Simulated gastro-intestinal digestion is widely employed in many fields of food and nutritional sciences, as conducting human trials are often costly, resource intensive, and ethically disputable. As a consequence, in vitro alternatives that determine endpoints such as the bioaccessibility of nutrients and non-nutrients or the digestibility of macronutrients (e.g. lipids, proteins and carbohydrates) are used for screening and building new hypotheses. Various digestion models have been proposed, often impeding the possibility to compare results across research teams. For example, a large variety of enzymes from different sources such as of porcine, rabbit or human origin have been used, differing in their activity and characterization. Differences in pH, mineral type, ionic strength and digestion time, which alter enzyme activity and other phenomena, may also considerably alter results. Other parameters such as the presence of phospholipids, individual enzymes such as gastric lipase and digestive emulsifiers vs. their mixtures (e.g. pancreatin and bile salts), and the ratio of food bolus to digestive fluids, have also been discussed at length. In the present consensus paper, within the COST Infogest network, we propose a general standardised and practical static digestion method based on physiologically relevant conditions that can be applied for various endpoints, which may be amended to accommodate further specific requirements. A frameset of parameters including the oral, gastric and small intestinal digestion are outlined and their relevance discussed in relation to available in vivo data and enzymes. This consensus paper will give a detailed protocol and a line-by-line, guidance, recommendations and justifications but also limitation of the proposed model. This harmonised static, in vitro digestion method for food should aid the production of more comparable data in the future.

https://hal.archives-ouvertes.fr/hal-01209876/document

A standardised static in vitro digestion method suitable for food – an international consensus

Polysaccharide-based films and coatings for food packaging: A review

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.

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

An overview of thermal energy storage systems

PLA composites: From production to properties

Mainly due to environmental aims, petroleum-based plastics are being replaced by natural polymers. In the last decades, starch has been evaluated in its film-forming ability for applications in the food packaging area. Characteristics of the starch film matrices, the film formation methods, and physicochemical properties of the starch films are reviewed in this paper. The influences of different components added in casting methods and thermoplastic processes have been also analyzed. Comparison of mechanical properties of newly prepared starch films and stored films reveals that the recrystallization phenomenon made the films more rigid and less stretchable. These effects can be inhibited by adding other polymers to the starch matrix. Other approaches to improve the starch films’ properties are the reinforcement by adding organic or inorganic fillers to the starch matrix as well as the addition of functional compounds. In this way starch films have improved mechanical and barrier properties and can act as a bioactive packaging. Physicochemical properties of the starch films showed a great variability depending on the compounds added to the matrix and the processing method. Nevertheless, dry methods are more recommendable for film manufacturing because of the greater feasibility of the industrial process. In this sense, a better understanding of the nano and microstructural changes occurring in the matrices and their impact on the film properties is required.

María José Fabra

Papers

Edible and Biodegradable Starch Films: A Review

Tensile properties and water vapor permeability of sodium caseinate films containing oleic acid–beeswax mixtures

Effect of re-crystallization on tensile, optical and water vapour barrier properties of corn starch films containing fatty acids

Microstructure and optical properties of sodium caseinate films containing oleic acid-beeswax mixtures

Effect of lipid self-association on the microstructure and physical properties of hydroxypropyl-methylcellulose edible films containing fatty acids