404 research outputs found
Effects of gelatin origin, bovine-hide and tuna-skin, on the properties of compound gelatin-chitosan films
With the purpose to improve the physico-chemical performance of plain gelatin and chitosan films, compound gelatin-chitosan films were prepared. The effect of the gelatin origin (commercial bovine-hide gelatin and laboratory-made tuna-skin gelatin) on the physico-chemical properties of films was studied. The dynamic viscoelastic properties (elastic modulus G', viscous modulus, G″ and phase angle) of the film-forming solutions upon cooling and subsequent heating revealed that the interactions between gelatin and chitosan were stronger in the blends made with tuna-skin gelatin than in the blends made with bovine-hide gelatin. As a result, the fish gelatin-chitosan films were more water resistant (∼18% water solubility for tuna vs 30% for bovine) and more deformable (∼68% breaking deformation for tuna vs 11% for bovine) than the bovine gelatin-chitosan films. The breaking strength of gelatin-chitosan films, whatever the gelatin origin, was higher than that of plain gelatin films. Bovine gelatin-chitosan films showed a significant lower water vapour permeability (WVP) than the corresponding plain films, whereas tuna gelatin-chitosan ones were only significantly less permeable than plain chitosan film. Complex gelatin-chitosan films behaved at room temperature as rubbery semicrystalline materials. In spite of gelatin-chitosan interactions, all the chitosan-containing films exhibited antimicrobial activity against Staphylococcus aureus, a relevant food poisoning. Mixing gelatin and chitosan may be a means to improve the physico-chemical performance of gelatin and chitosan plain films, especially when using fish gelatin, without altering the antimicrobial properties. © 2011 Elsevier Ltd.Peer Reviewe
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)
Potential antihypertensive effect of protein by-products from whitefish filleting after simulated gastrointestinal digestion
publishedVersio
Functional stability of gelatin–lignosulphonate films and their feasibility to preserve sardine fillets during chilled storage in combination with high pressure treatment
Macrovertebrate Zooarchaeology of the Phoenician site of Teatro Cómico (Cádiz)
En este trabajo presentamos el estudio zooarqueológico de los macromamíferos del yacimiento de época fenicia del Teatro Cómico. Los ovicápridos son la cabaña ganadera más importante seguidos del vacuno y el porcino según el periodo de ocupación. A continuación están representados el caballo y el perro, aunque con porcentajes pequeños. En cuanto a la fauna silvestre su representación es baja, destacando entre ellos el ciervo. Los datos taxonómicos, esqueléticos, y los patrones de mortandad, unidos al registro arqueológico, nos permiten concluir que las especies domésticas tuvieron una funcionalidad orientada a distintos usos económicos como la producción de leche y lana, lo cual es acorde a lo observado en otros yacimientos de este momento.This paper presents the zooarchaeological study of the macromammals recovered at the Phoenician site called Teatro Cómico. Ovicaprids constitute the main herding followed by cattle and porcine, depending on the occupation period. Other species, with a reduced representation, are horse and dog. Regarding wild fauna, a low presence was recorded, deer being the most significant species. Taxonomic and skeletal and death-patterns data, supplemented by the archaeological record, lead to the conclusion that the rearing of domestic species was oriented towards diverse economic uses such as milk and wool production, in line with contemporaneous records in other sites
Zooarchaeology of the Iron Age in Western Iberia: new insights from the Celtic oppidum of Ulaca
The Vettones were one of the most important Celtic peoples of the Late Iron Age in Western Iberia (between the Duero and Tagus Rivers). It is a period recognised from the spread of the cremation ritual in the cemeteries, the development of iron metallurgy, and the emergence of large fortified settlements—the characteristic oppida—that would finally be abandoned with the conquest of Hispania by Rome. Different types of evidence suggest that the Vetton economy was based on livestock. Palaeobotanical and carpological analyses reveal a major deforestation of the landscape, the conversion of large areas into pastures and cultivated fields, and the use of enclosures as cattle pens. The stone sculptures of bulls and pigs found throughout the mountainous areas of the region—the famous verracos—also reflect the value the Vettones placed on livestock. However, there have been very few studies devoted to the identification of faunal remains. In this text, we offer previously unpublished data on the animals found in the oppidum of Ulaca (Solosancho, Ávila, Spain), one of the largest in Celtic Iberia (third–first centuries BC), which we relate to other evidence from neighbouring sites. Thus, the state of the research into Vetton zooarchaeology is offered in the broader context of the Iberian Peninsula
Geometric Morphometrics and Machine Learning Models Applied to the Study of Late Iron Age Cut Marks from Central Spain
Recently the incorporation of artificial intelligence has allowed the development of valuable methodological advances in taphonomy. Some studies have achieved great precision in identifying the carnivore that produced tooth marks. Additionally, other works focused on human activity have managed to specify what type of tool or raw material was used in the filleting processes identified at the sites. Through the use of geometric morphometrics and machine learning techniques, the present study intends to analyze the cut marks of the Ulaca oppidum (Solosancho, Ávila, Spain) in order to identify the type of tools used during carcass modification. Although the Ulaca oppidum is an Iron Age site, the results suggest that most of the cut marks were produced with flint tools
Geometric Morphometrics and Machine Learning Models Applied to the Study of Late Iron Age Cut Marks from Central Spain
Recently the incorporation of artificial intelligence has allowed the development of valuable methodological advances in taphonomy. Some studies have achieved great precision in identifying the carnivore that produced tooth marks. Additionally, other works focused on human activity have managed to specify what type of tool or raw material was used in the filleting processes identified at the sites. Through the use of geometric morphometrics and machine learning techniques, the present study intends to analyze the cut marks of the Ulaca oppidum (Solosancho, Ávila, Spain) in order to identify the type of tools used during carcass modification. Although the Ulaca oppidum is an Iron Age site, the results suggest that most of the cut marks were produced with flint tools.During the development of the present work J.A. was funded by the Euskal Herriko Unibertsitatea [ESPDOC21/05]. This work has been partially funded by the Ministerio de Ciencia e Innovación (project PID2021-123721OB-I00 funded by MCIN/AEI/10.13039/501100011033/FEDER, UE) and Fundación Española para la Ciencia y la Tecnología (FCT-21-17318). M.Á.M.-G. and C.S.B. acknowledges the grant RYC2021-034813-I and RYC2021-034720-I respectively, funded by MCIN/AEI/10.13039/501100011033 and by European Union “NextGenerationEU”/PRTR
Clubs de lectura como estrategia para aumentar el conocimiento sobre nutrición entre la población general: Estudio piloto
Introduction: The spread of false news related to nutrition shows the need to provide general public validated information on food and health, inducing them to follow healthy dietary habits. Objective: To assess whether attendance to book clubs devoted to scientific disseminations books is a useful strategy for improving nutritional knowledge among the population. Methodology: 65 adults participated in a reading club, attending a research center once a month for 4 months to talk about informative scientific books on food/nutrition. The knowledge of the participants was monitored through a survey performed in all the sessions of the club. Results: Participants were mostly female with university studies. Attendance to the book clubs caused a significant increase (P < 0.05) in the number of correct answers on a questionnaire about common misbeliefs on the topics covered in the discussed books. Participants showed a high degree of satisfaction with the activity and willingness to read more scientific dissemination books, even when most of them were not previously usual readers. Conclusions: Book clubs based on popular science books and led by scientists with expertise in the field could increase nutritional knowledge among general population, which should be further explored in different socioeconomic contexts.Introducción: La difusión de noticias falsas relacionadas con la nutrición muestra la necesidad de proporcionar al público general información validada sobre alimentación y salud, induciendo a llevar hábitos dietéticos saludables. Objetivo: Evaluar si la asistencia a clubs de lectura dedicados a libros de divulgación científica es una estrategia útil para mejorar el conocimiento nutricional entre la población. Metodología: 65 adultos participaron en un club de lectura, asistiendo una vez al mes, durante 4 meses a un centro de investigación para conversar sobre libros científicos divulgativos de alimentación/nutrición. Se llevó a cabo un seguimiento de los conocimientos de los participantes a través de una encuesta realizada en todas las sesiones del club de lectura. Resultados: Los participantes fueron en su mayoría mujeres con estudios universitarios. La asistencia a los clubs de lectura provocó un aumento significativo (P < 0,05) en el número de respuestas correctas en un cuestionario sobre las creencias erróneas comunes en los temas tratados en los libros discutidos. Conclusiones: Los clubs de lectura basados en libros de divulgación científica y dirigidos por científicos con experiencia en el campo pueden aumentar el conocimiento nutricional entre la población en general, debiéndose explorar más a fondo en diferentes contextos socioeconómicos
Pandora: A new morphometric and statistical software for analysing and distinguishing cut marks on bones
Cut mark studies have experienced a useful development in the last few years. These studies have allowed us to obtain important information about human prehistory spanning from the origin of meat consumption for chronologies around 2.5 Ma, the detection of human hunting behavior during the lower Pleistocene, or even to determine the uses of diverse raw materials on carcases. Amongst the different analyses applied to the study of cut marks, there has been an increasing interest in using morphometry in order to differentiate and characterize the raw materials with which the effectors were made. These techniques have proven to be extremely useful. Nevertheless, this 3D methodology demands the use of expensive equipment and does not allow using an extensive sample, making it a complex and problematic technique. Maté-González et al. (2015) considered an alternative technique, by combining different disciplines involving geometric morphometrics, photogrammetry and multivariate statistics (multidisciplinary methodology). Here, we try to continue with this work presenting Pandora, a new open software capable of analysing a useful amount of variables from a statistical and morphometric view, accelerating and simplifying the process
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