Recep Gök

Technische Universität Braunschweig · Institute of Food Chemistry

Tea leaves are rich in diverse bioactive compounds. The tea accession TRI 2043 is unique due to its pigmented leaves caused by anthocyanins, clonal origin, resistance to blister blight disease, and high pubescence density. Because of its peculiarity, TRI 2043 is used to produce high-quality silver tip tea, a premium type of tea that commands high p...

Blaufränkisch is an upcoming grape variety on the national and international market. To date, there is very little research on the grape variety available on the evidence base of which viticultural and oenological decisions can be made to enhance its typicity and quality. However, preliminary studies have shown that C 13-norisoprenoid profiles are...

Introduction Citrus fruits are one of the most frequently counterfeited processed products in the world. In the juice production alone, the peels, divided into flavedo and albedo, are the main waste product. The extracts of this by-product are enriched with many bioactive substances. Newer extraction techniques generally have milder extraction cond...

Kombucha is a fermented, acidic beverage that dates back thousands of years as a remedy for various health problems in East Asia. Due to its health benefits, kombucha has gained popularity and attracted the attention of both consumers and researchers. The health benefits of kombucha are predominantly attributed to its bioactive compounds that have...

High-performance countercurrent chromatography (HPCCC) was used for the target-guided isolation of precursors of 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) from Riesling wine. In separated HPCCC fractions of an Amberlite® XAD®-2 extract obtained from a German Riesling, TDN-generating fractions were identified by the acid-catalyzed hydrolysis of t...

The typical Austrian fruity white and red wines are endangered by climate change. Not only higher alcohol contents and lower acidity but also changes in the aroma composition are expected. An indicator substance of aged wines of the variety 'Rheinriesling', 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN), causes the petrol-note (or kerosene off - avor)...

The C13-norisoprenoid aroma compounds 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) and biosynthetically related vitispirane (VS) are important contributors to the varietal aroma of Riesling wines and are released from glycosidically bound carotenoid breakdown products during bottle aging. TDN is appreciated by numerous winemakers, particularly in a...

1,1,6-Trimethyl-1,2-dihydronaphthalene (TDN) is known to elicit the perception of “petrol off-flavor” in wine, most prominent in the variety Riesling. This study was focused on the impact of matrix variables such as ethanol and carbonation on the odor detection threshold of TDN. Increasing carbonation nearly doubled the detection threshold in water...

The C13-norisoprenoid aroma compounds 1,1,6 trimethyl-1,2-dihydronaphthalene (TDN) and isomeric 2,10,10-trimethyl-6-methylene-1-oxaspiro[4.5]dec-7-enes, so-called vitispiranes, are considered to be biosynthetically related. They occur at higher concentrations especially in bottle aged Riesling wines and are important contributors for the varietal a...

The volatile compounds in commercial rums declared as aged 3, 7, 10, and 15 years were isolated by solvent extraction followed by solvent-assisted flavour evaporation and analysed by gas chromatography-olfactometry. According to the aroma extract dilution analysis, 19 potentially aroma-active compounds in the flavour dilution (FD) factor range of 8...

The link between nutrition, food and health is well established and the global interest in these areas generates new information every day. This book pulls together the latest research on flavour chemistry and nutritional and functional properties of food. Topics covered in flavour chemistry begin with an overview of the analysis, occurrence and fo...

This chapter presents an overview on the generation of the norisoprenoids 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) and β-damascenone in wine. TDN is responsible for a "kerosene note" in aged Riesling wines. Responsible for TDN formation are a number of reactive nonvolatile carotenoid cleavage products. For TDN formation warmer climates and incr...

The volatiles of rum matured in oak casks were carefully isolated by solvent extraction followed by solvent-assisted flavour evaporation. Among the 116 volatile compounds identified by GC–MS, seven of them were found for the first time in rum. Application of the aroma extract dilution analysis (AEDA) on the volatile fraction revealed 18 odour-activ...

In many subtropical and tropical countries the cashew nut production (Anacardium occidentale L., Anacardiaceae) is a valuable food crop and of high agroeconomical interest. Anacardic acids are phenolic lipids which have shown a wide spectrum of biological effects, such as antibacterial, and anti-tumor activities. In this preparative separation expe...