Microstructure design strategies to enhance aroma and tastant availability in foods

Nutritionally improving foods through reduction of sugar, salt and fat in foods is important to decrease the prevalence of diet related diseases. Common strategies used in the food industry often result in changes in perception of texture and flavour. The role of sugar in confectionery gels extends beyond just taste and sweetness purposes, as it also affects a variety of properties such as structure, texture and shelf life. Therefore, nutritionally improving confectionery gels using conventional strategies is difficult and it is important to develop novel routes to reformulate and modify energy density without compromising sensory quality. Two microstructure design strategies were investigated based on the properties of the hydrocolloids chosen, gelatine and starch, and the thermodynamic incompatibility of these hydrocolloids under certain conditions. Microstructure design strategies in literature have focused on sensory perception of modified products. However only few of these studies have investigated flavour release. Also there is limited understanding of how these strategies affect a matrix with mixed hydrocolloids and high solute concentration. This research addresses these gaps of knowledge. Firstly, gelatine and acid thinned starch gels were developed with the hydrocolloids existing as a miscible single phase, containing different gas inclusions as a dispersed phase. Different methods, chemical and mechanical, were trialled to produce gas filled gels (air, carbon dioxide, helium and nitrogen). An easy and quick way to produce gas filled gels by generating CO2 in situ was developed using sodium bicarbonate to react with acid in the gel. Maximum intensity of aroma release and sucrose release was significantly greater from gas filled gels compared to control gels of the same mass without CO2 inclusions (P<0.05, panellists n=1 for analytical method development). Aerated confectionery gels were developed using a thermally controlled mixing method. By correlating aroma and sucrose release with sensory time intensity analysis, for the first time, changes in flavour perception over time as a result of air inclusions was investigated. Overall flavour perception over time of aerated gels with 23% and 38% reduced density, and therefore a lower total mass of aroma and sugar and reduced calories, did not differ from the control non-aerated gel, as assessed by trained sensory panellists (n=10). X-ray CT scans of the gels provided a 3D view of bubble distribution inside the gel, and a quantitative comparison of bubble size between the gels. Bubble properties were investigated through addition of different gases, and significant differences in texture parameters of the gels produced with different gases such as hardness and springiness was observed (P<0.05). Initial aroma release rates in vitro were significantly slower for gels formed by incorporating helium (P<0.05), showing an extended release compared to the other gas types. Thus, offering a different release profile depending on desired flavour release profiles of a product. The second microstructure consisted of a phase separated gelatine-starch network, with a continuous phase rich in gelatine and a dispersed phase consisting of starch, and vice versa. A phase diagram was produced to investigate gels of different microstructures with the same effective concentration of gelatine and starch in each phase. Aroma release significantly differed in vitro but not when gels were consumed in vivo by panellists (n=5). The effects of sucrose concentration (0-60%) on the phase separated network was investigated. The microstructure changed with increased sucrose concentration as the dispersed starch phase became less aggregated at sucrose concentrations >40%. This resulted in increased interactions with more hydrophobic, less volatile compounds as a significant increase in affinity for the starch phase was observed for a majority of these compounds. Physicochemical properties of the aroma compound influence the interactions with gelatine or starch phase, and when the microstructure is changed the affinity for each phase may also change. Therefore, changes in matrix properties and resulting changes in aroma balance need to be carefully taken into consideration when changing the concentration of sucrose in hydrocolloid based foods. The aims of this research were to develop methods to produce different model systems and investigate the mechanisms of flavour release from gels with gas or a second hydrocolloid as a dispersed phase. Also, to investigate how changes in sucrose concentration affects components of the gel network for optimised delivery of aroma and tastants. Many studies have investigated sensory perception of gels with modified microstructures, however little is known about actual flavour release. Research into these microstructure design strategies has applications in foods that may be aerated such as protein bars, and foods with phase separated microstructures such as dairy desserts. Organoleptic quality of food is largely influenced by flavour, therefore understanding flavour release mechanisms is vital to be able to successfully reformulate foods to meet nutritional guidelines without affecting sensory perception and reducing product quality

Flavour distribution and release from gelatine-starch matrices

© 2020 The Authors Microstructure design of protein-polysaccharide phase separated gels has been suggested as a strategy to nutritionally improve food products. Varying the phase volumes of a phase separated matrix may affect texture and overall flavour balance of the final product, which are both important for consumer acceptance. The aims of this study were to investigate how modifying the phase volumes of a gelatine-starch biphasic mixture affected aroma release, and how addition of sucrose affects phase separation, flavour distribution and aroma release. Biphasic gels of different microstructures with the same effective concentration of gelatine and starch in each phase were developed. Microstructure significantly affected aroma release in vitro but not in vivo when panellists (n = 5) chewed and swallowed the sample. Addition of sucrose (0–60%) to the biphasic mixture significantly reduced water activity, affected the microstructure and affected aroma distribution in each phase and subsequent release rates depending on the physicochemical properties of the aroma volatile. In general, affinity for the gelatine phase for the less hydrophobic, more volatile compounds was not significantly affected by sucrose concentration. Whereas an increased affinity for the starch phase for the more hydrophobic, less volatile compounds was observed with increased sucrose as the starch phase becomes more dispersed at sucrose concentrations between 40 and 60%. The results of this study may be of interest to researchers and industry to enable prediction of how reformulation, such as reduction of sucrose, to meet nutritional guidelines may affect the overall aroma balance of a phase separated food matrix

Reducing sugar and aroma in a confectionery gel without compromising flavour through addition of air inclusions

Sugar plays an important role in both the flavour and structure of confectionery. Targets have been set to reduce sugar; however, common strategies often result in changes in flavour and consumer rejection. In this study, an approach was developed to reduce sugar in confectionery gels by aeration, without significantly affecting perceived chewiness. Gelatine based gels with a 23% and 38% reduction in density were formulated using aeration. Mean bubble size was consistent across all gels (0.05–0.06 mm). Time-intensity sensory evaluation was carried out by a trained sensory panel (n = 10). With aeration, no significant difference in overall flavour perception was observed in the 23% and 38% reduced sugar and aroma gels. Air inclusions create a greater surface area, therefore accelerating mass transfer of volatiles and release of sucrose at the food-saliva interface. Consequently, we propose that less calorie dense products can be produced without compromising flavour by using gel aeration technologies

The Yuan-Tseh Lee Array for Microwave Background Anisotropy

The Yuan-Tseh Lee Array for Microwave Background Anisotropy (AMiBA) is the first interferometer dedicated to studying the cosmic microwave background (CMB) radiation at 3mm wavelength. The choice of 3mm was made to minimize the contributions from foreground synchrotron radiation and Galactic dust emission. The initial configuration of seven 0.6m telescopes mounted on a 6-m hexapod platform was dedicated in October 2006 on Mauna Loa, Hawaii. Scientific operations began with the detection of a number of clusters of galaxies via the thermal Sunyaev-Zel'dovich effect. We compare our data with Subaru weak lensing data in order to study the structure of dark matter. We also compare our data with X-ray data in order to derive the Hubble constant.Comment: accepted for publication in ApJ (13 pages, 7 figures); a version with high resolution figures available at http://www.asiaa.sinica.edu.tw/~keiichi/upfiles/AMiBA7/pho_highreso.pd

The AMiBA Hexapod Telescope Mount

AMiBA is the largest hexapod astronomical telescope in current operation. We present a description of this novel hexapod mount with its main mechanical components -- the support cone, universal joints, jack screws, and platform -- and outline the control system with the pointing model and the operating modes that are supported. The AMiBA hexapod mount performance is verified based on optical pointing tests and platform photogrammetry measurements. The photogrammetry results show that the deformations in the inner part of the platform are less than 120 micron rms. This is negligible for optical pointing corrections, radio alignment and radio phase errors for the currently operational 7-element compact configuration. The optical pointing error in azimuth and elevation is successively reduced by a series of corrections to about 0.4 arcmin rms which meets our goal for the 7-element target specifications.Comment: Accepted for ApJ, 33 pages, 15 figure

A nationwide study of adults admitted to hospital with diabetic ketoacidosis or hyperosmolar hyperglycaemic state and COVID‐19

AimsTo investigate characteristics of people hospitalized with coronavirus-disease-2019 (COVID-19) and diabetic ketoacidosis (DKA) or hyperosmolar hyperglycaemic state (HHS), and to identify risk factors for mortality and intensive care admission.Materials and methodsRetrospective cohort study with anonymized data from the Association of British Clinical Diabetologists nationwide audit of hospital admissions with COVID-19 and diabetes, from start of pandemic to November 2021. The primary outcome was inpatient mortality. DKA and HHS were adjudicated against national criteria. Age-adjusted odds ratios were calculated using logistic regression.ResultsIn total, 85 confirmed DKA cases, and 20 HHS, occurred among 4073 people (211 type 1 diabetes, 3748 type 2 diabetes, 114 unknown type) hospitalized with COVID-19. Mean (SD) age was 60 (18.2) years in DKA and 74 (11.8) years in HHS (p < .001). A higher proportion of patients with HHS than with DKA were of non-White ethnicity (71.4% vs 39.0% p = .038). Mortality in DKA was 36.8% (n = 57) and 3.8% (n = 26) in type 2 and type 1 diabetes respectively. Among people with type 2 diabetes and DKA, mortality was lower in insulin users compared with non-users [21.4% vs. 52.2%; age-adjusted odds ratio 0.13 (95% CI 0.03-0.60)]. Crude mortality was lower in DKA than HHS (25.9% vs. 65.0%, p = .001) and in statin users versus non-users (36.4% vs. 100%; p = .035) but these were not statistically significant after age adjustment.ConclusionsHospitalization with COVID-19 and adjudicated DKA is four times more common than HHS but both associate with substantial mortality. There is a strong association of previous insulin therapy with survival in type 2 diabetes-associated DKA

Mitochondrial abnormalities in Parkinson's disease and Alzheimer's disease: can mitochondria be targeted therapeutically?

Mitochondrial abnormalities have been identified as a central mechanism in multiple neurodegenerative diseases and, therefore, the mitochondria have been explored as a therapeutic target. This review will focus on the evidence for mitochondrial abnormalities in the two most common neurodegenerative diseases, Parkinson's disease and Alzheimer's disease. In addition, we discuss the main strategies which have been explored in these diseases to target the mitochondria for therapeutic purposes, focusing on mitochondrially targeted antioxidants, peptides, modulators of mitochondrial dynamics and phenotypic screening outcomes

Microstructure design strategies to enhance aroma and tastant availability in foods

Nutritionally improving foods through reduction of sugar, salt and fat in foods is important to decrease the prevalence of diet related diseases. Common strategies used in the food industry often result in changes in perception of texture and flavour. The role of sugar in confectionery gels extends beyond just taste and sweetness purposes, as it also affects a variety of properties such as structure, texture and shelf life. Therefore, nutritionally improving confectionery gels using conventional strategies is difficult and it is important to develop novel routes to reformulate and modify energy density without compromising sensory quality. Two microstructure design strategies were investigated based on the properties of the hydrocolloids chosen, gelatine and starch, and the thermodynamic incompatibility of these hydrocolloids under certain conditions. Microstructure design strategies in literature have focused on sensory perception of modified products. However only few of these studies have investigated flavour release. Also there is limited understanding of how these strategies affect a matrix with mixed hydrocolloids and high solute concentration. This research addresses these gaps of knowledge. Firstly, gelatine and acid thinned starch gels were developed with the hydrocolloids existing as a miscible single phase, containing different gas inclusions as a dispersed phase. Different methods, chemical and mechanical, were trialled to produce gas filled gels (air, carbon dioxide, helium and nitrogen). An easy and quick way to produce gas filled gels by generating CO2 in situ was developed using sodium bicarbonate to react with acid in the gel. Maximum intensity of aroma release and sucrose release was significantly greater from gas filled gels compared to control gels of the same mass without CO2 inclusions (P<0.05, panellists n=1 for analytical method development). Aerated confectionery gels were developed using a thermally controlled mixing method. By correlating aroma and sucrose release with sensory time intensity analysis, for the first time, changes in flavour perception over time as a result of air inclusions was investigated. Overall flavour perception over time of aerated gels with 23% and 38% reduced density, and therefore a lower total mass of aroma and sugar and reduced calories, did not differ from the control non-aerated gel, as assessed by trained sensory panellists (n=10). X-ray CT scans of the gels provided a 3D view of bubble distribution inside the gel, and a quantitative comparison of bubble size between the gels. Bubble properties were investigated through addition of different gases, and significant differences in texture parameters of the gels produced with different gases such as hardness and springiness was observed (P<0.05). Initial aroma release rates in vitro were significantly slower for gels formed by incorporating helium (P<0.05), showing an extended release compared to the other gas types. Thus, offering a different release profile depending on desired flavour release profiles of a product. The second microstructure consisted of a phase separated gelatine-starch network, with a continuous phase rich in gelatine and a dispersed phase consisting of starch, and vice versa. A phase diagram was produced to investigate gels of different microstructures with the same effective concentration of gelatine and starch in each phase. Aroma release significantly differed in vitro but not when gels were consumed in vivo by panellists (n=5). The effects of sucrose concentration (0-60%) on the phase separated network was investigated. The microstructure changed with increased sucrose concentration as the dispersed starch phase became less aggregated at sucrose concentrations >40%. This resulted in increased interactions with more hydrophobic, less volatile compounds as a significant increase in affinity for the starch phase was observed for a majority of these compounds. Physicochemical properties of the aroma compound influence the interactions with gelatine or starch phase, and when the microstructure is changed the affinity for each phase may also change. Therefore, changes in matrix properties and resulting changes in aroma balance need to be carefully taken into consideration when changing the concentration of sucrose in hydrocolloid based foods. The aims of this research were to develop methods to produce different model systems and investigate the mechanisms of flavour release from gels with gas or a second hydrocolloid as a dispersed phase. Also, to investigate how changes in sucrose concentration affects components of the gel network for optimised delivery of aroma and tastants. Many studies have investigated sensory perception of gels with modified microstructures, however little is known about actual flavour release. Research into these microstructure design strategies has applications in foods that may be aerated such as protein bars, and foods with phase separated microstructures such as dairy desserts. Organoleptic quality of food is largely influenced by flavour, therefore understanding flavour release mechanisms is vital to be able to successfully reformulate foods to meet nutritional guidelines without affecting sensory perception and reducing product quality

Performance analysis on a high-temperature solar evacuated receiver with an inner radiation shield

A novel solar evacuated receiver as the key part of parabolic trough collector (PTC) was designed and constructed by authors. The novel evacuated receiver (NER) with an inner radiation shield can significantly decrease heat loss at higher operating temperatures when compared with the traditional evacuated receiver (TER). A thermodynamic model relying on the spectrum parameter model of radiation heat transfer was developed to predict the performances of evacuated receivers. Also, experiments using the novel evacuated receiver and traditional evacuated receiver were conducted in the laboratory under different parametric conditions to validate results obtained for the simulation. A comparison between simulation results and experimental data demonstrated that the model was able to yield satisfactory consistencies and predictions to a reasonable accuracy (with the root mean square deviations less than 6%). Results indicated that the novel evacuated receiver has a role in decreasing the total heat loss of receiver compared with the traditional receiver when the working temperature is higher than 296 °C, the heat loss reduction percentage of the novel evacuated receiver reaches 19.1% when the operating temperature is 480 °C, and the value of this percentage would be greater at higher working temperatures