Primary odorants of laundry soiled with sweat/sebum: Influence of lipase on the odor profile

Abstract

Odorants still attached to laundry soiled with human axillary sweat and sebum after a mild washing procedure [European full-scale, short-cycle wash (20 min wash, 15 min rinse) at 30°C, using color detergent at 3.5 g/L] were extracted and analyzed by aroma extract dilution analysis. Esters (ethyl-2-methylpropanoate and ethylbutanoate), ketones (1-hexen-3-one and 1-octen-3-one) and, in particular, aldehydes [(Z)-4-heptenal, octanal, (E)-2-octenal, methional, (Z)-2-nonenal, (E,Z)-2,6-nonadienal, (E,Z)-2,4-nonadienal, (E,E)-2,4-decadienal, and 4-methoxybenzaldehyde] were identified as primary odorants. Organic acids, which are dominant characteristic odorants in human axillary sweat, were, on the other hand, effectively removed during the washing process. The influence of lipase activity on the odor profile was investigated by analyzing selected sets of textile swatches, sampled from the right/left axillary of male runners, washed in the presence or absence of lipase. The swatches were examined by a sensory ranking analysis prior to the analytical odor analysis. Swatches selected for the subsequent odor analysis possessed greater odor intensity when washed in the presence of lipase than the corresponding swatches washed in the absence of lipase. The aroma extract dilution analysis revealed that aldehydes were present in slightly greater concentrations in swatches washed in the presence of lipase. The aldehydes are believed to be formed through oxidative degradation of triglycerides present in human sebum, which may be facilitated by lipase. Based on sensory panel results and dilution analysis of odorants, the impact of lipase on the odor impression was, however, minor and thus believed to be inadequate as explanation for malodor generation in laundry as experienced by the consumer.

Analysis of pattern recognition and dimensionality reduction techniques for odor biometrics

“…Although, the main component of this fluid is water (up to 98%), it also contains glicoproteins, lactic acid, sugars, amino acids and electrolytes. This sweat is originated from the extracellular fluid so it reflects the compounds present in the blood plasma [41]. In turn, apocrine glands are only present in the armpit, pubic area and areola.…”

The analytical determination of the uniqueness and persistence of the volatile components of human scent using optimized collection methods

“…Pure apocrine secretions are both odorless and sterile when first appearing on the skin's surface [25]. Apocrine secretion is known to contain steroid sulfates, cholesterol, and proteins [26].…”

“…Pure eccrine secretions have been shown to be white in appearance [25], and typically composed o f 98% water, but it also contains various organic and inorganic components [23]. Eccrine sweat originates in the extracellular fluid and, therefore, reflects the chemistry o f blood plasma [26]. The volatile components o f blood have been identified (Appendix B) and include alcohols, aldehydes, and alkanes [27,28].…”

Development of a Dynamic Headspace Concentration Technique for the Non-Contact Sampling of Human Odor Samples and the Creation of Canine Training Aids

“…When a glove was placed over the hand, the air flow slowed at first, but then eventually appeared to escape through the glove at a normal rate. Most studies have focused on apocrine-gland secretions in the axilla 26,34,[59][60][61][62] as they contribute largely to body malodor. It has been suggested that the precursors of odorous compounds are transported to the surface of the skin by carrier proteins where they interact with the microflora in this region to create odor.…”

“…The most common method has been to wipe sweat from an area of the body with gauze or a similar material, then to extract the sweat from the material. 26,34,[59][60][61] Another method has been to extract the sweat directly from a piece of clothing worn by the subject. 54,68 Such methods have tended to recover mostly short-chain fatty acids, in particular, the C 6 -C 11 straight-chain and branched acids, 54,59-61 iso-valeric acid, 54,69 and (E)-3-methyl-2-hexenoic acid 60,61 have been major…”