Grapefruit note

Typical Scheurebe wines are characterized by a jfruity aroma, which is described as redcurrant-like, often with a grapefruit note. In 1995 Darriet et al. identified 4-mercapto-4-methylpentan-2-one (MMP), responsible for the distinctive odor of box tree and cat urine (7). The perception threshold of this compound in wine has been reported to be very low (3 ng/1). Recent studies by Guth and coworkers (2) showed that MMP also significaiitly influences the aroma of Scheurebe wines. 

Typical bitter grapefruit note which resembles both bitter and sweet orange. Additionally, the peel oil is characterised as a peel-like, pronounced, watery, juicy, greenish citrus note. 

The especially fresh, juicy grapefruit note is due to the presence of R(-i-)-para-menthene-8-thiol which can be detected as a trace constituent in the ppb range of grapefruit oils ]46]. Other important potent odour-active volatiles of grapefmit juice are l-penten-3-one, l-hepten-3-one, hex-anal, 4-mercapto-4-methylpentan-2-one and 4,5-epoxy-(E)-2-decenal ]47]. 

Features Fresh herbal fragrance, grapefruit note Trade Name Synonyms Vertacetal 3/080315 t[Dragoco http //www.dragoco.com, http //www. symrise. com]... 

Buspirone (BuSpar) [Anxiolytic] WARNING Closely monitor for worsening depression or emergence of suicidality Uses Short-term relief of anxiety Action Antianxiety antagonizes CNS serotonin receptors Dose Initial 7.5 mg PO bid T by 5 mg q2-3d to effect usual 20-30 mg/d max 60 mg/d Contra w/ MAOI Caution [B, /-] Avoid w/ severe hepatic/renal insuff Disp Tabs SE Drowsiness, dizziness, HA, N, EPS, serotonin synd, hostility, depression Notes No abuse potential or physical/psychologic d endence Interactions T Effects W/ erythromycin, clarithromycin, itraconazole, ketoconazole, diltiazem, verapamil, grapefruit juice effects W/ carbamazepine, rifampin, phenytoin, dexamethasone, phenobarbital, fluoxetine EMS T Sedation w/ concurrent EtOH use grapefruit juice may T risk of adverse effects OD May cause dizziness, miosis, N/V symptomatic and supportive... 

Grapefruit, typically, has harsher flavor notes. Similar to other citrus oils, grapefruit oil is predominately composed of terpenes. There have been 206 volatile compounds identified in grapefruit juice. However, the flavor impact compounds are more dominant. Nootkatone and l-p-methene-8-thiol are the major compo-... 

FIGURE 17-4. Gradient chromatography. Mobile phase H20 to MeOH gradient. Flow rate 2 mL/min. Detector UV at 254 nm, 0.1 AUFS. Sample grapefruit peel extract, 25 /jlL. Recorder 0.2 in./min. Column Bondapak C 8/Porasil B, 2 mm ID x 60 cm. (Note Actual separation will depend upon the quality of the mobile phase and column packing.)... 

Many drugs will cause adverse effects if the dose is excessive but some cause adverse effects at the correct dose in certain individuals. This can be due to an increased sensitivity of the patient because of genetic or other factors (see pp. 29-31). There may also be side effects which are not apparent at low or therapeutic doses but which become more important at higher doses. Occasionally, unexpected and serious adverse effects occur in a few patients. Sometimes this is due to an interaction between two drugs or between a drug and a food constituent such as occurred with the drug terfenadine (used to treat hay fever) and grapefruit juice (see case note, pp. 33-4). 

Group 20 is a nice collection of wonderful sulphur compounds. Disulphides such as diallyl disulphide (Flavis 12.008, FEMA 2028) with onion- and garlic-like notes are followed by extremely powerful mercaptans like the grapefruit compound p-l-men-thene-thiol (Flavis 12.085, FEMA 3700). In addition, thiols with tropical sulphury notes complete the picture of interesting molecules. 

Epoxybergamottin, auraptene, meranzin, epoxyauraptene, bergamottin and isomeranzin are the most important constituents of the non-volatile range. Together with a number of other flavones and coumarins, they form a pattern which is typical for grapefruit oil and make up app. 3-5% of the oil [38, 39], (-i-)-Nootkatone is responsible for the typical bitter note. 

The aqueous grapefruit essence is characterised as an aqueous, juicy, fruity, woody, estery, sweaty nootkatone and acetal note. 

CIC The bitter taste originates from naringin. Nootkatone imparts the characteristic fresh woody odour. Acetaldehyde and ethyl butyrate improve the juicy note and 1-p-menthane-8-thiol is responsible for the typical exotic grapefruit character. 

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