Effect Of Ginger (Zingiber Officinale) Additive As An Antimicrobial Agent On The Storage Quality Of Raw Beef

Abstract

This study was undertaken to investigate the antimicrobial effect of ginger when added to ground beef and its influence on the chemical properties of ground beef. Throughout storage period of 10 days ginger was added in two different forms, dry and ginger oil extract. Dry ginger was added at 3 different concentrations for each treatment 5, 15 and 25% (w/w). The ginger oil extract was also added at 3 different concentrations 1, 5 and 10% (v/w). One sample of ground beef was untreated and was kept as a control. The samples were stored at 4°C and the tests were done at interval time (0, 3, 5, 7 and 10 days) of storage. The pH value, moisture content, and free fatty acids were measured. For all treatments the microbiological attributes of ground beef were assayed; total count, lactic acid bacteria, E. coli, and Salmonella. The results showed that the samples treated with 5, 15 and 25% dry ginger reduced the moisture content of beef to 67.8, 54.6 and 48.4% respectively after the tenth day of storage. The results also showed that samples treated with 1, 5 and 10% ginger oil extract reduced the moisture content of beef to 69.3, 64.3 and 61.3% respectively after the tenth day of storage. The pH value of the samples treated with 5, 15 and 25 % dry ginger decreased to 5, 4.9 and 6.1 respectively at day 3 of storage and to 6, 6.3 and 7.2 respectively after the tenth day of storage .The samples treated with 1, 5 and 10 % ginger oil extract reduced the pH value of beef to 5.2 in all treatments at day 3 of the storage, and to 6.1, 6.3 and 6.5 after the tenth day of storage. The treating of samples with 5 and 15% dry ginger had no effect on the free fatty acid content of beef while the sample treated with 25% dry ginger caused reduction in free fatty acid to 0.9 % after the tenth day of storage, where as treatment with 1 and 5% ginger oil extract did not affect the free fatty acid content after the tenth day of storage. Samples treated with the higher concentration of 25% dry ginger and 10% ginger oil had the greatest effect on free fatty acid content than the other concentrations. However on the microbiological analysis the results show that ginger oil had greater effect on the bacterial count of ground beef than dry ginger after the tenth day of storage compared with the control. Ginger oil had greater effect on lactic acid bacteria than dry ginger after the tenth day of storage. Also ginger oil had greater effect in suppressing the growth of E. coli and Salmonella than dry ginger