Metabolic Conversions by Lactic Acid Bacteria during Plant Protein Fermentations.

To secure a sustainable food supply for the rapidly growing global population, great efforts towards a plant-based diet are underway. However, the use of plant proteins comes with several challenges, such as improvement or removal of undesired flavours, and generation of desired texture properties. Fermentation holds large potential to alter these properties, but compared to dairy fermentations, our knowledge on strain properties in different plant-based substrates is still limited.

Replacement of meat by meat substitutes. A survey on person- and product-related factors in consumer acceptance.

What does it take to increase the consumption of meat substitutes and attract new consumers? We identified main barriers and drivers by a consumer survey (n=553) in the U.K. and the Netherlands.

Endothelial glycocalyx structure in the intact carotid artery: a two-photon laser scanning microscopy study.

Background: The endothelial glycocalyx (EG) is the carbohydrate-rich luminal lining of endothelial cells that mediates permeability and blood cell-vessel wall interactions. To establish an atheroprotective role of the EG, adequate imaging and quantification of its properties in intact, viable, atherogenesis-prone arteries is needed.

Methods: Carotid arteries of C57Bl6/J mice (n=22) were isolated including the bifurcation, mounted in a perfusion chamber, and perfused with fluorescent lectin wheat germ agglutinin-fluorescein isothiocyanate.

In vivo high-resolution structural imaging of large arteries in small rodents using two-photon laser scanning microscopy.

In vivo (molecular) imaging of the vessel wall of large arteries at subcellular resolution is crucial for unraveling vascular pathophysiology. We previously showed the applicability of two-photon laser scanning microscopy (TPLSM) in mounted arteries ex vivo. However, in vivo TPLSM has thus far suffered from in-frame and between-frame motion artifacts due to arterial movement with cardiac and respiratory activity.

Branched chain aldehydes: production and breakdown pathways and relevance for flavour in foods.

Branched aldehydes, such as 2-methyl propanal and 2- and 3-methyl butanal, are important flavour compounds in many food products, both fermented and non-fermented (heat-treated) products. The production and degradation of these aldehydes from amino acids is described and reviewed extensively in literature. This paper reviews aspects influencing the formation of these aldehydes at the level of metabolic conversions, microbial and food composition.

Flavour formation by lactic acid bacteria and biochemical flavour profiling of cheese products.

Flavour development in dairy fermentations, most notably cheeses, results from a series of (bio)chemical processes in which the starter cultures provide the enzymes. Particularly the enzymatic degradation of proteins (caseins) leads to the formation of key-flavour components, which contribute to the sensory perception of dairy products. More specifically, caseins are degraded into peptides and amino acids and the latter are major precursors for volatile aroma compounds.

Identification, cloning, and characterization of a Lactococcus lactis branched-chain alpha-keto acid decarboxylase involved in flavor formation.

The biochemical pathway for formation of branched-chain aldehydes, which are important flavor compounds derived from proteins in fermented dairy products, consists of a protease, peptidases, a transaminase, and a branched-chain alpha-keto acid decarboxylase (KdcA). The activity of the latter enzyme has been found only in a limited number of Lactococcus lactis strains. By using a random mutagenesis approach, the gene encoding KdcA in L.

Chemical conversion of alpha-keto acids in relation to flavor formation in fermented foods.

Formation of flavor compounds from branched-chain alpha-keto acids in fermented foods such as cheese is believed to be mainly an enzymatic process, while the conversion of phenyl pyruvic acid, which is derived from phenylalanine, also proceeds chemically. In this research, the chemical conversion of alpha-keto acids to aldehydes with strong flavor characteristics was studied, with the main focus on the conversion of alpha-ketoisocaproic acid to the aldehyde 2-methylpropanal, and a manganese-catalyzed reaction mechanism is proposed for this conversion. The mechanism involves keto-enol tautomerism, enabling molecular oxygen to react with the beta-carbon atom of the alpha-keto acid, resulting in a peroxide.

Two-photon microscopy for imaging of the (atherosclerotic) vascular wall: a proof of concept study.

Background: Understanding atherogenesis will benefit significantly from simultaneous imaging, both ex vivo and in vivo, of structural and functional information at the (sub)cellular level within intact arteries. Due to limited penetration depth and loss of resolution with depth, intravital and confocal fluorescence microscopy are not suitable to study (sub)cellular details in arteries with wall thicknesses above 50 microm.

Methods: Using two-photon laser scanning microscopy (TPLSM), which combines 3D resolution and large penetration depth, we imaged mouse carotid arteries.