Synopsis A vast array of cosmetic products are used routinely by consumers to alleviate a range of skin care problems. Consumer concern ranges from age-associated skin changes to complexion (e.g., spots and pimples) and dryness. However, a major cause for concern amongst European female consumers is skin dryness, which spans all age ranges and skin types. Utilizing instrumental procedures (Squametry and Image Analysis) the severity of skin dryness has been correlated with expert assessment and consumer perception of dryness. The sensitivity of these techniques enables one to follow the progression of dryness alleviation for a range of product forms (e.g., creams and lotions) as well as the purported mechanism of action of various ingredient systems (e.g., occlusivity, moisturization). While conventional cosmetic products are shown to be effective, these techniques can be used to aid in the assessment and formulation of more effective products. Efficacité des produit cosmétiques à l'allégement d'un spectre d'états de peau sèche selon des measures cliniques et au moyen d'instruments.

A model system consisting of a uniformly distributed sample of ground pork in conjunction with a nitrite containing curing solution was utilized to evaluate the formation of N-nitrosamines. Utilizing this system a wide variety of compounds were discovered to dramatically reduce the level of N-nitrosopyrrolidine (NPyr) formed during frying. Carbohydrates including the reducing sugars dextrose, ribose, lactose, and maltose, as well as liquid smoke preparations, were found to reduce NPyr levels by as much as 60%. In addition, when low levels of combinations of inhibitors glucose, liquid smoke, and a-tocopherol were incorporated, reductions in nitrosamine levels as great as 80% were observed in model systems as well as in pilot plant manufactured bacon.

Solutes commonly employed in curing solutions were evaluated for their effect on nitrosamine formation utilizing a ground pork model system. Sodium erythorbate and sodium ascorbate were found to be equally effective in reducing nitrosopyrrolidine levels. The incorporation of sodium tripolyphosphate or sucrose had no detectable effect on nitrosamine formation. However, sodium chloride, the solute present at the highest concentration in bacon curing solutions, exhibited a concentration dependent inhibition of nitrosopyrrolidine formation. Nitrosopyrrolidine levels in samples containing no added sodium chloride were found to be 50% higher than samples processed with 1.5% added salt.

A detailed reproducible procedure has been developed for the replication of human skin for scanning electron-microscopic evaluation. Utilizing a test surface, a number of negative and positive materials were evaluated for consistence and clarity of replication. Optimal replication parameters were determined and the method was successfully applied to the evaluation of human skin in vivo. Furthermore, a method was established which permitted repetitive examination of selected skin sites. Experimental results suggest that this replicating procedure can be used to monitor changes in the stratum corneum over time, and extend the range of stratum corneum magnifications.

A model bacon system has been developed which enables a more reproducible determination of N-nitrosamines when compared to conventional methods of bacon production. Utilizing this system, the effect of slice thickness and frying time on nitrosopyrrolidine (NPyr) formation has been demonstrated. Short frying periods (3 min/side) result in higher NPyr levels for thinrier sliced samples and longer frying periods (5 min/side) result in higher NPyr levels for thicker sliced samples. The level of N-nitrosamine formed is integrally related to slice thickness and frying time and may be explained when two factors are considered, the rate of N-nitrosamine formation and the rate of its volatilization.