Study of Processing Conditions during Enzymatic Hydrolysis of Deer By-Product Tallow for Targeted Changes at the Molecular Level and Properties of Modified Fats.

In most cases, the unused by-products of venison, including deer tallow, are disposed of in rendering plants. Deer tallow contains essential fatty acids and can be used to prepare products for everyday food and advanced applications. This work aimed to process deer tallow into hydrolyzed products using microbial lipases. A Taguchi design with three process factors at three levels was used to optimize the processing: amount of water (8, 16, 24%), amount of enzyme (2, 4, 6%), and reaction time (2, 4, 6 h). The conversion of the tallow to hydrolyzed products was expressed by the degree of hydrolysis. The oxidative stability of the prepared products was determined by the peroxide value and the free fatty acids by the acid value; further, color change, textural properties (hardness, spreadability, stickiness, and adhesiveness), and changes at the molecular level were observed by Fourier transform infrared spectroscopy (FTIR). The degree of hydrolysis was 11.8-49.6%; the peroxide value ranged from 12.3 to 29.5 µval/g, and the color change of the samples expressed by the change in the total color difference (∆E*) was 1.9-13.5. The conditions of enzymatic hydrolysis strongly influenced the textural properties: hardness 25-50 N, spreadability 20-40 N/s, and stickiness < 0.06 N. FTIR showed that there are changes at the molecular level manifested by a decrease in ester bonds. Enzymatically hydrolyzed deer tallow is suitable for preparing cosmetics and pharmaceutical matrices.

Characterization of Poultry Gelatins Prepared by a Biotechnological Method for Targeted Changes at the Molecular Level.

Chicken collagen is a promising raw material source for the production gelatins and hydrolysates. These can be prepared biotechnologically using proteolytic enzymes. By choosing the appropriate process conditions, such changes can be achieved at the molecular level of collagen, making it possible to prepare gelatins with targeted properties for advanced cosmetic, pharmaceutical, medical, or food applications. The present research aims to investigate model samples of chicken gelatins, focusing on: (i) antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis-3-etylbenzotiazolin-6-sulfonic acid (ABTS); (ii) the distribution of molecular weights via gel permeation chromatography with refractometric detection (GPC-RID); (iii) functional groups and the configuration of polypeptide chains related to molecular-level properties using Fourier transform infrared spectroscopy (FTIR); (iv) the microbiological populations on sabouraud dextrose agar (SDA), plate count agar (PCA), tryptic soy agar (TSA), and violet red bile lactose (VRBL) using the matrix-assisted laser desorption ionization (MALDI) method. Antioxidant activity towards ABTS radicals was more than 80%; activity towards DPPH radicals was more than 69%. The molecular weights of all gelatin samples showed typical α-, ß-, and γ-chains. FTIR analysis confirmed that chicken gelatins all contain typical vibrational regions for collagen cleavage products, Amides A and B, and Amides I, II, and III, at characteristic wavenumbers. A microbiological analysis of the prepared samples showed no undesirable bacteria that would limit advanced applications of the prepared products. Chicken gelatins represent a promising alternative to products made from standard collagen tissues of terrestrial animals.

The Effect of Cosmetic Treatment and Gel Laser Therapy on the Improvement of Comedogenic Skin Type.

Comedogenic skin care receives little attention compared to the care or treatment of more serious acne manifestations. Traditional therapies may have limited success with potential side effects. Cosmetic care supported by the effect of a biostimulating laser may offer a desirable alternative. The aim of the study was to evaluate the biological effectiveness of combined cosmetic treatment with lasotherapy on comedogenic skin type using noninvasive bioengineering methods. Twelve volunteers with comedogenic skin type underwent a 28-week application of Lasocare Basic 645® cosmetic gel containing Lactoperoxidase and Lactoferrin in combination with laser therapy (Lasocare® method). The effect of treatment on skin condition was monitored using noninvasive diagnostic methods. The parameters were the amount of sebum, the pore count, the ultraviolet-induced red fluorescence assessment of comedonic lesions (percentage of the area and quantification of orange-red spots), hydration, transepidermal water loss, and pH. A statistically significant decrease in sebum production was observed on the skin of the treated volunteers, as well as a decrease in porphyrins, indicating the presence of Cutibacterium acnes populating comedones and causing enlarged pores. The balance of epidermal water in the skin was regulated adjusting the acidity of the skin coat in individual zones, which decreased the presence of Cutibacterium acnes. Cosmetic treatment in combination with the Lasocare® method successfully improved the condition of comedogenic skin. In addition to transient erythema, there were no other adverse effects. The chosen procedure appears to be a suitable and safe alternative to traditional treatment procedures known from dermatological practice.

Enzyme Conditioning of Chicken Collagen and Taguchi Design of Experiments Enhancing the Yield and Quality of Prepared Gelatins.

During the production of mechanically deboned chicken meat (MDCM), a by-product is created that has no adequate use and is mostly disposed of in rendering plants. Due to the high content of collagen, it is a suitable raw material for the production of gelatin and hydrolysates. The purpose of the paper was to process the MDCM by-product into gelatin by 3-step extraction. An innovative method was used to prepare the starting raw material for gelatin extraction, demineralization in HCl, and conditioning with a proteolytic enzyme. A Taguchi design with two process factors (extraction temperature and extraction time) was used at three levels (42, 46, and 50 °C; 20, 40, and 60 min) to optimize the processing of the MDCM by-product into gelatins. The gel-forming and surface properties of the prepared gelatins were analyzed in detail. Depending on the processing conditions, gelatins are prepared with a gel strength of up to 390 Bloom, a viscosity of 0.9-6.8 mPa·s, a melting point of 29.9-38.4 °C, a gelling point of 14.9-17.6 °C, excellent water- and fat-holding capacity, and good foaming and emulsifying capacity and stability. The advantage of MDCM by-product processing technology is a very high degree of conversion (up to 77%) of the starting collagen raw material to gelatins and the preparation of 3 qualitatively different gelatin fractions suitable for a wide range of food, pharmaceutical, and cosmetic applications. Gelatins prepared from MDCM by-product can expand the offer of gelatins from other than beef and pork tissues.

Non-Alcohol Hand Sanitiser Gels with Mandelic Acid and Essential Oils.

Antimicrobial hand gels have become extremely popular in recent years due to the COVID-19 pandemic. Frequent use of hand sanitising gel can lead to dryness and irritation of the skin. This work focuses on the preparation of antimicrobial acrylic acid (Carbomer)-based gels enhanced by non-traditional compounds-mandelic acid and essential oils-as a substitute for irritating ethanol. Physicochemical properties (pH and viscosity), stability and sensory attributes of the prepared gels were investigated. Antimicrobial activity against representative Gram-positive and Gram-negative bacteria and yeasts was determined. The prepared gels with mandelic acid and essential oil (cinnamon, clove, lemon, and thyme) proved to have antimicrobial activity and even better organoleptic properties than commercial ethanol-based antimicrobial gel. Further, results confirmed that the addition of mandelic acid had a desirable effect on gel properties (antimicrobial, consistency, stability). It has been shown that the essential oil/mandelic acid combination can be a dermatologically beneficial hand sanitiser compared to commercial products. Thus, the produced gels can be used as a natural alternative to alcohol-based daily hand hygiene sanitisers.

The Effect of Application of Chicken Gelatin on Reducing the Weight Loss of Beef Sirloin after Thawing.

Freezing is one of the oldest and most-often-used traditional methods to prolong the shelf life of meat. However, the negative phenomenon of this process is the weight loss of water that occurs after the meat is thawed. Together with the water that escapes from the meat during thawing, there are large weight losses in this valuable raw material. Another negative aspect is that mineral and extractive substances, vitamins, etc. also leave the meat, resulting in irreversible nutritional losses of nutrients in the meat, which are subsequently missing for use by the consumer of the meat. The main goal of this work is to reduce these losses by using gelatin coatings. Gelatin was prepared from chicken paws according to a patented biotechnological procedure, which uses the very gentle principle of obtaining gelatin with the usage of enzymes. This unique method is friendly to the environment and innocuous for the product itself. At the same time, it ensures that the required principles achieve a circular economy with the use of the so far very-little-used slaughter byproducts, which in most parts of the world end up in uneconomic disposal by burning or landfilling without using this unique potential source of nutrients. Gelatin coatings on the surface of the beef steak were created by immersing the meat in a solution based on gelatin of different composition. A coating containing 3%, 5% or 8% gelatin with 10% or 20% glycerol (by weight of gelatin) and 1% glutaraldehyde crosslinker (by weight of gelatin) has proved to be effective. The amount of glutaraldehyde added to the coating is guaranteed not to exceed the permitted EU/U.S. legislative limits. In addition to weight loss, meat pH, color and texture were also measured. Freezing was done in two ways; some samples were frozen at a normal freezing temperature of -18 °C and the other part of the experiment at deep (shock) freezing at -80 °C. Defrosting took place in two ways, in the refrigerator and in the microwave oven, in order to use the common defrosting methods used in gastronomy. A positive effect of this coating on weight loss was observed for each group of samples. The most pronounced effect of coating was found for the least gentle method of freezing (-18 °C) and thawing (microwave), with the average weight loss of the coated samples differing by more than 2% from that of the uncoated sample. No negative effect of the coating was observed for other meat properties tested, such as pH, Warner-Bratzler Shear Force (WBSF) or color. Gelatin-based coating has a positive effect on reducing the weight loss of meat after thawing. Chicken gelatin prepared by a biotechnological process has a new application in improving the quality of meat due to the retention of water and nutrients in frozen and subsequently thawed beef, which can contribute to the better quality of the subsequently gastronomically prepared dish, while maintaining the weight and nutritional quality. This also results in economic savings in the preparation of highly-valued parts of beef.

Cyprinus carpio Skeleton Byproduct as a Source of Collagen for Gelatin Preparation.

Byproducts obtained from fish processing account for up to 70% of their live weight and represent a large amount of unused raw materials rich in proteins, fats, minerals, and vitamins. Recently, the management of the use of predominantly cold-water fish byproducts has become a priority for many processing companies. This paper describes the biotechnological processing of byproducts of warm-water Cyprinus carpio skeletons into gelatins. A Taguchi experimental design with two process factors (HCl concentration during demineralization of the starting material and the amount of enzyme during enzyme conditioning of the collagen) examined at three levels (0.5, 1.0 and 2.0 wt%; 0.0, 0.1 and 0.2 wt% respectively) was used to optimize the processing of fish tissue into gelatin. Depending on the preparation conditions, four gelatin fractions were prepared by multi-stage extraction from the starting material with a total yield of 18.7-55.7%. Extensive characterization of the gel-forming and surface properties of the prepared gelatins was performed. Gelatins belong to the group of zero-low-medium Bloom value (0-170 Bloom) and low-medium viscosity (1.1-4.9 mPa·s) gelatins and are suitable for some food, pharmaceutical, and cosmetic applications. During processing, the pigment can be isolated; the remaining solid product can then be used in agriculture, and H3PO4Ca can be precipitated from the liquid byproduct after demineralization. The carp byproduct processing technology is environmentally friendly and meets the requirements of zero-waste technology.

Preparation of Gelatin from Broiler Chicken Stomach Collagen.

With the increasing consumption of poultry meat around the world, the use of chicken stomachs as a source of collagen is being offered. The objective of this study was to extract gelatin from the stomachs of broiler chickens and to estimate their gel strength, ash content, viscosity, gelling point, melting point, clarity and digestibility. An innovative biotechnological method based on the conditioning of collagen with a microbial endoproteinase (Protamex®) and hot-water extraction was used to control the chemical and thermal denaturation process of collagen to prepare gelatin. The experiments were planned using a Taguchi design, 2 factors at 3 levels; factor A for the amount of proteolytic enzyme (0.10, 0.15 and 0.20%) and factor B for the extraction temperature (55.0, 62.5 and 70.0 °C). Data were statistically processed and analyzed at a significance level of 95%. The gelatin yield averaged 65 ± 8%; the gel strength ranged from 25 ± 1 to 439 ± 6 Bloom, the viscosity from 1.0 ± 0.4 to 3.40 ± 0.03 mPa·s, gelling point from 14.0 ± 2.0 to 22.0 ± 2.0 °C, melting point from 28.0 ± 1.0 to 37.0 ± 1.0 °C. The digestibility of gelatin was 100.0% in all samples; the ash content was very low (0.44 ± 0.02-0.81 ± 0.02%). The optimal conditions for the enzymatic treatment of collagen from chicken stomachs were achieved at a higher temperature (70.0 °C) and a lower amount of enzyme (0.10-0.15%). Conditioning chicken collagen with a microbial endoproteinase is an economically and environmentally friendly processing method, an alternative to the usual acid- or alkaline-based treatment that is used industrially. The extracted products can be used for food and pharmaceutical applications.

Collagen Hydrolysate Prepared from Chicken By-Product as a Functional Polymer in Cosmetic Formulation.

Chicken stomachs can be processed into collagen hydrolysate usable in cosmetic products. The aim of the study was to verify the effects of a carbopol gel formulation enriched with 1.0% (w/w) chicken hydrolysate on the properties of the skin in the periorbital area after regular application twice a day for eight weeks in volunteers ageed 50 ± 9 years. Skin hydration, transepidermal water loss (TEWL), skin elasticity and skin relief were evaluated. Overall, skin hydration increased by 11.82% and 9.45%, TEWL decreased by 25.70% and 17.80% (always reported for the right and left area). Generally, there was an increase in skin elasticity, a decrease in skin roughness, as the resonance times decreased by 85%. The average reduction of wrinkles was 35.40% on the right and 41.20% on the left. For all results, it can be seen that the longer the cosmetic gel formulation is applied, the better the results. Due to the positive effect on the quality and functionality of the skin, it is possible to apply the cosmetic gel formulation in the periorbital area. The advantage of the product with chicken collagen hydrolysate is also the biocompatibility with the skin and the biodegradability of the formulation.

Valorization of a By-Product from the Production of Mechanically Deboned Chicken Meat for Preparation of Gelatins.

In recent decades, food waste management has become a key priority of industrial and food companies, state authorities and consumers as well. The paper describes the biotechnological processing of mechanically deboned chicken meat (MDCM) by-product, rich in collagen, into gelatins. A factorial design at two levels was used to study three selected process conditions (enzyme conditioning time, gelatin extraction temperature and gelatin extraction time). The efficiency of the technological process of valorization of MDCM by-product into gelatins was evaluated by % conversion of the by-product into gelatins and some qualitative parameters of gelatins (gel strength, viscosity and ash content). Under optimal processing conditions (48-72 h of enzyme conditioning time, 73-78 °C gelatin extraction temperature and 100-150 min gelatin extraction time), MDCM by-product can be processed with 30-32% efficiency into gelatins with a gel strength of 140 Bloom, a viscosity of 2.5 mPa.s and an ash content of 5.0% (which can be reduced by deionization using ion-exchange resins). MDCM is a promising food by-product for valorization into gelatins, which have potential applications in food-, pharmaceutical- and cosmetic fields. The presented technology contributes not only to food sustainability but also to the model of a circular economy.

Hydration and Barrier Potential of Cosmetic Matrices with Bee Products.

Honey, honey extracts, and bee products belong to traditionally used bioactive molecules in many areas. The aim of the study was primarily to evaluate the effect of cosmetic matrices containing honey and bee products on the skin. The study is complemented by a questionnaire survey on the knowledge and awareness of the effects and potential uses of bee products. The effect of bee molecules at various concentrations was observed by applying 12 formulations to the skin of the volar side of the forearm by non-invasive bioengineering methods on a set of 24 volunteers for 48 h. Very good moisturizing properties have been found in matrices with the glycerin extract of honey. Matrices containing forest honey had better moisturizing effects than those containing flower honey. Barrier properties were enhanced by gradual absorption, especially in formulations with both glycerin and aqueous honey extract. The observed organoleptic properties of the matrices assessed by sensory analysis through 12 evaluators did not show statistically significant differences except for color and spreadability. There are differences in the ability to hydrate the skin, reduce the loss of epidermal water, and affect the pH of the skin surface, including the organoleptic properties between honey and bee product matrices according to their type and concentration.

Chicken Heads as a Promising By-Product for Preparation of Food Gelatins.

Every year, the poultry industry produces a large number of by-products such as chicken heads containing a considerable proportion of proteins, particularly collagen. To prepare gelatin is one of the possibilities to advantageously utilize these by-products as raw materials. The aim of the paper was to process chicken heads into gelatins. An innovative method for conditioning starting raw material was using the proteolytic enzyme. Three technological factors influencing the yield and properties of extracted gelatins were monitored including the amount of enzyme used in the conditioning of the raw material (0.4% and 1.6%), the time of the conditioning (18 and 48 h), and the first gelatin extraction time (1 and 4 h). The gelatin yield was between 20% and 36%. The gelatin gel strength ranged from 113 to 355 Bloom. The viscosity of the gelatin solution was determined between 1.4 and 9.5 mPa.s. The content of inorganic solids varied from 2.3% to 3.9% and the melting point of the gelatin gel was recorded between 34.5 and 42.2 °C. This study has shown that gelatin obtained from chicken heads has a promising potential with diverse possible applications in the food industry, pharmacy, and cosmetics.

Biotechnological Preparation of Gelatines from Chicken Feet.

In the European Union (EU), about five tons of poultry by-product tissues are produced every year. Due to their high collagen content, they represent a significant raw material source for gelatine production. The aim of the paper was the biotechnological preparation of gelatine from chicken feet. The influence of selected process factors on the gelatine yield, gel strength, viscosity, and ash of gelatine was observed; a two-level factor design of experiments with three variable process factors (enzyme addition, enzyme treatment time, and gelatine extraction time) was applied. After grinding and separating soluble proteins and fat, the purified raw material was treated in water at pH 7.5 with the addition of endoprotease at 23 °C and after thorough washing with water at 80 °C, gelatine was extracted. By the suitable choice of process conditions, gelatine with high gel strength (220-320 bloom), low ash content (<2.0%) and viscosity of 3.5-7.3 mPa·s can be prepared. The extraction efficiency was 18-38%. The presented technology is innovative mainly by the enzymatic processing of the source raw material, which is economically, technologically, and environmentally beneficial for manufacturers. Chicken gelatines are a suitable alternative to gelatines made from mammals or fish, and can be used in many food, pharmaceutical, and biomedical applications.

Transdermal absorption of active substances from cosmetic vehicles.

BACKGROUND: Cosmetic products mean any substance or mixture intended to be placed in contact with the external parts of the human body (eg, epidermis, lips) and should not pass to the lower parts and penetrate to the skin. As a part of evaluation of cosmetic safety, the transdermal absorption of substances should be investigated. MATERIALS AND METHODS: In vitro absorption was investigated with Franz diffusion cells on untreated porcine skin and specimens of the same treated with 15%wt. SLS. The integrity of the skin was discerned by gauging transdermal electrical conductivity (TEC), the concentration of caffeine absorbed by the samples of skin membrane by liquid chromatography, which took place by applying an emulsion and/or a gel containing active hydration agents (urea, sodium hyaluronate, and sericin). RESULTS: The greatest extent of caffeine penetration was seen for pretreatment with just SLS; similar results were in skin treated with the base gel with 10%wt. urea. In the skin treated with the base emulsion only, the amount of caffeine absorbed was twofold less; this increased after adding the active hydration substances. The values measured for TEC corresponded with the amount of caffeine absorbed. CONCLUSION: The gel proved to be the more potent vehicle for the active ingredient, as it demonstrated greater transdermal caffeine penetration than the emulsions, correlating with the degree of damage to the skin as detected by TEC.

In vivo efficacy and properties of semisolid formulations containing panthenol.

BACKGROUND: Panthenol is an active substance used in dermatology to protect the health of the skin, to treat defects in the morphology of the stratum corneum. In cosmetology, hydrating, softening, and barrier function of panthenol are utilized. Detailed studies evaluating the efficacy of panthenol in cosmetic and pharmaceutical semisolid formulations and establishing its optimum concentration are needed. OBJECTIVES: To investigate whether an addition of 5-13 wt% panthenol in o/w and w/o emulsions increases hydration and supports the barrier properties of the skin. Rheological properties and sensory analysis of prepared formulations are supplemented. METHODS: Noninvasive instrumental methods in vivo were used. The hydration and barrier effect of semisolid formulations on the skin were observed for 48 hour; testing was conducted on 40 women. The effect was compared with formulations without any content of panthenol. The rheological and organoleptic properties of the formulations were evaluated. RESULTS: After applying either form of the formulations containing 7-11 wt% of panthenol hydration of the skin increased, transepidermal water loss decreased. pH of the skin shifted toward neutral after application of tested formulations. The rheological properties of the formulations were influenced by the type of vehicle, the amount of panthenol, and temperature. Sensory evaluation of both semisolid forms revealed statistically significant differences in o/w formulations with regard to spreadability. CONCLUSIONS: The presence of panthenol in an o/w and w/o semisolid formulations significantly enhances skin barrier repair and hydration of the stratum corneum. Better vehicle for the active substance as regards hydration proved o/w formulations.

Stability and in vivo efficiency of natural cosmetic emulsion systems with the addition of vegetable oils

The aim of the paper is to test stability and biophysical properties of hydrophilic and lipophilic emulsions with selected vegetable seed oils: Limnanthes alba, Prunus amygdalus dulcis, Cannabis sativa, Rosa rubiginosa and Hellianthus annuus. Biophysical properties of emulsions are investigated in vivo using non-invasive instrumental methods (corneometry, tewametry and pH) in a group of 12 healthy women volunteers. Their stability profiles (colour, phase separation and centrifugation) under various temperatures (9, 25, 37 and 57 °C) and storage time (24 hours, 2, 7, 14, 21 and 28 days) were monitored. The moisturising activities of the emulsions supplemented with various oils were comparable. The lipophilic emulsions showed a better ability to improve the condition of the skin barrier due to formation of a surface lipid film. The tested formulations regulated the pH of the skin towards neutral values. Lipophilic emulsions showed earlier phase separation and changes in colour. The greatest resistance to thermal stress during storage was observed for the emulsion bases. Emulsions containing oils, except for those with rosehip and hempseed oils, were stable up to the temperature of 37 °C. The studied emulsion systems are excellent vehicles of vegetable oils and exhibit relatively good stability, benefiting the natural properties of skin.

Preparation of Keratin Hydrolysate from Chicken Feathers and Its Application in Cosmetics.

Keratin hydrolysates (KHs) are established standard components in hair cosmetics. Understanding the moisturizing effects of KH is advantageous for skin-care cosmetics. The goals of the protocol are: (1) to process chicken feathers into KH by alkaline-enzymatic hydrolysis and purify it by dialysis, and (2) to test if adding KH into an ointment base (OB) increases hydration of the skin and improves skin barrier function by diminishing transepidermal water loss (TEWL). During alkaline-enzymatic hydrolysis feathers are first incubated at a higher temperature in an alkaline environment and then, under mild conditions, hydrolyzed with proteolytic enzyme. The solution of KH is dialyzed, vacuum dried, and milled to a fine powder. Cosmetic formulations comprising from oil in water emulsion (O/W) containing 2, 4, and 6 weight% of KH (based on the weight of the OB) are prepared. Testing the moisturizing properties of KH is carried out on 10 men and 10 women at time intervals of 1, 2, 3, 4, 24, and 48 h. Tested formulations are spread at degreased volar forearm sites. The skin hydration of stratum corneum (SC) is assessed by measuring capacitance of the skin, which is one of the most world-wide used and simple methods. TEWL is based on measuring the quantity of water transported per a defined area and period of time from the skin. Both methods are fully non-invasive. KH makes for an excellent occlusive; depending on the addition of KH into OB, it brings about a 30% reduction in TEWL after application. KH also functions as a humectant, as it binds water from the lower layers of the epidermis to the SC; at the optimum KH addition in the OB, up to 19% rise in hydration in men and 22% rise in women occurs.

Comparison of metrological techniques for evaluation of the impact of a cosmetic product containing hyaluronic acid on the properties of skin surface.

The aim of this research was to evaluate mutual interchangeability of four principally different biometric instrumental techniques designed for objective measurement of changes in the physical, mechanical, and topographical properties of the skin surface treated with commercial antiaging cosmetic products with hyaluronic acid. The following instrumental devices were used: Visioscope PC 35, Corneometer Multiprobe Adapter MPA 6, Reviscometer RVM 600, and 3D scanner Talysurf CLI 500. The comparison of the individual methods was performed using cluster analysis. The study involved 25 female volunteers aged 40-65. Measurements were taken before and after 30 daily in vivo applications of an antiaging preparation to the skin surface in the periorbital area. A slight reduction in skin surface roughness was recorded in 55% of the volunteers. On the contrary, a worsening from their initial states was detected in 25% of the subjects, while for 20%, no significant change was reported. Cluster analysis confirmed that the mentioned methodologies can be divided into two basic clusters, namely, a cluster of methods recording the changes in skin relief by means of optical techniques, and a cluster of methods investigating changes in hydration and anisotropy. In practice, the techniques in different clusters are not interchangeable and should be assessed separately.

The cosmetic and dermatological potential of keratin hydrolysate.

BACKGROUND: Although keratin hydrolysates have become established as standard components in hair and nail cosmetics, studies on the moisturizing effects of keratin hydrolysates do not appear among contemporary literature. OBJECTIVES: To test if adding keratin hydrolysate into an ointment base increases hydration of the skin and improves skin barrier function, or diminishes trans-epidermal water loss. METHODS: Formulations were prepared containing 2%, 4%, and 6% keratin hydrolysates (based on weight of the ointment base). The moisturizing properties of keratin hydrolysates were tested by measuring skin hydration, trans-epidermal water loss and skin pH; measurements were carried out at intervals of 1, 2, 3, 4, 24, and 48 h. Testing was conducted on 10 women. RESULTS: As regards hydration, adding 2% keratin hydrolysate to the ointment base is optimal, as an increase of 14%-23% occurs in hydration of the stratum corneum. For trans-epidermal water loss, adding 4% KH to the ointment base is preferential, as this triggers a 26%-46% decrease in trans-epidermal water loss. CONCLUSIONS: Keratin hydrolysate acts as a humectant (it binds water from lower layers of the epidermis to the stratum corneum) as well as an occlusive (it reduces trans-epidermal water loss). The highly favorable properties of keratin hydrolysates are attributed to the wide distribution of keratin hydrolysates molecular weights; low-molecular weight fractions easily penetrate the SC, while high-molecular weight fractions form a protective film on the epidermis. Adding keratin hydrolysates to the ointment base did not cause phase separation even after 6 mo storage.

Moisturizing effect of topical cosmetic products applied to dry skin.

One of the complications of "diabetes mellitus" is termed diabetic foot syndrome, the first symptoms of which include changes in the skin's condition and properties. The skin becomes dehydrated, dry, and prone to excessive formation of the horny layer, its barrier function becoming weakened. This function can be restored by applying suitable cosmetic excipients containing active substances. The aim of this study was to evaluate and compare the effects of commercially available cosmetic products (CPs) designed for the care of diabetic foot, through a group of selected volunteers using noninvasive bioengineering methods. Statistical surveys (p < 0.05) evaluated these CPs as regards to their hydration effect and barrier properties. Special attention was devoted to CPs with the declared content of 10% urea, and that the influence of this preparation's ability to hydrate and maintain epidermal water in the epidermis was confirmed.