Limonene pepper

Although most consumers appreciate the fieriness of chile, capsaicinoids are not perceived through odor or taste receptors but through the nociceptive pain receptors described earlier. The compounds in chile fruit that create the flavor and aroma are produced in the fruit wall. Buttery et al. [90] generated vacuum steam distilled oil from green bell pepper macerate, with well over 40 peaks on subsequent GC/MS analysis. Of these peaks, the major flavor compound associated with bell pepper aroma was 2-methoxy-3-isobutylpyrazine (Fig. 8.1). They also reported several monoterpenoids in abundance, limonene, trans- 3-ocimene, and linalool as well as other aliphatic aldehydes and ketones. The flavor composition of dried red bell pepper powder (sweet paprika) extracted with ether identified 44 key peaks by GC/MS [91]. In these dried samples the key compounds were P-ionone and several furanones. The post-harvest processing and the different fruit maturities as well as possible varietal differences are all causes for the different aromatic profiles. 

Earlier workers established the presence of a-pinene, (3-pinene, 1-a-phellandrene, dl-limonene, piperonal, dihydrocarveol, a compound melting at 161°C, P-caryophyllene and a piperidine complex from the essential oil obtained by steam distillation of ground Malabar pepper. The above compounds were identified by the classical methods of derivatization and degradation. They also reported the presence of epoxy dihydrocary-... 

Dilution and concentration experiments on samples of dried black pepper berries from India and Malaysia, as well as enantioselec-tive analysis of optically active monoterpenes, indicated ( )-linalool, (-i-)-a-phellandrene, (-)-limonene, myrcene, (-)-a-pinene, 3-methylb-utanal and methylpropanal as the most potent odorants of black pepper. Additionally, 2-iso-propyl-3-methoxypyrazine and 2,3-diethyl-5-methylpyrazine were detected as important odorants of the black pepper sample from Malaysia, which had a mouldy, musty off-flavour (Jagella and Grosch, 1999a). Gamma irradiation was an effective means of decon-... 

The major monoterpene hydrocarbons present in pepper oil are a- and (3-pinenes, sabinene and limonene. Chemical structures of major aroma compounds are illustrated in Fig. 2.1. 

Thevanmundi, Poonjaranmunda, Valiakaniak-kadan and Subhakara. Some of the newly developed cultivars are Panniyur-1, Panniyur-2, Panniyur-3 and Panniyur-4. By adopting GC and GC-MS techniques, researchers have identified over 55 compounds from the volatile oil of these pepper cultivars. The major compounds identified were a- and (3-pinene, sabinene, limonene, P-caryophyllene, myrcene, p-cymene and caryophellene oxide (Gopalakrishnan et al., 1993 Menon et al., 2000, 2002, 2003 Menon and Padmakumari, 2005). Table 2.7 illustrates this variability among different popular cultivars. 

GC-MS. The major compounds were found to be trans-linalool oxide and a-terpineol, whereas the dry black pepper oil contained a- and (3-pinenes, d-limonene and (3-caryo-phyllene as major components. When fresh pepper oil was isolated by distillation and analysed by GC and GC-MS, the compounds were found to be of a different nature to that of fresh pepper aromatic compounds (Menon, 2000). 

Other flavouring compounds found in reasonable quantities are 14(3098) pen-tanal, 21 l-methyl-l/f-pyrrole, 23(3584) 1-penten-3-ol, 26(2633) (B)-(+)-limonene, 36 cis-2-heplenal, 40(2782) nonanal, 42(2805) l-octen-3-ol and 44(2362) decanal. The compound described as the character-imparting compound in bell peppers is 2-isobutyl-3-methoxypyrazine. This very powerful odour-ant has a threshold in water of 1 part in 10A12 (Govindarajan and Sathyanarayana, 1986). 

Pepper Piper nigrum ( )-/i-Pinene, ( )-limonene, (S)-a-phellandrene (46), ( )-linalool 95,101,102... 

PROP From steam distillation of dried fruit of PipernigmmL. (Fam. Piperaceae). Main constituents include a- and p-pinene, p-caryophyllene, 1-limonene, d-hydrocarveol, piperidine, and piperrine (FCTXAV 16,637,78). A colorless to greenish liquid odor and taste of pepper. Sol in fixed oils, mineral oil, propylene glycol sidy sol in glycerin. 

The odorants of black pepper are listed in Table 6.47. Their OAVs are calculated on the basis of odour threshold values in starch because at app. 45% it is the major component of the kernel [83]. As a result of its low odour threshold, linalool (no. 11) shows the highest OAV, followed by limonenes nos. 9a and 9b, (-)-P-pinene (no. 6a) and (S)-a-phellandrene (no. 8b). 

Figure 2. Black pepper 1 - a-pinene, 2 - sabinene, 3 - P-pinene, 4 - limonene + 1,8-cineole, 5 - y-terpinene, 6 - a-terpinolene, 7 - P-caryophellene, 8 - myristicine.

Capsicum frutescens. Volatiles of Cayenne pepper have been studied in a comprehensive GC-MS analysis (Cardeal et al. 2006). Its blend is composed of monoterpenes (e.g., limonene, P-phellandrene, sabinene, P-pinene, y-terpinene), oxidized congeners (e.g., linalool, terpinen-4-ol, a-pheUandrene epoxide), sesquiterpenes (see Sect. 7.3.1.1), and members of different other classes of metabolites. 

Fig. 22.1. Storage of ground black pepper at room temperature - changes in the concentrations of odorants, (a) ( - ) 3-methylbutanal, (o-o) a-pinene, ( - ) myrcene, ( - ) a-phellandrene (b) (A-A) limonene, (A—A) 1,8-cineol, ( —T) linalool...

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