j. $oc. Cosmet. Chem., 33,369-374 (November 1982) Abstracts The Annual Scientific Meetings and Seminars of the Society of Cosmetic Chemists are important venues for informing the participants about the state of the art and recent technical advances in the field of Cosmetic Science. To provide broader dissemination of that information, the Publication Committee has decided to publish in the Journal abstracts of the technical presentations made at these Meetings and Seminars.--The Editor. Society of Cosmetic Chemists Annual Scientific Meeting New York, NY, December 2-3, 1982. ODOR Skin microorganisms and body odors John L. Labows, Ph.D., Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104. The skin contains three glandular structures having unique secretions which play important roles in cutaneous ecology, particularly in determining the number and kinds of bacteria found in different body regions. Eccrine sweat glands play a central role in regulation of body heat and produce a hypotonic solution of water, Na +, K +, C1-- and urea. Cutaneous regions rich in eccrine sweat glands have high numbers of bacteria. Sebaceous glands provide a film of lipid which may play a role in the cohesiveness of the outer layer of stratum corneum. Areas rich in this gland are characterized by high numbers of Propionibacteria and Pityros- porum. In response to emotional stress, apocrine glands produce a cholesterol enriched substrate which in the presence of axillary bacteria (particu- larly aerobic diphtheroids) results in unique body odors. These various odors have been reproduced in vitro by allowing the appropriate microorganism to act on natural secretions and on selected culture media. The establishment of a normal skin odor profile of an individual will provide a baseline with which body odor changes due to variation in physiological states or bacterial populations can be compared. Human oral odors James G. Kostelc, Ph.D., Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104. The major source of odors emanating from the mouth is the oral cavity. Mouth air and saliva contain various amounts of low molecular weight volatile compounds. Many of these volatiles arise through putrefactive action of microflora on pro- teinaceous substrate in saliva. The most intense odor is manifested in all individuals after prolonged periods of reduced salivary flow, abstinence from food and liquid, and cessation of oral cleansing procedures. The principal malodorous constituents of mouth air are hydrogen sulfide and methyl mercaptan. The early morning concentrations of either or both odorants exceeds the objectional threshold in over 50% of the adult population these levels can be reduced to acceptable levels by appropriate oral hygiene. Hydrogen sulfide, methyl mercaptan, as well as other volatile oral chemicals have been used as diagnostic indicators of meta- 369

370 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS bolic and pathologic states. Gas chromatography with element specific detectors and gas chromatography/mass spectrometry have been employed to analyze the complex oral odors from several groups of subjects. The breath air and saliva of subjects with periodontal disease emits volatiles more rapidly than those subjects with healthy mouths. Several volatile malodorous compounds appear to be diagnostic of the active disease state. Prevailing biochemical conditions in the oral cavity during ovulation and menstruation favor accelerated production of volatiles. Several constituents show cyclic changes predictive of these important times. Novel instrumental methods for odor detec- tion Annette Lovett, Ph.D., SCIEX, 55 Glen Cameron Road, Thornhill, Ontario, Canada L3T 1P2. The analysis of volatiles presents unique problems to the analytical chemist. Ideally, what is required is a device which has the specificity and ease of sample introduction comparable to that of the nose, but without its memory effects, unpredictable response characteristics, and subjectivity in data analysis. A novel mass spectrometer, the TAGA 6000 triple quadrupole system, with a unique atmo- spheric pressure chemical ionization (APCI) ion source, has the ability to detect and characterize volatile chemicals in ambient air in real time. Chemicals are introduced into the ion source using air or other suitable carrier gas, without the need for a vacuum interface, permitting the direct sampling of a variety of environments. The TAGA 6000 APCI/MS/MS system has been used to analyze the headspace vapours of a number of naturally occur- ring and synthetically formulated fragrance and flavour mixtures without prior extraction, precon- centration, or chromatography. This system is par- ticularly suited for monitoring concentration changes of specific targeted compounds in cos- metic preparations or on the skin. Odor perception and masking Clair Murphy, Ph.D., San Diego State University, San Diego, CA 92182. Perceived odor intensity increases with increases in stimulus concentration, although intensity in- creases at a much slower rate. Increasing the odorant concentration ten-fold may produce only a two-fold or four-fold increase in perceived odor magnitude. When odorants are mixed, the per- ceived magnitude of the mixture will generally be less intense than the sum of the unmixed compo- nents. Often the mixture will be less intense than the stronger component smelled alone. These sup- pressive effects are magnified when the odorant has a trigeminal (irritating, cooling, or warming) impact or note. In these cases, a strong trigeminal sensation can completely mask an olfactory sensation. The potential for masking malodors with trigeminal sensations is obvious. A more complex form of masking takes place when a pleasing odor is generated by assimilating a malodor into an odor complex which includes the malodor as one of its notes. STRUCTURING OF COSMETICS Principles of applied rheology Mike R. Rosen, Ph.D., Union Carbide Corp., Old Saw Mill River Road, Tarrytown, NY 10591. The purpose of this paper is to review and update applied theology, to expand the awareness of cosmetic scientists in rheological fundamentals and their successful application in industry. A further purpose is to empower those interested in enthusi- astically embracing the powerful rheological method for cosmetic product design, characteriza- tion, and control. Specifically, this paper covers the definition of viscosity and a description of New- tonian and non-Newtonian behavior. Methods for describing different types of flow behavior are covered, including both qualitative and quantitative aspects. Brief mention is given to basic types of instrumentation and, finally, consideration is given to the various ways a liquid may be thickened. The stability and rheological properties of particulate dispersions Geoffrey D. Parfitt, Ph.D., Carnegie-Mellon Uni- versity, Pittsburgh, PA 15213. A variety of different theological behaviors has been demonstrated for dispersions of solid colloi- dal particles in liquid media at high particle volume concentration. These may be time independent (plastic, pseudoplastic, and dilatant), or time depen- dent (thixotropic), and all are related in some way to the state of dispersion of the particles. Systems that are stable to flocculation may not be stable to separation by gravity sedimentation a degree of fiocculation might be desirable to prevent the latter, thus leading to flow behavior characteristic of the structure of the system. Interactions between particles depend on the nature of the solid-liquid interface, and stability to flocculation is considered in terms of either the particle charge or the presence of an absorbed polymer layer. Charge and steric stabilization are discussed, as well as relevance to the rheology of concentrated dispersions of pig- ments and fillers in aqueous and non-aqueous media.