摘要:

AbstractQuantitative determination of the capsaicinoids and the gingerols, pungent constituents of chillies and ginger respectively, is important for objective assessment of the pungency of these spices and their oleoresins. High‐performance liquid chromatography (HPLC) procedures applicable to these groups of compounds have been reported from several laboratories. The principal difficulty with gingerol determinations hitherto has been the lack of a stable and easily purified analytical standard, since the gingerols (and their dehydration products, the shogaols) are labile, oily liquids which are difficult to purify. Since the capsaicinoids and the gingerols and their analogues have closely related chemical structures, the possibility of selecting from among them one easily purified crystalline compound to serve as an external standard for determination of both groups of compounds by HPLC was investigated. It was found that caprylic acid vanillyl amide (CVA), one of the minor naturally occurring capsaicinoids but an easily synthesized crystalline compound, was very suitable for this purpose, and that a commercially available mixture of capsaicin and dihydrocapsaicin could be used as a slightly less convenient alternative. Reversed‐phase HPLC methods based on this principle are described, and shown to be suitable for the analysis (without clean‐up) of chillies and ginger or their oleoresins. An acceptable level of precision (relative standard deviation less than 2% and 5% respectively) is demonstrated for the summed major pungent principles in dried chillies and dried ginger, and it is shown that fair agreement between the HPLC and spectrophotometric difference methods can be obtained for chillies of varying pungency l

ISSN:0882-5734    

DOI:10.1002/ffj.2730020102

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractSicilian lemon essential oil is a very high quality product which is offered to the international market at prices that are higher than those of the lemon essential oils produced in other citrus‐growing countries.Market competition sometimes leads producers to ‘blend’ genuine essential oil with less expensive products, which are generally ‘citral’ and orange terpenes.These terpenes, which are usually obtained from orange essential oil produced abroad, possess characteristics which modify the composition of lemon essential oil, even if added in only moderate quantities.In particular, the percentage of Δ3‐carene and the ratios of Δ3‐carene/α‐terpinene and Δ3‐carene/camphene can provide a good indication of the possible addition of orange essential oil or ‐of by‐products obtained therefrom to genuine lemon essential oil.After a study made on a great number of genuine lemon essential oils, on several samples of sweet orange terpenes, and on a large number of lemon oil and orange terpene blends we propose a gas chromatographic method which allows the detection of the addition of even 5% of sweet orange oil terpenes to gen

ISSN:0882-5734    

DOI:10.1002/ffj.2730020103

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

Abstract1H‐NMR examination of (+)‐terpinen‐4‐ol, performed in the presence of various molar ratios of a chiral lanthanide shift reagent Eu(hfc)3, showed that the enantiomeric composition of (+)‐terpinen‐4‐ol isolated from the essential oil of sweet marjoram is 73%(+): 27%(−). Peak assignment of the enantiomers was achieved by spiking the natural (+)‐enantiomer with the commercial (−)‐alcohol. The method will readily reveal adulteration of natural oils wi

ISSN:0882-5734    

DOI:10.1002/ffj.2730020104

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe sources of several additional isolates of interest from : ralian flora are listed along with details of yield, isolation procedure and use.

ISSN:0882-5734    

DOI:10.1002/ffj.2730020105

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe composition of the essential oil ofRhanterium epapposumOliv. (Compositae) growing in northeastern Iran has been investigated by TLC, liquid‐solid chromatography, capillary GLC, and GLC‐MS. The oil contained 107 volatile components of which 92% were terpenoids. The main constituents were α‐phellandrene, linalol, geraniol, bulnesol, and β‐phellandrene accounting for 55.6% of the oil. Non‐terpenoid aliphatic and aromatic structures have also be

ISSN:0882-5734    

DOI:10.1002/ffj.2730020106

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe junipers of Cubaare Juniperus lucayanaandJ. Saxicola, the latter being endemic to Pico Turquino in Cuba. In this first report on the oils of the junipers of Cuba, the leaf oils were first extracted and then analysed by GC‐MS.Juniperus lucayanafrom mainland Cuba and the Isle of Pines had oil yields (oven dry weight basis) of 0.58% (2 h) and 2.33% (24 h), and 0.40%(2 h), and 1.58% (24 h), respectively. The oils are dominated by α‐pinene (25–27%), limonene (23–27%), sabinene (11–12%) with small amounts of sesquiterpenes. The volatile leaf oil ofJ. saxicolawas obtained in yields (oven dry weight basis) of 0.30% (2 h) and 0.72% (24 h). Its oil is dominated by sabinene (25%) and α‐pinene (24%), and is more similar toJ. lucayanathan other species of the Caribbean. The oil compositions of other junipers of the Caribbean are included to aid in makin

ISSN:0882-5734    

DOI:10.1002/ffj.2730020107

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe volatile leaf oil ofEugenia javanicacontains γ‐terpinene (28.5%), α‐pinene (18.2%) andp‐cymene (13.7%) as major components. Another 59 components have been detected in the oil, 40 of which have been ide

ISSN:0882-5734    

DOI:10.1002/ffj.2730020108

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractGas chromatographic analysis of the steam volatile oil ofinthostachys glabrescensEpl. showed the presence of a large number of components, 36 of which comprised 95% of the oil. The major components were pulegone (45%) and menthone (18%). The identity of the components was checked by GC‐M

ISSN:0882-5734    

DOI:10.1002/ffj.2730020110

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

ISSN:0882-5734    

DOI:10.1002/ffj.2730020101

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY