Laminaria digitata phlorotannins decrease protein degradation and methanogenesis during in vitro ruminal fermentation.

Background: Phlorotannins (PhTs) are marine tannins consisting of phloroglucinol subunits connected via carbon-carbon and ether linkages. These have non-covalent protein binding properties and are, therefore, expected to be beneficial in protecting protein from hydrolysis during ruminal fermentation. In this study, the effectiveness of a methanolic PhTs extract from Laminaria digitata (10, 20, 40, 50, 75 and 100 g kg tannin-free grass silage, with or without addition of polyethylene glycol (PEG), was investigated in vitro on protection of dietary protein and reduction of methane (CH ) in ruminal fluid.

Resolubilization of Protein from Water-Insoluble Phlorotannin-Protein Complexes upon Acidification.

Marine phlorotannins (PhT) from Laminaria digitata might protect feed proteins from ruminal digestion by formation of insoluble non-covalent tannin-protein complexes at rumen pH (6-7). Formation and disintegration of PhT-protein complexes was studied with β-casein (random coil) and bovine serum albumin (BSA, globular) at various pH. PhT had similar binding affinity for β-casein and BSA as pentagalloyl glucose, as studied by fluorescence quenching.

Phlorotannin Composition of Laminaria digitata.

Introduction: Phlorotannins are complex mixtures of phloroglucinol oligomers connected via C-C (fucols) or C-O-C (phlorethols) linkages. Their uniformity in subunits and large molecular weight hamper their structural analysis. Despite its commercial relevance for alginate extraction, phlorotannins in Laminaria digitata have not been studied.

Enzymatic Browning in Sugar Beet Leaves (Beta vulgaris L.): Influence of Caffeic Acid Derivatives, Oxidative Coupling, and Coupled Oxidation.

Sugar beet (Beta vulgaris L.) leaves of 8 month (8) plants showed more enzymatic browning than those of 3 month (3). Total phenolic content increased from 4.

Effect of Plant Age on the Quantity and Quality of Proteins Extracted from Sugar Beet (Beta vulgaris L.) Leaves.

Effects of the developmental stage (e.g., young, mature, or senescent) of leaves on their chemical composition have been described in the literature.