Werner Grosch

Bio: Werner Grosch is an academic researcher from Ludwig Maximilian University of Munich. The author has contributed to research in topics: Linoleic acid & Aroma. The author has an hindex of 56, co-authored 152 publications receiving 10265 citations. Previous affiliations of Werner Grosch include Hess Corporation & Technische Universität München.

Identification of the most intense volatile flavour compounds formed during autoxidation of linoleic acid

Abstract: The volatile compounds formed during autoxidation of linoleic acid and methyl linoleate at 22–24 °C were analysed by high resolution gas chromatography and eluate sniffing. The application of this technique to stepwise diluted extracts of the volatile compounds allowed the determination of a new parameter, theD-value, which reveals the most intense flavour compounds of an extract.

Detection of potent odorants in foods by aroma extract dilution analysis

Abstract: Aroma extract dilution analysis (AEDA) is a quantitative gas chromatography olfactometry (GCO) procedure for determining the potency of odorants in food extracts. After the odorants with the highest flavour dilution factors have been identified, their concentrations in foods are quantified and their odour activity values (OAVs) are calculated. Applications of this new method to the study of several flavours and off-flavours are reviewed.

Studies on character impact odorants of coffee brews

Abstract: Twenty-two compounds, which had been revealed by dilution experiments as potent odorants, were quantified by stable isotope dilution assays in brews prepared from roasted Arabica (Coffea arabica) and Robusta coffees (Coffea canephora var. Robusta). Calculation of odor activity values (OAVs; ratio of concentration to odor threshold) indicated 2-furfurylthiol, 3-mercapto-3-methylbutyl formate, methanethiol, β-damascenone, methylpropanal, and 3-methylbutanal as the most potent odorants. However, the rankings of the OAVs were different in the two coffee brews. The extraction yields obtained during the preparation of the brews were determined for 17 odorants. Polar compounds (e.g. guaiacol, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 3-hydroxy-4,5-dimethyl-2(5H)-furanone, 2,3-butanedione) were extracted with higher yields (75−100%); nonpolar compounds (e.g. β-damascenone, 2-isobutyl-3-methoxypyrazine) gave yields of only 10−25%. The overall odor of the models containing the odorants in the concentration levels that...

Beneficial Effects of Green Tea—A Review

Abstract: Tea is the most consumed drink in the world after water. Green tea is a 'non-fermented' tea, and contains more catechins, than black tea or oolong tea. Catechins are in vitro and in vivo strong antioxidants. In addition, its content of certain minerals and vitamins increases the antioxidant potential of this type of tea. Since ancient times, green tea has been considered by the traditional Chinese medicine as a healthful beverage. Recent human studies suggest that green tea may contribute to a reduction in the risk of cardiovascular disease and some forms of cancer, as well as to the promotion of oral health and other physiological functions such as anti-hypertensive effect, body weight control, antibacterial and antivirasic activity, solar ultraviolet protection, bone mineral density increase, anti-fibrotic properties, and neuroprotective power. Increasing interest in its health benefits has led to the inclusion of green tea in the group of beverages with functional properties. However, although all the evidence from research on green tea is very promising, future studies are necessary to fully understand its contributions to human health, and advise its regular consumption in Western diets, in which green tea consumption is nowadays limited and sporadic.

Mechanisms of free radical oxidation of unsaturated lipids

Abstract: The primary producs formed from the autoxidation of lipids can be understood based upon a mechanism that involves five different reaction types. These reactions are: reaction of a carbon radical and molecular oxygen, atom transfer of a hydrogen from substrate to the chain carrying peroxyl, fragmentation of the chain carrying peroxyl to give oxygen and a carbon radical, rearrangement of the peroxyl, and cyclization of the peroxyl. The mechanisms of these primary reaction steps has been the focus of extensive research over the past fifty years, and the current level of understanding of these transformations is the subject of this review.

Biochemical pathways for the production of flavour compounds in cheeses during ripening: A review

Abstract: The principal pathways for the formation of flavour compounds in cheese (glycolysis, lipolysis and proteolysis) are reviewed. Depending on variety, microflora and ripening conditions, lac- tate may be metabolized by a number of pathways to various compounds which contribute to cheese flavour or off-flavours. Citrate metabolism by citrate-positive lactococci or Leuconostoc spp. is important in certain varieties (e.g., Dutch cheeses). Lipolysis results directly in the formation of flavour compounds by liberating free fatty acids (FFA). FFA may also be metabolized to alkan-2-ones and fatty acid lactones. Proteolysis of the caseins to a range of small- and intermediate-sized peptides and free amino acids (FAA) probably only contributes to the background flavour of most cheese varieties, but FAA are important precursors for a range of poorly-understood catabolic reactions which produce volatile compounds essential for flavour.