1,720,976 research outputs found
Comparative influence of active PLA and PP films on the quality of minimally processed cherry tomatoes
No full textMinimally processed fruits and vegetables (F&V) are highly prone to oxidative deterioration and despite many efforts, no tangible solution has been found. Thus, this study was designed to evaluate the influence of antioxidant-releasing PLA (polylactic acid) and PP (polypropylene) films incorporated with orange peel extract (OPE) on the quality of cherry tomatoes during storage. Films were characterized based on color parameters, barrier properties and potential migration of volatile compounds from packaging into the food systems. The success of OPE encapsulation and molecular interactions between extract and polymeric chains was confirmed by FT-IR. The release analysis was performed in terms of DPPH radical scavenging activity and through GC-MS analysis (through liquid injection and SPME). Finally, the influence of the packaging material on the quality of cherry tomatoes was ascertained through oxidative enzyme activity and the production of volatile organic compounds. The effect of the extract on the oxygen permeability depends by the film. There was a significant difference (p < 0.05) in compounds that migrated from the control and active PLA films as observed through GC-MS. Finally, cherry tomatoes packed with active PLA films displayed more total polyphenolic content (TPC) retention and reduced volatile compounds (i.e., hexanal) at the end of storage as compared to PP films. Thus, active PLA films have the potential to be used as a replacement packaging material to PP for cherry tomatoes
Valorization of organic biomass through the production of active biopolymer film based on sodium caseinate, guar gum, and beeswax
No full textBoosting Food Packaging Sustainability Through the Valorization of Agri-Food Waste and By-Products
Full text linkThe environmental concerns associated with synthetic polymers have intensified the search for sustainable and biodegradable alternatives, particularly for food packaging applications. Natural biopolymers offer promising solutions due to their biodegradability, reduced environmental impact, and reliance on renewable resources. Among these, agri-food waste and by-products have gained significant attention as valuable feedstocks for polymer production, supporting a circular economy approach. This review critically examines the current status of biopolymers derived from plant, animal, and microbial sources, focusing on their physical and chemical properties and their application in food packaging. The findings underscore that the properties of plant- and animal-based biopolymers are heavily influenced by the source material and extraction techniques, with successful examples in biodegradable films, coatings, and composite materials. However, a critical gap remains in the characterization of microbial biopolymers, as research in this area predominantly focuses on optimizing production processes rather than evaluating their material properties. Despite this limitation, microbial biopolymers have demonstrated considerable potential in composite films and fillers. By addressing these gaps and evaluating the key factors that influence the success of biopolymer-based packaging, we contribute to the ongoing efforts to develop sustainable food packaging solutions and reduce the environmental impact of plastic waste
Can synthetic biology really empower microbial biopolymers as efficient food contact materials?
No full textInternational audienceThis opinion paper explores the potential of integrating synthetic biology into microbial polymers to produce tailored biopolymers for food packaging applications. Synthetic biology has shown precise control over metabolic machinery, enabling the manipulation of pathways involved in microbial biopolymer production. However, there is limited literature available on utilizing the same pathways for designing tailored biopolymers suitable as efficient food contact materials. This is primarily due to the regulatory status of microbial polymers as determined by food safety authorities. One possible solution is to leverage synthetic biology tools by adopting safety assessment protocols established within the regulatory framework. By considering the advantages of synthetic biology-driven microbial polymers, this innovative approach has the potential, not only to replace conventional methods but also to provide additional value by addressing environmental concerns associated with traditional food packaging
Study on the Properties of PLA- and PP-Based Films for Food Applications Incorporating Orange Peel Extract from Agricultural by-Products
Full text linkThe aim of this work was to develop active packaging based on polypropylene (PP) and polylactic acid (PLA) matrices using a high value by-product extracted from orange peel as an active compound for food packaging applications. Different films with and without orange peel extract (OPE) based on PP and PLA were obtained via cast extrusion and characterized in terms of their mechanical, thermal, optical, and sealing properties. The films obtained were transparent, but when OPE was incorporated, the transmittance spectrum decreased, causing slight coloration. Mechanical properties were affected by the incorporation of OPE, as elongation at break and tensile strength increased in the cross-direction of the PP film, although the main differences found were related to the polymer itself. In addition, sealing strength also increased via the incorporation of OPE in the PP matrix. However, thermal properties were not affected by OPE in the PP matrix but slightly decreased stability in PLA. Regarding antimicrobial activity in in vitro studies, no inhibition of the growth of Listeria innocua, Saccharomyces cerevisiae, Aspergillus niger, or Escherichia coli was observed. Finally, antioxidant activity was observed in in vitro studies with 2,2-Diphenyl-1picrylhydrazyl (DPPH) radical. The results of this study showed that the obtention of materials with OPE incorporated into the PLA and PP matrix is feasible. The new materials obtained can be used for applications of oxidation-sensitive fresh products
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
