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Treatment of Beluga, Huso huso, with ß-naphthoflavone increased liver microsomal cytochrome P450 and 7-ethoxyresorufin Odealkylation. ß-naphthoflavone treatment caused a 15-26 fold increase in 7-ethoxyresorufin O-deethylase (7-EROD) activity of beluga liver microsomes. Cytochrome P4501A1 was purified from the liver microsomes of beluga which was collected at the Shahid Behshti Center, Rasht. Purification of cytochrome P4501A1 involved anion exchange chromatography of Emulgen LS114 and cholate solubilized microsomes on DEAE-sepharose fast flow columns. The major fraction, cytochrome P4501A1 was further purified by polyethylene glycol and gel filteration on sephacryl S-200 column. Cytochrome P4501A1, purified 16-fold with a specific content of 8.89 nmoles P450 per mg protein, produced a single band on SDS-polyacrylamide gel electrophoresis having monomer molecular weight of 58±1 KDa. The beluga P450 hemoprotein showed an absorption maximum at 477nm in CO-difference spectrum and a strong immunoreactivity with Mab anti cod P4501A1.

BACKGROUND This study was aimed to synthesize polymeric chitosan nanoparticles (CSNPs) from Macrobrachium nipponense shells using sodium triphosphate (TPP) as a crosslinker that was incorporated with spirulina extract (SPE) to improve the shelf life of pike‐perch during refrigerated storage (4 °C). RESULTS The encapsulation efficiency (EE) of SPE‐loaded CSNPs decreased from 67% to 32%, and loading capacity (LC) was increased (10–14%) depending on their loaded SPE concentrations. The initial burst effect, followed by a slow‐release at pH 7 (24 h), was observed. Free SPE and SPE incorporated CSNPs decreased microbial counts (total viable count, total psychotropic count, pseudomonas, and lactic acid bacteria) compared to control and unloaded CSNPs. Samples treated with free SPE or SPE‐loaded CSNPs showed higher changes in odor, color, TVB‐N (total volatile basic nitrogen), and TBA (thiobarbituric acid) compared with the unloaded CSNPs batch (P ≤ 0.05) until the tenth day of storage. However, fish fillets coated with SPE‐loaded CSNPs had the highest overall consumer acceptability and the lowest values for TVB‐N and TBA at the end of storage (14th day). Controlled release of bioactive compounds in batches treated with SPE‐CSNPs could delay the microbial degradation and enhance chemical reactions (TBA and TVB‐N) in comparison to pure SPE during storage time. CONCLUSION The incorporation of SPE in polymeric CSNPs can be considered as a promising material for controlled delivery of natural bioactive agents, and preservation of Pike perch quality during refrigerator storage. © 2022 Society of Chemical Industry.