On-Line Gas Chromatography Combustion/Pyrolysis Isotope Ratio Mass Spectrometry (HRGC-C/P-IRMS) of Pineapple (Ananas comosus L. Merr.) Volatiles

Abstract

By use of extracts prepared by liquid-liquid separation of the volatiles from self-prepared juices of pineapple fruits (Ananas comosus) (n = 14) as well as commercial pineapple recovery aromas/water phases (n = 3), on-line capillary gas chromatography-isotope ratio mass spectrometry was employed in the combustion (C) and the pyrolysis (P) modes (HRGC-C/P-IRMS) to determine the delta(13)C(VPDB) and delta(2)H(VSMOW) values of selected pineapple flavor constituents. In addition to methyl 2-methylbutanoate 1, ethyl 2-methylbutanoate 2, methyl hexanoate 3, ethyl hexanoate 4, and 2,5-dimethyl-4-methoxy-3[2H]-furanone 5, each originating from the fruit, the delta(13)C(VPDB) and delta(2)H(VSMOW) data of commercial synthetic 1-5 and "natural" (biotechnologically derived) 1-4 were determined. With delta(13)C(VPDB) data of pineapple volatiles 1-4 varying from -12.8 to -24.4 per thousand, the range expected for CAM metabolism was observed. Compound 5 showed higher depletion from -20.9 to -28.6 per thousand. A similar situation was given for the delta(2)H(VSMOW) values of 3-5 from pineapple ranging from -118 to -191 per thousand, whereas 1 and 2 showed higher depleted values from -184 to -263 per thousand. In nearly all cases, analytical differentiation of 1-5 from pineapple and natural as well as synthetic origin was possible. In general, natural and synthetic 1-5 exhibited delta(13)C(VPDB) data ranging from -11.8 to -32.2 per thousand and -22.7 to -35.9 per thousand, respectively. Their delta(2)H(VSMOW) data were in the range from -242 to -323 per thousand and -49 to -163 per thousand, respectively.

Effects of Film Mulching on Aroma Components of Pineapple Fruits

“…In this present study, besides one kind of heterocycle was detected in the treatment fruits harvested in winter, esters and alkenes were the main aroma components of pineapple fruits harvested in both winter and summer (Table 1), which agreed with previous reports (Preston et al, 2003;Elss et al, 2005).…”

“…Also film mulching treatment increased the total relative content of ester components and decreased the alkene components of pineapple fruits harvested in both winter and summer. Preston et al(2003) reported that the esters containing sulfur such as propanoic acid, 3-(methylthio)-, methyl ester and 3-(methylthio) propanoic acid ethyl ester were the characteristic aroma components of pineapple fruits. In this study, there was one ester containing sulfur, propanoic acid, 3-(methylthio)-, methyl ester with relative content of 1.40%, detected in the film mulching fruits harvested in winter, and no ester containing sulfur was detected in the control fruits harvested in winter.…”

Influences of organic manure addition on the maturity and quality of pineapple fruits ripened in winter

“…In addition to one type of alcohol identified in the fruits of T1, esters and alkenes were the main aroma components of all of the pineapple fruits (Table 2). This result confirmed previous reports that aroma components of pineapple fruits were predominated by esters and alkenes (Preston et al, 2003;Elss et al, 2005;Liu et al, 2011b).…”

“…The sulfur-containing esters, propanoic acid, 3-(methylthio)-methyl ester and 3-(methylthio) propanoic acid ethyl ester, were the characteristic aroma components of pineapple fruits (Engel et al, 1990;Preston et al, 2003). Similar to a previous study (Liu et al 2011a), only one characteristic ester, propanoic acid, 3-(methylthio) -methyl ester, was identified in the present study.…”

IRMS delta values (13C) of nandrolone and testosterone products available in the UK: Implications for anti‐doping

“…available in large quantities from the waste of sisal plants, is known to be used for the synthesis of cortisol 23,24. Though little research has been done on the carbon isotope ratio signature of sisal plants, research on the carbon delta value of other CAM plants such as pineapple has been undertaken and offers some support to the hypothesis proposed here 25. This photosynthetic mechanism results in less discrimination of 13 C during carbon fixation and therefore will produce delta values that are less negative than soy-derived steroids but more like those observed for the four endogenous-like N preparations seen in this study.…”