Indirect monitoring of TORC1 signalling pathway reveals molecular diversity among different yeast strains

Saccharomyces cerevisiae is the main species responsible for the alcoholic fermentation in wine production. One of the main problems in this process is the deficiency of nitrogen sources in the grape must, which can lead to stuck or sluggish fermentations. Currently, yeast nitrogen consumption and metabolism are under active inquiry, with emphasis on the study of the TORC1 signalling pathway, given its central role responding to nitrogen availability and influencing growth and cell metabolism. However, the mechanism by which different nitrogen sources activates TORC1 is not completely understood. Existing methods to evaluate TORC1 activation by nitrogen sources are time-consuming, making difficult the analyses of large numbers of strains. In this work, a new indirect method for monitoring TORC1 pathway was developed on the basis of the luciferase reporter gene controlled by the promoter region of RPL26A gene, a gene known to be expressed upon TORC1 activation. The method was tested in strains representative of the clean lineages described so far in S. cerevisiae. The activation of the TORC1 pathway by a proline-to-glutamine upshift was indirectly evaluated using our system and the traditional direct methods based on immunoblot (Sch9 and Rps6 phosphorylation). Regardless of the different molecular readouts obtained with both methodologies, the general results showed a wide phenotypic variation between the representative strains analysed. Altogether, this easy-to-use assay opens the possibility to study the molecular basis for the differential TORC1 pathway activation, allowing to interrogate a larger number of strains in the context of nitrogen metabolism phenotypic differences.     

Influence of guar gum on the baking quality of gluten-free cheese bread made using frozen and chilled dough

The aim of the study was to assess the effect of guar gum on the quality and textural properties of gluten-free (GF) cheese bread made using chilled and frozen GF cheese dough. The guar gum addition was at 3.5% (G3.5), 4% (G4) and 4.5% (G4.5) levels, based on the weight of the cheese in the product. Samples of frozen dough with 3.5% guar gum and of chilled dough with 4.5% guar gum were chosen for sensory analysis as they had the closest hardness and specific volume to samples of fresh dough and dough without guar gum (Control). The overall consumer acceptance of samples that had been processed using freezing treatment presented the lowest liking score due to the light salty taste.     

Antimicrobial Coatings for Food Contact Surfaces: Legal Framework,Mechanical Properties,and Potential Applications

Food contact surfaces (FCS) in food processing facilities may become contaminated with a number of unwanted microorganisms, such as Listeria monocytogenes, Escherichia coli O157:H7, and Staphylococcus aureus. To reduce contamination and the spread of disease, these surfaces may be treated with sanitizers or have active antimicrobial components adhered to them. Although significant efforts have been devoted to the development of coatings that improve the antimicrobial effectiveness of FCS, other important coating considerations, such as hardness, adhesion to a substrate, and migration of the antimicrobial substance into the food matrix, have largely been disregarded to the detriment of their translation into practical application. To address this gap, this review examines the mechanical properties of antimicrobial coatings (AMC) applied to FCS and their interplay with their antimicrobial properties within the framework of relevant regulatory constraints that would apply if these were used in real‐world applications. This review also explores the various assessment techniques for examining these properties, the effects of the deposition methods on coating properties, and the potential applications of such coatings for FCS. Overall, this review attempts to provide a holistic perspective. Evaluation of the current literature urges a compromise between antimicrobial effectiveness and mechanical stability in order to adhere to various regulatory frameworks as the next step toward improving the industrial feasibility of AMC for FCS applications.     

Structural topology optimization under limit analysis

Structural and Multidisciplinary Optimization - The objective of this paper is to look for structural designs arising from topological optimization procedures that aim at maximizing the loading...     

Dietary Fiber Concentrates from Fruit and Vegetable By-products: Processing,Modification, and Application as Functional Ingredients

The food industry is continuously looking for new sources of dietary fiber (DF) to use as an ingredient due to its well-known health benefits associated to its consumption. Usually, DF used for this purpose is obtained from cereal products or their by-products; however, by-products produced from the fruit and vegetable industry have comparatively higher DF content with more diverse compositions. DF concentrates (DFC), obtained by the processing of fruit and vegetable by-products, are suitable for food formulations because of their unique technological functionalities and applicabilities, both closely related to the DF composition. This review describes the DF definition and analytical procedures for its quantification, the processing of fruit and vegetable by-products aimed to obtain high quality DFC, as well as the control of the processing conditions to obtain DFC with specific functionalities. Furthermore, it deals with the role of the modifications by thermal and non-thermal technologies, as well as of the application of DFC in several food formulations.