The role of plant vasculature in tackling N2O emissions.

Rising demand for protein-rich foods can impact N2O emissions from croplands. Recent research has pointed to the role of modified plant vasculature in grain protein increase. Here we highlight how discovering the mechanistic role of plant vasculature in protein improvement and nitrogen-use efficiency could reduce global N2O emissions.

Challenges facing sustainable protein production: Opportunities for cereals.

Rising demands for protein worldwide are likely to drive increases in livestock production, as meat provides ∼40% of dietary protein. This will come at a significant environmental cost, and a shift toward plant-based protein sources would therefore provide major benefits. While legumes provide substantial amounts of plant-based protein, cereals are the major constituents of global foods, with wheat alone accounting for 15-20% of the required dietary protein intake. Improvement of protein content in wheat is limited by phenotyping challenges, lack of genetic potential of modern germplasms, negative yield trade-offs, and environmental costs of nitrogen fertilizers. Presenting wheat as a case study, we discuss how increasing protein content in cereals through a revised breeding strategy combined with robust phenotyping could ensure a sustainable protein supply while minimizing the environmental impact of nitrogen fertilizer.

Effects of agro-forestry systems on the physical and chemical characteristics of green coffee beans.

Twenty agroforestry systems consisting of different management practices (conventional and organic) and shade types were set up for coffee plantations in 2,000 at the Tropical Agricultural Research and Higher Education Center (CATIE), Turrialba, Costa Rica. The physical (density, bulk density, moisture content, and roasting loss) and chemical attributes (mineral, total lipid, fatty acids, caffeine, and carbohydrate contents) of harvested green coffee beans were investigated. The full sun and Erythrina shade tree systems significantly improved (p < 0.05) the density of the green coffee beans and decreased (p < 0.05) the moisture content and roasting loss of the green coffee beans. The intensive organic (IO) management practice significantly increased some mineral contents, such as K, P, and Ca, in green coffee beans. The full sun system also significantly promoted (p < 0.05) some mineral contents, such as Ca and Mn, in green coffee beans. In terms of total lipid and fatty acids (FAs), compared with the moderate conventional (MC) management practice, the IO management practice was beneficial as it significantly increased (p < 0.05) the total lipid and FAs contents in the green coffee beans, while the Erythrina shade tree system significantly increased (p < 0.05) the total lipid and FAs contents of green coffee beans more efficiently than the other shade types. The caffeine content of green coffee beans was significantly higher (p < 0.05) under the intensive conventional (IC) and IO management practices than under the MC management practice and higher under the full sun system than under the shaded system. The Erythrina shade tree system significantly improved (p < 0.05) the carbohydrate content of green coffee beans. Overall, in consideration of sustainability, the IO management practice associated with the Erythrina shade tree system would be a useful combination for the local farmers to grow coffee trees.

Effect of sweeteners and carbonation on aroma partitioning and release in beverage systems.

The effect of monosaccharides (glucose, fructose and galactose) and disaccharides (sucrose and lactose) at 10, 20 and 30 % w/v on the in-vitro aroma partitioning of C4 - C10 aldehydes and ethyl esters, as well as limonene (concentration of aroma compounds at 1 µg mL-1), was studied using atmospheric pressure chemical ionisation-mass spectrometry. An increase in sugar concentration from 0 to 30 % w/v resulted in a significant increase in partitioning under static headspace conditions for the majority of the compounds (p < 0.05), an effect generally not observed when 10 % w/v sucrose was substituted with low-calorie sweeteners (p > 0.05). The complexity of the system was increased to model a soft drink design - comprising water, sucrose (10, 20 and 30 % w/v), acid (0.15 % w/v), carbonation (∼7.2 g/L CO2) and aroma compounds representative of an apple style flavouring, namely ethyl butanoate and hexanal (10 µg mL-1 each). Although the addition of sucrose had no significant in-vivo effect, carbonation significantly decreased breath-by-breath (in-vivo) aroma delivery (p < 0.05). To understand the physical mechanisms behind aroma release from the beverage matrix, the effect of sucrose on the kinetics of the matrix components was explored. An increase in sucrose concentration from 0 to 30 % w/v resulted in a significant decrease in water activity (p < 0.05), which accounted for the significantly slower rate of self-diffusion of aroma compounds (p < 0.05), measured using diffusion-ordered spectroscopy-nuclear magnetic resonance spectroscopy. No significant effect of sucrose on carbon dioxide volume flux was found (p > 0.05).

Reviving grain quality in wheat through non-destructive phenotyping techniques like hyperspectral imaging.

A long-term goal of breeders and researchers is to develop crop varieties that can resist environmental stressors and produce high yields. However, prioritising yield often compromises improvement of other key traits, including grain quality, which is tedious and time-consuming to measure because of the frequent involvement of destructive phenotyping methods. Recently, non-destructive methods such as hyperspectral imaging (HSI) have gained attention in the food industry for studying wheat grain quality. HSI can quantify variations in individual grains, helping to differentiate high-quality grains from those of low quality. In this review, we discuss the reduction of wheat genetic diversity underlying grain quality traits due to modern breeding, key traits for grain quality, traditional methods for studying grain quality and the application of HSI to study grain quality traits in wheat and its scope in breeding. Our critical review of literature on wheat domestication, grain quality traits and innovative technology introduces approaches that could help improve grain quality in wheat.

The role of inorganic-phosphate, potassium and magnesium in yeast-flavour formation.

Inorganic-phosphate, potassium, and magnesium are key-minerals required for yeast growth, metabolism, and survival, the present work investigated its impact in yeast-flavour formation using a multi-factor experimental design, which was used to generate a range of phosphorous-potassium-magnesium resulting in a 28-point D-optimal design. Samples were evaluated using HPLC (ethanol), GC-MS (aroma), and CountStar (total yeast cell). Results revealed that yeast requires a minimal amount of inorganic-phosphate, potassium, and magnesium (250, 500, and 70 mg/L, respectively) to support yeast-growth and ethanol/flavour formation. Inorganic-phosphate was important for fatty acid esters formation/short chain fatty acid (SCFA) reduction. Potassium was important in the formation of acetate esters/higher alcohols. Magnesium was the most important inorganic element for ester formation/SCFA reduction; furthermore, ethanol production is magnesium-dependent. In conclusion, inorganic phosphate, potassium and magnesium play an important role in yeast-growth, esters and higher alcohols formation; and SCFA reduction. Ethanol formation is Mg-dependent.

Sensory perception and consumer acceptance of commercial and salt-reduced potato crisps formulated using salt reduction design rules.

Successful salt (NaCl) reduction strategies are required to reduce the salt content of snacks while maintaining saltiness perception and consumer acceptance. Previous research suggests that particle physicochemical design rules (small particle size, low density, low hydrophobicity, optimised particle shape) can be leveraged to produce salt particles that enhance saltiness perception. This study aimed to validate these design rules by applying optimised model salts to unsalted potato crisps at a 30% reduced salt content to produce prototype products. A selection of commercial products were also chosen to represent the salt content and crisp style of the broader market, with the aim to investigate the potential of other salt reduction strategies including; direct salt removal without compensation for loss of salt content and increasing time in mouth, while exploring the impact of consumer mouth behaviour type on consumer product preference. Nine products varying in salt content (6 standard, 1 crinkle-cut, 1 thick-cut batch-fried, 1 baked reconstituted potato) were subject to descriptive sensory analysis with a trained panel (n = 11). A subset (seven products) were assessed for consumer acceptance (n = 93). A salt reduction of 30% was achieved while maintaining saltiness perception and consumer acceptance using model salts, while direct removal of salt without perceptual impact was only achievable by 15%. To investigate key drivers of liking, consumers were segmented based on product liking and mouth behaviour. Results suggested that whilst salt content was the primary driver, specific texture profiles were polarising. However, mouth behaviour had minimal influence on preference. These results validate previously described physicochemical design rules for developing novel salt particles for salt reduction and inform ingredient design for the food and flavour industries.

Flavour compounds affect protein structure: The effect of methyl anthranilate on bovine serum albumin conformation.

This study aims to understand possible effects of flavour compounds on the structure and conformation of endogenous proteins. Using methyl anthranilate (a grape flavour compound added to drinks, confectionery, and vape-liquids) and bovine serum albumin (BSA, a model serum protein) we designed experimental investigations using analytical ultracentrifugation, size exclusion chromatography small angle X-ray scattering, and fluorescence spectroscopy to reveal that methyl anthranilate spontaneously binds to BSA (ΔG°, ca. -21 KJ mol-1) which induces a conformational compactness (ca. 10 %) in the monomer structure. Complementary molecular modelling and dynamics simulations suggested the binding occurs at Sudlow II of BSA via establishment of hydrogen bonds with arginine409, lysine413 and serine488 leading to an increased conformational order in domains IA, IIB and IIIB. This work aims to set the foundation for future research on flavour-protein interactions and offer new sets of opportunities for understanding the effects of small compounds on protein structure.

Mechanisms of umami taste perception: From molecular level to brain imaging.

Due to unique characteristics, umami substances have gained much attention in the food industry during the past decade as potential replacers to sodium or fat to increase food palatability. Umami is not only known to increase appetite, but also to increase satiety, and hence could be used to control food intake. Therefore, it is important to understand the mechanism(s) involved in umami taste perception. This review discusses current knowledge of the mechanism(s) of umami perception from receptor level to human brain imaging. New findings regarding the molecular mechanisms for detecting umami tastes and their pathway(s), and the peripheral and central coding to umami taste are reviewed. The representation of umami in the human brain and the individual variation in detecting umami taste and associations with genotype are discussed. The presence of umami taste receptors in the gastrointestinal tract, and the interactions between the brain and gut are highlighted. The review concludes that more research is required into umami taste perception to include not only oral umami taste perception, but also the wider "whole body" signaling mechanisms, to explore the interaction between the brain and gut in response to umami perception and ingestion.

Impact of cooking on the sensory perception and volatile compounds of Takifugu rubripes.

Takifugu rubripes is well-known for its unique flavour but can also develop a putrid off-note. To eliminate off-note and promote desirable flavour, four cooking processes (boiling, steaming, microwave-heating and roasting) were explored to determine their effects on cooked T. rubripes. The temperature and water dynamics, physico-chemical properties were analysed and correlated with sensory qualities. The changes of centre temperature dynamics during cooking decreased the water mobility and led to varied sensory properties. Six out of ten orthonasal aroma attributes and four out of five mouthfeel attributes were significantly different among samples (p < 0.05). Based on partial least squares regression analysis, orthonasal aroma attributes "roasted" and "earthy/putrid fish" highly correlated with the volatile compounds generated from Maillard reaction and lipid oxidation, respectively; meanwhile mouthfeel attributes of chewy/fibre and tender/juicy were highly associated with water loss and moisture, respectively. This study provides insights for optimising cooking conditions to create desirable fish flavour.

Prediction of coffee aroma from single roasted coffee beans by hyperspectral imaging.

Coffee aroma is critical for consumer liking and enables price differentiation of coffee. This study applied hyperspectral imaging (1000-2500 nm) to predict volatile compounds in single roasted coffee beans, as measured by Solid Phase Micro Extraction-Gas Chromatography-Mass Spectrometry and Gas Chromatography-Olfactometry. Partial least square (PLS) regression models were built for individual volatile compounds and chemical classes. Selected key aroma compounds were predicted well enough to allow rapid screening (R2 greater than 0.7, Ratio to Performance Deviation (RPD) greater than 1.5), and improved predictions were achieved for classes of compounds - e.g. aldehydes and pyrazines (R2 âˆ¼ 0.8, RPD âˆ¼ 1.9). To demonstrate the approach, beans were successfully segregated by HSI into prototype batches with different levels of pyrazines (smoky) or aldehydes (sweet). This is industrially relevant as it will provide new rapid tools for quality evaluation, opportunities to understand and minimise heterogeneity during production and roasting and ultimately provide the tools to define and achieve new coffee flavour profiles.

Evaluation of volatile metabolites as potential markers to predict naturally-aged seed vigour by coupling rapid analytical profiling techniques with chemometrics.

Rapid volatile detection methods for seed vigour rely heavily on artificial ageing (AA), however the comparability of volatile organic compounds (VOCs) to natural ageing (NA) and practicability of the detection models were not well known. In this study, VOCs between AA and NA sweet corn seeds were compared and Partial Least Squares Regression (PLS-R) modelswere constructed based on AA to predict the seed vigour of NA. A total of 33 VOCs were identified, among which aldehydes showed the highest consistency between NA and AA. Furthermore, a AS-PLS-R model with variable importance in projection (VIP > 1) and Pearson Correlation Coefficient (r > 0.9) algorithms, which was built on 3 volatile markers: benzaldehyde monomer, n-nonanal, 1-butanol monomer, achieved the best performance (R2p of 0.901 and RMSEP of 0.050). Therefore, coupling Gas Chromatography- Ion Mobility Spectrometry (GC-IMS) with chemometrics can be an effective way to monitor and predict stored seeds vigour.

Impact of cold plasma on the biomolecules and organoleptic properties of foods: A review.

Cold plasma is formed by the nonthermal ionization of gas into free electrons, ions, reactive atomic and molecular species, and ultraviolet (UV) radiation. This cold plasma can be used to alter the surface of solid and liquid foods, and it offers multiple advantages over traditional thermal treatments, such as no thermal damage and increased output variation (due to the various input parameters gas, power, plasma type, etc.). Cold plasma appears to have limited impact on the sensory and color properties, at lower power and treatment times, but there has been a statistically significant reduction in pH for most of the cold plasma treatments reviewed (p < 0.05). Carbohydrates (cross linking and glycosylation), lipids (oxidation), and proteins (secondary structure) are more significantly impacted due to cold plasma at higher intensities and longer treatment times. Although cold plasma treatments and food matrices can vary considerably, this review has identified the literary evidence of some of the influences and impacts of the vast array of cold plasma treatment parameters on the biomolecular and organoleptic properties of these foods. Due to the rapidly evolving nature of the field, we have also identified that authors prioritize the presentation of different information when publishing from different research areas. Therefore, we have proposed a number of key physical and chemical cold plasma parameters that should be considered for inclusion in all future publications in the field.

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.

Influence of essential inorganic elements on flavour formation during yeast fermentation.

The relative concentration of available inorganic elements is critical for yeast growth and metabolism and has potential to be a tool leading to directed yeast flavour formation during fermentation. This study investigates the influence of essential inorganic elements during alcoholic fermentation of brewers wort, fermented using three independent yeast strains, Saccharomyces pastorianus W34/70, and Saccharomyces cerevisiae strains M2 and NCYC2592 under a range of conditions replicated for each yeast strain. 10 treatments were applied: 1 control and 9 inorganic supplementations: standard brewers wort, ammonia-nitrogen, inorganic phosphate, potassium, magnesium, copper, zinc, iron, manganese and a composite mixture, Twenty-five chemical markers were evaluated by HPLC (ethanol, glycerol), and GC-MS (aroma). There was a significant change in volatile aroma compounds during fermentation, which was more prominent when supplemented with ammonia nitrogen, inorganic phosphate, potassium or magnesium (P < 0.05). Heavy metal ions mostly had a negative effect on the flavour formation.

The role of sodium chloride in the sensory and physico-chemical properties of sweet biscuits.

Salt is included in many foods which consumers do not regard as salty. This "hidden-salt" may offer functional benefits but is often overlooked in sodium reduction strategies. This study investigated its role in shortbread-like sweet biscuits (1.05 g NaCl/100 g). Sensory tests revealed significant flavour and texture differences after a salt reduction of 33% (0.86 g/ 100 g). This was explained by differences in the partitioning of hydrophobic aroma compounds into the headspace and a significant impact on structure. Texture analysis and X-ray-µCT measurements revealed a reduced hardness with larger and more air cells in salt-reduced biscuits. It is suggested that salt impacts on cereal proteins by altering their aggregation around flour particles and at bubble walls and that slower water loss occurs in salted matrices during baking. Hence, this study revealed the key properties significantly affected by salt reduction and proposes an explanation which will help to develop a targeted "hidden-salt" reduction strategy.

Total lipid prediction in single intact cocoa beans by hyperspectral chemical imaging.

This work aimed to explore the possibility of predicting total fat content in whole dried cocoa beans at a single bean level using hyperspectral imaging (HSI). 170 beans randomly selected from 17 batches were individually analysed by HSI and by reference methodology for fat quantification. Both whole (i.e. in-shell) beans and shelled seeds (cotyledons) were analysed. Partial Least Square (PLS) regression models showed good performance for single shelled beans (R2 = 0.84, external prediction error of 2.4%). For both in-shell beans a slightly lower prediction error of 4.0% and R2 = 0.52 was achieved, but fat content estimation is still of interest given its wide range. Beans were manually segregated, demonstrating an increase by up to 6% in the fat content of sub-fractions. HSI was shown to be a valuable technique for rapid, non-contact prediction of fat content in cocoa beans even from scans of unshelled beans, enabling significant practical benefits to the food industry for quality control purposes and for obtaining a more consistent raw material.

Probing the effect of aroma compounds on the hydrodynamic properties of mucin glycoproteins.

Aroma compounds are diverse low molecular weight organic molecules responsible for the flavour of food, medicines or cosmetics. Natural and artificial aroma compounds are manufactured and used by the industry to enhance the flavour and fragrance of products. While the low concentrations of aroma compounds present in food may leave no effect on the structural integrity of the mucosa, the effect of concentrated aroma volatiles is not well understood. At high concentrations, like those found in some flavoured products such as e-cigarettes, some aroma compounds are suggested to elicit a certain degree of change in the mucin glycoprotein network, depending on their functional group. These effects are particularly associated with carbonyl compounds such as aldehydes and ketones, but also phenols which may interact with mucin and other glycoproteins through other interaction mechanisms. This study demonstrates the formation of such interactions in vitro through the use of molecular hydrodynamics. Sedimentation velocity studies reveal that the strength of the carbonyl compound interaction is influenced by compound hydrophobicity, in which the more reactive short chain compounds show the largest increase in mucin-aroma sedimentation coefficients. By contrast, the presence of groups that increases the steric hindrance of the carbonyl group, such as ketones, produced a milder effect. The interaction effects were further demonstrated for hexanal using size exclusion chromatography light scattering (SEC-MALS) and intrinsic viscosity. In addition, phenolic aroma compounds were identified to reduce the sedimentation coefficient of mucin, which is consistent with interactions in the non-glycosylated mucin region.

Policy, toxicology and physicochemical considerations on the inhalation of high concentrations of food flavour.

Food flavour ingredients are required by law to obtain prior approval from regulatory bodies, such as the U.S. Food and Drug Administration (FDA) or the European Food Safety Authority (EFSA) in terms of toxicological data and intended use levels. However, there are no regulations for labelling the type and concentration of flavour additives on the product, primarily due to their low concentration in food and generally recognised as safe (GRAS) status determined by the flavour and extract manufacturers' association (FEMA). Their status for use in e-cigarettes and other vaping products challenges these fundamental assumptions, because their concentration can be over ten-thousand times higher than in food, and the method of administration is through inhalation, which is currently not evaluated by the FEMA expert panel. This work provides a review of some common flavour ingredients used in food and vaping products, their product concentrations, inhalation toxicity and aroma interactions reported with different biological substrates. We have identified several studies, which suggest that the high concentrations of flavour through inhalation may pose a serious health threat, especially in terms of their cytotoxicity. As a result of the wide range of possible protein-aroma interactions reported in our diet and metabolism, including links to several non-communicable diseases, we suggest that it is instrumental to update current flavour- labelling regulations, and support new strategies of understanding the effects of flavour uptake on the digestive and respiratory systems, in order to prevent the onset of future non-communicable diseases.

Growth Spectrum Complexity Dictates Aromatic Intensity in Coriander (Coriandrum sativum L.).

Advancements in availability and specificity of light-emitting diodes (LEDs) have facilitated trait modification of high-value edible herbs and vegetables through the fine manipulation of spectra. Coriander (Coriandrum sativum L.) is a culinary herb, known for its fresh, citrusy aroma, and high economic value. Studies into the impact of light intensity and spectrum on C. sativum physiology, morphology, and aroma are limited. Using a nasal impact frequency panel, a selection of key compounds associated with the characteristic aroma of coriander was identified. Significant differences (P < 0.05) were observed in the concentration of these aromatics between plants grown in a controlled environment chamber under the same photosynthetic photon flux density (PPFD) but custom spectra: red (100%), blue (100%), red + blue (RB, 50% equal contribution), or red + green + blue (RGB, 35.8% red: 26.4% green: 37.8% blue) wavelengths. In general, the concentration of aromatics increased with increasing numbers of wavelengths emitted alongside selective changes, e.g., the greatest increase in coriander-defining E-(2)-decenal occurred under the RGB spectrum. This change in aroma profile was accompanied by significant differences (P < 0.05) in light saturated photosynthetic CO2 assimilation, water-use efficiency (Wi), and morphology. While plants grown under red wavelengths achieved the greatest leaf area, RB spectrum plants were shortest and had the highest leaf:shoot ratio. Therefore, this work evidences a trade-off between sellable commercial morphologies with a weaker, less desirable aroma or a less desirable morphology with more intense coriander-like aromas. When supplemental trichromatic LEDs were used in a commercial glasshouse, the majority of compounds, with the exception of linalool, also increased showing that even as a supplement additional wavelength can modify the aromatic profile increasing its complexity. Lower levels of linalool suggest these plants may be more susceptible to biotic stress such as herbivory. Finally, the concentration of coriander-defining aromatics E-(2)-decenal and E-(2)-hexenal was significantly higher in supermarket pre-packaged coriander leaves implying that concentrations of aromatics increase after excision. In summary, spectra can be used to co-manipulate aroma profile and plant form with increasing spectral complexity leading to greater aromatic complexity and intensity. We suggest that increasing spectral complexity progressively stimulates signaling pathways giving rise to valuable economic traits.