11 research outputs found
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/m2 24h for laminated film with added 5 g of beeswax to 66.96 g/m2 24h for the film with 25 g of beeswax, compared to 290.64 g/m2 24h 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
Structural characterisation of starch based edible films with essential oil addition
Present study investigated structure of starch based edible films with essential oil addition. Films were obtained from water solutions containing gelatinized modified starch, polyol, guar-xantan gum modified mixture and essential oil by casting it on a Petri dish and evaporating at room temperature for 72h. Both, glycerol and guar-xantan modified mixture, had role to improve film flexibility and enable better film folding and handling. Two sample groups were obtained: starch based edible films with black cumin oil addition and starch based edible films with black pepper oil addition. Both essential oils were added in three different concentrations. Starch based edible film without essential oil addition was used as blank shot. Structural properties were determined by analyzing spectra obtained by FT-IR Spectrometer in the spectral range of 4000–400 cm−1 with a 4.0 cm−1 resolution. Software Omnic 8.1. and TQ Analyst were used to operate the FTIR spectrometer, collect and present all the data. Results pointed to quantitative law dependency between added amount of essential oils and spectra absorption values for both sample groups and FTIR spectra were used to calculate coefficient of correlation
Antioxidative activity of chitosan and chitosan based biopolymer film
Growing consumer demand for the food without chemical preservatives focused significant extent of research in the direction of finding natural compounds that can be used in food preservation. In this context, natural substances with strong antimicrobial and antioxidant properties, like essential oils, as well as natural biopolymers, particularly draw attention. Natural biopolymers can serve as carriers of the active components, such as essential oils in order of their sustained release to the food during storage, and may themselves exhibit activity in protecting foods from oxidation and/or microbial spoilage. Chitosan has been extensively studied as semi-natural polymer with expressed bioactive properties. While antimicrobial activity of chitosan solution in different acids has been confirmed towards different bacteria, yeasts and moulds, reports concerning intensity, underlying machanism and different factors afecting antioxidant activity of chitosan vary through the available literature. This paper presents a review in the field of antioxidative activity of chitosan with different properties, as well as chitosan based biopolymer films in order to clarify this aspect of chitosan bioactivity and confront different reports found in the literature
Effect of chitosan coating with the addition of caraway essential oil and beeswax on oxidative stability of petrovská klobása sausage
The aim of this paper was to examine the effect of chitosan coating with the addition of caraway essential oil and beeswax on lipid oxidation protection, as well as aroma and water content preservation of traditional dry fermented Petrovská klobása sausage.
During the entire storage period, TBARS index value in coated sausage was lower compared to the control (P–1 and 0.66±0.03 mg kg–1, while after seven months of storage, these values were 0.82±0.05 mg kg–1 and 0.67±0.02 mg kg–1, respectively. While content of saturated aliphatic aldehydes increased in control sausage (P<0.05), it remained unchanged in coated sausage during 7 months of storage. Lipid oxidation protective effect could be correlated to higher marks for aroma of coated sausage during the entire storage period (P<0.05). Coating slowed moisture loss of coated sausage compared to the control (P<0.05)
Effect of the Addition of Carnauba Wax on Physicochemical Properties of Chitosan Films
Influence of storage period on properties of biopolymer packaging materials and pouches
Bilayer biodegradable films based on pumpkin oil cake (PuOC) and zein, as
well as pouches made from these materials, were prepared, and the changes of
their mechanical, physicochemical and barrier properties were analyzed during
four weeks of storage. Heat seal quality of formed pouches and composition of
the gas atmosphere in the pouches were also monitored. The results showed
that the bilayer film had a thickness of 300 ± 10 (μm), and no its changes
were observed during the storage time. The tensile strength of the tested
film increased slightly in the third week, but the elongation at break showed
a decreasing trend during the whole storage period. The decreases in the
moisture content, total soluble matter and swelling of the obtained film,
were also observed. After one month of storage, the O2 transmission rate of
tested films, increased from 27 to 64 (ml/m2 24h 1 bar), and the CO2 gas
transmission rate from 147 to 188 (ml/m2 24h 1 bar). The heat seal strength
of the PuOC/Zein pouches decreased during the whole storage period. The
percentage of O2 in PuOC/Zein pouches increased up to 7 times during the
storage period; however, the percentage of CO2 decreased up to 18 times
already after one week, and then remained stable in the rest of the storage
period. These results are, to a smaller extent, due to the gas transmission
rate through the material, especially for CO2 , and to a greater extent, due
to the low heat seal strength, which decreased through the storage period,
and probably influenced the content of the gases in the pouches.[Project of
the Serbian Ministry of Education, Science and Technological Development,
Grant no. 46010
Effect of endpoint internal temperature on mineral contents of roasted pork loin
The study investigated how variations in endpoint internal roasting temperatures of 51, 61, 71, 81 and 91 °C influenced mineral contents (mg/100 g WW, wet weight) of pork loin (M. longissimus thoracis et lumborum, n= 12). Pork was roasted in oven set to 163 °C. In both raw and cooked samples, phosphorous was determined by the standard spectrophotometric method while metals (potassium, sodium, magnesium, calcium, zinc, iron, copper and manganese) were determined by flame atomic absorption spectrometry after mineralisation by dry ashing. All roasting treatments led to significantly increased mineral contents, except for sodium, compared to raw meat. As endpoint temperature was increased, mineral contents increased, reaching numerically or significantly highest contents at 61 °C for calcium, 71 °C for manganese and 91 °C for phosphorous, potassium, sodium, magnesium, zinc, iron and copper
The effect of the COVID-19 pandemic on severe asthma care in Europe: Will care change for good?
peer reviewedBackground The coronavirus disease 2019 (COVID-19) pandemic has put pressure on healthcare services, forcing the reorganisation of traditional care pathways. We investigated how physicians taking care of severe asthma patients in Europe reorganised care, and how these changes affected patient satisfaction, asthma control and future care. Methods In this European-wide cross-sectional study, patient surveys were sent to patients with a physician-diagnosis of severe asthma, and physician surveys to severe asthma specialists between November 2020 and May 2021. Results 1101 patients and 268 physicians from 16 European countries contributed to the study. Common physician-reported changes in severe asthma care included use of video/phone consultations (46%), reduced availability of physicians (43%) and change to home-administered biologics (38%). Change to phone/video consultations was reported in 45% of patients, of whom 79% were satisfied or very satisfied with this change. Of 709 patients on biologics, 24% experienced changes in biologic care, of whom 92% were changed to home-administered biologics and of these 62% were satisfied or very satisfied with this change. Only 2% reported worsening asthma symptoms associated with changes in biologic care. Many physicians expect continued implementation of video/phone consultations (41%) and home administration of biologics (52%). Conclusions Change to video/phone consultations and home administration of biologics was common in severe asthma care during the COVID-19 pandemic and was associated with high satisfaction levels in most but not all cases. Many physicians expect these changes to continue in future severe asthma care, though satisfaction levels may change after the pandemic. © The authors 2022