Steam distillation-extractions

C) Steam distillation, extraction, and evaporation (Waller et al. 113. 14]) were completed and the resulting mixtures bioassayed. 

Uri ne Acidify steam distill extract with methylene chiori de GC/MS No data No data Angerer 1985 o... 

Volatile constituents of cupuacu were isolated by steam distillation-extraction of pulp or juice [2].The identification of volatile constituents was based on mass spectral analysis. The pleasant aroma compounds were mainly esters (Fig. 8.2). Targe amounts of ethyl butanoate and small amounts of ethyl acetate, butyl acetate, and butyl isobutanoate were described. 

The first study on the volatile composition of bacuri revealed linalool, 2-hep-tanone, and czs-3-hexenyl acetate as the most important flavour compounds [2]. Volatiles were isolated by a steam distillation-extraction of pulp. 

Recovery of naturally occurring esters is accomplished by steam distillation, extraction, pressing, or by a combination of these processes. Synthetic esters are generally prepared by reaction of an alcohol with an organic acid in the presence of a catalyst such as sulfuric acid, p tolucitcsullonic acid, or mcthancsulfonic acid. 

The diagram of the micro steam distillation-extraction apparatus is given. The recovery yield is given for test compounds. 

Diagrams of SDE under vacuum and solvent consideration are given. The reader can also consult the additional literature giving other details relative to the methodology i.e., the Chrompack user manual contains a drawing of themicro steam distillation extraction apparatus. 

Solvent Liquid/liquid extraction (LLE) Steam distillation/extraction (SDE) Solvent microextraction (SME) - SDME - LPME - DLLME Headspace-solvent-microextraction (HS-SME) - Headspace single-drop microextraction (HS-SDME) - Headspace liquid phase microextraction (HS-LPME) ... 

Oxidation of 9,10-Dihydroxystearic Acid.116 The Use of Aqueous Ethanol as the Solvent. A solution of 6 g. of potassium periodate in 300 cc. of N sulfuric add at 20° is added rapidly to a solution of 8 g. of 9,10-dihydroxystearic add (m.p. 132°) in 400 cc. of alcohol at 40°. After ten minutes the clear solution is cooled to 15° and diluted with suffident water to dissolve the predpitated potassium sulfate. Extraction with ether gives an oily product, which is submitted to steam distillation. Extraction of the distillate with ether yields 3.2 g., or 89%, of pure pelargonaldehyde as a colorless oil boiling at 76-77° (11 mm.). 

The important odorant, 2-acetyltetrahydropyridine (ACTPY), has already been mentioned in the previous section. ACTPY and ACPY play key roles in the aroma of popcorn.227 Freeze-dried maize contains relatively high amounts of proline (155), whereas ornithine is not detectable (< 5 mg kg ) Schieberle treated a low-molecu-lar-mass fraction of an aqueous extract of maize in different ways and determined ACTPY and ACPY by isotope dilution assay (Table 5.2). Steam-distillation extraction gave 130 times as much ACTPY than ACPY however, in the presence of added 2-oxo-propanal, the amount of the former was multiplied by 4, but that of the latter by 29. Dry-heating, as in popping, increased the latter further, but the former became undetectable. 

Method A Steam-distillation extraction with diethyl ether, 2 h. 

Certain compounds present in the essential oil can be changed by the steam. This can be ill strated by comparing a steam-distilled extract with that of the solvent extract. In rose extracts compounds such as phenylethyl alcohol make up a major proportion of the solvent-extracted material, but this is practically all lost in the steam distillation extract as it dissolves in the water. However, the process can be advantageous in German chamomile, where matricin is decomposed to form the characteristic blue compound chamazulene. 

This experiment is intended to illustrate the complementary nature of analytical LC with steam distillation by measuring the composition of a steam-distilled extract of a spice. 

If other steam distilled extracts are to be analyzed, prepare the extract as in Activity D-l and D-2 and prepare the standard as in Activity D-3 and D-4. 

Hydrolysed protein preparations have been used to attract various insects. The general subject of insect attractant use both in nature and by man is introduced, with particular reference to the Tephritid family of fruit flies. The work of the Biocommuni-cation Chemistry Research Unit on the identification of the active attractant compounds in the hydrolysed corn protein, Nu-Lure Insect Bait (NLIB) is discussed. Different isolates have been obtained by running simultaneous steam distillation-extractions (SDE) under vacuum and atomospherlc pressure and under basic and acidic conditions. Chemical fractionation of these isolates has also been accomplished. Chemical identification by gas chromatography/mass spectrometry (gc/ms) is discussed. 

We are examining those commonly used baits, the protein hydrolysates. Initial studies have used the corn gluten hydrolysate commonly known as PIB-7 or, now, as Nu-Lure Insect Bait (NLIB). This material was used in the recent successful Medfly eradication program in California. Since the fruit flies are probably attracted to the volatile emanations from the bait, we have used equipment and techniques previously developed by members of our group for flavor research. For example, a modified Likens-Nickerson simultaneous steam distillation-extraction head was developed by Flath and Forrey (67.). Also, there is a 90 liter... 

Our first separation method involved running the simultaneous steam distillation extraction under 100 mm vacuum in order to minimize heat effects. This was followed by extraction under atmospheric pressure in order to get more complete recovery. This atmospheric extraction was run for 10 days, using a fresh hatch of solvent each day (68-69). Approximately 10 times as much material was collected each day at atmospheric pressure as was collected under vacuum. Since Schultz, et. al. (70) showed that many non-water-soluble alcohols, esters, aldehydes, and ketones can he recovered by this system in less than 3 hours, the collection of a large amount of material after 10 days is indicative of a very complex and probably dynamic system. Gas chromatograms for these extracts (68.) and some compound identifications (69.) have been reported. (Other reports on the identification of volatiles from protein hydrolysates are given In references 71-75). Prelminary results have shown that the vacuum extracts are more attractive for the Medfly than the atmospheric ones. 

High resolution fused silica capillary columns were used to examine, and in some cases to compare, flavor and aroma essences obtained by 1) direct headspace injection, 2) simultaneous steam distillation extraction, 3) standard Soxhlet extraction using dichloromethane, and 4) high pressure Soxhlet extraction using liquid CO2 Developments in smaller- and larger-diameter fused silica open tubular columns, and columns coated with a bonded polyethylene glycol stationary phase were also explored. 

Figure 4 shows the chromatographic results of a black pepper sample examined by (from the top) 1) direct on-column headspace injection, 2) steam distillation-extraction, and 3) Soxhlet extraction with dichloromethane, and with 4) liquid CO2. Again, the results are quite reasonable, and in good agreement with those shown in Figure 2. Note that CO2 seems fully as effective (and Indeed, in some cases more effective) an extractant as dichloromethane. ...

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