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Summary: Our previous study found that glycation with uronic acid‐type reducing sugar enhanced the anti‐inflammatory effect of fish myofibrillar protein (Mf) via the Maillard reaction, and the molecular mechanism of enhanced anti‐inflammatory effect was investigated in this study. Mf was glycated with various reducing sugars at 60 °C and 35% relative humidity. After pepsin‐trypsin digestion, the anti‐inflammatory effects were evaluated by assessing secretions of pro‐inflammatory cytokines and expressions of LPS‐stimulated signalling pathway‐related genes in RAW 264.7 macrophages. Mf glycated with uronic acid‐type reducing sugars: glucuronic acid, galacturonic acid and alginate oligosaccharide, suppressed expression of cd14 and further suppressed expressions of tlr4 and myd88 comparing with intact and glycated Mf with glucose and galactose. Furthermore, uronic acid‐glycated Mf significantly suppressed expressions and secretions of pro‐inflammatory cytokines. The results indicate that uronic acid‐type glycation enhances anti‐inflammatory effect of Mf by attenuating expression of cd14 and enhancing the Mf‐induced suppression in TLR4‐MyD88‐dependent inflammatory signalling pathway. [ABSTRACT FROM AUTHOR]

A separation process was established to sequentially fractionate and recover three anti-inflammatory components derived from sugars, phycobiliprotein, and chlorophyll from the hot-air-dried thalli of the red alga dulse (Palmaria palmata). The developed process consisted of three steps, without the use of organic solvents. In Step I, the sugars were separated by disrupting the cell wall of the dried thalli with a polysaccharide-degrading enzyme, and a sugar-rich extract (E1) was obtained by precipitating the other components, which were simultaneously eluted by acid precipitation. In Step II, the residue suspension from Step I was digested with thermolysin to obtain phycobiliprotein-derived peptides (PPs), and a PP-rich extract (E2) was obtained by separating the other extracts using acid precipitation. In Step III, solubilized chlorophyll was obtained by heating the residue, which was acid-precipitated, neutralized, and re-dissolved to concentrate the chlorophyll-related components (Chls)-rich extract (E3). These three extracts suppressed inflammatory-cytokine secretion by lipopolysaccharide (LPS)-stimulated macrophages, confirming that the sequential procedure had no negative effects on the activities of any of the extracts. The E1, E2, and E3 were rich in sugars, PPs, and Chls, respectively, indicating that the anti-inflammatory components were effectively fractionated and recovered through the separation protocol. [ABSTRACT FROM AUTHOR]

To improve the antioxidant activity of collagen molecules using Maillard-type glycation, the relation between antioxidant activity and progress indexes for the Maillard reaction must be understood. In this study, lyophilized tilapia scale collagen was mixed with a half weight of alginate oligosaccharide (AO) or glucose and incubated at 60 °C and 35% relative humidity for up to 18 h to produce the Maillard-type glycated collagen (C-AO and C-Glu, respectively). As glycation progressed, the amount of conjugated sugar coupled with UV-vis absorbance at 294 nm and 420 nm increased more rapidly in C-Glu than in C-AO, and the available lysine decreased rapidly in C-Glu compared with C-AO. The early-to-middle- and late-stage products of the Maillard reaction were involved in enhanced antioxidant activity of digested C-AO and digested C-Glu, respectively. Additionally, C-AO acquired the antioxidant activity without marked available lysine loss. The cytoprotective effect of collagen in H2O2-induced damage was enhanced by glycation, achieved by reducing malondialdehyde content and increasing superoxide dismutase and catalase activities. These results indicate that AO is an excellent reducing sugar that enhances the health benefits of collagen without excessive loss of lysine, which is a nutritional problem of the Maillard-type glycation. [ABSTRACT FROM AUTHOR]

The most important part of good quality for surimi-based products is the ability of frozen surimi to form gel. Attempts have been made to make frozen surimi with chum salmon, a low-cost fish in abundant supply in the Pacific Northwest. A study was done of the gel-forming characteristics of chum salmon and the optimum conditioons for this process. With protease inhibitor, gels were formed at relatively low temperatures. Gel strength was highest at 50 and 60 degrees celsius. Chum salmon surimi revelaed no evidence of suwari and no myosin heavy chain cross-linking.

Alginate oligosaccharide (AO) was prepared using genetically modified E. coli and the production efficiency was compared with the purification from a culture medium of P. elyakovii. It was found that genetic recombinant technology for the production of alginate lyase could be used for the functional improvement of fish myofibrillar proteins by conjugation with AO.