Saretze erreakzioaren kontrola proteinazko filmen eta biokonpositeen propietateak

169 p.Lan honen helburu orokorra arrain-gelatinan oinarrituriko materialen propietateak hobetzea da. Bertan, produktu eta aplikazio berrietarako industriako hondakinetatik eta azpi-produktuetatik lehengaiak lortzearen garrantzia azpimarratzen da. Gelatinaren berezko hidrofilotasuna filmen hauskortasun altuaren eta urarekiko sentikortasunaren erantzule dela aintzakotzat hartuta, propietate funtzional hauen hobekuntza Maillard izeneko saretze erreakzioa ahalbidetzen duen laktosaren gehikuntzaren bidez aztertu da. Maillard erreakzioarengan, eta beraz filmen propietateengan laktosa kantitateak, berokuntzak eta soluzioaren pH-ak duten eragina aztertu da eta pH basikoan Maillard erreakzioaren kontrola berokuntza denboraren funtziopean burutu da. Maillard erreakzioan zehar konposatu antioxidatzaileak sortzen direnez, saretutako gelatinazko filmen ahalmen antioxidatzailea aztertzearekin batera, filma eratzeko soluzioan gehituriko kurkumatik eratorritako konposatuak filmen propietate antioxidatzaileengan duen eragina ere aztertu da. Filmen azterketa sakon baten ostean, estrusio eta injekzio bidez lorturiko laktosa bidez saretutako gelatinazko biokonpositeen propietateak aztertu dira. Azkenik, prozesatze baldintzen eragina gelatinazko filmen propietate funtzionalengan nahiz materialaren ingurumen-inpaktua aztertu dira, filmen abantailak eta hobetu beharreko alderdiak identifikatzeko helburuarekin

Saretze erreakzioaren kontrola proteinazko filmen eta biokonpositeen propietateak

169 p.Lan honen helburu orokorra arrain-gelatinan oinarrituriko materialen propietateak hobetzea da. Bertan, produktu eta aplikazio berrietarako industriako hondakinetatik eta azpi-produktuetatik lehengaiak lortzearen garrantzia azpimarratzen da. Gelatinaren berezko hidrofilotasuna filmen hauskortasun altuaren eta urarekiko sentikortasunaren erantzule dela aintzakotzat hartuta, propietate funtzional hauen hobekuntza Maillard izeneko saretze erreakzioa ahalbidetzen duen laktosaren gehikuntzaren bidez aztertu da. Maillard erreakzioarengan, eta beraz filmen propietateengan laktosa kantitateak, berokuntzak eta soluzioaren pH-ak duten eragina aztertu da eta pH basikoan Maillard erreakzioaren kontrola berokuntza denboraren funtziopean burutu da. Maillard erreakzioan zehar konposatu antioxidatzaileak sortzen direnez, saretutako gelatinazko filmen ahalmen antioxidatzailea aztertzearekin batera, filma eratzeko soluzioan gehituriko kurkumatik eratorritako konposatuak filmen propietate antioxidatzaileengan duen eragina ere aztertu da. Filmen azterketa sakon baten ostean, estrusio eta injekzio bidez lorturiko laktosa bidez saretutako gelatinazko biokonpositeen propietateak aztertu dira. Azkenik, prozesatze baldintzen eragina gelatinazko filmen propietate funtzionalengan nahiz materialaren ingurumen-inpaktua aztertu dira, filmen abantailak eta hobetu beharreko alderdiak identifikatzeko helburuarekin

Characterization of glucose-crosslinked gelatin films reinforced with chitin nanowhiskers for active packaging development

To find renewable and sustainable alternatives to reduce the severe environmental impact of single-use synthetic plastic packaging, glucose-crosslinked gelatin films containing different amounts of chitin nanowhiskers (CNWs) were prepared. CNWs were first prepared by acid hydrolysis of chitin from shrimps, and characterized (morphological and thermal properties), before their addition into film-forming formulations. The films were heat-treated to promote the chemical crosslinking Maillard reaction (MR), between glucose and gelatin. The films then became less soluble (from 100% to ∼10%), thermally more stable, had a notably improved UV–vis light absorption capacity, and presented significantly enhanced tensile strength (from 42 to 77 MPa) and Young's modulus (from 1476 to 2921 MPa), however, they also became less flexible (from 17% to 7%) and transparent. These property alterations were mainly related to changes in crystallinity, the MR and to a lesser extent, to the formation of noncovalent (electrostatic and hydrogen bonding) interactions between CNWs and gelatin. Furthermore, due to the formation of MR products, the films turned yellow/dark brown and released antioxidant compounds (inhibition ∼33%) while immersed in water, which gave the films their active properties (stabilization of free radicals). These films have considerable potential as reinforced active packaging films for renewable food packaging applications.The authors would like to thank the Ministry of Business, Innovation and Employment of New Zealand (MBIE, Biocide Toolbox programme) and the Spanish Ministry of Science and Innovation (projects PID2019-108361RB-I00 and AGL2017-84161-C2-1-R) for funding. A.E. thanks the State Research Agency of Spain within the Juan de la Cierva - Incorporation action (IJC2019-039697I)

3D-Printed Hybrid Collagen/GelMA Hydrogels for Tissue Engineering Applications

Bioprinting is an emerging technology involved in the fabrication of three-dimensional tissue constructs for the repair and regeneration of various tissues and organs. Collagen, a natural protein found abundantly in the extracellular matrix of several tissues, can be extracted from collagen-rich tissues of animals such as sheep, cows, rats, pigs, horses, birds, and marine animals. However, due to the poor printability of collagen bioinks, biocompatible collagen scaffolds that mimic the extracellular matrix (ECM) are difficult to fabricate using bioprinting techniques. Gelatin methacrylate (GelMA), a semi-synthetic polymer with tunable physical and chemical properties, has been found to be a promising biomaterial in various bioprinting applications. The printability of collagen can be improved by combining it with semi-synthetic polymers such as GelMA to develop hybrid hydrogels. Such hybrid hydrogels printed have also been identified to have enhanced mechanical properties. Hybrid GelMA meshes have not previously been prepared with collagen from ovine sources. This study provides a novel comparison between the properties of hybrid meshes with ovine skin and bovine hide collagen. GelMA (8% w/v) was integrated with three different concentrations (0.5%, 1%, and 2%) of bovine and ovine collagen forming hybrid hydrogels inks that were printed into meshes with enhanced properties. The maximum percentage of collagen suitable for integration with GelMA, forming hybrid hydrogels with a stable degradation rate was 1%. The water-soluble nature of ovine collagen promoted faster degradation of the hybrid meshes, although the structural crosslinking was identified to be higher than bovine hybrid meshes. The 1% bovine collagen hybrid meshes stood out in terms of their stable degradation rates

Developing active and intelligent films through the incorporation of grape skin and seed tannin extracts into gelatin

To achieve sustainability in the wine industry, by-products from winery operations are being diverted from waste streams and turned into beneficial use. Grape seed tannin (SeedT) and skin tannin (SkinT) extracts were used to modify the properties of gelatin films, and to prepare active/intelligent films. The SeedT extract showed a higher phenolic content (similar to 440 mg gallic acid (GA)/g extract) and antioxidant inhibition (similar to 20 %) than the SkinT extract (14 mg GA/g extract, 2 % antioxidant inhibition), while both extracts presented colour variations with an increase of solution pH. The addition of extracts into the gelatin formulation resulted in coloured and transparent films with lower wettability (water contact angle increased up to 92 degrees) and higher UV-light absorbance (secondary antioxidant function) properties. The films were capable of releasing tannins by up to 20 % which led to antioxidant inhibition values of up to 13 % (primary antioxidant function). The addition of SkinT tannins into the films provided the films with a pH indicator ability (intelligent function).The authors would like to thank the State Research Agency of Spain within the Juan de la Cierva - Incorporation action (IJC2019-039697I) and the Ministry of Business, Innovation and Employment (MBIE, Biocide Toolbox programme)

Esne-gazuratik eratorritako film biodegradagarriak

Cheese factories in Euskadi produce a significant amount of whey and its discharge can cause important environmental damages. Therefore, the objective of this study was to prepare biodegradable films using whey protein. In this way, the films prepared with proteins obtained from agroindustrial bio-waste not only will reduce the amount of food waste, but also may help increase the shelf life of foodstuffs. Among different film manufacturing techniques, compression moulding was selected to produce films based on whey protein with the aim of reducing production time and promoting more sustainable processes. After optimising the film manufacturing process, the physical, chemical, barrier, optical and mechanical properties of the films were assessed. In addition to the properties of the films, an environmental impact study of the samples was conducted as well.; Euskadiko gaztandegietan esne-gazur ugari sortzen da eta haren isurketak kalteak eragin ditzake ingurumenean. Horregatik, ikerketa honen helburua film biodegradagarriak ekoiztea da, esne-gazuraren proteina erabiliz. Elikagaien industriako bio-hondakinetatik datorren proteinan oinarritutako elikadura-ontzien bidezko irtenbide honek, hondakinen kopurua murrizteaz gain, elikagaien bizitza erabilgarria handitzea du helburu. Esne-gazuraren proteinan oinarritutako filmak sortzeko, hainbat prozesatze-metodo erabil daitezke eta, lan honetan, konpresioa aukeratu da, ekoizpen-denborak murrizteko eta prozesu iraunkorragoak sustatzeko. Filmen eraketa-prozesua optimizatu ondoren, lortutako filmen propietate fisiko-kimikoak, optikoak, mekanikoak eta hesi-propietateak aztertu dira. Horretaz gain, filmen ingurumen-inpaktuaren azterketa egin da

Whey Protein Films for Sustainable Food Packaging: Effect of Incorporated Ascorbic Acid and Environmental Assessment

The management of food waste and by-products has become a challenge for the agri-food sector and an example are whey by-products produced in dairy industries. Seeking other whey valorisation alternatives and applications, whey protein films for food packaging applications were developed in this study. Films containing different amounts (0, 5, 10, and 15 wt%) of ascorbic acid were manufactured via compression-moulding and their physicochemical, thermal, barrier, optical, and mechanical properties were analysed and related to the film structure. Additionally, the environmental assessment of the films was carried out to analyse the impact of film manufacture. Regarding physicochemical properties, both FTIR and water uptake analyses showed the presence of non-covalent interactions, such as hydrogen bonding, between whey protein and ascorbic acid as band shifts at the 1500–1700 cm−1 region as well as a water absorption decrease from 380% down to 240% were observed. The addition of ascorbic acid notably improved the UV-Vis light absorbance capacity of whey protein films up to 500 nm, a relevant enhancement for protecting foods susceptible to UV-Vis light-induced lipid oxidation. In relation to the environmental assessment, it was concluded that scaling up film manufacture could lead to a reduction in the environmental impacts, mainly electricity consumption.The authors would like to thank Basque Government (KK-2021/00131 and IT1658-22) for its financial support

3D-Printed Mucoadhesive Collagen Scaffolds as a Local Tetrahydrocurcumin Delivery System

Native collagen doughs were processed using a syringe-based extrusion 3D printer to obtain collagen scaffolds. Before processing, the rheological properties of the doughs were analyzed to determine the optimal 3D printing conditions. Samples showed a high shear-thinning behavior, reported beneficial in the 3D printing process. In addition, tetrahydrocurcumin (THC) was incorporated into the dough formulation and its effect on collagen structure, as well as the resulting scaffold’s suitability for wound healing applications, were assessed. The denaturation peak observed by differential scanning calorimetry (DSC), along with the images of the scaffolds’ surfaces assessed using scanning electron microscopy (SEM), showed that the fibrillar structure of collagen was maintained. These outcomes were correlated with X-ray diffraction (XRD) results, which showed an increase of the lateral packaging of collagen chains was observed in the samples with a THC content up to 4%, while a higher content of THC considerably decreased the structural order of collagen. Furthermore, physical interactions between collagen and THC molecules were observed using Fourier transform infrared (FTIR) spectroscopy. Additionally, all samples showed swelling and a controlled release of THC. These results along with the mucoadhesive properties of collagen suggested the potential of these THC–collagen scaffolds as sustained THC delivery systems.This research was funded by MCI/AEI/FEDER, UE (RTI2018-097100-B-C22) and Provincial Council of Gipuzkoa

Arrain-hondakinak baloratzea, gazta ontziratzeko

Elikagaiak ontziratzeko filmak aztertzea garrantzitsua da, ikerketaren bidez gaur egun merkatuan dauden ontziratzeen propietateak hobetzea ahalbidetu baitaiteke. Kasu honetan, polimero berriztagarri eta biodegradagarri bat erabiliz, hainbat azido zitriko kantitatetako filmak egin dira. Haien propietateak aztertu dira, bai eta gazten ontziratzean duten jarrera. Arrain-gelatinazko film hauek film komertzialek eskaintzen ez dituzten zenbait propietate interesgarri erakutsi dituzte; esaterako, gaztak bere koipea gordetzea eta ez lehortzea ahalbidetzen dute