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Highlights: [•] Flavour of medium and long shelf-life Charentais cantaloupe melons was compared. [•] Volatile and semi-volatile profiles were correlated with sensory data using multifactorial analysis. [•] Maturity at harvest has a significant impact on the flavour of medium-shelf life fruit. [•] Maturity at harvest had much less impact on a long shelf-life genotype. [•] Esters and sulphur-compounds were more abundant in mature medium shelf-life fruit. [Copyright &y& Elsevier]

Abstract: Novel acidic varieties of muskmelon (Cucumis melo L.) are emerging onto the UK market. These melons contain almost twice the amount of citric acid compared to standard melons and are described as ‘zesty and fresh’. This study compared the flavour components of three acidic varieties with a standard Galia-type melon. The volatile and semivolatile compounds were extracted, using dynamic headspace extraction (DHE) or solid-phase microextraction (SPME) and solid phase extraction (SPE), respectively, followed by gas chromatography–mass spectrometry (GC–MS) and gas chromatography–olfactometry (GC–O). More than 50 volatile and 50 semivolatile compounds were identified in the headspace and the SPE extracts, respectively. GC–O revealed 15 odour-active components in the headspace, with esters being consistently higher in the acidic variety. This study showed quantitative and qualitative differences among all four varieties and key differences between acidic varieties and standard melons. [Copyright &y& Elsevier]

Control and optimisation of flavour is the ultimate challenge for the food and flavour industry. The major route to flavour formation during thermal processing is the Maillard reaction, which is a complex cascade of interdependent reactions initiated by the reaction between a reducing sugar and an amino compound. The complexity of the reaction means that researchers turn to kinetic modelling in order to understand the control points of the reaction and to manipulate the flavour profile. Studies of the kinetics of flavour formation have developed over the past 30 years from single- response empirical models of binary aqueous systems to sophisticated multi-response models in food matrices, based on the underlying chemistry, with the power to predict the formation of some key aroma compounds. This paper discusses in detail the development of kinetic models of thermal generation of flavour and looks at the challenges involved in predicting flavour. Copyright © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

[Display omitted] • Retention in the mouth following brushing determines the efficiency of toothpastes. • New in vitro methodologies developed to evaluate toothpaste retention in the oral cavity. • Retention in the oral cavity depends on the type of polymer used in the formulation. • The use of polymers with strong mucoadhesive properties can improve retention in the mouth. Retention of active ingredients of toothpastes in the mouth following brushing determines the efficiency of these oral care formulations. In this study, new in vitro methodologies for the observation and measurement of toothpaste retention in the oral cavity were developed and used to evaluate the efficiency of formulations containing different mucoadhesive hydrophilic polymers. The findings suggest that using Carbopol ETD 2020 and Carbopol Ultrez 10 as binders in toothpaste prolongs the retention time of these formulations in the oral cavity. The in vitro methodologies tested, coupled with texture analysis, were able to accurately characterise the behaviour of the toothpaste and produce detailed images showing how it is retained in the oral cavity. This study has not only produced a new method for studying the behaviour of toothpaste and other formulations in the oral cavity but is also the first to investigate how different types of mucoadhesive binders can be used to improve toothpaste retention. [ABSTRACT FROM AUTHOR]

[Display omitted] • The oral cavity has a very diverse bacterial flora that inhabits it. • Modern oral care products are complex formulations containing many ingredients. • Advanced formulations provide extended release of ingredients vital for dental health. • Further research on new ways of increasing the retention time of formulations in the mouth is needed. This review explores the physical, chemical and structural properties of key components of oral care products, whilst looking at the challenges which need to be overcome to continue to improve the efficacy of oral care, and improve dental health. Oral care has been an essential part of all populations and cultures around the world for thousands of years. To maintain good oral health, dental plaque causing bacteria and malodour must be controlled whilst also strengthening and protecting the teeth to prevent dental caries. Advanced modern formulations need to provide controlled and extended release of ingredients vital for dental health. With modern day products such as toothpastes and mouthwashes, it has never been easier to maintain good oral hygiene and health, yet the incidence of dental caries is still on the rise. The complex formulations of modern toothpastes and mouthwashes makes them one of the most sophisticated pharmaceutical products on the market today. The demands of the consumer coupled with the complexity of the oral cavity make it one of the most challenging development processes. [ABSTRACT FROM AUTHOR]

The aim of this work was to identify volatiles that contribute to the aroma of cooked cheese, including the role of fat content in their development during cooking. Volatiles and odorants in cooked mature Cheddar were identified using a combination of SPME (solid‐phase microextraction)/GC–O (gas chromatography–olfactometry) and SPME/GC–MS (gas chromatography–mass spectrometry). A selection of the odorants was quantitated in six cheeses, uncooked and cooked, (mature Cheddar, high‐, medium‐, and low‐fat mild Cheddar, mozzarella, and Parmesan). Many compounds showed significant differences between cooked and uncooked cheese; Strecker aldehydes, pyrazines, and furanones were all significantly higher in cooked cheeses than in uncooked cheese, while ethyl esters (key odorants in uncooked cheese) were not detected in any of the cooked cheese. Principal component analysis demonstrated that fat concentration in mild Cheddar was positively correlated with the formation of potential odorants (the Strecker aldehydes, methanethiol, 2‐methylketones, and fatty acids) upon cooking. Potential lipid precursors for these compounds are discussed. Practical Application: This research can be used by the dairy industry to develop better cheeses, especially low‐ and reduced‐fat cheeses, for use in cooked applications such as toppings for pizzas and ready meals. Alternatively, this research describes key volatile compounds in cooked cheese that can be used by the flavoring industry to develop authentic cooked cheese flavorings. [ABSTRACT FROM AUTHOR]

BACKGROUND: Wheat distillers' grains (WDG) and seaweeds are recommended as alternative protein sources and enteric methane mitigators in dairy cow diets, respectively, but little is known about their impact on milk quality and safety. In the present study, 16 cows in four 4 × 4 Latin squares were fed isonitrogenous diets (50:50 forage:concentrate ratio), with rapeseed meal (RSM)‐based or WDG‐based concentrate (230 and 205 g kg−1 dry matter) and supplemented with or without Saccharina latissima. RESULTS: Replacement of RSM with WDG enhanced milk nutritional profile by decreasing milk atherogenicity (P = 0.002) and thrombogenicity (P = 0.019) indices and the concentrations of the nutritionally undesirable saturated fatty acids – specifically, lauric (P = 0.045), myristic (P = 0.022) and palmitic (P = 0.007) acids. It also increased milk concentrations of the nutritionally beneficial vaccenic (P < 0.001), oleic (P = 0.030), linoleic (P < 0.001), rumenic (P < 0.001) and α‐linolenic (P = 0.012) acids, and total monounsaturated (P = 0.044), polyunsaturated (P < 0.001) and n‐6 (P < 0.001) fatty acids. Feeding Saccharina latissima at 35.7 g per cow per day did not affect the nutritionally relevant milk fatty acids or pose any risk on milk safety, as bromoform concentrations in milk were negligible and unaffected by the dietary treatments. However, it slightly reduced milk concentrations of pantothenate. CONCLUSION: Feeding WDG to dairy cows improved milk fatty acid profiles, by increasing the concentrations of nutritionally beneficial fatty acids and reducing the concentration of nutritionally undesirable saturated fatty acids, while feeding seaweed slightly reduced pantothenate concentrations. However, when considering the current average milk intakes in the population, the milk compositional differences between treatments in this study appear relatively small to have an effect on human health. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Phospholipids are an important precursor for the generation of carbonyl compounds that play a significant role in the characteristic aroma of deep‐fat fried foods. RESULTS: Phospholipids extracted from hen egg yolks were added into sunflower oil (2.0 g kg−1) and heated with or without chicken meat at 160 °C for 10 min, and then dynamic headspace extraction and gas chromatography–mass spectrometry were used to extract and analyse the volatiles. The results showed that the characteristic deep‐fat frying odorants, such as (E,E)‐2,4‐decadienal and (E,Z)‐2,4‐decadienal, as well as 1‐octen‐3‐one, (E)‐2‐nonenal, octanal, methional, dimethyl disulfide and alkylpyrazines, had increased by 3–65 times in the sunflower oil with added phospholipids, and increased up to six times in chicken meat that had been treated with phospholipids prior to heating. CONCLUSION: There is potential for the food industry to use low levels of phospholipids, particularly egg yolk phospholipids, to increase deep‐fat frying odorants in a wide range of deep‐fried products. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Highlights • Phospholipids and neutral lipids extracted from egg yolk were added to chicken meat. • GC–MS showed key volatiles significantly increased when phospholipids were added. • Sensory profiling showed an increase in chicken meat aroma. • Addition of neutral lipids had very little impact on the volatile profile or aroma. • Addition of egg yolks phospholipids can be applied to improve chicken meat aroma. Abstract Lipids, particularly phospholipids, are known to play a significant role in the characteristic aroma of the different meat species. Both neutral lipids and phospholipids were extracted from egg yolk and added to minced chicken (1% w/w) prior to cooking in water at 100 °C for 20 min. Sensory analysis of the broths showed that the addition of phospholipids significantly increased the chicken meat aroma whereas the addition of neutral lipids did not. GC–MS analysis showed a significant increase in most of the lipid-derived volatile components when the phospholipids were added, especially 2,4-decadienal, which is a characteristic odour impact compound in chicken. There were very few significant changes in the volatile profile when the neutral lipids were added. These data provide direct evidence that the addition of phospholipids can enhance chicken meat aroma, and addition of egg yolk phospholipids could be applied to improve chicken meat aroma. [ABSTRACT FROM AUTHOR]

Polysaccharides have many roles across both the food and pharmaceutics industries. They are commonly used to enhance viscosity, stabilise emulsions and to add bulk to food products. In the pharmaceutics industry, they are also utilised for their mucoadhesive nature. Mucoadhesive polysaccharides can facilitate retention of active ingredients at mucosal sites for a prolonged time and formulations can be designed to control their release and bioavailability. This study investigates how polysaccharides, with differing physicochemical properties (e.g. functional groups and molecular weight), affect the release and perception of flavour compounds from films. Polysaccharide films were prepared using either high or low viscosity carboxymethyl cellulose, pullulan or hydroxypropyl methylcellulose. Glucose, vanillin or a combination of both was also added to the films to assess the effect of flavour release and perception over time. The films were assessed for glucose release in vitro , swelling and disintegration times, and mucoadhesive ability. Results show that flavour release and perception depend on the polysaccharide matrix properties; this includes how quickly the films dissolve, the rate of release of tastant compounds, and the mucoadhesive strength of the polysaccharide. A higher viscosity and slower disintegration time resulted in slower release of glucose in vitro and flavour perception in vivo . [ABSTRACT FROM AUTHOR]

Mapping molecular structure to odor perception is a key challenge in olfaction. We used graph neural networks to generate a principal odor map (POM) that preserves perceptual relationships and enables odor quality prediction for previously uncharacterized odorants. The model was as reliable as a human in describing odor quality: On a prospective validation set of 400 out-of-sample odorants, the model-generated odor profile more closely matched the trained panel mean than did the median panelist. By applying simple, interpretable, theoretically rooted transformations, the POM outperformed chemoinformatic models on several other odor prediction tasks, indicating that the POM successfully encoded a generalized map of structure-odor relationships. This approach broadly enables odor prediction and paves the way toward digitizing odors. [ABSTRACT FROM AUTHOR]

The shift in consumer landscape towards vegan, vegetarian and flexitarian diets has created an unprecedented challenge in creating meat aroma from plant-based alternatives. The search for potential vegan solutions has thus led to a renewed interest in authentic meat flavour profiles. To gain a better understanding of the qualitative odour differences between boiled beef and boiled chicken, aroma extracts were isolated using Likens-Nickerson simultaneous distillation-extraction (SDE), selected expressly because the in-situ heating of the sample facilitates the capture of aroma intermediates during the cooking process, thereby mimicking the cooking of meat in stocks and stews. The extracts were then analysed by Gas Chromatography-Mass Spectrometry (GC-MS) and GC-Olfactometry (GC-O). Most of the volatiles identified in this study were sulfur-containing compounds, such as sulfides, thiols, mercaptoaldehydes and mercaptoketones, which are derived from the Maillard reaction. Meanwhile, lipid oxidation results in the formation of unsaturated aldehydes, such as alkenals and alkadienals. Families of thiazoles and 3-thiazolines were found in the extracts. Two novel 3-thiazolines (5-ethyl-2,4-dimethyl-3-thiazoline and 2-ethyl-4,5-dimethyl-3-thiazoline) which may also contribute to the meaty aroma were identified in this work and synthesised from their respective aldehyde and mercaptoketone precursors. [ABSTRACT FROM AUTHOR]

Control of aroma formation during production of barley malt is critical to provide consistent and high-quality products for the brewing industry. Malt quality can be affected by the inherent variability of raw material and processing conditions, leading to inconsistent and/or undesirable profiles. Dried green malts were cured isothermally at 65, 78 and 90 °C for 8.4 h, and characteristic aroma compounds (Strecker aldehydes), precursors and intermediate compounds were analysed over time. By kinetic modelling of Strecker aldehydes, based on fundamental chemical pathways, we showed that degradation of Amadori rearrangement products and short-chain dicarbonyls was more sensitive to temperature change due to their higher activation energies compared to other kinetic steps. This study can help maltsters to manipulate formation of Strecker aldehydes, via raw material screening and process control, and hence optimise the organoleptic quality of malts and their products, such as non-alcoholic beers, where these aldehydes play a key role. [Display omitted] • A mathematical model for aroma formation during malt kilning has been developed. • The model was built using industrially germinated barley kilned on a pilot scale. • The concentration and kinetic profiles of ARP during malt kilning are reported for the first time. • The model shows a greater reduction of the degradation of ARP at lower temperatures. • We now understand the impact of temperature change on different steps of the reaction. [ABSTRACT FROM AUTHOR]

• Heating time increases oral retention of whey protein up to 1 min post-consumption. • Heating whey protein concentrate increases free thiol concentration. • Heating changes secondary and tertiary structures of whey protein concentrate. • Circular dichroism found protein unfolding and changes to β-barrel with heating. • Nuclear magnetic resonance found heating leads to hydrophobic group exposure. This study investigated structural changes and the in vivo retention in the oral cavity of heated whey protein concentrate (WPC). Heated WPC was shown to have both a higher retention time in the oral cavity compared to unheated whey protein up to 1 min post swallow, and a concomitant increase in free thiol concentration. Nuclear magnetic resonance and circular dichroism demonstrated structural changes in the secondary and tertiary structures of the WPC upon heating. Structural loss of the β-barrel was shown to increase during heating, leading to the exposure of hydrophobic regions. The increase in free thiols and hydrophobic regions are two factors which are known to increase mucoadhesive strength and hence increase oral retention of heated whey protein which may subsequently increase the perception of mouthdrying. [ABSTRACT FROM AUTHOR]

Among those many individuals who experience a reduced odor sensitivity (hyposmia/anosmia), some individuals also have disorders that lead to odor distortion, such as parosmia (i.e. distorted odor with a known source), or odor phantoms (i.e. odor sensation without an odor source). We surveyed a large population with at least one olfactory disorder (N = 2031) and found that odor distortions were common (46%), with respondents reporting either parosmia (19%), phantosmia (11%), or both (16%). In comparison to respondents with hyposmia or anosmia, respondents with parosmia were more likely to be female, young, and suffering from post-viral olfactory loss (P < 0.001), while respondents with phantosmia were more likely to be middle-aged (P < 0.01) and experiencing symptoms caused by head trauma (P < 0.01). In addition, parosmia, compared to phantosmia or anosmia/hyposmia, was most prevalent 3 months to a year after olfactory symptom onset (P < 0.001), which coincides with the timeline of physiological recovery. Finally, we observed that the frequency and duration of distortions negatively affects the quality of life, with parosmia showing a higher range of severity than phantosmia (P < 0.001). Previous research often grouped these distortions together, but our results show that they have distinct patterns of demographics, medical history, and loss in quality of life. [ABSTRACT FROM AUTHOR]

Detection thresholds are used routinely to determine the odour-active compounds in foods. The composition of a food matrix, such as hydrophobicity or solids content, has an impact on the release of flavour compounds, and thus on thresholds. In the case of beer, thresholds determined in alcoholic beer may not be the same for alcohol-free beer (AFB). Therefore, the aim of this study was to determine detection thresholds for aroma compounds typically found in beer, within a model AFB. The model was designed to match the sugar concentration and pH of an AFB brewed by a cold contact process. Thresholds were measured using a 3-AFC procedure and calculated using either Best Estimate Threshold (BET) method or by logistic regression. Moreover, an algorithm for the removal of false positives was applied to adjust the assessors' raw responses. Retronasal thresholds were generally lower than orthonasal. Those calculated by BET were significantly higher (p < 0.05) than those from logistic regression, and removal of false positives also produced significantly higher thresholds than those from raw data. The use of logistic regression has the advantage of providing the mathematical model describing the behaviour of the group. The results from this study can be used to better understand the role of flavour compounds in AFB and the effect of the calculation method to prevent under- or overestimated results. Unlabelled Image • Aroma thresholds for 26 compounds were determined in an alcohol-free beer matrix. • Polar compounds showed an increase in orthonasal aroma thresholds in this matrix. • Methods for calculating aroma thresholds from 3-AFC tests were compared. • Best Estimate Thresholds gave significantly higher values than logistic regression. • Results and confidence intervals were affected by the presence of false positives. [ABSTRACT FROM AUTHOR]

Highlights • The formation of acrylamide from maltose was investigated. • Chemical reactions of acrylamide formation in french fries were modelled kinetically. • The model accounted for heat and moisture transfer during typical frying conditions. • Maltose contributed <10% to total acrylamide formation. • The contribution from Maillard reaction vs. sugar-asparagine conjugates is discussed. Abstract In light of a recent update in EU regulations governing levels of acrylamide in foodstuffs, further understanding of the role of different precursors is fundamental to extending mitigation strategies into a wider product range. Kinetic modelling was used to investigate the role of maltose in the formation of acrylamide during the finish-frying of french fries. The maltose concentration of raw white potato strips was systematically increased from 0 to 1.4% to observe the effect of this reducing disaccharide on acrylamide formation. A mathematical model, incorporating glucose, fructose and maltose and based on known Maillard reaction pathways, was developed which showed that acrylamide formation from maltose only contributed <10% to the total acrylamide. An additional kinetic model allowed for the formation of acrylamide directly from sugar-asparagine glycoconjugates. This model suggested that under these conditions, it is unlikely that acrylamide is formed directly from the maltose-asparagine conjugate. [ABSTRACT FROM AUTHOR]

The objective of this work is to determine the extent to which changes in the skim milk powder (SMP) manufacturing process alter the volatile profile of SMP, and whether these changes are carried through to a final product when the SMP is used as an ingredient and subjected to further processing. The manufacture of SMP is a multistage process involving a preliminary concentration step, heat treatment, and a drying stage. However, the methods and conditions used by the industry are not standardized, and the inherent variability in the production of SMP has consequences for the end-users, such as the confectionery industry, where the SMP is used as an ingredient during the production of milk chocolate, white chocolate, and caramel. This study investigates the effect of each stage of the manufacturing process on the concentration of reducing sugars and available amino groups (as precursors of the Maillard reaction) as well as on the volatile products of the Maillard reaction and lipid degradation. Eight types of SMP were produced using combinations of different processing conditions: concentration (by evaporation or reverse osmosis), heat treatment (low heat or high heat), and drying (spray-drying or freeze-drying). Maillard precursors were quantified after each processing stage and volatile compounds were extracted using solid-phase microextraction, and analyzed by gas chromatography-mass spectrometry. The resulting SMP were incorporated into a model white chocolate system, produced under varying conching conditions. We demonstrate not only that changes in the SMP manufacturing conditions affect the volatile profile of SMP, but also that these differences can be carried through to a final product when the SMP is used to prepare a model white chocolate. Understanding these differences is important to the industry for controlling the flavor of the end product. [ABSTRACT FROM AUTHOR]

The mucoadhesion between polymeric substances and mucosal membranes, widely exploited in the pharmaceutics industry to prolong drug residence, has been investigated as a means of retaining taste or aroma molecules in the oral cavity. This study shows that the mucoadhesive properties of carboxymethyl cellulose, a commonly used polysaccharide in the food and pharmaceutics industry, can modify retention, release and perception of sodium over time. A three-part study was designed coupling in vitro retention using ex vivo porcine tongue, sensory perception with a trained panel and in vivo retention of sodium ions in human volunteers. The findings suggest that although salt perception is stunted in samples containing a random coil, ionic, mucoadhesive thickener, the retention of sodium ions in the mouth is prolonged due to the mucoadhesive nature of the polysaccharide. Not only has this study-investigated mucoadhesion of liquid formulations in the oral cavity but it is also the first to link the mucoadhesive nature of a commonly used polysaccharide to the organoleptic properties of a food. [ABSTRACT FROM AUTHOR]

The role of mucoadhesion in the perception and sensory characterisation of food products is becoming more apparent. Traditionally, mucoadhesives are used to enhance drug permeability and retention at mucosal membranes in the body, by adherence to a mucosal membrane formed through various interactions between the mucoadhesive and proteins present in the mucosa. Many polysaccharides used in the food industry as thickeners, emulsifiers, stabilisers and fat replacers also have mucoadhesive properties, and are commonly used in the pharmaceutical industry in drug formulations. More recently, there has been an increasing interest in utilising these polysaccharides as mucoadhesives to modulate the organoleptic properties of food. This review reflects on the recent developments in mucoadhesion and the limited research into the impact of mucoadhesion when designing food formulations and modifying the organoleptic properties of food. It will also outline the areas of food science that could benefit from an understanding of mucoadhesion, mainly focusing on developing an understanding of how mucoadhesion may explain results found from sensory studies involving polysaccharides. Furthermore, possible negative impacts of mucoadhesion in foodstuff will be explored. An overview of methods for the measurement of mucoadhesion is also provided. An understanding of the mucoadhesive nature of polysaccharides may be useful to the food industry with regard to new product design. [ABSTRACT FROM AUTHOR]

Whey proteins are becoming an increasingly popular functional food ingredient. There are, however, sensory properties associated with whey protein beverages that may hinder the consumption of quantities sufficient to gain the desired nutritional benefits. One such property is mouth drying. The influence of protein structure on the mouthfeel properties of milk proteins has been previously reported. This paper investigates the effect of thermal denaturation of whey proteins on physicochemical properties (viscosity, particle size, zeta-potential, pH), and relates this to the observed sensory properties measured by qualitative descriptive analysis and sequential profiling. Mouthcoating, drying and chalky attributes built up over repeated consumption, with higher intensities for samples subjected to longer heating times ( p < 0.05). Viscosity, pH, and zeta-potential were found to be similar for all samples, however particle size increased with longer heating times. As the pH of all samples was close to neutral, this implies that neither the precipitation of whey proteins at low pH, nor their acidity, as reported in previous literature, can be the drying mechanisms in this case. The increase in mouth drying with increased heating time suggests that protein denaturation is a contributing factor and a possible mucoadhesive mechanism is discussed. [ABSTRACT FROM AUTHOR]

• Inorganic salts affected formation of flavour compounds and processing contaminants. • In the presence of salts, acrylamide, Strecker aldehydes and pyrazines decreased. • Furans and furfurals increased when acrylamide decreased. • Calcium lactate was less efficient in reducing acrylamide than calcium chloride. • Calcium lactate increased some flavour compounds while other salts decreased them. Among many strategies known to mitigate acrylamide formation, addition of cations, particularly calcium, is effective and can be used in bakery products. In this study, the effects of NaCl, KCl, CaCl 2 , MgCl 2 , sodium lactate, calcium lactate, and magnesium lactate on aroma and acrylamide formation were investigated in glucose/wheat flour dough systems during heating. Addition of salts inhibited Maillard reaction in favour of caramelisation, with divalent cations found to be most effective. The impact of salts on acrylamide reduction became less effective with increasing temperature. Most Strecker aldehydes and pyrazines decreased in the presence of salts, however CaCl 2 and calcium lactate increased the concentration of furans, furfurals, and diketones. Calcium lactate also increased some ethyl-substituted pyrazines at high temperatures. Reduction of acrylamide with salts is associated with higher amounts of furan derivatives and decreased amounts of Strecker aldehydes and pyrazines. The mechanisms behind these changes are discussed. [ABSTRACT FROM AUTHOR]

• Jackfruit seeds were processed and roasted to generate chocolate aroma. • Aroma was compared in seeds that were dried, acidified or fermented prior to roasting. • Typical cocoa aroma compounds were produced in all cases. • 40 different pyrazines were identified and confirmed with bespoke process reactions. • Fermented jackfruit seeds produced the most cocoa-like aroma. The seeds of the jackfruit (Artocarpus heterophyllus Lam.) are an abundant waste-stream in Brazil and a potential source of chocolate aroma. The aim of the study was to characterise the aroma compounds in flours prepared from the roasted jackfruit seeds and compare them with a typical Brazilian cocoa powder. Jackfruits seeds were either left untreated, acidified or fermented before drying and roasting. The volatiles were extracted using solid phase micro extraction or solid phase extraction and analysed by gas chromatography mass spectrometry. The most odour-active volatiles were identified by GC-Olfactometry. Most of the compounds known to be odour-active character impact compounds in cocoa products were also found in the jackfruit seed flours, however, the jackfruit seeds produced many additional pyrazines, some of which were responsible for the characteristic earthy "roasted jackfruit seed" aroma. The fermented sample had the most similar aroma profile to cocoa powder. [ABSTRACT FROM AUTHOR]

• An enhancement of baked flavour in a low-acrylamide potato-based snack was achieved. • There was no concomitant increase in acrylamide. • This was achieved by adding a synergistic combination of amino acids and precursors. • Key precursors were 2,3-pentanedione, Gly, Ala, Val, Leu, Ile and Met. • Enhancement was confirmed using both sensory and instrumental (GC–MS) analysis. The aim of this study was to increase the baked flavour of low-acrylamide potato products. Strecker aldehydes and pyrazines make an important contribution to the flavour of potato products and are formed alongside acrylamide in the Maillard reaction. However, the Maillard reaction can be directed in favour of aroma formation by selecting appropriate precursors and intermediates based on the fundamental chemistry involved. Selected precursors were added to potato dough prior to baking. Addition of glycine and alanine together doubled high impact pyrazines and addition of 2,3-pentanedione or 3,4-hexanedione also promoted the formation of key trisubstituted pyrazines. Quantitative descriptive profiling of sensory attributes indicated that baked flavour was increased most when both Strecker aldehydes and pyrazines were increased together. This work shows that it is possible to enhance baked flavour in low-acrylamide products by adding a specifically targeted combination of amino acids and key intermediates, without increasing acrylamide concentration. [ABSTRACT FROM AUTHOR]