MICROBIAL ASPECTS OF LAMB MEAT TREATED WITH LACTIC AND ACETIC ACIDS

The present study was carried out to assess the ability of organic acids to improve the quality of fresh lamb meat chilled at 7 ْC for 24, 48, 72 hours, 7& 14 day and freezed at -18 ْC after treatment with organic acids (lactic and acetic 1&2%) which resulted in significant improvement of nearly all parameters over the control of 25 samples from different lamb carcasses. Such treatments exerted a significant antibacterial effect which is of public heath importance and prolong the shelf life of carcasses on trial. The pH value revealed highest record at 14 day chilling. The organic acids revealed dramatic effects as antimicrobial agent. The total aerobic bacterial count revealed reciprocal reduction percent 70.87, 64.09, 71.07 and 60.54% in chilling for 7 day after treatment with 1&2% lactic and acetic acid respectively. The reciprocal reduction percents were 62.37 to 62.S3% and 57.96 and 57.38% in 1& 2% lactic and acetic acids. On applying the psychrophilic bacteria the reciprocal reduction percent means at the 7th day of chilling were 49.54, 73.33, 53.36 and 38.04% respectively with same acids treatments .On apply freezing for one month the reduction values reciprocal to the means were 29.41, 15.00, 26.71 and 15.88% respectively. The lowest records of total coliform counts were shown on the 7th day chilling. The reciprocal reduction percent of means were 73.65, 65.04, 77.84 and 68.59. After month of freezing the corresponding reductions were 53.51, 45.51. 63.72 and 45% with acid treatments respectively. The reduction percent of total Enterobacteriaceae counts of the means were 68.06, 62.24, 71.81and 64.77% after 7 days of chilling lamb meat post acid treatment. Salmonella count revealed means zero after 7, 14 day of chilling lamb meat; also, means were zero after freezing for month post acids treatments. Staphylococcus aureus count: revealed highest reduction at the 7th day post chilling and the reciprocal reductions were 42.86, 60.53, 59.46 and 33.33% respectively. Total mould and yeast count showed reduction percents of 56.74, 52.07, 52.94 and 39.02% after 72 hour of treated chilled lamb meat. After freezing, reduction percents were 26.97, 29.75, 16.99% in lactic acid 1, 2% and acetic acid 1% where count increased in acetic acid 2%. The means of Proteolytic bacterial count reduced to 13.49, 42.26, 22.99 and 38.65% in 1, 2% lactic acid and 1 & 2% acetic acid treated lamb carcasses. The lipolytic bacterial count reductions were 32.86, 59.37, 31.86 and 60.88% respectively. Coliforms were detected in lower incidence in the treated sample including E.coli, Enterobacter spp, Khlebsiella spp., Edwardesiella tarda and Serratea rubidea. The acid treatment lower the occurrence of coliform where 2% concentration was more efficient than 1% The same results were detected in identified Staphylococcus aureus and Salmonella enteritidis in addition to the identified moulds