Mariana Altenhofen da Silva

Bio: Mariana Altenhofen da Silva is an academic researcher from Federal University of São Carlos. The author has contributed to research in topics: Natamycin & Vinasse. The author has an hindex of 15, co-authored 26 publications receiving 2033 citations. Previous affiliations of Mariana Altenhofen da Silva include State University of Campinas.

Effect of calcium and/or barium crosslinking on the physical and antimicrobial properties of natamycin-loaded alginate films

Abstract: The preparation of alginate films with suitable properties requires a two-step contact with reticulating agents: initially a weakly structured pre-film is formatted which is further crosslinked in a second stage by immersion in a more concentrated solution. The present work evaluated the effects of a combined crosslinking procedure using calcium and barium ions on the physical and morphological properties of alginate-based films containing natamycin as antimicrobial agent. The release behavior of natamycin in water was evaluated as well as the antimicrobial activity against four target microorganisms, which are common cheese product contaminants. Films attributes were affected by the type of ion used in the second stage while the natamycin release rate and the antimicrobial activity were influenced by the ion used in the first stage. Films crosslinked with Ba2+ in the first and Ca2+ in the second stage (Ba–Ca films) exhibited physical properties very similar to films crosslinked with calcium in both stages. Release kinetics of natamycin in water fitted well to Fick's second law diffusional model, with effective diffusivity values ranging from 0.40 × 10−11 to 1.74 × 10−11 cm2/s. Ba–Ca films presented the lowest natamycin diffusion coefficient and the smallest inhibition zone diameter against the four microorganisms tested.

American Society for Testing and Materials

Abstract: The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

Edible films and coatings: Structures, active functions and trends in their use

Abstract: Edible films and coatings are thin layers of edible materials applied on food products that play an important role on their conservation, distribution and marketing. Some of their functions are to protect the product from mechanical damage, physical, chemical and microbiological activities. Their use in food applications and especially highly perishable products such as horticultural ones, is based on some particular properties such as cost, availability, functional attributes, mechanical properties (flexibility, tension), optical properties (brightness and opacity), the barrier effect against gases flow, structural resistance to water and microorganisms and sensory acceptability. In this piece of work, the lastest advances on their composition (polymers to be used in the structural matrix), including nanoparticles addition, and properties have been reviewed, as well as the trends in the research about their different applications, including oil consumption reduction in deep-fat fried products, their use in combination with bioactive compounds that bring foodstuff additional functions and shelf life extension of highly perishable products.

Progress in bio-based plastics and plasticizing modifications

Abstract: Over the coming few decades bioplastic materials are expected to complement and gradually replace some of the fossil oil based materials. Multidisciplinary research efforts have generated a significant level of technical and commercial success towards these bio-based materials. However, extensive application of these bio-based plastics is still challenged by one or more of their possible inherent limitations, such as poor processability, brittleness, hydrophilicity, poor moisture and gas barrier, inferior compatibility, poor electrical, thermal and physical properties. The incorporation of additives such as plasticizers into the biopolymers is a common practice to improve these inherent limitations. Generally, plasticizers are added to both synthetic and bio-based polymeric materials to impart flexibility, improve toughness, and lower the glass transition temperature. This review introduces the most common bio-based plastics and provides an overview of recent advances in the selection and use of plasticizers, and their effect on the performance of these materials. In addition to plasticizers, we also present a perspective of other emerging techniques of improving the overall performance of bio-based plastics. Although a wide variety of bio-based plastics are under development, this review focuses on plasticizers utilized for the most extensively studied bioplastics including poly(lactic acid), polyhydroxyalkanoates, thermoplastic starch, proteinaceous plastics and cellulose acetates. The ongoing challenge and future potentials of plasticizers for bio-based plastics are also discussed.