Improvement of Water Vapor Barrier Properties of Chitosan-Collagen Laminated Casings using Beeswax

Collagen casings are commercially used in sausage production. In this paper, collagen film that is used for sausage casings was laminated with chitosan film to produce barrier casing film. Chitosan coating was prepared by dissolving chitosan powder in 1% acetic acid. After dissolving chitosan, caraway essential oil, wetting agent Tween 20 and different amounts of beeswax, from 0 to 25 g were added to the solution. The solution was coated on collagen film surface in three layers, using a sponge brush to make laminated films. Films were air dried at temperature t = 23 °C ± 2 °C. Uncoated collagen film was used as reference. Film thickness, water vapor barrier properties and FTIR spectra were determined. With growing amount of beeswax added to the chitosan layer, film thickness grew from 112 µm for laminated film with 5 g of beeswax to 225 µm for film with 25 g of beeswax, compared to 83 µm for collagen film. Water vapor barrier properties improved with growing amount of beeswax in chitosan layer, ranging from 130.71 g/m224h for laminated film with added 5 g of beeswax to 66.96 g/m224h for the film with 25 g of beeswax, compared to 290.64 g/m224h for collagen film. Addition of beeswax showed great potential in lowering water vapor permeability of laminated collagen-chitosan film. FTIR spectra could be used to determine quantitative law dependency between added amount of beeswax and spectra absorption values,as well as to prove compactness of chitosan-beeswax layer

Determination of nickel content in the semimembranosus muscle of pigs produced in Vojvodina

The content of nickel was investigated in the M. semimembranosus of sixty-nine pigs from ten different genetic lines produced in Vojvodina. Nickel was determined by flame atomic absorption spectrometry after mineralization by dry ashing. The difference in the nickel content in the analyzed muscle tissues among different genetic lines of pigs was not significant (P > 0.05). Nickel levels ranged from 12.93 to 80.18 μg/100 g, with a general average of 32.41 μg/100 g. The average level of nickel was found to be higher than the levels observed in pork in some developed countries

The Effect of Cantharellus Cibarius Addition on Quality Characteristics of Frankfurter during Refrigerated Storage

The antioxidant and antimicrobial properties of Cantharellus cibarius decoction and the effect of mushroom addition on the physicochemical and microbiological properties of frankfurters during refrigerated storage were studied. Mushroom addition significantly reduced (p lt 0.05) the formation of total aerobic mesophilic bacteria during storage. Regarding the texture, there was no negative effect in frankfurters with the mushroom added, compared to the control group of sausages. Generally, C. cibarius can be used as a natural ingredient in order to prevent the growth of microorganisms in cooked pork sausages, causing an extension in shelf life during chilled storage

Interdimensional radial discrete diffraction in Mathieu photonic lattices

We demonstrate transitional dimensionality of discrete diffraction in radial-elliptical photonic lattices. Varying the order, characteristic structure size, and ellipticity of the Mathieu beams used for the photonic lattices generation, we control the shape of discrete diffraction distribution over the combination of the radial direction with the circular, elliptic, or hyperbolic. We also investigate the transition from one-dimensional to two-dimensional discrete diffraction by varying the input probe beam position. The most pronounced discrete diffraction is observed along the crystal anisotropy direction

Ultimate pH, colour characteristics and proximate and mineral composition of edible organs, glands and kidney fat from Saanen goat male kids

Ultimate pH value and instrumental colour (CIEL*a*b* values) characteristics, proximate (moisture, protein, total fat and total ash) and mineral composition (K, P, Na, Mg, Ca, Zn, Fe, Cu, Ni and Mn) were determined in 10 (heart, tongue, lungs, spleen, liver, kidney, brain, testicle, thymus and kidney fat) edible by-products of Saanen goat male kids. Many significant or numerical differences were found in the mean values of quality characteristics among the edible by-products. Among edible organs and glands, liver had the lowest surface CIEL* value (darkest colour), and the highest levels of protein, Zn, Cu and Mn. Furthermore, the highest pH(24h), total ash, K, P and Mg levels were determined in the thymus. The testicle had the highest moisture, Ca and Ni levels. The spleen had the lowest fresh cut cross-section CIEL* value (darkest colour), and the highest Fe level. The highest total fat content and Na level were determined in the brain and kidney, respectively. Among all the edible by-products, kidney fat had the highest pH(24h), surface CIEL* value (lightest colour) and total fat content, and the lowest moisture, protein, total ash, K, P, Na, Mg, Ca, Zn, Fe, Cu, Ni and Mn levels

Effect of Packaging Methods and Storage Time on Oxidative Stability of Traditional Fermented Sausage

In this paper influence of packaging method (vacuum and modified atmosphere packaging) on lipid oxidative stability and sensory properties of odor and taste of the traditional sausage Petrovská klobása were examined. These parameters were examined during storage period (7 months). In the end of storage period, vacuum packed sausage showed better oxidative stability. Propanal content was significantly lower (P<0.05) in vacuum packed sausage compared to these values in unpacked and modified atmosphere packaging sausage. Hexanal content in vacuum packed sausage was 1.85 µg/g, in MAP sausage 2.98 µg/g and in unpacked sausage 4.94 µg/g. After 2 and 7 months of storage, sausages packed in vacuum had the highest grades for sensory properties of odor and taste

Towards the mechanisam of stabilization of TPD thin films with UV light

Triphenyldiamine (TPD) or N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)benzdine is a well known hole-transporting material often used in electroluminescent devices. In bulk material glass transition temperature TTPDg ~ 60°C [1] is rather low and for sufficiently thin films (thickness d ~ 30 nm) deposited on a fused-silica substrate, dewetting occurs even at room temperature [2]. Morphological changes, which are often related to low Tg, lead to degradation of device performance in which thin film s are incorporated. That is why it is interesting to find a way to stabilize thin films. Following a brief report [3] on increased stability of UV irradiated TPD films, we focused on elucidating the underlying mechanism, since an explanation of chemical changes on molecular level has not yet been given. Thin amorphous TPD films were produced in physical vapor deposition (PVO) process on a fused silica or glass substrates. Immediately after evaporation one half of each sample was exposed to UV light under ambient conditions in order to compare effects of irradiation on a single film. Illuminated and non-illuminated areas of films are characterized using UV-visible spectroscopy and atomic force microscopy (AFM). Decrease in absorption bands intensity was observed after irradiation, indicating a chemical change in the sample. AFM study clearly shows that dewetting process at room temperature is stopped for irradiated samples thinner than 30nm. Illuminated samples remained stable even after few weeks of storage under ambient conditions and after 24h exposure to temperatures T > TTPDg. From proton nuclear magnetic resonance and mass spectrometry measurements, we find that photo-excited TPD reacts with oxygen from air, which leads to oxidation and hydroxylation of small amount of TPD molecules. W e conclude that increased thermal stability of irradiated films is due to hydrogen bonding among TPD molecules and molecules formed in hydroxylation process

Mehanizam gašenja fotoluminescencije u tankim filmovima N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)benzidine osvetljenih UV svetlošću u vazduhu

The mechanism of photoluminescence (PL) quenching of thin amorphous N,N'-bis(3-methylphenyl)- N,N'-bis(phenyl)benzidine (TPD) films exposed to UV light in air is studied. TPD is small organic molecule widely used in production of organic light emmiting devices (OLEDs). Photoluminescence of TPD films decays exponentially with time of irradiation, i.e. with the increase of concentration of impurities (photo-oxidized TPD molecules) generated by UV irradiation in air. Intensity of PL decreases to half of its original value when the concentration of impurities reaches 0.4%. Average distance between impurities (acceptors) is almost an order of magnitude larger than average distance between host TPD molecules (donors). Direct long range Forster energy transfer is ruled out as the mechanism of PL quenching, as the overlap between donor and acceptor is lacking, and exciton self-diffusion in TPD films is postulated for the mechanism. The presence of oxidation products is confirmed by infrared (IR) spectroscopy. Vibrational spectra of TPD molecule and few other possible products of photo-oxidation of TPD molecule, obtained by density functional theory, are compared to experimental IR spectra.U ovom radu je prikazana studija mehanizma gašenja fotoluminescencije (FL) tankih amorfnih filmova N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)benzidine (TPD) izloženih UV zračenju u vazduhu. TPD je organski molekul koji se često koristi u izradi organskih svetlećih dioda (OLED). Prilikom izlaganja TPD filmova UV zračenju u vazduhu, dolazi do fotooksidacije TPD molekula, te iz tog razloga fotoluminescencija TPD filmova opada eksponencijalno sa vremenom osvetljavanja filmova, odnosno sa povećanjem koncentracije nečistoća nastalih usled fotooksidacije. Intenzitet fotoluminescencije opadne na polovinu svoje početne vrednosti u slučaju kada je 0.4 % nečistoća prisutno u filmu. U tom slučaju je srednje rastojanje između nečistoća (akceptora) šest puta veće od srednjeg rastojanja između TPD molekula (donora). Direktan dugodometni Forsterov transfer energije je odbačen kao mehanizam gašenja fotoluminescencije jer je spektralno preklapanje emisije donora i apsorpcije akceptora zanemarljivo. Iz ovog razloga je postulirana ekscitonska difuzija u TPD filmovima, analogno nalazima u postojećoj literaturi. Prisustvo produkata oksidacije je potvrđeno uz pomoć infracrvene (IR) spektroskopije. Takodje, izračunat je IR spektar koristeći teoriju funkcionala gustine (DFT) i dobijeno je dobro slaganje sa eksperimentalnim rezultatima

New distribution data of some Pontic and submediterranean plant species in Serbia

We present here the distribution of 11 rare Pontic and submediterranean plant species in Serbia based on field research, herbarium and literature data. These taxa were mapped on 10 x 10 km2 UTM grid. The following taxa were analyzed: Dianthus pinifolius Sibth. &amp; Sm., Doronicum hungaricum Reichenb. fil., Sedum stefco Stefanov, Sempervivum zeleborii Schott, Trifolium pignantii Fauche &amp; Chaub., Ranunculus illyricus L., Potentilla chrysantha Trev., Prunus tenella Batsch, Saxifraga bulbifera L., Linaria pelisseriana (L) Miller and Gagea bohemica (Zausc) Schul. &amp; Schul

Influence of season on pig carcass and M. semimembranosus quality

Partial dissection method showed significantly higher (P&lt;0.05) meat yield in carcasses of pigs fattened in the winter (57.5%), comparing with the meat yield of pigs fattened in the autumn (55.2 %), but not significantly higher comparing to the meat yield of pigs fattened in spring (56.4 %) (P&gt;0.05). On the basis of technological parameters (pHi, pHu, colouru -