scholarly journals Impact of processing on important cocoa off-flavour compounds

2021 ◽  
Author(s):  
Daniela Füllemann ◽  
Silva D. Neiens ◽  
Martin Steinhaus
Keyword(s):  
Threshold Value ◽  
Flavour Compounds ◽  
Chocolate Industry ◽  
Odour Threshold ◽  
A Minor

AbstractThe compounds responsible for smoky and mouldy–musty off-flavours in fermented cocoa have recently been elucidated; however, their behaviour during further processing into chocolate was still unclear. The compounds 2-methoxyphenol, 3-methylphenol, 4-methylphenol, 3-ethylphenol, 4-ethylphenol, and 3-propylphenol known to contribute to smoky off-flavours showed a tendency towards a minor increase during roasting and processing into cocoa liquor. This increase amounted to 1.4-fold at the most, however, was clearly compensated by losses of 30–63% during further processing into chocolate mass and conching. Among the off-flavour compounds identified in mouldy–musty smelling cocoa, faecal, mothball-like 3-methyl-1H-indole showed a clear decrease during roasting and processing into cocoa liquor, at least at rather high roasting temperatures, and a further decrease during processing into chocolate mass and conching. In contrast, faecal, mothball-like 1H-indole substantially increased during roasting and processing into cocoa liquor, namely from concentrations below its odour threshold value to concentrations up to 8 times beyond its odour threshold value. During processing into chocolate mass and conching, 1H-indole remained virtually unchanged. The data suggested that the monitoring of off-flavour compounds at the incoming goods inspection in the chocolate industry should not be limited to the fermented beans as such but additionally include the analysis of a bean sample after test roasting to correctly assess the off-flavour potential of 3-methyl-1H-indole and 1H-indole.

scholarly journals Odour-active compounds in liquid malt extracts for the baking industry

2021 ◽  
Author(s):  
Nadine S. Rögner ◽  
Veronika Mall ◽  
Martin Steinhaus
Keyword(s):  
Threshold Value ◽  
Starting Material ◽  
Minor Amount ◽  
Malt Extract ◽  
Important Process ◽  
Gas Chromatography Olfactometry ◽  
Odour Threshold ◽  
A Minor ◽  
Baking Industry ◽  
Insight Into

AbstractAn odorant screening by gas chromatography–olfactometry (GC–O) and a crude aroma extract dilution analysis (AEDA) applied to the volatiles isolated from a light and a dark liquid malt extract (LME) by solvent extraction and solvent-assisted flavour evaporation (SAFE) identified 28 odorants. Fifteen major odorants were subsequently quantitated and odour activity values (OAVs) were calculated as ratio of the concentration to the respective odour threshold value (OTV). Important odorants in the light LME included 3-(methylsulfanyl)propanal (OAV 1500), (E)-β-damascenone (OAV 430), and 4-ethenyl-2-methoxyphenol (OAV 91). In the dark LME, sotolon (OAV 780), 3-(methylsulfanyl)propanal (OAV 550), (E)-β-damascenone (OAV 410), acetic acid (OAV 160), and maltol (OAV 120) were of particular importance. To get an insight into the changes during malt extract production, the quantitations were extended to the malt used as the starting material for both LMEs. Addition of a minor amount of water to malt before volatile extraction was shown to be effective to cover the free as well as the bound malt odorants. Results showed that some LME odorants originated from the starting material whereas others were formed during processing. Important process-induced LME odorants included (E)-β-damascenone and 4-ethenyl-2-methoxyphenol in the light LME as well as maltol, sotolon, (E)-β-damascenone, and 2-methoxyphenol in the dark LME. In summary, the odorant formation during LME production was shown to be more important than the transfer of odorants from the malt.

Image Adaptive Thresholding for Multiphase Wavy Flow

2014 ◽  
Author(s):  
Mustafa Al-Nasser ◽  
Moustafa Elshafei ◽  
Abdelsalam Al-Sarkhi
Keyword(s):  
Multiphase Flow ◽  
Flow Analysis ◽  
Threshold Value ◽  
Adaptive Thresholding ◽  
Correct Identification ◽  
Wave Shape ◽  
Uniform Illumination ◽  
Gas Phases ◽  
A Minor

Multiphase flow measurement is a very challenging issue in process industry. One of the promising approaches for multiphase flow analysis is image processing. Image segmentation is very important step in multiphase flow analysis. Determination of appropriate threshold value is very critical step for correct identification of the liquid and gas phases. There are two main thresholding techniques: Global and Adaptive. Adaptive thresholding is more suitable for multiphase flow case due to it’s adaptability to image conditions such non-uniform illumination and noise. In this work, six adaptive thresholding techniques are examined for the case of wavy flow regime. These algorithms are used to estimate the wave shape and mix region between liquid and gas. In general, the adaptive algorithms are able to compensate for non-uniform illumination and they are able to estimate wave shape and mix region correctly. The execution time for the adaptive techniques is higher than global thresholding technique, but with the availability of new powerful PCs, it will become a minor issue.

Odour measurement - factors affecting olfactometry panel performance

1996 ◽  
Vol 34 (3-4) ◽  
pp. 549-556 ◽  
Author(s):  
P. J. Bliss ◽  
T. J. Schulz ◽  
T. Senger ◽  
R. B. Kaye
Keyword(s):  
Data Bank ◽  
Type I ◽  
Type Ii ◽  
Factors Affecting ◽  
Natural Logarithm ◽  
Odour Threshold ◽  
One Step ◽  
The Mean ◽  
A Minor ◽  
Over 40 Years

To identify factors affecting olfactometry panel performance in the measurement of environmental odours, a data bank of odour threshold measurements including 923 individual panel tests on environmental odours and 145 tests on standards were analysed statistically. There is an evident decrease in olfactory sensitivity to environmental odours with age. The group threshold tends to be one step lower for a 25 year increase in average age of panel members for Type I odours (piggery, feedlot, landfill and mushroom composting) and for 36 years increase for Type II odours (sewage and industrial coke works). The threshold for N-butanol tends to be 1 step lower for an increase of 15 years in age. People who are over 40 years old exhibited a greater variation than younger people. Although there was a minor gender difference in the sensitivity to butanol standard, it was not statistically significant (mean natural logarithm butanol threshold was 3.65 for males and 3.84 for females). Similar minor differences were exhibited in Confidence Index (CI), 1.72 for females (std. dev. 0.73) and 1.81 for males (std. dev. 0.77). Using “guess and correct” as criterion to determine individual thresholds in the forced choice olfactometry, the mean natural logarithm of ppb butanol is 1.365 lower than that for “certain and correct”. The standard deviation for “guess” and “certain” criteria were 1.093 and 0.911 respectively. The “certainty” criterion gave a better repeatability than the “guess” criterion.

concentrations of odorcxis carpaunds with annoyance have still to be impro­ ved. At this mcment the knowledge in this field is far inferior to the knowledge for the sense of view and the sense of hearing. But there is no reason why we would not acquire the same understanding. Although knowledge on the correlation of odorous compounds concen­ tration and odour impression is still limited, it is used in all types of olfactometry. Indeed diluting this concentration by adding pure air is a general practice. Also many investigations were performed where che­ micals are added to air and used in psychophysical experiments. Many spea­ kers in this workshop will present data in this field. Here only chemical analysis will be dealt with. 2. PRINCIPES The goal of chemical analysis of odorous compounds in air is to de­ termine all substances, which interact with odour perception cells in our nose, both qualitatively and quantitatively. However, with a few excep­ tions all carpcunds with certain vapor pressure have an odour, meaning that their volatilized molecules react with the membrane of odour recep­ tor cells. As will be shewn, always hundreds of compounds are present in air; this means that the analysis would be very complex. However as was said before, our sense of smell is selective : for some products it is very sensitive for other compounds it is much less sensitive. Table I : Odour threshold values (ppb) of some organics Compounds Odour threshold Compound Odour threshold butane 1.3 106 acetic acid 40 butane 500 propionic acid 190 butanol 300 butyric acid 38 butanal 15 valeric acid 8 butanethiol 0.8 hexanoic acid 42 Several extensive lists of threshold values, i.e. the minimum concentration in air, that is detected by 50% of the population, have been published (1, 2,3,4). However published threshold values for a particular compound can vary over a number of orders of magnitude, so they have to be treated with scepticism. This selectivity makes chemical analysis of odour easier : many com­ pounds, although present in ambient air, and although they have an odour in pure form, are not contributing to the odour, while their concentration is far inferior to the threshold value. On the other hand the sensitivity is high for a range of compounds, higher than any chemical analysis can cope with directly. These canpaunds have to be concentrated frcm the odorous air, so that higher amounts are available for the analytical technique. If this concentrating could be done with the same selectivity of odour recep­ tor cells, there would not be much of a problem. Hcwever the actual know­ ledge of this interaction is far too limited - in fact it is inexisting -to speculate on an analytical application. With all of the biochemical de­ velopments, it is not excluded that at a certain mcment it beccmes feasible, but right new the only way is to use crude physicochemical methods, such as

1986 ◽  
pp. 168-168
Keyword(s):  
Chemical Analysis ◽  
Threshold Value ◽  
Ambient Air ◽  
Threshold Values ◽  
Minimum Concentration ◽  
Analytical Technique ◽  
Odour Threshold ◽  
Physicochemical Methods ◽  
Odorous Compounds ◽  
Odour Perception

scholarly journals Reduction of odorous compounds emissions from swine slurry by electrolytic treatments and copper addition

2017 ◽  
Vol 48 (1) ◽  
pp. 12-20
Author(s):  
Mauro Podrecca ◽  
Alessandro Chiumenti ◽  
Francesco Da Borso ◽  
Marco Contin ◽  
Maria De Nobili
Keyword(s):  
Volatile Fatty Acids ◽  
Swine Manure ◽  
Threshold Value ◽  
Graphite Electrodes ◽  
Swine Slurry ◽  
Copper Electrodes ◽  
Copper Addition ◽  
Current Passage ◽  
Odour Threshold ◽  
Electrolytic Treatment

Swine livestock farms represent potential sources of emissions of gaseous compounds and odors in relation to slurry management, manure treatment, and particularly, storage. Electrolytic treatments of slurries were proposed to solve this pressing problem. Electrolytic treatment consists of the passage of a low electric current through the liquid phase of swine manure in storage basins determined by two or more electrodes with alternated polarisation. We investigated the mechanisms of odour reduction and evaluated the effects of current intensity and of anodically dissolved copper (Cu2+) ions. Fresh swine slurry was subject to electrolytic treatment in a bench top experiment, at 25 mA and 75 mA for 32 days with either copper or graphite electrodes. Emissions of methane, hydrogen sulphide, and volatile fatty acids were measured. Effects of copper addition to fresh swine slurry were also monitored in a bench top scale trial. Reduction of emissions was found to be due to both current passage and copper dissolution. Reduction of foul emissions in graphite electrodes assays resulted lower than in copper electrodes assays, although the direct additions of Cu2+ ions had a much larger effect than could be predicted from the results of electrolytic treatments with copper electrodes, probably due to the greater uniformity in distribution in swine manure. A simple empiric odour threshold value normalised index, odour offensiveness index of slurries, was found to be effective in differentiating treatments.

Synthesis and odour thresholds of mixed halogenated anisoles in water

2004 ◽  
Vol 49 (9) ◽  
pp. 115-119 ◽  
Author(s):  
A. Díaz ◽  
C. Fabrellas ◽  
M. T. Galceran ◽  
F. Ventura
Keyword(s):  
Water Samples ◽  
Profile Analysis ◽  
Flavour Compounds ◽  
Odour Threshold ◽  
Flavour Profile

Earthy-musty off-flavour compounds in water samples are usually associated with the presence of geosmin and 2-methylisoborneol. However, the presence of 2,3,6- and 2,4,6-trichloroanisoles or other halogenated anisoles can impart objectionable tastes and odours to the water even at very low trace levels. This paper shows the synthesis of non-commercial 2,3,6- and 2,4,6- mixed chloro/bromoanisoles which can be present in bromide rich waters and could also be suspected of imparting earthy-musty off-flavours to the water. All the synthesized compounds were subjected to the flavour profile analysis (FPA) method and their odour threshold concentrations (OTC) in water were carried out giving values in the low ng/L range.

In situ irradiation effects studies in medium- and high-voltage TEM

1995 ◽  
Vol 53 ◽  
pp. 234-235
Author(s):  
Charles W. Allen
Keyword(s):  
Cross Section ◽  
Particle Flux ◽  
Threshold Value ◽  
High Energy ◽  
Irradiation Damage ◽  
Defect Complexes ◽  
Lattice Position ◽  
Electrons And Ions ◽  
The Masses

With respect to structural consequences within a material, energetic electrons, above a threshold value of energy characteristic of a particular material, produce vacancy-interstial pairs (Frenkel pairs) by displacement of individual atoms, as illustrated for several materials in Table 1. Ion projectiles produce cascades of Frenkel pairs. Such displacement cascades result from high energy primary knock-on atoms which produce many secondary defects. These defects rearrange to form a variety of defect complexes on the time scale of tens of picoseconds following the primary displacement. A convenient measure of the extent of irradiation damage, both for electrons and ions, is the number of displacements per atom (dpa). 1 dpa means, on average, each atom in the irradiated region of material has been displaced once from its original lattice position. Displacement rate (dpa/s) is proportional to particle flux (cm-2s-1), the proportionality factor being the “displacement cross-section” σD (cm2). The cross-section σD depends mainly on the masses of target and projectile and on the kinetic energy of the projectile particle.

Rating Post-Operative Backs (Part I)

1997 ◽  
Vol 2 (4) ◽  
pp. 1-3
Author(s):  
James B. Talmage
Keyword(s):  
Spinal Stenosis ◽  
Foot Drop ◽  
Neurogenic Claudication ◽  
Root Damage ◽  
Fourth Edition ◽  
Minor Strain ◽  
Injury Model ◽  
Strain Type ◽  
A Minor ◽  
Anterior Tibialis

Abstract The AMA Guides to the Evaluation of Permanent Impairment, Fourth Edition, uses the Injury Model to rate impairment in people who have experienced back injuries. Injured individuals who have not required surgery can be rated using differentiators. Challenges arise when assessing patients whose injuries have been treated surgically before the patient is rated for impairment. This article discusses five of the most common situations: 1) What is the impairment rating for an individual who has had an injury resulting in sciatica and who has been treated surgically, either with chemonucleolysis or with discectomy? 2) What is the impairment rating for an individual who has a back strain and is operated on without reasonable indications? 3) What is the impairment rating of an individual with sciatica and a foot drop (major anterior tibialis weakness) from L5 root damage? 4) What is the rating for an individual who is injured, has true radiculopathy, undergoes a discectomy, and is rated as Category III but later has another injury and, ultimately, a second disc operation? 5) What is the impairment rating for an older individual who was asymptomatic until a minor strain-type injury but subsequently has neurogenic claudication with severe surgical spinal stenosis on MRI/myelography? [Continued in the September/October 1997 The Guides Newsletter]

Pelvic Impairments

2018 ◽  
Vol 23 (4) ◽  
pp. 9-10
Author(s):  
James Talmage ◽  
Jay Blaisdell
Keyword(s):  
Pelvic Ring ◽  
Reproductive Organs ◽  
High Impact ◽  
Pelvic Fractures ◽  
Motor Dysfunction ◽  
Impact Event ◽  
Concomitant Injuries ◽  
Rating Process ◽  
Pass Through ◽  
A Minor

Abstract Pelvic fractures are relatively uncommon, and in workers’ compensation most pelvic fractures are the result of an acute, high-impact event such as a fall from a roof or an automobile collision. A person with osteoporosis may sustain a pelvic fracture from a lower-impact injury such as a minor fall. Further, major parts of the bladder, bowel, reproductive organs, nerves, and blood vessels pass through the pelvic ring, and traumatic pelvic fractures that result from a high-impact event often coincide with damaged organs, significant bleeding, and sensory and motor dysfunction. Following are the steps in the rating process: 1) assign the diagnosis and impairment class for the pelvis; 2) assign the functional history, physical examination, and clinical studies grade modifiers; and 3) apply the net adjustment formula. Because pelvic fractures are so uncommon, raters may be less familiar with the rating process for these types of injuries. The diagnosis-based methodology for rating pelvic fractures is consistent with the process used to rate other musculoskeletal impairments. Evaluators must base the rating on reliable data when the patient is at maximum medical impairment and must assess possible impairment from concomitant injuries.

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