The incomplete degradation of bio-based and biodegradable plastics (BBPs) in soils causes multiple threats to soil quality, human health, and food security. Plastic residuals can interact with soil microbial communities. We aimed to link the structure and enzyme-mediated functional traits of a microbial community composition that were present during poly (butylene succinate-co-butylene adipate (PBSA) decomposition in soil with (PSN) and without (PS) the addition of nitrogen fertilizer ((NH4 )2SO4 ). We identified bacterial (Achromobacter, Luteimonas, Rhodanobacter, and Lysobacter) and fungal (Fusarium, Chaetomium, Clonostachys, Fusicolla, and Acremonium) taxa that were linked to the activities of ß-glucosidase, chitinase, phosphatase, and lipase in plastic-amended soils. Fungal biomass increased by 1.7 and 4 times in PS and PSN treatment, respectively, as compared to nonplastic amended soil. PBSA significantly changed the relationships between soil properties (C: N ratio, TN, and pH) and microbial community structure; however, the relationships between fungal biomass and soil enzyme activities remained constant. PBSA significantly altered the relationship between fungal biomass and acid phosphatase. We demonstrated that although the soil functions related to nutrient cycling were not negatively affected in PSN treatment, potential negative effects are reasoned by the enrichment of plant pathogens. We concluded that in comparison to fungi, the bacteria demonstrated a broader functional spectrum in the BBP degradation process

This thesis has an approved one-year embargo applied to it. Please, refer to the corresponding forms, and please, so not publish immediately until the embargo has been sorted out. The thesis contains two unpublish papers and patents pending. Thank you! / Conventional single-use plastic packaging has contributed significantly to the health and well-being of our society but also negatively impacted our environment due to its persistence after use. Since recycling is not a complete solution, rapidly biodegradable materials like thermoplastic starch (TPS) blends offer a more sustainable alternative. Additionally, to stave off the premature breakdown of starch-containing materials as well as extend the shelf life of enclosed foods, microbial control strategies need to be developed. To overcome the inherent brittleness of TPS, this work explores the potential of xylitol and erythritol as melt plasticizers for waxy corn starch (̴100% amylose). Characterizations revealed that both xylitol and erythritol can gelatinize and plasticize starch under 25% wt. Particularly, xylitol demonstrated superior plasticizing and compatibilizing effects, leading to a ductile TPS packaging film with uncharacteristically high elongation at break (EB, 422% ± 48%). The ductile TPS was blended with up to 70% Ecovio bioplastic without requiring compatibilizers and retaining much of its EB value (298 ± 24%). Using xylitol as a melt plasticizer also enhanced the mechanical and hydrophobic qualities of the TPS/Ecovio film as well as its oxygen permeability and puncture extension. Furthermore, polymerized curcumin copolymer (PCEG) was investigated as a grafted coating onto the developed TPS/Ecovio® blend. The antimicrobial activity of PCEG and PCEG coating film was evaluated against foodborne bacteria. The polymerized curcumin by itself demonstrated antimicrobial activity against the gram-negative bacteria Escherichia coli BL21 and Pseudomonas aeruginosa PA01, as well as the gram-positive bacterium Staphylococcus aureus. Additionally, the PCEG-coated films showed surface inhibition of Glutamicibacter soli (IAI-3), a gram-positive bacterium making polymerized curcumin copolymer coatings a suitable approach to add antimicrobial features in thermoplastic starch composites for biodegradable food packaging. / Thesis / Master of Applied Science (MASc) / Canada's Zero Plastics initiative represents a commitment to the environment while upholding the advancements in food safety and public health that come with single-use food packaging. Achieving this balance demands the creation of novel materials. These materials should mimic the qualities of synthetic polymers but have the added ability to decompose naturally in the environment upon reaching the end of their utility. A significant challenge in this effort is preventing the premature degradation of starch-containing packaging materials. Moreover, extending the shelf life of the food they enclose is equally crucial. To solve this paradox, the development of microbial control strategies becomes imperative. This study highlights the antimicrobial potential of a polymerized curcumin copolymer (PCEG) as a coating on a blend of thermoplastic starch (TPS)/xylitol/Ecovio®, creating an innovative packaging film. The curcumin copolymer coating exhibited antimicrobial properties, suggesting its potential use in thermoplastic starch composites for biodegradable food packaging.

The Norwegian Food Research Institute (Nofima) and the University of Borås worked together to develop this project. The commonly used packaging materials pose a serious threat to the environment, as they are produced from nonrenewable crude oil and cannot decompose naturally. Despite some manufacturers' claims of their products being eco-friendly or sustainable, they are not entirely made from renewable resources and are not biodegradable. Nevertheless, some bio-based materials have emerged as a viable alternative that can naturally break down and safely decompose in the environment. Despite many studies, biopolymers possess limited mechanical and barrier properties, which restricts their potential for use in products. To overcome this limitation, polymer blending can be employed to enhance their final properties and make them more suitable for various applications. The objective of this project was to design sustainable food packaging using biopolymers. PHBV, one of the PHA’s bio-based polymers, was blended with other polymers to enhance its properties as a sustainable food packaging material. Through blending, PHAs'physical, chemical, and thermal properties can be enhanced to obtain exceptional films for food packaging purposes. Finally, in this work, a bio-based polymer, polyhydroxyalkanoate, was used to producea biodegradable packaging system for potential food packaging applications. The effect of the physical modification of PHBV on mechanical and barrier properties was studied by blending it with biodegradable polymers such as PLA and PBAT. Thermal properties were analyzed using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and FourierIItransform infrared spectroscopy (FTIR) while the mechanical properties were evaluated by tensile test. Barrier properties were characterized using water vapor transmission rate (WVTR). The mechanical performance of PHBV 50%: PBAT 50% blend has been significantly improved, leading to better tensile properties. The high crystallinity of the PHBV 50%: PBAT 50% blend than other blends have been found to enhance the barrier properties of the polymer film, according to DSC analysis. FTIR investigations have suggested no difference in absorption peaks between the blends and the neat material. Furthermore, WVTR investigations have shown that PHBV50%: PBAT50% exhibits excellent barrier properties against water vapor, making it a highly promising material.

No description available.

This research is the first systematic investigation of solid-state orientation as a novel method for controlling drug release from biodegradable polymers. The effect of various degrees of polymer orientation was studied in oriented Poly (L-lactic acid) (PLA) films containing curcumin and theophylline as model drugs. Additionally, direction specific drug release was studied from oriented PLA rods containing paracetamol. The films oriented to 2X uniaxial constant width (UCW) or 2X2Y biaxial draw ratio showed retardation of drug release, when their nematic structure was stabilised by the presence of crystalline theophylline. Contrarily, the same films when contained solid solution of curcumin, shrunk in the release medium and exhibited a release profile similar to the un-oriented films. All films oriented to the UCW draw ratio ≥ 3X contained α crystalline form of PLA and showed acceleration of drug release proportionate to the draw ratio. According to the proposed mechanism augmented formation of water filled channels in these films was responsible for faster drug release. Similarly, the paracetamol loaded PLA rods die-drawn to uniaxial draw ratios ≥ 3X exhibited enhancement of drug release. Importantly, the amount of drug released along the oriented chain axis was significantly larger than that in the perpendicular direction. Drug release from the die-drawn rods was accelerated by a greater degree than that observed from the oriented films. This can be correlated to the differences in their size, geometry and the crystalline form of PLA. In conclusion, the current study provided substantial evidence that solid-state orientation can offer a control over drug release from PLA.

No / This review summarises the recent developments in the synthesis and applications of polymers derived from malic acid. There has been an increased interest in the design of sustainable and biodegradable polymers as a result of the drive to use renewable feedstocks as an alternative to petrochemicals in addition to their significant potential in biomedical applications. Synthetic strategies to access polymers from malic acid based on both condensation and ring-opening polymerization, across a broad range of conditions, are reviewed along with their advantages and limits. The role that such materials are studied for in biomedical applications is discussed, and their environmental impact based on the biodegradability of the malic polymer backbone is outlined. / The Royal Society, EPSRC, BBSRC

<p>U okviru disertacije, kori&scaron;ćenjem ve&scaron;tačkih neuronskih mreža razvijeni su modeli za predviđanje količina ambalažnog i biorazgradivog komunalnog otpada u Republici Srbiji do kraja 2030. godine. Razvoj modela baziran je na zavisnosti između ukupne potro&scaron;nje domaćinstva i generisane količine dva posmatrana toka otpada. Pored toga, na bazi zavisnosti sa bruto domaćim proizvodom (BDP), definisan je i model za projekciju zastupljenosti osnovnih opcija tretmana komunalnog otpada u Republici Srbiji za isti period. Na osnovu dobijenih rezultata, stvorene su polazne osnove za procenu potencijala za reciklažu ambalažnog otpada, kao i za procenu u kojoj meri se može očekivati da određene količine biorazgradivog otpada u narednom periodu ne budu odložene na deponije, &scaron;to je u skladu sa savremenim principima upravljanja otpadom i postojećim zahtevima EU u ovoj oblasti.</p> / <p>By using artificial neural networks, models for prediction of the quantity of<br />packaging and biodegradable municipal waste in the Republic of Serbia by<br />the end of 2030, were developed. Models were based on dependence<br />between total household consumption and generated quantities of two<br />observed waste streams. In addition, based on dependence with the Gross<br />Domestic Product (GDP), a model for the projection of share of different<br />municipal solid waste treatment options in the Republic of Serbia for the same<br />period, was created. Obtained results represent a starting point for assessing<br />the potential for recycling of packaging waste, and determination of<br />biodegradable municipal waste quantities which expected that in the future<br />period will not be disposed at landfills, in accordance with modern principles<br />of waste management and existing EU requirements in this area.</p>

<p>Предмет докторске дисертације је развој јестивих, биоразградивих, активних филмова на бази скроба са додатком есенцијалних уља зачинског биља и њихова примена за паковање одабраног прехрамбеног производа. Глобални допринос овог рада иде у прилог развоју области биоразградивих, јестивих, активних амбалажних материјала.<br />Основно истраживање се базира на испитивању могућности добијања скробних филмова влажним поступком (&quot;casting&quot; метода), модификацији врста и количина додатих компонената које улазе у састав филмогене смеше и карактеризацији добијених филмова ради побољшања особина формираног филма. Својства значајна за примену добијених материјала су физичко-хемијске особине (садржај влаге, способност бубрења), механичке особине (дебљина, затезна јачина и издужење при кидању), баријерне особине (пропустљивост водене паре), структурне (АТР-ФТИР спектрометрија и дифракција X зрака), термалне, оптичке и биолошке особине (антимикробна и антиоксидативна активност).<br />Обзиром на велики број параметара који утичу на формирање филма, као и на особине формираних филмова, испитано је међусобно деловање више фактора на могућност продукције и особине добијеног филма. Избор и оптимизација процесних параметара и моделовање продукције филмова изведено је имплементирањем компјутерске и аналитичке методологије.<br />На основу приказаних резултата, може се закључити да је синтетисан активан јестиви скробни филм оптимизованих физичко-хемијских, механичких, баријерних, термалних и биолошких карактеристика. Синтетисаном скробном филму смањена је способност бубрења, унапредјене су механичке особине (вредности затезних јачина опадају, уз истовремено повећање вредности издужења при кидању). Значајан је утицај додатка есенцијалних уља на вредности пропустљивости водене паре, а њиховим додатком постигнута је и<br />изражена биолошка активност.<br />На основу детаљне карактеризације, одабрани су филмови оптимизованих својстава за примену у заштити осмотски дехидрираног свињског меса током периода складиштења. Осмотски дехидрирано месо је упаковано у комерцијалан високо-баријеран амбалажни материјал у атмосферским условима и у условима модификоване атмосфере, док је други део узорака претходно заштићен скробним премазом са оптимизованим особинама, а затим упакован на исти начин. Утицај оптимизоване скробне превлаке на осмотски дехидрирано месо испитан је праћењем промена параметара квалитета током<br />складиштења.<br />Резултати су показали да јестиви, активни скробни премаз значајно доприноси стабилности упакованог осмотски дехидрираног меса и то у погледу оксидације липида, микробиолошке стабилности и позитивног утицаја на сензорне карактеристике осмотски дехидрираног меса током периода складиштења.</p> / <p>Predmet doktorske disertacije je razvoj jestivih, biorazgradivih, aktivnih filmova na bazi skroba sa dodatkom esencijalnih ulja začinskog bilja i njihova primena za pakovanje odabranog prehrambenog proizvoda. Globalni doprinos ovog rada ide u prilog razvoju oblasti biorazgradivih, jestivih, aktivnih ambalažnih materijala.<br />Osnovno istraživanje se bazira na ispitivanju mogućnosti dobijanja skrobnih filmova vlažnim postupkom (&quot;casting&quot; metoda), modifikaciji vrsta i količina dodatih komponenata koje ulaze u sastav filmogene smeše i karakterizaciji dobijenih filmova radi poboljšanja osobina formiranog filma. Svojstva značajna za primenu dobijenih materijala su fizičko-hemijske osobine (sadržaj vlage, sposobnost bubrenja), mehaničke osobine (debljina, zatezna jačina i izduženje pri kidanju), barijerne osobine (propustljivost vodene pare), strukturne (ATR-FTIR spektrometrija i difrakcija X zraka), termalne, optičke i biološke osobine (antimikrobna i antioksidativna aktivnost).<br />Obzirom na veliki broj parametara koji utiču na formiranje filma, kao i na osobine formiranih filmova, ispitano je međusobno delovanje više faktora na mogućnost produkcije i osobine dobijenog filma. Izbor i optimizacija procesnih parametara i modelovanje produkcije filmova izvedeno je implementiranjem kompjuterske i analitičke metodologije.<br />Na osnovu prikazanih rezultata, može se zaključiti da je sintetisan aktivan jestivi skrobni film optimizovanih fizičko-hemijskih, mehaničkih, barijernih, termalnih i bioloških karakteristika. Sintetisanom skrobnom filmu smanjena je sposobnost bubrenja, unapredjene su mehaničke osobine (vrednosti zateznih jačina opadaju, uz istovremeno povećanje vrednosti izduženja pri kidanju). Značajan je uticaj dodatka esencijalnih ulja na vrednosti propustljivosti vodene pare, a njihovim dodatkom postignuta je i<br />izražena biološka aktivnost.<br />Na osnovu detaljne karakterizacije, odabrani su filmovi optimizovanih svojstava za primenu u zaštiti osmotski dehidriranog svinjskog mesa tokom perioda skladištenja. Osmotski dehidrirano meso je upakovano u komercijalan visoko-barijeran ambalažni materijal u atmosferskim uslovima i u uslovima modifikovane atmosfere, dok je drugi deo uzoraka prethodno zaštićen skrobnim premazom sa optimizovanim osobinama, a zatim upakovan na isti način. Uticaj optimizovane skrobne prevlake na osmotski dehidrirano meso ispitan je praćenjem promena parametara kvaliteta tokom<br />skladištenja.<br />Rezultati su pokazali da jestivi, aktivni skrobni premaz značajno doprinosi stabilnosti upakovanog osmotski dehidriranog mesa i to u pogledu oksidacije lipida, mikrobiološke stabilnosti i pozitivnog uticaja na senzorne karakteristike osmotski dehidriranog mesa tokom perioda skladištenja.</p> / <p>The subject of the doctoral thesis is the development of<br />edible biodegradable active films based on starch with<br />the addition of herbal essential oils and their<br />application in packaging of selected food products.<br />Basic research is examination of the possibility of<br />obtaining starch films by wet method (&quot;casting&quot;<br />method), modification of the types and amounts of<br />added components that constitute the film forming<br />mixture and characterization of films in order to<br />improve the characteristics. Characteristics important<br />for the implementation of the obtained materials<br />include the physico-chemical properties (moisture<br />content, solubility), mechanical properties (thickness,<br />tensile strength and elongation at break), barrier<br />properties (water vapor permeability), structural (ATRFTIR<br />spectroscopy and X ray diffraction), thermal,<br />optical and biological properties (antimicrobial and<br />antioxidant activity).<br />Considering the large number of parameters that affect<br />the film formation, as well as the properties of the<br />films, interactions of multiple factors on the possibility<br />of production and properties of the produced film were<br />examined. Selection and optimization of process<br />parameters and modeling of film production were<br />performed by implementing computer and analytical<br />methodology.<br />Based on these results, it can be concluded that it were<br />synthesized active edible starch films with optimized<br />physico-chemical, mechanical, barrier, thermal and<br />biological characteristics. Synthesized starch film had<br />reduced solubility, improved mechanical properties (tensile strength values declined, while elongation at</p><p>break increased). There is a significant influence of the<br />addition of essential oils on the water vapor<br />permeability value with expressed biological activity.<br />The global contribution of this investigation favors the<br />development of the biodegradable edible active<br />packaging materials scientific field.<br />Based on the detailed characterization, film with<br />optimized characteristics was selected for protection of<br />osmotically dehydrated pork during storage.<br />Osmotically dehydrated meat is wrapped in commercial<br />high-barrier packaging material in atmospheric<br />conditions and in conditions of modified atmosphere,<br />while the second part of the sample is packaged in the<br />same way, but previously protected with optimized<br />starch edible coating. Influence of optimized starch<br />coating on the osmotic dehydrated meat was examined<br />by monitoring the quality change during storage in<br />order to preserve the quality and shelf life of packed<br />meat.<br />The results showed that an edible starch based active<br />coating contributes significantly to the stability of the<br />packaged osmotically dehydrated meat during the<br />storage period in terms of lipid oxidation,<br />microbiological stability and positive influence on the<br />sensory characteristics of the osmotically dehydrated<br />meat during the storage period.</p>

Les essais préliminaires pour préparer des alcoolates de fer à partir du bichlorure ou bibromure de fer (II), en les combinant avec des ligands de type diimino pyridine, ont engendré la formation de complexes homoleptiques et hétéroleptiques, dépendant des substituants sur les branches imines du ligand. Ces complexes homoleptiques octaédriques et paramagnétiques ont été étudiés par rapport à leurs propriétés spectroscopiques et cristallographiques. De plus, la synthèse des complexes de fer hétéroleptique a engendré de bons précurseurs penta-coordonnés pour les réactions de substitution de ligands avec des alcoolates de métaux alcalins, de manière à produire les dialcoolates de fer (II) désirés. Des techniques d’analyse telles que la spectroscopie UV-vis, l’analyse élémentaire, la spectrométrie de masse à haute résolution et la cristallographie aux rayons X ont été utilisées pour caractériser ces complexes de fer. L’activité catalytique de ces complexes de fer (II) a aussi été étudiée par rapport à la polymérisation du lactide; les dialcoolates convoités ont été générés in-situ en raison de la difficulté à produire et à isoler les dérivés alcoolates des complexes diimino pyridine de fer. Une étude approfondie a aussi été faite sur les réactions de polymérisation, surtout par rapport aux valeurs de conversion à l’échelle du temps, ainsi qu’à la tacticité des chaines de polymères obtenues. Ces analyses ont été effectuées par l’entremise de la spectroscopie de résonance magnétique nucléaire, de la chromatographie d’exclusion stérique, et de la spectrométrie de masse MALDI (désorption-ionisation laser assistée par matrice). / Initial attempts to prepare iron alkoxide complexes, from iron (II) dichloride or dibromide, in combination with various bis(imino) pyridine ligands, led to the formation of homoleptic and heteroleptic complexes depending on the N-substituents on the imino moieties. A study was made of the resulting paramagnetic octahedral homoleptic complexes, with respect to their spectroscopic properties, as well as their crystallographic parameters. Alternatively, the synthesis of penta-coordinate heteroleptic iron (II) complexes provided good precursors for the ligand substitution reactions with alkaline alkoxides, to produce the desired iron bis(alkoxide) derivatives. Methods such as UV-vis spectroscopy, elemental analysis, high resolution mass spectrometry and X-ray crystallography were used for the characterization of these iron complexes. The catalytic activity of these iron (II) complexes was investigated with respect to lactide polymerization; the desired bis(alkoxide) species were generated in-situ due to the difficulties in isolating pure alkoxide derivatives of the bis(imino) pyridine iron (II) complexes. An informative study was made of both time-scale conversion values, as well as tacticity properties of the resulting polylactic acid chains, through proton nuclear magnetic resonance spectroscopy, gel permeation chromatography, as well as MALDI (matrix-assisted laser desorption/ionization) mass spectrometry measurements.

La biomasse représente l’une des principales alternatives à l’utilisation du pétrole dans la plasturgie. Grâce à leurs propriétés fonctionnelles, les caséinates sont une matière première prometteuse pour la fabrication de films plastiques pour des applications dans l’emballage biodégradable et hydrosoluble. La transformation du caséinate de sodium par les techniques habituellement utilisées dans la plasturgie a été démontrée. Des extrudats de caséinate plastifié au glycérol ont été obtenus au moyen d’une extrudeuse bi-vis corotative. La caractérisation physico-chimique du matériau obtenu a confirmé la thermostabilité de cette protéine et a montré la dépendance du comportement du matériau vis-à-vis de l’humidité ambiante. Pour une variation du taux d’Humidité Relative, de 40 à 90% et une augmentation de la concentration du glycérol, plastifiant hygroscopique, le matériau passe d’un état vitreux (rigide) à un état caoutchouteux (mou). Des films fins ont été ensuite réalisés, à partir des extrudats thermoplastiques, par extrusion gonflage. La perméabilité à la vapeur d’eau des films de caséinate de sodium a été étudiée et a montré que ces matériaux sont de mauvaises barrières à l’humidité. La deuxième partie a été consacré à l’étude de mélanges caséinate de sodium/caséinate de calcium d’un côté et caséinate de sodium/PBAT de l’autre. Le mélange des deux caséinates a permis d’augmenter la tenue mécanique du mélange, à partir de 50% de caséinate de calcium, et de retarder le transfert hydrique à travers le film. Dans le même sens, l’ajout du PBAT, a augmenté jusqu’à deux fois plus, le module d’Young des mélanges mais a baissé la résistance au transfert d’humidité du film à cause de l’incompatibilité des deux polymères / Biomass is one of the main alternatives to the use of oil in plastics field. Due to their various functional properties, caseinates are considered as an interesting raw material for making biodegradable and water-soluble packaging. The transformation of sodium caseinate by the processes used for synthetic plastics industry has been demonstrated. A corotating twin-screw extruder was used to get glycerol plasticized caseinate pellets. The physicochemical properties of the obtained material have confirmed the thermal stability of this protein and demonstrated the influence of surrounding moisture on material behavior. With the Relative Humidity varying from 40 to 90% and increasing the glycerol content, an hydrous plasticizer, the mechanical properties of sodium caseinate based materials changed from those of glassy (rigid) to rubbery (soft) plastics. The pellets were then taken over to make film using a blown-film extruder. The water vapour permeability of blown film was studied and showed that sodium caseinate based films are a poor moisture barrier. The second part dealt with the sodium caseinate blend. Sodium caseinate/calcium caseinate and sodium caseinate/PBAT blends was performed. Adding calcium caseinate, started from 50%, improved the mechanical properties and delayed hydrous transfer through the film. Concerning the sodium caseinate/PBAT blends, adding PBAT increased until twice more the material’s Young modulus but decreased the moisture transfer resistance because of the incompatibility between the two polymers