Search

In this study, effects of red (Palisada perforata and Gracilaria corticata), brown (Sargassum angustifolium and Polyclada indica) and green (Ulva compressa and Caulerpa taxifolia) Persian Gulf seaweed extracts on thermal kinetic parameters of black cumin (Nigella sativa) oil was investigated in comparison with those of BHT and α-tocopherol. Oxidative stability of black cumin oil samples were investigated using Rancimat at 363, 383, and 403 K. Apart from P. indica extract, all other seaweed extracts were effective on improving oxidative stability indices of black cumin oil samples. Red seaweed extracts were the most effective in reducing the severity of temperature-related effects on black cumin oil oxidation rate. In addition, these antioxidants were able to reduce black cumin oil oxidation by forming an activated complex with more structured configuration. The extent of decrease in frequency factor and entropy were 80.77% and 14.83% for G. corticata extract, respectively and also 82.66% and 15.45% for P. perforata extract, respectively. The highest increase in Gibbs free-energy of activation was observed for G. corticata extract followed by BHT, P. perforata extract, and α-tocopherol. In conclusion, red seaweed extracts can be proposed as suitable sources of natural antioxidants for improving oxidation kinetic of black cumin oil. [ABSTRACT FROM AUTHOR]

Mayonnaise is one of the most commonly used sauces all over the world but it is vulnerable to oxidation because of its high oil content. Using natural antioxidants instead of synthetic ones is a popular and promising topic in the food industry. The aim of this study was to increase the oxidative stability of mayonnaise using cold-pressed black cumin oil (BCO), which has high antioxidant activity due to its phenolic content. Four different mayonnaise formulations were used: Mayo-Control, Mayo-5% BCO, Mayo-10% BCO, and Mayo-20% BCO, which refer to a 0 (control), 5, 10, and 20% BCO replacement of total sunflower oil content, respectively. Thymoquinone content of the mayonnaises including BCO increased with the increasing BCO ratios. At the end of the storage for 4 weeks at 20 °C, peroxide values of Mayo-Control, Mayo-5% BCO, Mayo-10% BCO, and Mayo-20% BCO samples were recorded as 36.07 ± 1.51, 26.76 ± 0.67, 25.60 ± 0.57, and 17.66 ± 1.93 meq O2/kg oil, respectively. The conjugated diene and triene values of the mayonnaises prepared by adding BCO were lower than those of the control group during storage. Overall acceptability of Mayo-5% BCO in sensory analysis was higher than that of Mayo-Control. Using BCO in mayonnaise improved its oxidative stability and flavor. [ABSTRACT FROM AUTHOR]

The control of pathogenic bacteria and oxidative factors is important to keep microbiological and physicochemical traits of meat products. In this study, cold-pressed black cumin seed oil (BCSO) was incorporated (at levels of 1, 2, and 4%, w/w) into ground beef meat (GBM) to test the antimicrobial activity of BCSO on the growth inhibition of food-borne pathogens ( Listeria monocytogenes Scott A and Salmonella Enteritidis PT4) artificially inoculated (~4.5 log CFU/g) in air-packed GBM during storage at 4 °C for 15 days. BCSO was analyzed for fatty acids, sterols, tocopherols, and thymoquinone using gas chromatography and high-performance liquid chromatography. BCSO induced higher inhibition zone (15-17 mm) against both pathogenic bacteria as compared with the control. The BCSO supplementation retarded the total bacterial count, while the food-borne pathogens were unable to grow in BCSO-supplemented GBM during cold storage for 15 days. After 15 days, S. Enteritidis PT4 was more resistant than L. monocytogenes Scott A in GBM supplemented with 4% BCSO. In general, the shelf life of BCSO-supplemented GBM was extended under refrigerated conditions with low microbial loads. BCSO-supplemented GBM also improved oxidative stability and sodium dodecyl sulfate polyacrylamide gel electrophoresis profile. [ABSTRACT FROM AUTHOR]