Deterioration mechanism of lemon flavor. 2. Formation mechanism of off-odor substances arising from citral

Abstract

801some other Cg components, e.g., (Zl-6-nonenal or (2)-6nonenyl acetate, which were described by Buttery et al. (1982) to possess strong melon-like aroma far below the level of detection used in this study, seems probable.Registry No. , 95-16-9. LITERATURE CITEDAbd El-Baki, M. M.; A s h , A.; El-Samahy, S. K.; Abd El-Fadeel, M. G. Dtsch. Leben.sm.-Rundsch. Velluz, A.; Passerat, J.-P.; Ohloff, G. J. Sci. Food Renold, W.; Niif-Muller, R.; Keller, U.; Willhalm, B.; Ohloff, G. Schultz, T. H.; Flath, R. A.; Mon, T. R.; Eggling, S. B.; Teranishi, Tressl, R.; Engel, K.-H.; Kossa, M.; Koppler, H. J. Agric. Food Winter, M.; Kloti, R. Helv. Chim.p-Mentha-195-dien-8-01 (3a) and p-mentha-l(7),2-dien-8-01 (3b) were isolated from deteriorated citral as major components and were identified by IR, EI-MS, FI-MS, ' H NMR, and 13C NMR. When 3a or 3b was treated with aqueous citric acid, an equlibrium mixture of 3a-3b isomers (55:45) resulted and both isomers were subsequently converted to p-cymen-8-01(6) by disproportionation and redox reactions.

Antioxidant activity of plant extracts on the inhibition of citral off‐odor formation

“…This alcohol undergoes a dehydration process and transforms to a, p-dimethylstyrene. Kimura et al [5] reported that a, p-dimethylstyrene and p-cymene were responsible for the off-odor of deteriorated lemon. In an oxygen environment, the end products of citral degradation consist of 80% a, p-dimethylstyrene and 8% cymene.…”

Comprehensive two‐dimensional gas chromatographic analysis of commercial lemon‐flavored beverages

“…Candidate compounds were selected from the list of components contained in lemon juice [9] or deteriorated lemon juice [10][11][12][13]. Unless the position on the 2-D map agreed exactly with those of the authentic components, the spots were recorded as unidentified.…”

“…Thus, the presence of such alcohol components, not observed in fresh juice, may plausibly be due to the deterioration of some terpenic compounds under aqueous acidic conditions, common to lemon-flavored beverages. In order to identify these deterioration products, if present in the samples even without heat challenge, known deterioration compounds from citral [10][11][12][13] were injected and analyzed by GC6GC. The presence of pcymen-8-ol (s20), and p-methylacetophenone (s19) were confirmed.…”

Synthesis of Aristotelia‐Type Alkaloids. Part III. (3R,4R)‐ and (3R,4S)‐1‐p‐menthene‐3,8‐diol and the corresponding racemates: Preparation and assignment of configuration

“…HCI solution for 35 days. Kimura et al [9] studied the decomposition of citral in the presence of EtOH and citric acid and isolated acompound ('Peak 18') which was homogeneous on TLC and GLC, but which they considered to be a 1:l mixture of the ethoxy alcohols 10 and 11. A critical reevaluation of the reported spectroscopic data led us to the conclusion that the Japanese group actually had a single isomer in their hands since it displayed only 12 signals in the I3C-NMR spectrum and since the 'H-NMR signals for the EtO group are readily accounted for by analyzing this groups as an A M X , spin system with JRu = 9 Hz.…”

“…Kimura et a/. [9] stated that the diols were extremely unstable in acid and isolated what they considered to be a I : 1 mixture of the two ethoxy alcohols 10 and 11.…”