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Incorporation of polysaccharide-based nanofillers is an effective strategy to fabricate bio-nanocomposite films with preferable mechanical, barrier, and surface hydrophobicity properties compared to pure biopolymer films. The objective of this research is to investigate the influence of starch nanocrystals obtained from native (NSNC) and waxy rice starch (WSNC) on the physical-chemical properties of pullulan-based nanocomposite films and their preservation performance on fresh beef.Continuous SNCs network structure was observed for pullulan-10% SNCs nanocomposite films, whereas the percolation network of SNCs was destroyed and became no longer continuous with increasing SNCs concentration up to 20% in pullulan films. Among the tested films, pullulan-10% SNCs films showed the highest TS values, lowest WVP and OTR values, due to the formation of percolating SNCs network in pullulan matrix. It is noteworthy that the WVP and OTR values of pullulan-10% WSNC films were significantly lower than that of pullulan-10% NSNC films, probably due to higher hydrophobicity and crystallinity of WSNC compared with NSNC. Beef pieces coated with pullulan-SNCs films had higher LPullulan-SNCs nanocomposite films, especially pullulan-WSNC films, could be potentially used as a coating material for fresh beef due to their desirable oxygen and water barrier properties. © 2022 Society of Chemical Industry.

BACKGROUND Steam explosion is increasingly being used in the food processing industry as an efficient pretreatment technology. It is currently being used to pretreat adzuki beans at a pressure of 0.25-1.0 Mpa for 30 s and 90 s. In this study, the total polyphenol (TP) content in adzuki beans, including free polyphenols (FP) and bound polyphenols (BP), and their antioxidant activity, were determined after steam explosion treatment. RESULTS The results showed that steam explosion can form large cavities and intercellular spaces, which aid the release of polyphenols. After steam explosion, the FP, BP, and TP content increased. The antioxidant capacity of FP and BP also increased, which demonstrated that there was a positive correlation between the polyphenol content and antioxidant capacity. Compounds of FP and BP were further identified by high-performance liquid chromatography (HPLC). Protocatechin was the main ingredient in FP and BP, and protocatechin was higher in FP. Isoquercetin only exists in FP, and caffeic acid only in BP. After steam explosion, an increase in the protocatechin, catechin, and epicatechin content was detected in FP and BP. The phenolic compound and antioxidant capacity yield was increased at a pressure of 0.25-0.75 Mpa, however it decreased at 1.0 Mpa. A pressure of 0.75 Mpa for 90 s is the optimal condition for polyphenol separation in adzuki beans. CONCLUSION A proper and reasonable steam explosion can effectively increase the release of phenolics and enhance the antioxidant capacity in adzuki beans. © 2020 Society of Chemical Industry.

BACKGROUND Plant polyphenols are rich in blueberries that have a wide range of properties beneficial to human health. There are two types, according to the solubility of polyphenols, which were defined as extractable polyphenols (EPP) and non-extractable polyphenols (NEPP), respectively. At present, in most of reports, ‘total polyphenol’ refers only to EPP excluding NEPP. In this paper, the effects of EPP and NEPP on lipopolysaccharides (LPS) induced production of nitric oxide (NO) and gene expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in RAW264.7 cells via nuclear factor-κB (NF-κB) signalling pathway were compared. RESULTS The results showed that EPP and NEPP from blueberries significantly inhibited the LPS-induced production of NO and gene expression of iNOS and COX-2 in cells. The constitutive level of p65 sub-unit of NF-κB was obviously detected after the treatments with EPP or NEPP. By contrast, the level of phosphorylated p65 (P-p65) was strongly inhibited by EPP or NEPP. EPP had a stronger inhibition on the gene expression of iNOS and COX-2 than that of NEPP. CONCLUSION These findings of inhibition of iNOS and COX-2 mRNA expression through the suppression of NF-κB suggest that EPP and ENPP from blueberries have significant anti-inflammatory effect and may be a potential medicine. © 2015 Society of Chemical Industry

Plant polyphenols are rich in blueberries that have a wide range of properties beneficial to human health. There are two types, according to the solubility of polyphenols, which were defined as extractable polyphenols (EPP) and non-extractable polyphenols (NEPP), respectively. At present, in most of reports, 'total polyphenol' refers only to EPP excluding NEPP. In this paper, the effects of EPP and NEPP on lipopolysaccharides (LPS) induced production of nitric oxide (NO) and gene expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in RAW264.7 cells via nuclear factor-κB (NF-κB) signalling pathway were compared.The results showed that EPP and NEPP from blueberries significantly inhibited the LPS-induced production of NO and gene expression of iNOS and COX-2 in cells. The constitutive level of p65 sub-unit of NF-κB was obviously detected after the treatments with EPP or NEPP. By contrast, the level of phosphorylated p65 (P-p65) was strongly inhibited by EPP or NEPP. EPP had a stronger inhibition on the gene expression of iNOS and COX-2 than that of NEPP.These findings of inhibition of iNOS and COX-2 mRNA expression through the suppression of NF-κB suggest that EPP and ENPP from blueberries have significant anti-inflammatory effect and may be a potential medicine. © 2015 Society of Chemical Industry.