The effects of modified atmosphere and vacuum packaging on quality of chub mackerel

Quality and shelf life of filleted chub mackerel packaged in air, vacuum (VP) and modified atmosphere packing (MAP) (O-2/CO2/N-2, 5%/70%/25%) conditions and stored at +4 degrees C were investigated by measurement of sensory, chemical and microbiological analyses. Acceptability scores for odour, taste and texture of cooked air packaged, VP and MAP chub mackerel decreased with storage time. The sensory scores of chub mackerel stored in air, VP and MAP at +4 degrees C were 10 and 12 days, respectively. Total volatile basic nitrogen and trimethylamine nitrogen values gave acceptable results for up to 9 days for the chub mackerel stored in air, VP and 11 days for MAP storage. VP fillets presented the lowest thiobarbituric acid values. Mesophilic counts for air-VP and MAP samples exceeded 6 log CFU g(-1) after 7 and 11 days of cold storage, respectively. The results obtained from this study showed that the shelf life of chub mackerel stored in cold storage (+4 degrees C), as determined by overall acceptability of all data, is 9 days for air-packaged and VP fish and 12 days for MAP fish

Kinase Targets for Mycolic Acid Biosynthesis in Mycobacterium tuberculosis.

Mycolic acids (MAs) are the characteristic, integral building blocks for the mycomembrane belonging to the insidious bacterial pathogen Mycobacterium tuberculosis (M.tb). These C60-C90 long a-alkyl-ß-hydroxylated fatty acids provide protection to the tubercule bacilli against the outside threats, thus allowing its survival, virulence and resistance to the current antibacterial agents. In the post-genomic era, progress has been made towards understanding the crucial enzymatic machineries involved in the biosynthesis of MAs in M.tb in which two discrete fatty acid synthases systems (FAS-I and FAS-II) were discovered. However, gaps still remain in the exact role of the phosphorylation and dephosphorylation regulatory mechanisms within these systems. To date, a total of 11 serine-threonine protein kinases (STPKs) are found in M.tb. Most enzymes implicated in the MAs synthesis were found to be phosphorylated in vitro and/or in vivo. For instance, phosphorylation of KasA, KasB, mtFabH, HadAB/BC, InhA, MabA, FadD32 and PcA downregulated their enzymatic activity, while phosphorylation of VirS increased its enzymatic activity. These observations suggest that the kinases and phosphatases system could play a role in M.tb adaptive responses and survival mechanisms in the human host. As the mycobacterial STPKs do not share a high sequence homology to the human's, there has been some early drug discovery efforts towards developing potent and selective inhibitors as novel antitubercular agents. Recent updates to the kinases and phosphatases involved in the regulation of MAs biosynthesis will be presented in this minireview, including their known small molecule inhibitors