Pavel Mokrejs

Processing poultry feathers into keratin hydrolysate through alkaline-enzymatic hydrolysis

Poultry feathers make up for as much as 8.5% of chicken weight and represent a considerable amount of almost pure keratin waste which is not being adequately utilized at the present time. The present study dealt with the processing of poultry feathers through a two-stage alkaline-enzymatic hydrolysis. In the first stage, feathers were mixed with a 0.1 or 0.3% KOH water solution in a 1 : 50 ratio and were incubated at 70°C for 24 h. After adjusting pH to 9, the effects examined in the second processing stage on the amount of degraded feathers were those of proteolytic enzyme additions (1-5%), time (4-8 h) and temperature (50-70°C). Processing feathers in 0.3% KOH and hydrolysing for 8 h in the second stage at 70°C with a 5% dose of enzyme (relative to dry feathers weight) produced approx. 91% degradation. Keratin hydrolysate is distinct for its high nitrogen content and reasonable inorganic solids level. Two-stage technology of alkaline-enzymatic hydrolysing of poultry feathers in an environment of 0.3% KOH achieves high efficiency under quite mild reaction conditions (temperature not exceeding 70°C with pH in a mildly alkaline region), and is feasible from an economic viewpoint. Keratin hydrolysate can find particular application in packaging technology (films, foils and encapsulates).

Preparation of microfibers from wood/ionic liquid solutions

Two types of ionic liquids, 1-ethyl-3-methylimidazolim acetate and 1-ethyl-3-methylimidazolium lactate, were employed for the direct processing of pine wood into microfibers. The concentration of 5 wt.% of wood in ionic liquids was rated as the most appropriate for electrospinning. The fibers were electrospun into the collector water bath. The final structure varied from individual microfibers to fiber bundles. It was demonstrated that 1-ethyl-3-methylimidazolium lactate is a powerful solvent and provides the direct transformation of pristine pine wood into the non-wovens.

Interactive software application for calculation of non-stationary heat conduction in a cylindrical body

In this paper we present software application used for the study of heat transfer problems that is a part of education of subject Process Engineering taught at the Tomas Bata University in Zlín. The application speeds up calculation of non‐stationary heat conduction and visualizes temperature distribution in the cylindrical body.

The cosmetic and dermatological potential of keratin hydrolysate

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.

Verification of toe allowance of children's footwear and its categorisation

This study verifies the declared sizes of childrens footwear, categorising it according to gender and age, the cut of the upper, the assembling method, the material of the upper, the lining material, the fastening, the heights of the upper and the heights of the heel. The study looked into the allocation given to toe allowance, which represents growing room for a childs foot, while ensuring the shoes remain comfortable. Research was conducted on 115 pairs of childrens footwear, at the French sizes of 22, 25 and 30. It was found that in all examples at size 22, the recommended design specifications for toe allowance were most consistently observed, while for size 25 this applied in 91% of cases, but an alarming percentage – 54% of pairs – was discerned for size 30. This provision for growth exists to prevent possible damage to the soft tissues of childrens feet and also to prevent forefoot deformities from occurring. Maintaining the specifications for toe allowance also contributes to easier customer guidance when selecting the optimum shoe size.

Effect of initial melting temperature on crystallization of polypropylene/organoclay nanocomposites

Polypropylene (PP) nanocomposites were prepared by melt intercalation using an intermeshing co-rotating twin-screw extruder. The influence of organoclay (Cloisite 20A) and maleic anhydride modified polypropylene (PP-MA) on various properties was explored. The effect of the initial melting temperature on crystallization kinetics was investigated by differential scanning calorimetry (DSC) and optical microscopy. DSC has revealed a gradual decrease in crystallization kinetics with an increase in initial melting temperature for two-component systems (PP/PP-MA and PP/20A). However, in the case of a three-component system (PP/PP-MA/20A), the decrease of crystallization kinetics in the range of initial melting temperature being 200–240 °C was followed by an increase in the temperature range 240–260 °C. After initial melting at 250 °C, many spherulites were discovered in the three-component system. This unusual crystallization behavior was explained with the help of Fourier transform infrared spectroscopy (FTIR), where an increase in the Si-O peak with the increasing initial melting temperature was detected, which indicates the presence of large surface of clay layers. The morphology of nanocomposites was also investigated by transmission electron microscopy (TEM). The X-ray diffraction (XRD) analysis has revealed a decrease in the peak intensity with an increase in initial melting temperature, which suggests exfoliation caused by fast diffusion at high temperatures.

In vivo efficacy and properties of semisolid formulations containing panthenol

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.

Optimization of Protein Mixture Filtration

In this paper there is described filtering process for separating reaction mixture after enzymatic hydrolysis to process the chromium tanning waste [1]. Filtration process of this mixture is very complicated because it is case of mixture filtration with compressible cake. Successful process strongly depends on mathematical describing of filtration, calculating optimal values of pressure difference, specific resistant of filtration cake and temperature maintenance which is connected with viscosity change. The mathematic model of filtration with compressible cake we verified in laboratory conditions on special filtration device developed on our department. Industrial filtration differs from that in laboratory merely in the quantity of material being processed and in the necessity of processing it as cheaply as possible. In order to increase capacity while keeping filter dimensions not particularly large, the filter area per volume unit of plant gets increased as well as the difference between pressures before and behind the filtering screen or filter cake. A variety of different filter types are used and they depend on whether the particle content in liquid is low or high, whether the filter operates intermittently, semicontinuously or continuously, and on how the pressure difference is produced. Liquid flows through the cake and screen under the influence of a difference between pressures before the cake and behind the screen. We solved problems connected with filtration of reaction mixture after enzymatic hydrolysis.

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.