Characterization of Odorants Causing an Atypical Aroma in White Pepper Powder (Piper nigrum L.) Based on Quantitative Measurements and Orthonasal Breakthrough Thresholds

• Published in: Journal of agricultural and food chemistry Vol. 53; no. 15; pp. 6049 - 6055
• Main Authors: Steinhaus, Martin, Schieberle, Peter
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 27.07.2005; Amer Chemical Soc
• Subjects: Agriculture; Agriculture, Multidisciplinary; Animals; Biological and medical sciences; Butyric Acid - analysis; Chemistry; Chemistry, Applied; Cresols - analysis; Fish and seafood industries; Food industries; Food Science & Technology; Fruit - chemistry; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Humans; Life Sciences & Biomedicine; Odorants - analysis; Physical Sciences; Piper nigrum; Piper nigrum - chemistry; Science & Technology; Skatole - analysis; Smell; Time Factors; pepper; 3-methylindole; off-flavor; 4-methylphenol; OFF-FLAVOR COMPOUNDS; skatole; UNDESIRABLE ODORANTS; aroma extract dilution analysis; stable isotope dilution analysis; IMPACT ODORANTS; 3-methylphenol; JUICE; aroma; DILUTION; Measurement; Edible fish; Vegetables; Pepper; Bell pepper; Extract; Powder; Characterization; Dicotyledones; Piper nigrum; Angiospermae; Aroma; Threshold; stable Isotope dilution analysis; Bass; Piperaceae; Isotope dilution; Flavor; Spermatophyta
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf0506030

Application of the aroma extract dilution analysis on an extract of white pepper powder showing an intense fecal, cowshed-like off-flavor revealed 3-methylindole (fecal, swine-manure) and 4-methylphenol (fecal, horse-like) with the highest flavor dilution (FD) factors among the 22 odor-active compounds detected. In addition, high FD factors and/or undesirable odor qualities suggested 3-methylphenol (phenolic), butanoic acid (cheese-like), and 2- and 3-methylbutanoic acid (cheese-like) as well as pentanoic acid and hexanoic acid (cheese-like odors) as contributors to the malodor. Although the intensities of the off-note were clearly different in 50 commercial samples of white pepper, quantitation of 3-methylindole and 3- and 4-methylphenol as well as of the five short-chain acids by means of stable isotope dilution assays showed similar concentrations in most of the samples. Storage of a freshly ground white pepper powder for up to 7 months revealed a significant decrease in the typical odor qualities of white pepper and an increase in the fecal odor note with storage time. Because the concentrations of the odorants mentioned above were not much changed during storage, possibly very volatile odorants, such as α-pinene, which are able to mask the malodor, are lost during storage of, in particular, pepper powders. On the basis of odor activity values, which were calculated using breakthrough thresholds, in particular, 3-methylindole, 4-methylphenol, 3-methylphenol, and butanoic acid could be suggested as the main sources of the fecal off-flavor. Keywords: Pepper; aroma; off-flavor; aroma extract dilution analysis; skatole; 3-methylindole; 4-methylphenol; 3-methylphenol; stable isotope dilution analysis