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The increasing need for sustainable food choices places a demand on developing palatable foods from lower impact production and with a suitable shelf-life. In this context, knowledge of the sensory properties of whole sterilised chickpeas is required to be able to make them more attractive to the consumers. The sensory quality of chickpeas is largely dependent on the aroma and flavour, which can be influenced by storage conditions. In this study, sterilised chickpeas in two different packaging materials with different oxygen permeabilities, stored up to 52 weeks at ambient temperature (20 °C) were investigated using both descriptive sensory profiling and gas chromatography – mass spectrometry – olfactometry analysis (GC-MS-O). During storage, intense, sulphury and meat-like aromas decreased in intensity, while with longer storage time hay-like, green-like and potato-like flavours and aromas became more apparent. A total of 40 odour-active volatiles were detected, of which some had properties reminiscent of the chickpea flavour profiles. However, no clear relationships could be established between these odorants and the sensory changes observed during storage by descriptive sensory analysis. It was concluded that, significant changes in the sensory attributes of sterilised chickpeas occurred during 52 weeks of storage, but that packaging material does not seem to largely influence the sensory attributes during storage., Graphical abstract Image 1, Highlights • Significant sensory changes occur in sterilised chickpeas during 52 weeks storage. • 40 odour-active volatiles are detected in the sterilised chickpeas. • Sulphur compounds formed during sterilisation change during storage. • Hay and green attributes are perceived more intense with increased storage time. • Oxygen permeability of packaging does not impact the sensory quality during storage.

Effect of depuration on content of geosmin in pikeperch (Sander lucioperca) produced in a commercial RAS farm was examined during a 15-day period. Concentrations of geosmin in the fish were related to geosmin content in the water. For depuration, half of the water volume in a 230 m3 production tank was replaced daily with geosmin-free water. After 8 days of depuration and absence of feeding, content of geosmin in the fish was reduced from 710 ± 245 ng/kg to 165 ± 50 ng/kg (mean ± SD, p < .01). Additional depuration for 7 days only reduced the geosmin content to 135 ± 24 ng/kg. Geosmin concentration in the water was initially 34 ng/L but declined to 10 ng/L after 15 days. Changes in geosmin concentrations in water of the depuration tank indicated that geosmin was released by the fish during the depuration. In addition to removal of geosmin, the depuration also decreased concentrations of 28 different volatile compounds from the fish. Sensory analysis showed decrease in intensity of geosmin flavor upon depuration and improved the overall sensory quality of the fish after 2 weeks of depuration. Our study shows that geosmin and other off-flavors in pikeperch from RAS production can efficiently be removed to be a level that is below the threshold to most consumers.

Pulsed electric field (PEF) was applied to basil leaves prior air drying at 40 °C. The parameters of the electric treatment were designed in such a way that (i) electroporated the tissue reversibly, provoking a permanent opening of the stomatal guard cells and (ii) electroporated the tissue irreversibly, damaging the cells. Treated leaves lost some volatile compounds due to both PEF treatments, probably related with the direct effect of permeabilization on the secretory cells of glandular trichomes. Upon drying, the irreversible permeabilization treatment showed the highest influence on the profile of volatiles in the dried leaves showing better retention of some terpenoids than the control. The performed statistical analysis allowed to select six compounds that can be used as markers both for the effect of pre-treatments prior dehydration and for the effects of dehydration itself on the volatile compounds of basil leaves.

A total of 56 key volatile compounds present in natural and alkalized cocoa powders have been rapidly evaluated using a non-target approach using stir bar sorptive extraction gas chromatography mass spectrometry (SBSE-GC–MS) coupled to Parallel Factor Analysis 2 (PARAFAC2) automated in PARADISe. Principal component analysis (PCA) explained 80% of the variability of the concentration, in four PCs, which revealed specific groups of volatile characteristics. Partial least squares discriminant analysis (PLS-DA) helped to identify volatile compounds that were correlated to the different degrees of alkalization. Dynamics between compounds such as the acetophenone increasing and toluene and furfural decreasing in medium and strongly alkalized cocoas allowed its differentiation from natural cocoa samples. Thus, the proposed comprehensive analysis is a useful tool for understanding volatiles, e.g., for the quality control of cocoa powders with significant time and costs savings.

Ultra-high temperature (UHT) processed lactose-reduced milk containing added green tea extract (GTE) at two concentrations (0.1% and 0.25%) was stored at 22 ± 2 °C for one year. The effect of GTE addition on physical stability, protein binding, and sensory quality was evaluated. Sedimentation in skim milk and creaming of full fat milk were inhibited by addition of GTE. The formation of Maillard-related flavour compounds was inhibited during storage as determined by dynamic headspace GC–MS. Using Western blot analysis, milk proteins were found to be highly conjugated to polyphenols. Addition of GTE before UHT treatment resulted in increased bitterness and astringency in UHT milk and this remained during storage. Even though GTE addition improved the physical stability and inhibited Maillard reactions in the milk, the taste and flavour contribution from GTE was dominating throughout storage, and alternative sources of polyphenols should be explored for increasing shelf-life stability of long-life milk.

The objective of this study was to investigate the impact of endo- and exo-peptidase treatment on certain structural characteristics of peptides and volatile compounds of porcine hemoglobin and whole blood hydrolysates. Porcine hemoglobin and whole blood were hydrolyzed by endo- and exo-peptidases. The presence of exopeptidases reduced the bitterness and altered the volatile profiles of protein hydrolysates. Exopeptidase treatment can release terminal amino acids from peptides, which in turn may contribute to formation of volatile compounds by Maillard reactions. In contrast, endopeptidases conferred a slightly bitter taste and different volatile profiles. For hemoglobin hydrolysates, principal component analysis revealed that proteases were categorized into three groups based on endo- or exo-peptidase activity. Whole blood is a more complex raw material, yet the proteases were still categorized in a similar fashion. This work contributes to understanding structural characteristics responsible for taste and volatile profiles of protein hydrolysates.

High lipid and high protein infant formula milk powders were stored at water activity of 0.11, 0.33 and 0.53 for up to fourteen weeks at 40 °C to investigate the effect of storage water activity on physicochemical properties and formation of volatiles to thereby recommend optimal storage water activity conditions. Water activity of the powders was determined during storage together with surface colour, glass transition temperature combined with dynamic headspace sampling followed by gas chromatography/mass spectrometry. The principal component analysis (PCA) showed that the optimal water activity for storage of high lipid infant formula milk powder, for which lipid oxidation was found to be the critical quality parameter, is aw = 0.33 with lowest lipid oxidation, while for high protein infant formula milk powder, for which protein degradation was found to be the critical quality parameter, aw = 0.11 is optimal to limit formation of Maillard reaction products.

Beer is one of the most popular beverages in the world and it has an irreplaceable place in culture. Although invented later than ale, lager beers dominate the current market. Many factors relating to the appearance (colour, clarity and foam stability) and sensory characters (flavour, taste and aroma) of beer, and other psychological determinants affect consumers’ perception of the product and defines its drinkability. This review takes a wholistic approach to scrutinise flavour generation in the brewing process, focusing particularly on the contribution of the raw ingredients and the yeasts to the final flavour profiles of lager beers. In addition, we examine current developments to improve lager beer flavour profiles for the modern consumers., Beer is one of the most popular beverages in the world. This review takes a wholistic approach to examine how flavours are produced in the brewing process, focusing particularly on the contribution of the raw ingredients and the yeasts to the final flavour profiles of lager beers.

Soy protein isolates were fermented by three commercial Lactobacillus helveticus strains for a maximum of seven days to investigate the resulting proteolysis. The proteolytic activity of the most active strain (LH88) was further analyzed (LC-MS/MS and GC-MS) and it was shown that the β-conglycinin α subunit 1, β-conglycinin α' subunit, glycinin G1, and 2S albumin were specifically degraded. Peptigram analysis and visualization of the crystal structure showed that the hydrolysis sites of β-conglycinin α subunit, α' subunit, and the glycinin G1 were located on the surface of the molecule or at the mobile disordered region, hence being highly accessible for the proteinase of LH88. The proteins were partially further degraded to free amino acids, and subsequently catabolized to volatile compounds. However, most of the proteins remained native, even after seven days of fermentation, thus additional modification of protein structure or adjustment of fermentation conditions are required for effective generation of flavor compounds.

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Protein degradation, rheological properties, sensory properties and the aroma profile of soft brined cheese made from camel milk using two levels of coagulant (camel chymosin) [55 and 85 International Milk Clotting Units (IMCU) L−1] and two levels of brine (2% or 5% NaCl, w/w) were investigated over a ripening period of 60 d. Casein degradation in soft brined camel milk cheese significantly (p

Introduction: Umami is a basic taste. However, practitioners often refer to it as a flavour, indicating that sensory interactions may affect the gustatory response. Dashi is a basic soup stock that can be made simply by extracting seaweed into water (Mouritsen, Williams, Bjerregaard, & Duelund, 2012). By creating a sensory diverse set of dashis, we can explore odour-induced umami enhancement by omitting the sense of smell in sensory characterization of the dashis. Methods: Dashis were made from 16 seaweeds (9 different species) collected from locations in 6 different countries, following procedures of Mouritsen et al. (2012). Samples were characterised by standard sensory descriptive analysis (with and without olfactory input), HPLC (Mouritsen, Duelund, Calleja, & Frøst, 2017) and GC (Juhari & Petersen, 2018). Results: Main effects of olfactory stimulation was found for the basic tastes umami (p=0.001), sweet (p=0.017), and the flavour roasted (p=0.01), with decreases in intensity when olfactory input is prevented. Similar effects were found for the aftertastes astringent, metallic and fatty. However, odour-induced enhancement, indicated by statistical interactions between olfactory input and samples was only seen for umami (p=0.018) and astringent (p=0.009). HPLC analysis demonstrated that three samples (table 1) with high umami intensity had very low glutamate content. Scrutinizing the aroma compound concentration by GC identifies a set of candidates that can have increased umami (table 1). Conclusions: Sensory interactions between basic tastes and aroma compounds were found in seaweed dashi. Odours that enhance umami were observed in three samples with very low glutamate content. A number of potential odour-induced umami enhancing aroma compounds is suggested (table 1). Odour-induced umami enhancement can be used to create more palatable foods with simple and sustainable means.

This study explored the amino acid utilisation by Debaryomyces hansenii and Yamadazyma triangularis grown on cheese agar at 16 °C and 25 °C. The consumption of amino acids was species- and strain-dependent and greatly affected by temperature. For D. hansenii, the consumption of most amino acids was higher at 25 °C compared with 16 °C, contrary to Y. triangularis. Debaryomyces hansenii produced more 2- and 3-methyl-butanal, 3-methyl-1-butanol, and 2-phenylethanol, and consumed more of the corresponding amino acids, isoleucine, leucine, and phenylalanine, respectively, than Y. triangularis at 25 °C. Yamadazyma triangularis produced more volatile sulphur compounds, and consumed more of their precursor, methionine, than D. hansenii at 16 °C. Moreover, Y. triangularis seemed able to markedly consume the volatile sulphur compounds at 25 °C. These results may contribute to the selection of appropriate yeasts to be used in the cheese industry.

The effect of epigallocatechin gallate enriched green tea extract (GTE) on flavor, Maillard reactions and protein modifications in lactose-hydrolyzed (LH) ultrahigh temperature (UHT) processed milk was examined during storage at 40 °C for up to 42 days. Addition of GTE inhibited the formation of Strecker aldehydes by up to 95% compared to control milk, and the effect was similar when GTE was added either before or after UHT treatment. Release of free amino acids, caused by proteolysis, during storage was also decreased in GTE-added milk either before or after UHT treatment compared to control milk. Binding of polyphenols to milk proteins was observed in both fresh and stored milk samples. The inhibition of Strecker aldehyde formation by GTE may be explained by two different mechanisms; inhibition of proteolysis during storage by GTE or binding of amino acids and proteins to the GTE polyphenols.

Wine is often used as an ingredient in butter sauces such as hollandaise sauce, but normally in its reduced form. Hollandaise sauce is an emulsion, and roughly consists of a continuous phase (water based ingredients) and a dispersed phase (fat). In addition, hollandaise sauce contains varying amounts of incorporated air, seen as air bubbles in the sauce. In this study, the influence of wines and wine reductions on sauce flavor was studied. Butter sauces, where the aqueous phase of the sauces varied, were made and analyzed. Four different types of white wine (Chardonnay, Riesling, Sauvignon blanc and a blended wine) and these wines’ corresponding wine reductions were incorporated in butter sauce to produce model products (eight sauces in total). In the reductions, approximately 51% of the volume was removed by evaporation. The wines were selected based on both non-volatile composition and aroma differences. A trained sensory panel (n=10) evaluated sauce flavor and texture. Volatile profiles of sauces were studied by GC-MS, and sauce texture was evaluated by texture analysis, microscopy and dry matter measurements. Results showed that the degree of reduction is more important for sauce flavor than the wine type.

Different types of cheese powder were added to meat emulsion sausages in order to address its influence on chemical composition, volatile compounds profile and sensory properties, and its potential to reduce salt content through boosting saltiness. Addition of cheese powder to emulsion sausages modified their profile of volatile compounds. Blue cheese increased some ketones, alcohols, and esters, while brown cheese brought typical Maillard reaction compounds. Overall, addition of cheese powders to sausages enhanced the intensity of flavour traits. A mixture of hard and blue cheese powder showed the highest effect on boosting saltiness, while brown cheese powder showed the strongest umami and meat flavour boosting effect, and sausages with added blue cheese powder showed a more intense aftertaste. Hardness significantly increased due to the addition of blue cheese powder. Addition of cheese powder to emulsion sausages might be an interesting tool to boost flavour and reduce salt content in cooked sausages with no negative effect on saltiness or overall flavour.

Flavour matching can be viewed as trying to reproduce a specific flavour. This is a time consuming task and may lead to flavour mixtures that are too complex or too expensive to be commercialized. In order to facilitate the matching, we have developed a new mathematical model, called Prioritizer. Based on the chemical composition of a mixture of volatiles (a target flavour profile), from a set of different ingredients, the model can suggest an initial selection of ingredients needed to reproduce the flavour. The model also allows the user to prioritize properties of the flavour, given the cost of the different raw materials, the allowed number of ingredients and relative importance of flavour components (represented e.g. by perception threshold values). The limit of detection of the equipment used to measure the target flavour profile puts a limit to what flavours can be matched, but it will be shown that the model offers a good initial estimate for reproducing flavour.

Accurate measurement of chemosensory function is challenging. For assessing olfactory function, the most commonly applied test is the olfactory identification test. The ability to choose the correct descriptor for an odour among different false descriptors is central for the efficacy of these tests. Across several validation studies of the identification tests, the use of closely related descriptors was found to cause low identification rates. We hypothesised that this could be caused by a high chemical resemblance between the odorant and the listed odour descriptor options. By analysing the chemical overlap between the odorant and the odours used as descriptors, we investigated if chemical resemblance could be a possible confounder in olfactory identification tests.We used gas chromatography-mass spectrometry to detect volatile compounds in the falsely identified odorant. The headspace analysis was repeated on three samples to ensure correct chemical compound detection. Compounds previously identified in odours of false descriptors were identified through a literature review.This study identified a widespread chemical overlap between citrus odours commonly used as descriptors in clinical olfactory identification tests, which can complicate the distinction between normosmic and anosmic patients.These findings emphasise the importance of thorough considerations when selecting new odorant descriptors during the modification of odour identification tests and the importance of revalidation after modifying descriptors.The degree of chemical resemblance between the odours used as descriptors can be used to adjust the level of difficulty in identification tests; contrasted odours will increase the specificity of detecting anosmia in a clinical test, whereas odours with larger chemical resemblance may be more sensitive when evaluating subtle effects of e.g. olfactory training.

A comprehensive technical feasibility study was conducted of a bioethanol demonstration plant with the aim of converting parts of an existing fuel-grade bioethanol production into a more valuable solvent-grade ethanol. The study focuses on the separation unit, which consists of three consecutive distillation columns and a dehydration step using molecular sieves. This separation unit did not permit sufficient removal of crotonaldehyde and methanol for obtaining solvent-grade ethanol. Therefore, an additional distillation column after the dehydration step was investigated by simulation. It is operated at subatmospheric pressure and enables simultaneous removal of methanol, crotonaldehyde, and water in the distillate. The distillate meets the fuel-grade ethanol specifications, while the bottom product meets the solvent-grade specifications. It enables around 70% solvent-grade ethanol production and employs a vacuum pump that is already used in the considered plant. A stationary operating point is characteriz...

The present study aimed to investigate coffee flavour perception and release as function of serving temperature to support standardisation in the specialty coffee branch. The coffee cultivar Bourbon Caturra was evaluated at six serving temperatures ranging from 31°C to 62°C. Coffee samples were analysed by dynamic headspace sampling gas chromatography-mass spectrometry and descriptive analyses using sip-and-spit tasting. The release of volatiles followed mostly the van't Hoff principle and was exuberated at temperatures above 40°C. Aliphatic ketones, alkylpyrazines, some furans and pyridines increased most notably at temperatures ⩾50°C. The changes in volatile release profiles could explain some of the sensory differences observed. The flavour notes of 'sour', 'tobacco' and 'sweet' were mostly associated with the coffees served at 31-44°C, whereas coffees served between 50°C and 62°C exhibited stronger 'overall intensity', 'roasted' flavour and 'bitter' notes.

There has been an increasing interest in the use of selected non-Saccharomyces yeasts in co-culture with Saccharomyces cerevisiae. In this work, three non-Saccharomyces yeast strains (Metschnikowia viticola, Metschnikowia fructicola and Hanseniaspora uvarum) indigenously isolated in Denmark were used in sequential fermentations with S. cerevisiae on three cool-climate grape cultivars, Bolero, Rondo and Regent. During the fermentations, the yeast growth was determined as well as key oenological parameters, volatile compounds and sensory properties of finished rose wines.; Results: The different non-Saccharomyces strains and cool-climate grape cultivars produced wines with a distinctive aromatic profile. A total of 67 volatile compounds were identified, including 43 esters, 14 alcohols, five acids, two ketones, a C13-norisoprenoid, a lactone and a sulfur compound. The use of M. viticola in sequential fermentation with S. cerevisiae resulted in richer berry and fruity flavours in wines. The sensory plot showed a more clear separation among wine samples by grape cultivars compared with yeast strains.; Conclusion: Knowledge on the influence of indigenous non-Saccharomyces strains and grape cultivars on the flavour generation contributed to producing diverse wines in cool-climate wine regions. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

In this study, we compare the effects of single- and double-cycle HP treatments at 600 MPa on inactivation of the natural microflora and physicochemical properties of whole and skimmed milk of high bacterial load. The results show that two-cycled HP (2 × 2.5 min) was more effective (P 0.05) in physicochemical properties of milk in comparison to single cycled HP (1 × 5 min). In addition to the expected milk protein structure changes, HP at 600 MPa caused only slight effects on milk fat and lactose. Minor decreases in levels of short chain fatty acids were observed with the cycled treatments, and the volatiles in general decreased after HP treatment, depending mostly on the pressure time but also on cycling in skimmed milk. The study confirmed the superior effect of two-cycle HP on microbial inactivation, and shows a slightly better preservation of the physical-chemical milk quality. Industrial relevance Multi-cycling HP has been shown to be advantageous for microbial inactivation, but limited information is available regarding the effect on milk components in whole milk or skimmed milk. The present study compares the psychochemical properties of whole and skimmed milk processed by multi-cycling in comparison to single cycle HP treatment. Double cycled HP presented a superior effect on microbial inactivation and slightly better preservation of milk quality than one continuous HP.

Ethanol concentration in batters prepared with alcoholic beverages was measured upon deep frying, using static headspace GC-MS. The concentration decreased dramatically during the first two minutes of frying resulting in a concentration of maximum 0.28 ± 0.03 g/100 g. Frying for another two minutes had an insignificant effect on the concentrations. The measured concentrations resulted in 0.14 g ethanol per serving, which is considered very low and not problematic for human consumption. When the batter was fried as a coating for fish, the concentrations were slightly higher than when fried alone, namely 0.69 ± 0.21 g/100 g after two minutes of frying.

Made available in DSpace on 2020-12-10T19:41:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-10-31 Danish Council for Strategic Research Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Aim To determine major sources of microbially produced geosmin in the commercially important aquaculture fish species tilapia. Methods and Results Abundance and composition of geosmin-producing bacteria in water and fish biosphere (intestine, digesta, and fins) of Nile tilapia (Oreachromis niloticus) raised in net cages in Brazilian freshwater farms were examined. By combining qPCR of the geosmin synthase geoA gene and 16S rRNA gene amplicon sequencing to identify potential geosmin-producing organisms, we observed that the proportion and composition of geosmin producers appeared to be rather similar in the water, digesta, intestinal mucous, and on skin, making up about 0.1-0.2% of the total bacterial densities. A high proportion of Cyanobacteria and other putative geosmin producers affiliated to the Actinomycetales were identified in the intestinal mucous layer. The main uptake site for geosmin in fish is traditionally assumed to be through the gill surface, but the present results suggest that uptake by the intestinal tract may represent a major source of geosmin uptake in fish. Conclusion The high abundance of geosmin-producing bacteria in the intestinal mucous layer and digesta may indicate that the digestive system in fish is an important, but hitherto overlooked, source of geosmin and likely other off-flavors in fish. Aalborg Univ, Dept Chem & Biosci, Aalborg, Denmark Univ Copenhagen, Dept Plant & Environm Sci, Copenhagen, Denmark Univ Copenhagen, Dept Food Sci, Sect Design & Consumer Behav, Copenhagen, Denmark Sao Paulo State Agribusiness Technol Jau, Jau, Brazil Univ Estadual Paulista Julio Mesquite Filho, Inst Biociencias, Dept Parasitol, Botucatu, SP, Brazil Univ Estadual Paulista Julio Mesquite Filho, Inst Biociencias, Dept Parasitol, Botucatu, SP, Brazil Danish Council for Strategic Research: 3050-00008A FAPESP: 3050-00008A3050-00008A FAPESP: 2013/50504-5

Umami taste is associated with deliciousness and was first suggested as a basic taste by Kikunae Ikeda in 1909 when he discovered that the brown seaweed konbu (Saccharina japonica), used to provide aqueous extracts for the Japanese soup stock dashi, contains very large amounts of free glutamate. We have performed a comparative analysis of the free amino acid contents of 20 different species of brown seaweeds used for human consumption from around the world, belonging to the 12 genera Nereocystis, Macrocystis, Laminaria, Saccharina, Undaria, Alaria, Postelsia, Himanthalia, Ecklonia (former Eisenia), Sargassum, Fucus, and Corda. We furthermore measured mineral and iodine contents as well as identified a range of volatile compounds and estimated their influence on the perception of umami taste. The results provide a basis on which chefs and food producers can control umami sensation in food items using some of the most popular species of edible brown seaweeds.

The influence of fermentation temperatures (8°C, 16°C, and 32°C) and yeast levels (2%, 4%, and 6% of the flour) on the formation of volatile compounds in the crust of whole meal wheat bread was investigated. The fermentation times were regulated to optimum bread height for each treatment. The volatile compounds were extracted by dynamic headspace extraction and analyzed by gas chromatography-mass spectrometry. The results were evaluated using multivariate data analysis and ANOVA. In all crust samples 28 volatile compounds out of 58 compounds were identified and the other 30 compounds were tentatively identified. Higher fermentation temperatures promoted the formation of Maillard reaction products 3-methyl-1-butanol, pyrazine, 2-ethylpyrazine, 2-ethyl-3-methylpyrazine, 2-vinylpyrazine, 3-hydroxy-2-butanone, 3-(methylsulfanyl)-propanal, and 5-methyl-2-furancarboxaldehyde whereas at lower temperature (8°C) the formation of 2- and 3-methylbutanal was favored. Higher levels of yeast promoted the formation of 3-methyl-1-butanol, 2-methyl-1-propanol and 3-(methylsulfanyl)-propanal, whereas hexanal was promoted in the crust fermented with lower yeast level.

The effect of two Oenococcus oeni strains, Viniflora® CiNe™ and Viniflora® CH11, with and without cinnamoyl esterase activity, respectively, on the contents of the hydroxycinnamic acids (HCAs) p-coumaric and ferulic acid, and their respective volatile phenols, 4-ethylphenol and 4-ethylguaiacol, was investigated over six months in Cabernet Sauvignon wines inoculated with two different Brettanomyces bruxellensis strains, CBS 73 and CBS 2499. Both CiNe™ and CH11 showed growth and malolactic fermentation in the wines. There were no clear growth interactions between B. bruxellensis and O. oeni. Furthermore, B. bruxellensis did not inhibit MLF by CiNe™ or CH11. The HCA concentrations in all wines increased until 114 days of fermentation, after which they decreased from day 114 to day 180. Wines inoculated with CiNe™ had the highest concentrations of HCAs throughout the fermentations. While CiNe™ degraded more of the tartaric ester bound forms of HCAs into free HCAs, there was no significant difference in the production of volatile phenols as compared with wines inoculated with CH11. However, there was a significant difference between wines with the two strains of B. bruxellensis in the level of volatile phenols and HCAs on day 180. Thus, the level of volatile phenols in wine depends more on strain differences of B. bruxellensis than on cinnamoyl esterase activity of O. oeni.

Nowadays, the use of non-Saccharomyces yeasts in combination with Saccharomyces cerevisiae is being recognised to enhance the analytical composition of the wines. The aim of this work was to evaluate the influence of indigenous non-Saccharomyces yeasts on the flavour character of wines from the cool-climate grape cultivar Solaris in Denmark. The volatile and non-volatile compounds as well as the sensory properties of wines were evaluated. Solaris wines with Hanseniaspora uvarum sequentially inoculated with S. cerevisiae produced a larger amount of glycerol as well as heptyl acetate and 2-phenylethyl acetate. This co-culture fermentation also produced higher amounts of ethyl acetate and acetic acid, reducing the possibility of its use in winemaking. Three Metschnikowia strains, a M. chrysoperlae strain and two M. fructicola strains, gave a comparable production of volatile compounds. These wines were characterised by several floral and fruity attributes. The Metschnikowia strains turned out to be promising in winemaking from Solaris grapes.

Caraway (Carum carvi) is used as a vegetable; more commonly, the fruits are used to flavour foods or as a preservative. Quality is a key issue; however, little is known about the respective influences of type of material and location and the interaction of these factors on essential oil composition. In this study, wild populations and commercial cultivars from the Nordic germplasm collection were examined. Plants were grown in two locations (Iceland and Sweden) and essential oil composition and phenotypic characteristics identified. Carvone and limonene were the two major compounds detected at levels around 14 and 70% of total peak area, respectively. Also p-cymene, trans-β-ocimene, α-Terpinolene and myrcene each were detected at levels above or around 2%. In total, 47 compounds were detected of which 40 were identified. The effects of material type and location were established, where location had a greater impact than genotype. In 15 out of the 35 compounds detected at levels below 2%, significant location-dependent differences were detected. For morphological traits, genotype had a more significant effect than location.

The influence of fermentation temperatures (8, 16, and 32°C) and yeast levels (2, 4, and 6%) on the formation of volatile compounds in the crumb of whole-meal wheat bread was investigated. Volatile compounds were extracted by dynamic headspace extraction and analyzed by gas chromatography–mass spectrometry. Results were evaluated with multivariate data analysis and ANOVA. Bread fermented at a high temperature (32°C) had higher peak areas of the Maillard reaction products 2-furancarboxaldehyde, 2-acetylfuran, 2-methylpyrazine, and phenylacetaldehyde compared with bread fermented at lower fermentation temperatures. Bread fermented at low temperatures (8 and 16°C) was characterized by having higher peak areas of the fermentation products 3-methylbutanal, 2-methylbutanal, ethyl acetate, ethyl hexanoate, ethyl propanoate, and 3-methylbutanol. Fermentation of bread with 6% yeast resulted in a higher peak area of the important fermentation product 2-phenylethanol. It also reduced the peak areas of important lipi...

Quality of whole milk pasteurized by high hydrostatic pressure processing (HPP: 600 MPa for 5 min) or HPP combined with microfiltration (MF + HPP) were compared with two conventional heat treatments, low temperature long time (LTLT: 63 °C for 30 min) and high temperature short time (HTST: 72 °C for 15 s). Inactivation of microorganisms, changes in volatiles, protein denaturation, gastric digestion, and sensory quality were evaluated after 8 days of storage at 5 °C. Total bacterial and E.coli counts were reduced to approximately the same level for both high pressure and heat treated milks. The denaturation of β-lactoglobulin was significantly higher for high-pressurized milks, while no significant differences were found in gastric in-vitro protein digestion compared with heat treated milks. The results of volatile compounds revealed that HTST and HPP-treated milks exhibited very similar aroma profiles, while LTLT-milks were characterized by higher levels of ketones. After 8 days storage, the sensory analysis showed that LTLT milk was the one that differed most from the other three milks with highest intensities of all the sensory attributes, while no tangible differences were found between HTST and any HPP and MF + HPP milk, except for Boiled Taste that was slightly but significantly lower for MF + HPP.

Whey protein isolate (WPI) is widely used as a protein ingredient in foods, but undergoes thermal treatment before and during application to make the final product. The aim of the present study was to determine the temperature dependency of formation of volatiles that potentially act as off-flavours in reconstituted WPI solutions (3%, w/v) heated for different temperature–time combinations (50–90 °C for 5–10 min). Differences in orthonasal aroma were evaluated by triangle tests by a sensory panel. The panel could distinguish between samples heated for 10 min at 60 °C and 70 °C. Analysis by headspace gas chromatography-mass spectrometry (GC-MS) showed that heating the samples at 90 °C for 10 min significantly increased the concentration of dimethyl disulphide and dimethyl trisulphide compared with heating at 80 °C for 10 min or below, which suggests that sulphur-derived odour could be decreased by decreasing the heating temperature by 10 °C.

There has been a growing interest towards creating defined mixed starter cultures for alcoholic fermentations. Previously, metabolite differences between single and mixed cultures have been explored at the endpoint of fermentations rather than during fermentations. To create metabolic footprints of metabolites that discriminate single and mixed yeast cultures at two key time-points during mixed culture alcoholic fermentations. 1H NMR- and GC–MS-based metabolomics was used to identify metabolites that discriminate single and mixed cultures of Lachancea thermotolerans (LT) and Saccharomyces cerevisiae (SC) during alcoholic fermentations. Twenty-two metabolites were found when comparing single LT and mixed cultures, including both non-volatiles (carbohydrate, amino acid and acids) and volatiles (higher alcohols, esters, ketones and aldehydes). Fifteen of these compounds were discriminatory only at the death phase initiation (T1) and fifteen were discriminatory only at the death phase termination (T2) of LT in mixed cultures. Eight metabolites were discriminatory at both T1 and T2. These results indicate that specific metabolic changes may be descriptive of different LT growth behaviors. Fifteen discriminatory metabolites were found when comparing single SC and mixed cultures. These metabolites were all volatiles, and twelve metabolites were discriminatory only at T2, indicating that LT-induced changes in volatiles occur during the death phase of LT in mixed cultures and not during their initial growth stage. This work provides a detailed insight into yeast metabolites that differ between single and mixed cultures, and these data may be used for understanding and eventually predicting yeast metabolic changes in wine fermentations.

1. Two experiments were carried out in parallel with male Ross 308 broilers over 37 d. An experiment with a total of 736 broilers was performed to study the effect of dietary inclusion of crimped kernel maize silage (CKMS) on broiler production and meat quality. Another study with 32 broilers was carried out from 21-25 d to investigate the inclusion of CKMS on nutrient digestibility.2. In both trials, 4 dietary treatments were used: wheat based feed (WBF), maize based feed (MBF), maize based feed supplemented with 15% CKMS (CKMS-15) and maize based feed supplemented with 30% CKMS (CKMS-30).3. Compared with MBF, the DM intakes of broilers receiving CKMS-15 and CKMS-30 respectively were numerically 7.5 and 6.2 % higher, and FCR were 6 and 12 % poorer (significant for CKMS 30%), although there were no significant differences in AME content between the three diets. At 37 d, the body weight of birds receiving 15% CKMS was similar to birds fed with MBF. However, the inclusion of 30% CKMS decreased broiler growth. Dietary supplementation with CKMS significantly reduced the apparent digestibility of phosphorus. The fat digestibility was significantly lower for CKMS-30 than for the other 3 diets.4. Broiler mortality decreased significantly when CKMS was added to the diet.5. The consumption of drinking water was significantly lower in all maize based diets as compared to WBF and was lowest in broilers fed CKMS-30.6. An improved litter quality in terms of dry matter content and a lower frequency of foot pad lesions was observed with broilers supplemented with both dietary levels of CKMS.7. The addition of CKMS to maize based diets increased juiciness, tenderness and crumbliness of the meat.8. In conclusion, the dietary supplementation of 15% CKMS had no negative effect on broiler growth and positively influenced bird welfare in terms of mortality and foot pad health. Therefore, the addition of 15% CKMS to maize based diets is considered an advantageous feeding strategy in broiler production

Sensory evaluations were conducted on wheat-flour porridge and baked-bread samples, made from wheat varieties with known odour and flavour variations. The purpose was to determine if these odour and flavour variations were expressed in baked-bread. In all, 24 wheat varieties were used for porridge evaluation, from these eight were selected for bread evaluation. Porridge and bread results were compared. Variations were found in both evaluations. Five odour- and nine flavour descriptors were found to be common to both wheat porridge and bread. The results for two descriptors: “cocoa” and “oat porridge” were correlated between the wheat porridge and bread samples. Analysis of whole-meal and low-extraction samples revealed that the descriptors “malt”, “oat-porridge”, “ollebrod”, “cocoa” and “grain” mostly characterized wheat bran, while descriptors for “maize”, “bean-shoots”, “chamomile”, “umami”, and “fresh grass” mostly characterized wheat endosperm. Low-extraction bread made from four different varieties also differentiated for five odour- and six flavour descriptors. These results indicate that variations in wheat flavour and odour directly affect bread flavour and odour even in low-extraction bread. This knowledge is important to the baking industry and to plant breeders as wheat aroma could possibly become a future quality parameter in breeding.

The ability of a protease added during mashing in a pilot-scale brew to release protein-derived thiols as antioxidants and thereby improve flavor stability during storage was investigated. The protease treatment resulted in increased protein-derived thiol concentrations in fresh beer produced at a pilot scale compared with a control beer without protease treatment, and electron spin resonance lag phase analysis also demonstrated improved oxidative stability of the protease-treated beer. However, the protease treatment also resulted in high sulfite levels and, therefore, it was not possible to conclude that the improvement in oxidative stability was solely a direct effect of increased levels of protein-derived thiol concentrations. The development of papery character and volatile linear aldehydes was inhibited when the protease-treated beer was stored at 35°C but the protease treatment also resulted in increased concentrations of free amino acids in beer, resulting in a more fruity aged or vinous character...

Analysis of volatile compounds was performed on 81 wheat varieties and landraces, grown under controlled greenhouse conditions, in order to investigate the possibility of differentiating wheat varieties according to their volatile compound profiles. Volatile compounds from wheat samples were extracted by dynamic headspace extraction and analysed by gas chromatography-mass spectrometry. Seventy-two volatile compounds were identified in the wheat samples. Multivariate analysis of the data showed a large diversity in volatile profiles between samples. Differences occurred between samples from Austria compared to British, French and Danish varieties. Landraces were distinguishable from modern varieties and they were characterised by higher averaged peak areas for esters, alcohols, and some furans. Modern varieties were characterised by higher averaged peak areas for terpenes, pyrazines and straight-chained aldehydes. Differences in volatile profiles are demonstrated between wheat samples for the first time, based on variety. These results are significant to plant breeders and commercial users of wheat.

Roselle (Hibiscus sabdariffa L.) is considered an underexploited food crop with nutritional and large scale processing potential. Roselle can be utilized as a functional food, mainly due to being rich in vitamin C, anthocyanins, other phytochemicals, and natural color. Although Roselle has been widely planted and consumed, little is known about the composition of aroma profiles. In this study, seventeen samples of dried Roselle calyx were collected from eight countries and the aroma profiles were determined by dynamic headspace sampling and GC-MS and GC-olfactometry. Furthermore, total soluble solids, pH, and color L* a* b* were determined, and sugars and acids were measured using ion chromatography. There were significant (p 0.05) differences in all measured variables in physicochemical properties and non-volatile compounds. A total of 135 volatiles were identified mainly terpenes, aldehydes, esters, furans, and ketones. Thirty-seven odorants were reported as potentially important aroma compounds based on GC-olfactometry. This study provides valuable information for future commercial utilization of Roselle in the food industry.