Search

The nutritional components of Spirulina residue were determined and evaluated. The insoluble dietary fiber was prepared by alkaline acid treatment from algae residue. The swelling capacity, water holding capacity and grease holding capacity were determined. Insoluble dietary fiber was obtained from Spirulina residue after extraction of phycobiliprotein by alkali acid treatment. Its swelling capacity, water retention capacity and oil retention capacity were measured. The adsorption capacity of dietary fiber for sodium cholate and NO2– was studied. The adsorption capacity of sodium cholic acid and NO2- by dietary fiber was researched. The results indicated that algae residue was rich in nutrients, mainly including protein, carbohydrate and water. The content of phosphorus, magnesium and calcium in minerals was the highest. Algae residue was rich in essential amino acids (lysine, valine, leucine and isoleucine) and non essential amino acids (arginine, glutamine and glutamate). The insoluble dietary fiber had a certain water holding capacity, grease holding capacity and swelling capacity, and the adsorption capacity of sodium cholic acid was relatively obvious. In the simulated human gastric fluid environment of pH=2, it had better adsorption on NO2–. This study results will provide a basis for the high value utilization of Spirulina residue.

Objective: Collagen was extracted from the skin of Micropterus salmoides and used to explore the effect of enzyme types on the antioxidant activity of collagen peptides. Methods: Four kinds of enzymes were used, namely alkaline protease, neutral protease, papain and trypsin. The enzymatic hydrolysis of collagen Alkaline protease enzymatically hydrolyze collagen peptide （APP）, Neutral protease enzymatically hydrolyze collagen peptide （NPP）, Papain enzymatically hydrolyze collagen peptide（PP）, Trypsin hydrolysis of collagen peptide（TP）, were obtained and compared their total antioxidant activity, including reducing activity, DPPH, ·OH and O-2·free radical scavenging ability, ferrous ion chelating ability and lipid Oxidation inhibitory activity. Results: Four kinds of proteases enzymatically hydrolyze collagen peptides all have antioxidant activity, and the antioxidant capacity was positively correlated with the concentration of collagen peptides. Among them, APP has the best antioxidant activity. The total antioxidant activity and reducing activity respectively were 1.725 and 0.958, and the scavenging rates for DPPH and O-2·radical respectively were 56.35% and 38.41%, respectively. Conclusion: The collagen peptides hydrolyzed by alkaline protease have better antioxidant activity.

Background: When Angiostrongylus cantonensis develops from the third and fourth stage, it needs to change its host from the middle host, snail to the final host, rat. However, the mechanism involved in this change remains unclear., Methods: The transcriptome differences of the third and fourth stages of A. cantonensis were explored by next-generation Illumina Hiseq/Miseq sequencing in China, in 2018., Results: Overall, 137 956 488 clean reads and 20 406 213 373 clean bases of the two stages larvae were produced. Based on the queries against the Gene Ontology (GO), NCBI non-redundant protein sequences (Nr), Swissprot, and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, 14 204 differentially expressed genes (DEGs) were predicted. GO enrichment analysis revealed 5660 DEGs with the top s categories as followings: biological process (GO:0008150, related to 5345 DEGs), cellular component (GO:0005575, related to 5297 DEGs), molecular function (GO:0003674, related to 5290 DEGs). In KEGG enrichment analysis, 116 genes were related to oxidative phosphorylation and 49 genes involved in the glycolytic process., Conclusion: Metabolism changes, especially oxidative phosphorylation and glycolysis, might play a key role in A. cantonensis infection of its final rat host. Many other pathways might also contribute to the transcriptome changes between these two life stages. Overall, additional studies are needed for further details., Competing Interests: Conflict of interest The authors declare that there is no conflict of interest., (Copyright © 2020 Guo et al. Published by Tehran University of Medical Sciences.)