Dehydration products of 2-methylisoborneol are not responsible for off-flavor in the channel catfish

Mills, O. E.; Chung, Si Yin; Johnsen, Peter B.

doi:10.1021/jf00034a032

Cited by 18 publications

(17 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All these VOCs have been reported previously in Cyanobacteria, Actinomycetes, certain fungi (Cho et al 2006;Dionigi et al 1991;Fischer et al 1999;Jensen et al 1994;Lovell and Sackey 1973, 1986, Lovell et al 1986Mills et al 1993), and bacteria (Gerber and Lechevalier 1965;Martin et al 1987;Wood and Snoeyink 1977). To the best of our knowledge, this is the first example among polydesmid millipedes in which the composition of defense allomones changes during the nymphal stages, from a mixture of PDs and VOCs to only VOCs.…”

Section: Discussionsupporting

confidence: 67%

“…Eight peaks were identified by comparing mass spectra and retention times to authentic standards (Table 1): benzaldehyde (A), 1-octen-3-ol (1), E-2-octen-1-ol (3), benzoyl cyanide (B), benzoic acid (C), mandelonitrile (D), geosmin (5), and mandelonitrile benzoate (E). Two other peaks, 2-methyl-2-bornene (2; Mills et al 1993) and 2-methyl-isoborneol (4; Martin et al 1987), were elucidated on the basis of their mass spectra (MS library) and retention indices (Dickschat et al 2005). Compounds A-E (polydesmid compounds, hereafter abbreviated as PDs) were found only in 1st instars, whereas some or all of compounds 1-5 (volatileorganic compounds, presumably of microbial origin, as discussed later and hereafter abbreviated as VOCs) were found in both instars.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Chemical Polymorphism in Defense Secretions during Ontogenetic Development of the Millipede Niponia nodulosa

et al. 2014

View full text Add to dashboard Cite

A mixture of defense compounds (benzaldehyde, benzoyl cyanide, benzoic acid, mandelonitrile, and mandelonitrile benzoate), found commonly in cyanogenic polydesmid millipedes, was identified in the non-cyanogenic millipede Niponia nodulosa. These compounds were major components in 1st-4th instars, but were absent in older instars and adults. Extracts of older instars and adults contained 1-octen-3-ol, 2-methyl-2-bornene, E-2-octen-1-ol, 2-methyl-isoborneol, and geosmin; these compounds were minor components in 1st-4th instars. This ontogenetic allomone shift may be explained by the high cost of biosynthesis of polydesmid compounds from L-phenylalanine being offset by their potency in protecting the insect during fragile and sensitive growth stages. However, as the cuticle hardens in older juveniles (5th, 6th, 7th instars) and adults, this allows for a switch in defense to using less effective and less costly volatile organic compounds (presumably microbial in origin) that are ubiquitous in the millipede's habitat or are produced by symbiotic microbes and may be readily available through food intake or aspiration.

show abstract

Section: Discussionsupporting

confidence: 67%

Section: Resultsmentioning

confidence: 99%

Chemical Polymorphism in Defense Secretions during Ontogenetic Development of the Millipede Niponia nodulosa

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Although Martin et al (1988a, b) claimed that the MIB dehydration products may be at least partially responsible for musty odor in catfish, a subsequent study (Mills et al 1993) clearly demonstrated that those compounds do not have a musty taste or odor. Other researchers (Finato et al 1992, Napolitano et al 1996 have synthesized various cyclic and noncyclic tertiary alcohols and shown them to have earthy or earthy/camphor odors resembling that of MIB.…”

Section: Applicationmentioning

confidence: 96%

Dehydration of the off-flavor chemical 2-methylisoborneol by the R-limonene-degrading bacteria Pseudomonas sp. strain 19-rlim and Sphingomonas sp. strain BIR2-rlima

Eaton

2011

Biodegradation

View full text Add to dashboard Cite

The terpene 2-methylisoborneol (MIB), a major cause of off-flavor in farm-raised catfish and drinking water, is transformed by various different terpene-degrading bacteria. Two of these, the R-limonene-degrading strains Pseudomonas sp. 19-rlim and Sphingomonas sp. BIR2-rlima, dehydrated MIB with the formation of odorless metabolites 2-methylenebornane and 4-methylcamphene. These metabolites which have a structural resemblance to camphor, could be further transformed by camphor-degrading bacteria to more oxidized products. The bacterial dehydrations demonstrated here may have application in removing MIB where it is a problem.

show abstract

“…Dehydration is a chemical reaction that involves the loss of water from the reacting molecule. Dehydration of 2-MIB under acidic conditions and with thionyl chloride in pyridine has been reported in the literature (Sumitomo et al 1987;Martin et al 1988;Mills et al 1993;Schumann and Pendleton 1997). Based on mass spectrum and 1 H and 13 C NMR analysis, 2-methyl-2-bornene, 2-methylenebornane, and 1-methylcamphene are suspected as the dehydration products of 2-MIB.…”

mentioning

confidence: 89%

“…Geosmin and 2-MIB are tertiary alcohols, and thus are easy to dehydrate under acidic conditions (Gerber and Lechevalier 1965;Gerber 1967;Sumitomo et al 1987;Martin et al 1988;Mills et al 1993;Schumann and Pendleton 1997). Dehydration is a chemical reaction that involves the loss of water from the reacting molecule.…”

mentioning

confidence: 99%

Effect of pH on the Analysis of 2-MIB and Geosmin in Water

Hsieh

Hung

Wang

et al. 2011

Water Air Soil Pollut

View full text Add to dashboard Cite

2-Methylisoborneol (2-MIB) and trans-1,10-dimethyl-trans-9-decalol (geosmin) are two commonly observed taste and odor compounds present in drinking water sources. The effects of pH on the analysis of the two chemicals are investigated using a gas chromatograph and mass spectrometric detector (GC/MSD) coupled with three preconcentration methods, namely solid-phase microextraction (SPME), purge-and-trap concentration (PTC), and liquid-liquid extraction (LLE). At neutral and alkaline pH conditions, the concentrations detected for both compounds remain constant. However, a substantial reduction of concentration for both chemicals is observed when the water solution pH is less than 5. Under acidic conditions (pH≅2.5), the 2-MIB concentrations detected by GC/MSD coupled with SPME, PTC, and LLE are 87%, 16%, and 37% lower than those measured at pH 6-7, respectively. For geosmin, a decrease in concentration is only observed when using GC/MSD-SPME, presumably due to the higher extraction temperature compared to the other two techniques. The pH-dependent behavior was attributed to dehydration of the tertiary alcohols of 2-MIB and geosmin under acidic conditions. The dehydration for 2-MIB and geosmin is reversible, and the analysis can be mitigated by adjusting the water solution pH back to a neutral condition.

show abstract

Dehydration products of 2-methylisoborneol are not responsible for off-flavor in the channel catfish

Cited by 18 publications

References 9 publications

Chemical Polymorphism in Defense Secretions during Ontogenetic Development of the Millipede Niponia nodulosa

Chemical Polymorphism in Defense Secretions during Ontogenetic Development of the Millipede Niponia nodulosa

Dehydration of the off-flavor chemical 2-methylisoborneol by the R-limonene-degrading bacteria Pseudomonas sp. strain 19-rlim and Sphingomonas sp. strain BIR2-rlima

Effect of pH on the Analysis of 2-MIB and Geosmin in Water

Contact Info

Product

Resources

About