Identification of novel malodour compounds in laundry

Abstract

We investigated malodorous compounds on clothes in daily use and identified, for the first time, middle-chain fatty acids responsible for the malodour often described as 'wet and dirty dust-cloth-like'. Application of a preparative fraction collector and gas chromatography-mass spectrometry of the acidic volatile fraction carefully isolated from used clothes revealed the newly identified odorants responsible for unpleasant odours. In particular, the olfactory threshold of 4-methyl-3-hexenoic acid (4M3H), which has the 'wet and dirty dust-cloth-like' odour, was found to be the lowest among the detected fatty acids. Although 4M3H was present in trace amounts in the clothes tested (up to 5 mg/50 g cloth), an aroma extract dilution analysis revealed that it contributed the highest to the overall strength of malodour on them. In addition, quantitative analysis of the detected fatty acids in the clothes revealed a correlation between the logarithm of several fatty acid concentrations (their amount in the clothes) and the overall odour intensity. In particular, 4M3H showed a high correlation value (r = 0.72, p < 0.05). These results provide proof that these odorants can be used as indicators to assess the effectiveness of detergents and to develop a new deodorant technology.

Characterization of Microbial Communities in Household Washing Machines

“…Until now microorganisms have been identified to be responsible for malodour in laundry [12,13] and few microorganisms have been isolated and identified to be characteristic for biofilms from washing machines [8]. It is a fact that the characteristics of washing procedures changed to low temperatures and detergents without bleaching agent are preferred [14].…”

Identification of the Compounds Responsible for the Sweat-Like Odor in Hop (Humulus lupulus L.) Volatile Oil

“…Very recently, (E)-4-methyl-3-hexenoic acid has been determined to be an odor-active compound in some natural sources, such as yuzu (Miyazato et al, 2013) and kabosu (Tomiyama, Aoki, Oikawa, Sakurai, Kasahara, & Kawakami, 2012). Further, Takeuchi, Hasegawa, Ishida, and Kashiwagi (2012) have reported (E)-4-methyl-3-hexenoic acid as the key odorous component responsible for the malodor in laundry. In our study, among the seven sweat-like-odor active compounds, (E)-4-methyl-3-hexenoic acid, along with 3-methylbutanoic acid and 2-methylbutanoic acid, has a high FD factor value of 32.…”

Moraxella Species Are Primarily Responsible for Generating Malodor in Laundry

“…An aliquot (100 l) of the bacterial suspension (10 6 CFU/ml) was inoculated onto small pieces (2 by 2 cm) of sterilized used-towel samples and incubated at 30 or 35°C for 1 day. The odor sensory test of the samples was performed by the method of Takeuchi et al (35) as follows. Three panelists who had been trained in the test for at least 3 years directly sniffed the samples and ranked the overall odor intensities of the samples.…”

“…In our survey in 2008, 86% of the respondents (580 women whose ages ranged from 20 to 60 and who lived in the Tokyo metropolitan district) reported detecting a "wet-and-dirty-dustcloth-like malodor" of laundry. Recently, Takeuchi et al (35) have identified the agent that is frequently detected in clothes with a strong malodor as 4-methyl-3-hexenoic acid (4M3H), which accounts for the sweaty and wet-and-dirty-dustcloth-like malodor. Although 4M3H is present in trace amounts (up to 5 g/50 g of cloth) in clothes, it contributes most highly to the overall strength of such a malodor (35).…”

“…Recently, Takeuchi et al (35) have identified the agent that is frequently detected in clothes with a strong malodor as 4-methyl-3-hexenoic acid (4M3H), which accounts for the sweaty and wet-and-dirty-dustcloth-like malodor. Although 4M3H is present in trace amounts (up to 5 g/50 g of cloth) in clothes, it contributes most highly to the overall strength of such a malodor (35). Similar branched unsaturated fatty acids have been reported.…”