Influence of packaging and packing conditions on the quality of kashkaval

S obzirom da je ambalaža važan faktor u očuvanju kvaliteta tvrdih sireva, cilj ovog istraživanja je proučavanje uticaja ambalažnih materijala i uslova pakovanja na promene konfekcioniranog Kačkavalja. Kačkavalj je sir mediteranskog porekla, a nedovoljno je proučen sa aspekta uticaja ambalaže. U okviru istraživanja izvršena su ispitivanja nekoliko ambalažnih materijala domaće proizvodnje i jednog uvoznog ambalažnog materijala, koji se koristi za pakovanje konfek- cioniranih sireva. Za odabrane ambalažne materijale određeni su IC spektri, barijerna i fizičko-mehanička svojstva kvalitet formiranja ambalaže i koncentracije gasova u ambalaži. Barijerna svojstva, odnosno propustljivosti vodene pare i gasova su osnovna svojstva plastičnih ambalažnih materijala, koja regulišu razmenu gasova i vodene pare između sira i okoline, utičući time na tok i intenzitet biohemijskih procesa u siru. Barijerna svojstva takođe omogućavaju i primenu različitih uslova pakovanja, kao što su vakuum ili modifikovana atmosfera. Kačkavalj upakovan u ambalažne materijale dobrih barijernih svojstava, odnosno niske propustljivosti gasova, posebno kiseonika, i vodene pare, imao je najniži sadržaj peroksida, najmanji gubitak mase, najbolja senzorna svojstva, najmanju tvrdoću, izraženu silom kompresije, kao i drugačiju distribuciju isparljivih komponenata arome, u odnosu na sir upakovan u ambalažne materijale lošijih barijernih svojstava. Na osnovu ostvarene zaštite upakovanog Kačkavalja, izdvojili su se, pored uvoznog ambalažnog materijala i domaći ambalažni materijali polipropilen lakiran sa PVDC/polietilen i poliamid/polietilen. Od primenjenih uslova pakovanja najbolji zaštitni efekat pokazalo je pakovanje pod vakuumom.The packaging is of great importance for the quality of preservation of hard cheeses, so the aim of the investigations was to determine the influence of packaging materials and packing conditions on the changes of consumer-size packaged hard cheese variety, Kashkaval. Kashkaval originates from Mediterranean area and is insufficiently studied from the aspect of packaging effect. Several domestic and one imported packaging material which have been used for the packing of consumer-size cheeses were investigated. Infra-red spectra, barrier and physico-mechanical characteristics, quality of formed packaging and concentration of gases in the packaging were determined. The barrier characteristics, i.e. the water vapour and gases permability are the basic characteristics of packaging materials which regulate the exchange of gases and water vapour between the chesse and environment, this affecting the flow and intensity of biochemical changes in the cheese. The barrier characteristics enable the application of different packing conditions, like vacuum of modified atmosphere. It was found that Kashkaval cheese packed in packaging materials of good barrier characteristics, i.e. low gases permeability, especially exygen and water vapour, had the lowest peroxides content, lowest mass loss, best sensory characteristics, lowest hardness expressed as the compression force, as well as different distribution of volatile aroma components compared to cheese packed in materials of worse barrier characteristics. On the basis of the achieved protection of packed Kashkaval, the domestic packaging materials polypropylen lacquered with PVDC/polyethylene and polyamid/polyethylene in addition to the imported packaging material were outatanding. The packing under vacuum exibited the best protecting effect

Effect of glycerol content and pH value of film-forming solution on the functional properties of protein-based edible films

The work is concerned with the effects of glycerol content and pH value of film forming solution on the functional properties of protein-based films. The films were produced of chicken breast proteins, dissolved under either acidic (pH 3) or alkaline (pH 11) conditions, with different concentrations of glycerol (35%, 50% and 65% w/w of protein content). Glycerol content affected significantly mechanical properties, water vapor permeability, color at pH 3 and film solubility (p<0.05). The pH value had significant influence on light transmission, color, transparency and film solubility (p<0.05). Considering the results of mechanical properties and film solubility, the obtained films are in the acceptable range for the use as a packaging material. It was estimated that water vapor permeability, color, light transmission and transparency need to be improved for the application

Svojstva jestivih kolagenskih filmova prevučenih kitozanom

The objective of this study is to determine physical, mechanical and barrier properties of chitosan-laminated collagen film. Commercial collagen film, which is used for making collagen casings for dry fermented sausage production, was laminated with chitosan film layer in order to improve the collagen film barrier properties. Different volumes of oregano essential oil per 100 mL of filmogenic solution were added to chitosan film layer: 0, 0.2, 0.4, 0.6 and 0.8 mL to optimize water vapour barrier properties. Chitosan layer with 0.6 or 0.8 % of oregano essential oil lowered the water vapour transmission rate to (1.85±0.10)·10–6 and (1.78±0.03)·10–6 g/(m2·s·Pa) respectively, compared to collagen film ((2.51±0.05)·10–6 g/(m2·s·Pa)). However, chitosan-laminated collagen film did not show improved mechanical properties compared to the collagen one. Tensile strength decreased from (54.0±3.8) MPa of the uncoated collagen film to (36.3±4.0) MPa when the film was laminated with 0.8 % oregano essential oil chitosan layer. Elongation at break values of laminated films did not differ from those of collagen film ((18.4±2.7) %). Oxygen barrier properties were considerably improved by lamination. Oxygen permeability of collagen film was (1806.8±628.0)·10–14 cm3/(m·s·Pa) and values of laminated films were below 35·10–14 cm3/(m·s·Pa). Regarding film appearance and colour, lamination with chitosan reduced lightness (L) and yellowness (+b) of collagen film, while film redness (+a) increased. These changes were not visible to the naked eye.Svrha je ovoga rada bila odrediti fizikalna i kemijska svojstva, te propusnost kolagenskog filma prevučenog kitozanom. Komercijalni kolagenski film, koji se upotrebljava za izradu crijeva za kobasice, prevučen je kitozanom radi poboljšanja propusnosti. Filmu su dodane različite količine esencijalnog ulja origana (0; 0,2; 0,4; 0,6 i 0,8 mL u 100 mL otopine filma), čime se optimirala njegova propusnost za vodenu paru. Sloj kitozana s dodatkom 0,6 % esencijalnog ulja origana smanjio je transmisiju vodene pare na (1,85±0,10)·10-6, a s dodatkom 0,8 % ulja origana na (1,78±0,03)·10-6 g/(m2·s·Pa), u usporedbi s kolagenskim filmom ((2,51±0,05)·10-6 g/(m2·s·Pa)). Film prevučen kitozanom nije imao bolja mehanička svojstva od kolagenskog filma. Granična se čvrstoća filma prevučenog kitozanom s dodatkom 0,8 % esencijalnog ulja origana smanjila s (54,03±3,77) na (36,29±4,02) MPa. Vrijednosti se istezljivosti kolagenskih filmova nisu razlikovale od onih filmova prevučenih kitozanom. Propusnost je kisika znatno poboljšana dodatkom kitozana, pa je u kolagenskom filmu iznosila (1806,79±628,01)·10-14 cm3/(m·s·Pa), a u filmu prevučenom kitozanom 35·10-14 cm3/(m·s·Pa). Dodatkom su se kitozana promijenili izgled i boja filma, tj. smanjio se intenzitet osvjetljenja (L) i žute (+b) boje, a pojačao intenzitet crvene (+a), što nije bilo vidljivo golim okom

Mogućnosti savremenog pakovanja hrane

Quality and stability of different food products depend, to a great extent on packaging materials used, but also on requirements and procedures of modern packing. The improvement of packing process in a conventional sense means modernization of equipment, perfection of qualitative properties of applied packaging materials, or use of vacuum packing or modified atmosphere packing. Modern packing means also the use of active and intelligent packaging. The role of modern food packing is not only a passive protection and selling of products. The active packaging affects the conditions in the packed food, so the shelf life is prolonged and the quality maintained. The intelligent packaging communicates with the surrounding giving some information on the quality of the packed product. Regarding the aspect of environmental importance of packaging materials, the possibility to use biopolymers and edible packaging materials is also reviewed. The paper presents not only the traditional functions of packaging but also the processes of active and intelligent packing. The application of new packing procedures for packing of different food products is discussed.U savremenim uslovima svi prehrambeni proizvodi se pakuju. Kvalitet i održivost različitih prehrambenih proizvoda u mnogome zavisi od primenjenih ambalažnih materijala, ali i od savremenih uslova i postupaka pakovanja. Unapređenje procesa pakovanja u klasičnom smislu, podrazumeva modernizaciju opreme, poboljšanje kvalitativnih svojstava primenjenih ambalažnih materijala, ili primenu vakuma ili pakovanja u modifikovanoj atmosferi. Savremeno pakovanje podrazumeva i primenu aktivnog i inteligentnog pakovanja. Moderno pakovanje hrane nema više samo pasivnu ulogu u zaštiti i prodaji proizvoda, nego, aktivno pakovanje menja stanje u upakovanoj hrani, da bi se produžila njegova trajnost i održao kvalitet. Inteligentno pakovanje komunicira sa okolinom dajući pojedine informacije o kvalitetu upakovanog proizvoda. U radu je dat prikaz funkcija ambalaže po tradicionalnom konceptu kao i prikaz aktivnog i inteligentnog procesa pakovanja. Zbog značaja ekološkog aspekta ambalažnih materijala, dat je i prikaz mogućnosti primene biopolimera i jestivih ambalažnih materijala. Razmatrana je mogućnost primene ovih novih postupaka pakovanja za pakovanje različitih prehrambenih proizvoda

Novi trendovi pakovanja u industriji prerade mleka

Shelf life and quality of different food products depend a lot on packaging materials used and also on conditions and processes of modern packing. The enabling of packing process in classical sense, assumes modernization of equipment, improvement of quality characteristics of applied packaging materials, or use of vacuum or packing in modified atmosphere. The role of modern food packing is not passive any more regarding protection and selling of products. The active packing affects the condition of the food packed, so the shelf life is prolonged and the quality maintained. The intellectual packing communicates with the surroundings giving some information on the quality of the product packed. This paper gives a review of the conditions in the dairies, from the aspect of packing. The basic definitions, and the review of different active and intelligent packing are also given (removal of oxygen, removal of ethylene, moisture regulation, antimicrobial effect,... (indicators of temperature, pH.). The possibility of use of these new packing processes (removal of oxygen, cholesterol immobilization, lactose immobilization, antimicrobial packing) for packing of milk and dairy products was reviewed.Moderno pakovanje hrane nema više samo pasivnu ulogu u zaštiti i prodaji proizvoda, nego aktivno pakovanje menja stanje u upakovanoj hrani, da bi se produžila njegova trajnost i održao kvalitet. Inteligentno pakovanje komunicira sa okolinom dajući pojedine informacije o kvalitetu upakovanog proizvoda. U radu je dat osvrt na sadašnje stanje u mlekarama sa aspekta pakovanja. Takođe su date osnovne definicije, kao i pregled različitih postupaka aktivnog i inteligentnog pakovanja. Razmatrana je mogućnost primene ovih novih postupaka za pakovanje, kako mleka i mlečnih proizvoda, tako i drugih prehrambenih proizvoda

Hydrophobic silica nanoparticles as reinforcing filler for poly (lactic acid) polymer matrix

Properties of poly (lactic acid) (PLA) and its nanocomposites, with silica nanoparticles (SiO2), as filler were investigated. Neat PLA films and PLA films with different percentage of hydrophobic fumed silica nanoparticles (0.2, 0.5, 1, 2, 3 and 5 wt. %) were prepared by solution casting method. Several tools were used to characterize the influence of different silica content on crystalline behavior, and thermal, mechanical and barrier properties of PLA/SiO2 nanocomposites. Results from scanning electron microscope (SEM) showed that the nanocomposite preparation and selection of specific hydrophobic spherical nano filler provide a good dispersion of the silica nanoparticles in the PLA matrix. Addition of silica nanoparticles improved mechanical properties, the most significant improvement being observed for lowest silica content (0.2wt.%). Barrier properties were improved for all measured gases at all loadings of silica nanoparticles. The degree of crystallinity for PLA slightly increased by adding 0.2 and 0.5 wt. % of nano filler

Some physical and chemical properties of wrapping for processed cheeses

Ambalažni materijali i ambalaža od velikog su značaja za očuvanje kvaliteta i održivosti topljenih sireva. U radu su obavljena komparativna istraživanja fizičko-kemijskih karakteristika omotača za pakovanje topljenih sireva oblika kobasice (testirani su uzorci uvoznih folija različite boje i jedna domaća folija). Uspoređujući rezultate određivanja površinske mase, debljine i sila kidanja materijala, može se zaključiti da istraženi uzorak domaće folije nije dostigao nivo kvalitete uvoznih folija. Rezultati određivanja propustljivosti folija na svjetlost i na zrak ukazuju da domaća folija ima slične karakteristike kao i uvozne. Rezultati istraživanja uvoznih folija, koje su se u našim mljekarama pokazale kao dobre za pakovanje topljenih sireva, mogu poslužiti kao osnova za određivanje kvalitete koji se traži od naših proizvođača ambalažnih materijala za pakovanje topljenih sireva.Wrapping materials are of great importance for keeping quality and shelf-life of processed cheese. The comparative investigations of physical and chemical properties of wrappings for processed cheese are carried out in this study. The samples of imported foils of different colors and one foil of domestic producer were investigated. By comparing of results obtained from determinations of surface mass, thickness and material break forces it has been concluded that investigated samples of domestic foil did not reach the quality level of imported foils. The results obtained for light transmission and air permeability show the similar characteristics of domestic and comparative, imported foils. The results obtained for imported foils, which are recognized in out dairies as applicable for wrapping of processed cheese, can serve as base for quality requirements in domestic production of wrapping for the same product

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

Primjena uobičajenih materijala za pakiranje u proizvodnji probiotičkog svježeg sira

The aim of this work was to investigate the application of common packaging materials polypropylene (PP) and polystyrene (PS) in the probiotic fresh cheese production packaging. Probiotic and traditional cheeses were produced from milk with standardized milk fat content of 2.3 g/100 g including the application of two cultures (probiotic and traditional). The samples were packed in the PP and PS cups and stored at 4 ºC for 30 days. The observed permeability of gases through the two applied packaging materials was significantly different. Cheese samples were analysed for microbiological properties whereby lactic acid bacteria, Bifidobacterium sp. and aerobic mesophilic bacteria (AMB) were determined. Packaging materials showed no significant effect on the content of ascorbic acid which is known to be sensitive to the presence of oxygen.Cilj ovog rada bio je ispitati mogućnost primjene uobičajenih materijala za pakiranje - polipropilena (PP) i polistirena (PS) u proizvodnji probiotičkog svježeg sira. Probiotički i tradicionalni sir proizvedeni su iz mlijeka s 2,3 g/100 g mliječne masti primjenom probiotičke i tradicionalne starter kulture. Uzorci su pakirani u PP i PS-čaše i skladišteni 30 dana na 4 ºC. Propusnost plinova kroz dva primijenjena materijala za pakiranje bila je značajno različita. U uzorcima sira uzetih za mikrobiološku analizu određene su bakterije mliječne kiseline, Bifidobacterium i aerobne mezofilne bakterije (AMB). Utjecaj materijala za pakiranje na sadržaj askorbinske kiseline, osjetljive na prisustvo kisika, nije bio značajan

Reakcija sorti soje na pojačanu ishranu azotom

The paper presents the variability of productive traits of six soybean varieties grown in conditions of increased nitrogen nutrition in the period 2006-2008. The trials were conducted in South Banat on the chernozem soil type. Soybean was grown under rain-fed conditions. Morphological traits were analyzed prior to harvest, while the grain yield was measured after harvest. The results show significant variations in the tested traits among the examined genotypes. The highest average yield had variety Sava, while in dry 2006, the higher yields achieved early varieties Proteinka and Valjevka. Increased nitrogen nutrition did not significantly affect the yield, especially in years with favorable rainfall schedule. Differences in production traits varied strongly among experimental years.U radu je proučavana varijabilnost produktivnih osobina šest sorti soje gajenih u uslovima pojačane ishrane biljaka azotom u periodu od 2006. do 2008. godine. Ogledi su postavljeni u južnom Banatu na zemljištu tipa černozem. Soja je gajena u uslovima prirodnog vodnog režima. Analize morfoloških osobina urađene su pre berbe soje, prinos zrna je određen posle berbe oglednih parcela. Rezultati su pokazali da između genotipova postoje značajna variranja u ispitivanim osobinama. Najveći prosečni prinos imala je sorta Sava, dok su u sušnoj 2006. godini, veće prinose ostvarile rane sorte Proteinka i Valjevka. Pojačana ishrana azotom nije značajno uticala na prinos, posebno u godinama sa povoljnijim rasporedom padavina. Razlike u proizvodnim osobinama su jako varirale po godinama istraživanja