31 research outputs found
Lactose hydrolysis potential and thermal stability of commercial β-galactosidase in UHT and skimmed milk
Biogenic amines formation in Bigeye tuna steaks and whole Skipjack tuna
Putrescine, cadaverine and histamine formation was monitored in fresh and frozen/thawed Bigeye tuna steaks (Thunnus obesus) and whole Skipjack (Katsuwonus pelamis) stored at room temperature and in ice and to determine the potential use of putrescine and cadaverine as indicators of decomposition. While all biogenic amines were formed during both storage conditions, putrescine was formed at a much lower rate and concentration. For both storage conditions and species, cadaverine appeared prior to and/or accumulated at a faster rate than histamine. Skipjack tuna had a faster accumulation of cadaverine than Bigeye under the same storage conditions. The results indicated that cadaverine, either alone or with histamine, could be used as an index of decomposition for Skipjack and Bigeye tuna
Quality Assessment of Filtered Smoked Yellowfin Tuna (\u3ci\u3eThunnus albacares\u3c/i\u3e) Steaks
Filtered smoke (FS) has been used to preserve taste, texture, and/or color in tuna and other fish species. This treatment is particularly important in color preservation during frozen storage. The objective of this study was to compare changes in the quality profiles of FS-treated and untreated (UT) yellowfin tuna (Thunnus albacares) steaks stored in 3 ways: room temperature (21 to 22 °C), refrigerated (4 to 5 °C), and iced (0 °C). FS and UT steaks were processed from the same lot of fish and analyzed for chemical, microbiological, lipid oxidation, color, and sensory profiles. Similar trends were seen for microbial proliferation and accumulation of apparent ammonia and total volatile base nitrogen (TVB-N) during the storage temperatures evaluated. Notable exception in quality profile was found in lipid oxidation which was, as expected, lower for treated samples at all storage temperatures for TBARS (P \u3c 0.05) and lower or significantly (P \u3c 0.05) lower for POV values. FS increased the initial redness value significantly (P \u3c 0.05). Unlike UT product, there was no loss of color value concomitant with quality changes for FS-treated tuna for all storage temperatures evaluated
Impact of quality parameters on the recovery of putrescine and cadaverine in fish using methanol-hydrochloric acid solvent extraction
Methanol (MeOH) extraction by AOAC Official MethodSM 996.07 has resulted in low amine recoveries in fresh fish tissue. Addition of 25% 0.4 M HCl to the 75% methanol- water extraction solvent resulted in higher recoveries of putrescine and cadaverine. Average putrescine recovery increased from 55 to 92% in flounder, scup, bluefish, and salmon; from 92 to 98% in mackerel; and from 83 to 107% in processed mackerel. Average cadaverine recovery increased from 57 to 95% in flounder, scup, bluefish, and salmon; from 91 to 97% in mackerel; and from 92 to 108% in processed mackerel. Fish stored on ice for 12 days also showed differences between background concentrations determined with the two solvents. However, the values decreased with storage time, indicating that degradation of the protein matrix may cause more comparable measurements between the two solvents. However, consistently higher putrescine and cadaverine measurements were determined using MeOH-HCl. Although significant differences in the extraction of amines from the high-fat fish tissue were not seen between MeOH and MeOH-HCl, it would be ideal to have one solvent for biogenic amine extraction. This study confirms that MeOH-HCl is a better solvent for complete extraction and recovery of putrescine and cadaverine in fresh and processed fish tissues. © 2012 Publishing Technology
Antimicrobial activity of 1% cetylpyridinium chloride against listeria spp. on fish
Cetylpyridinium chloride (CPC) was evaluated as an antimicrobial against Listeria monocytogenes (LM) and Listeria innocua (LI) on fish. LI and LM showed the same reduction profile and the same minimum inhibitory and bactericidal concentrations. When CPC was applied to a diced fish matrix, reductions of 3.17-3.26 and 3.07-3.19 log were determined for LI and LM, respectively. Antimicrobial activity of CPC against LI resulted in initial reductions of 2.8-3.1 log in fresh fish fillets, 0.9-1.1 log in smoked fish fillets, and 3.2-3.4 log on fish skin. Effectiveness of CPC against total plate counts on fish skin showed reductions of 2.4-2.9 log. Copyright © Taylor & Francis Group, LLC
Diabetes risk status and physical activity in pregnancy: U.S. BRFSS 2011, 2013, 2015, 2017
Background: Pregnant women without complications are advised to engage in physical activity (PA) to mitigate adverse outcomes. Differences may exist among pregnant women of diverging diabetes status in meeting national PA recommendations. We sought to examine differences in aerobic activity (AA) and muscle strengthening activity (MSA) by diabetes risk status (DRS) among pregnant women in the United States. Methods: The sample (n = 9,597) included pregnant women, age 18–44 years, who participated in the 2011, 2013, 2015, and 2017 Behavioral Risk Factor Surveillance System. Levels of DRS include: no diabetes (ND), high risk for diabetes (HRD) due to self-reported gestational diabetes or pre-diabetes, and overt diabetes due to self-reported, clinically diagnosed diabetes (DM). Odds ratios (ORs) and 95% confidence intervals (CI) for meeting PA recommendations were obtained. Covariates included age, race, education, household child count, alcohol consumption, and smoking status. Results: Findings revealed that on average, DM had 46.5 fewer minutes of weekly AA compared to ND. Furthermore, a significantly lower OR (0.39; CI 0.19–0.82) for meeting both recommendations was observed in DM as compared to ND after adjustment. Conclusions: We observed that pregnant women with overt diabetes had a lower odds of engaging in PA, while those at high risk were similar in their PA engagement to ND. Future studies aimed at assessing determinants of PA behavior may help guide efforts to promote exercise in pregnant women with diabetes