth behaviour type on the perception and liking of potato crisps were also investigated. Physicochemical design rules for salt particles were established by measuring adhesion properties, dissolution and temporal saltiness perception of a diverse range of salts (n = 8) with varying physical and chemical properties (size, density, shape, hydrophobicity and flow properties). Findings determined that salt particles should be small in particle size, have a low density, low hydrophobicity and an optimised particle shape. Optimised model salts identified in this study were used to validate the design rules when topically applied to potato crisps. Inter-individual differences in salivary flow rate and sodium concentration affected salt taste threshold but did not predict the perceived saltiness intensity of supra-threshold concentrations. Furthermore, the high salt taste sensitivity group consumed significantly more salt than the low salt taste sensitivity group, suggesting that ‘salt-responsive’ individuals seek more salt-containing foods, or high salt consumers may develop these behaviours due to their diet. The selected optimised model salts and established particle design rules enabled a 30 % salt reduction in potato crisps while maintaining saltiness perception and consumer acceptance. Comparatively, only 15 % salt reduction was achieved without sensorial impact by directly removing salt. Other potential strategies investigated did not enhance saltiness perception or product liking, highlighting the utility of design rules to develop new optimised salt particles. Mouth behaviour type did not impact saltiness liking or perception of potato crisps. However, the ‘suckers’ group liked the texture of the whole product set significantly less than the other mouth behaviour classifications (crunchers, chewers, smooshers). This research contributes to the knowledge of salt reduction strategies in snack foods, specifically around the developed physicochemical design rules and the importance of considering individual salivary parameters when assessing the perception of saltiness. The physicochemical design rules developed within this research could also be utilised in other flavour particles to facilitate sugar reduction and optimise flavour delivery

Investigating sodium reduction in the UK diet through salt particle design and understanding contributions of food oral processing on perception

The global food industry urgently requires effective sodium reduction solutions to increase health credentials and align with changing salt reduction targets. Previously investigated strategies for sodium reduction in potato crisps (e.g. salt enhancers, replacers and direct salt removal) have proven limitations and challenges. Therefore, studies presented in this thesis focused on redesigning salt particles to deliver optimum saltiness in snacks by developing and validating a range of physicochemical design rules to achieve effective salt reduction. It is also important to consider variations in consumer perception due to inter-individual differences in oral processing parameters and their impact on dietary intake. Therefore, the relationship between salivary parameters, saltiness perception and dietary intake, and the impact of mouth behaviour type on the perception and liking of potato crisps were also investigated. Physicochemical design rules for salt particles were established by measuring adhesion properties, dissolution and temporal saltiness perception of a diverse range of salts (n = 8) with varying physical and chemical properties (size, density, shape, hydrophobicity and flow properties). Findings determined that salt particles should be small in particle size, have a low density, low hydrophobicity and an optimised particle shape. Optimised model salts identified in this study were used to validate the design rules when topically applied to potato crisps. Inter-individual differences in salivary flow rate and sodium concentration affected salt taste threshold but did not predict the perceived saltiness intensity of supra-threshold concentrations. Furthermore, the high salt taste sensitivity group consumed significantly more salt than the low salt taste sensitivity group, suggesting that ‘salt-responsive’ individuals seek more salt-containing foods, or high salt consumers may develop these behaviours due to their diet. The selected optimised model salts and established particle design rules enabled a 30 % salt reduction in potato crisps while maintaining saltiness perception and consumer acceptance. Comparatively, only 15 % salt reduction was achieved without sensorial impact by directly removing salt. Other potential strategies investigated did not enhance saltiness perception or product liking, highlighting the utility of design rules to develop new optimised salt particles. Mouth behaviour type did not impact saltiness liking or perception of potato crisps. However, the ‘suckers’ group liked the texture of the whole product set significantly less than the other mouth behaviour classifications (crunchers, chewers, smooshers). This research contributes to the knowledge of salt reduction strategies in snack foods, specifically around the developed physicochemical design rules and the importance of considering individual salivary parameters when assessing the perception of saltiness. The physicochemical design rules developed within this research could also be utilised in other flavour particles to facilitate sugar reduction and optimise flavour delivery

Evaluation of Hydrogen Storage in Metal Organic Frameworks by Bridged Hydrogen Spillover

Hydrogen has the potential to be the next energy carrier. The ability to use hydrogen in fuel cell technologies depends largely on the ability to store hydrogen efficiently. Metal-Organic Frameworks (MOFs) belong to an interesting set of materials that consists of porous channels and have been shown to carry potential for hydrogen storage when added to metal catalysts. MOFs alone show no potential to store hydrogen, but when added to metal catalyst they can exhibit a spillover effect to increase hydrogen storage capacity. The key critical issues with MOFs are to validate the promises that MOFs can provide with spillover, since spillover intricately linked to more standard H2 storage mechanisms. The current project focuses on the synthesis of Isoreticular Metal Organic Framework-8 (IRMOF-8) added to platinum on Activated Carbon (AC) and bridged together with sucrose to enhance the spillover effect. In order to reach hydrogen storage goals, a method must be proven to have enough capacity for the adsorption/resorption (reversibility) at ambient and 120 bar reasonable pressures. With the tremendous interest in spillover materials for hydrogen storage, NREL and DOE have dedicated resources to synthesize specific materials and to develop, perform, and validate the requisite measurements

Hotspots of Biased Nucleotide Substitutions in Human Genes

Genes that have experienced accelerated evolutionary rates on the human lineage during recent evolution are candidates for involvement in human-specific adaptations. To determine the forces that cause increased evolutionary rates in certain genes, we analyzed alignments of 10,238 human genes to their orthologues in chimpanzee and macaque. Using a likelihood ratio test, we identified protein-coding sequences with an accelerated rate of base substitutions along the human lineage. Exons evolving at a fast rate in humans have a significant tendency to contain clusters of AT-to-GC (weak-to-strong) biased substitutions. This pattern is also observed in noncoding sequence flanking rapidly evolving exons. Accelerated exons occur in regions with elevated male recombination rates and exhibit an excess of nonsynonymous substitutions relative to the genomic average. We next analyzed genes with significantly elevated ratios of nonsynonymous to synonymous rates of base substitution (dN/dS) along the human lineage, and those with an excess of amino acid replacement substitutions relative to human polymorphism. These genes also show evidence of clusters of weak-to-strong biased substitutions. These findings indicate that a recombination-associated process, such as biased gene conversion (BGC), is driving fixation of GC alleles in the human genome. This process can lead to accelerated evolution in coding sequences and excess amino acid replacement substitutions, thereby generating significant results for tests of positive selection

“Making Every Second Count”: Utilizing TikTok and Systems Thinking to Facilitate Scientific Public Engagement and Contextualization of Chemistry at Home

TikTok is a social media video-based phone application which enables creative and engaging videos to be shared on social media platforms worldwide. TikTok has been applied to create fun, exciting, and engaging 15–60 s long chemistry outreach educational videos, to encourage public dissemination of science with a systems thinking approach. With the creation of an online TikTok account called “The Chemistry Collective” by undergraduate students, 16 educational videos were created, with approximately 8,500 views. Upon surveying participants, viewers of these TikTok videos strongly agreed that they had learned something new about chemistry since watching these videos (4.66/5.00) and had an increased interest in chemistry (82.7% agreed). As such, TikTok can be used to enhance public and undergraduate student engagement with chemistry and science education, together with facilitating the ability of the public to understand how chemistry can be fun, can be performed at home, and is part of our daily lives

Physicochemical design rules for the formulation of novel salt particles with optimised saltiness

Novel sodium reduction strategies are urgently required by the food industry. We hypothesised that redesigning salt crystals (size, density, hydrophobicity and flow properties) will offer a new route to increase saltiness and therefore reduce sodium. Eight salts were compared with different physicochemical properties, the resultant particles were characterised and adhesion to product, loss in-pack, rate of dissolution and ultimately saltiness perception were evaluated. Principle findings included that particle adhesion was driven by particle size (r = -0.85, p = 0.008), bulk density (r = -0.80, p = 0.017) and flow properties (r = 0.77, p = 0.015); loss in-pack was associated with particle size and hydrophobicity of the salt particle while dissolution and/or saltiness perception was also driven by particle size and hydrophobicity of the salt particle. The findings offer a new set of design rules for future ingredient design for the food and flavour industries

Age group determines the acceptability of protein derived off-flavour

© 2021 The Authors Many older adults fail to meet their daily protein requirements, potentially due to social, physical and medical factors, including sensory and appetite changes. Additionally, our previous research has identified potential sulfurous off-flavours, originating from heat-treatment of protein ingredients, which could play a role in consumer acceptance. This study aims to determine the hedonic impact of these potential off-flavours when added to a dairy beverage, identify the specific off-flavour concentrations which cause rejection by consumers, and lastly investigate difference in acceptance between older and younger consumers. A rejection threshold (RjT) protocol was used, in combination with Best Estimate Thresholds (BET), whereby sulfurous flavours (dimethyl sulfide, dimethyl disulfide and dimethyl trisulfide), and diacetyl were added to create a range of concentrations. 95 participants (younger n = 49, 18–38 years; older n = 46, 60–79 years) tasted 7 pairs of samples (one blank and one with ascending off-flavour concentration) and selected their preferred samples. Sulfurous flavours negatively impacted consumer acceptance, however, the extent to which they impart a negative effect differs between age groups. Younger adults rejected samples containing low concentrations of sulfurous off-flavours (1.55 ppb), however, older adults rejected samples with concentrations over 3 times higher (5.08 ppb). When combined with sulfurous flavours, diacetyl increased the rejection threshold for both groups. In conclusion, these observations imply that a greater quantity of off-flavour may be present before acceptance is reduced in the older consumer group. Moreover, diacetyl demonstrates partial masking abilities of sulfurous off-flavours, and BET gave a more conservative estimate of acceptability. This knowledge will help guide sensory innovation of high-protein beverages for older consumers to support product acceptance and optimal intake

An Appetite to Win: Disordered Eating Behaviours amongst Competitive Cyclists

Competitive cyclists may be vulnerable to disordered eating (DE) and eating disorders (ED) due to perceived body composition optimization and external influences within cycling culture and from stakeholders. Therefore, this study aimed to assess DE and ED risk in competitive cyclists using the Eating Attitudes Test (EAT-26), explore differences in responses based on sex, discipline, and level of competition, and to gain insights into contributing factors towards DE via open-ended survey questions. In total, 203 participants completed a mixed-method questionnaire. Eating disorders were reported by 5.7% (n = 11) of participants, with three being historic cases. The median (inter-quartile range) EAT-26 score was 8 (12) of a total possible score of 78. Disordered eating risk was observed in 16.7% of participants due to an EAT-26 score ≥20. Female participants had significantly higher scores than male participants (12.5 ± 17.5 vs. 6.5 ± 10.0; p = 0.004). There was no significant difference between road cyclists and off-road cyclists (7.0 ± 13.25 vs. 8.0 ± 10.5; p = 0.683). There was a significant difference in scores between novice/club/regional and national/elite/professional cyclists (6.0 ± 11.25 vs. 10.5 ± 12.0; p = 0.007). Thematic analysis of open-text responses found that the social environment of competitive cycling contributed towards DE behaviours and body image issues. These findings indicate competitive cyclists do appear to be an ‘at risk’ population for DE/ED. Therefore, there is need for stakeholders to enhance nutritional services, nutrition education, and create supportive athlete environments