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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]

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]

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]

• 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]

• 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]

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]