Search

ABSTRACTThe effects of atmospheric pressure plasma jet (APPJ) treatment on the physicochemical and conformational properties of myofibrillar protein (MP) isolated from mandarin fish. The findings revealed that after exposing MP to APPJ for 0–12 s, there was a significant (P

During the processing of the large yellow croaker, the further utilization of the by-products (e.g., the liver) generated in the processing process can provide opportunities for value addition and increase profitability, promoting the sustainable use of raw materials. Therefore, we have studied the detailed nutritional composition of the large yellow croaker liver (LYCL), which ultimately helps in the development of nutritional and functional products. The results showed that the LYCL has a lower moisture content (45.71%) than fish meat, 8.25% protein, and 37.97% fats. In addition, LYCL contained the full range of amino acids. Unsaturated fatty acids accounted for 62.63%, of which EPA and DHA account for 9.42%. It was rich in phospholipids, vitamins and trace elements. Heavy metal elements such as Hg, As, Cd were lower than the heavy metal limit standards for fish in China. Aldehydes, ketones and alcohols in the liver have the greatest impact on odor.

In order to evaluate the relationship between of endogenous enzymes and physiochemical indicators during the processing of dry-salted Decapterus maruadsi produced by the traditional method. The evolution of the endogenous enzymes (cathepsin B, cathepsin L, cathepsin H, acid lipase, neutral lipase, and phospholipase) and physical and chemical parameters (moisture content, salt content and pH) of dry-salted Decapterus maruadsi during processing were investigated. Principal component analysis and Pearson correlation coefficient analysis were used to explore the main factors influencing the endogenous enzyme activity and the interactions between endogenous enzymes. The following results were observed during the processing of dry-salted Decapterus maruadsi: the salt content could stimulate cathepsin (L and B) activity and inhibit lipase activity; a lower moisture content could inhibit lipase activity, while the inhibitory effect on cathepsin was inconspicuous; pH had a minor influence on the endogenous enzyme activities; cathepsin B and L could partially inhibit lipase activity.

Pinctada fucata muscles were hydrolysed by alcalase and filtered using ultrafiltration membranes to obtain peptides with molecular weights (MWs) less than 5 kDa. The percolate was then freeze-dried and named crude antioxidant peptides mixture from Pinctada fucata muscles (AOP). In this study, AOP was purified sequentially using sephadex gel chromatography, next reversed-phase high-performance liquid chromatography. The MW of the antioxidant peptide from P. fucata muscle was 1039.56 Da. The amino acid sequence was Gly–Ala–Gly–Leu–Pro–Gly–Lys–Arg–Glu–Arg based on matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF). The natural peptide exhibits good scavenging capacity against free radicals; the IC50 of scavenging 2,2-diphenyl-1-picrylhydrazyl and ∙OH of FC2 were closer to vitamin C and butylated hydroxytoluence; however, the IC50 values of $$ \cdot {\rm{O}}_2^ - $$ of FC2 were a bit poor. Its antioxidant activity was attributed to the hydrophobic amino acid residues enriched in the N-terminal and electrophilic ability mediated by Glu and electron acceptors such as Lys and Arg. The synthesized peptide exhibited a reduced ability to scavenge free radicals compared to the natural peptide. The proposed method is a feasible technique to prepare antioxidant peptides from P. fucata and could be useful to obtain ingredients in nutraceutical and cosmetic applications.

ABSTRACT In this study, POU1F1 gene polymorphism was detected in five sheep populations (large-tailed Han, small-tailed Han, Yuxi fat-tailed, Lanzhou large-tailed, and Mongolian sheep), using DNA pooling and sequencing, to provide theoretical basis for the breeding of excellent sheep varieties. Three single-nucleotide polymorphism (SNP) loci of POU1F1 gene were detected in five sheep populations, namely C355T (C/T), C71G (C/G), and C330G (C/G). C and T frequencies of C355T were 0.67/0.33, 0.81/0.19, 0.67/0.33, 1.00/0.00, and 0.93/0.07, respectively, in large-tailed Han, small-tailed Han, Yuxi fat-tailed, Mongolian, and Lanzhou large-tailed sheep. C of C355T locus was the dominant allele in five sheep populations. C and G allele frequencies of C330G locus were detected in Yuxi fat-tailed sheep; their frequencies were 0.75 and 0.25, respectively. C and G allele of C71G locus were only detected in Yuxi fat-tailed and large-tailed Han sheep; their frequencies were 0.87/0.13 and 0.87/0.13, respectively. The cluster analysis based on POU1F1 gene sequence showed that bactrian camel, dromedary, and wild camel clustered first, and dolphin and killer whales clustered according to taxonomy. Although the four species Tibetan antelope, buffalo, goat, and sheep were alone, they got close and the relative genetic relationship was intimate according to the dendrogram. The mutation site analysis of the POU1F1 gene in five sheep populations in this study would be favorable for uncovering the function of POU1F1 gene deeply.