الملخص الإنجليزي
Traditionally meat is dried in the sun in many regions of the Sultanate of Oman. A range of meals is prepared using dried beef, camel, and goat meats. Humid seasons and other weather conditions may cause deterioration of the meat product before consumption. In this study, thirty longissimus dorsi (LD) muscles from Omani male goats were dried by five methods (sun, air, vacuum, freeze and modified atmosphere drying) in order to assess the quality and safety of dried meat. Samples of dried strips from the longissimus dorsi were evaluated for microbial and physico chemical characteristics in order to assess the quality.
Microbial determinations included total aerobic plate count, Staphylococcus aureus, Pseudomonas and identification of moulds. Whereas physico-chemical properties were characterised by PH, expressed juice, peroxide values (PV), colour L*, a*, b* values and fatty acids composition. The different methods of drying had a significant effect on microbial and physico-chemical features of dried meat. Aerobic plate count findings showed a significant difference between the fresh and the different dried samples, Compared to other drying methods, sun dying had least effect on the aerobic plate count.
The level of aerobic plate count of sun-dried samples remained significantly higher (p<0.05) than the level on dried samples using other techniques. There was no significant difference (p>0.05) between air-drying, vacuum drying, and freeze-drying on the aerobic plate count. After six weeks of storage, no significant difference (p>0.05) was found between vacuum drying, freeze-drying, and MA drying. Pseudomonas spp. were sensitive to sun drying as their number significantly (p<0.05) decreased by approximately 1000-fold immediately after drying. A significant (p<0.05) count reduction by a factor of about 10", was found with air, vacuum and freeze-drying methods. However, after six weeks of storage, there was an increase in the level of Pseudomonas, with the sun drying, but not with other drying techniques (including modified atmosphere drying). However, this increase is not significant (p>0.05).
Staphylococci were particularly resistant to sun drying; their numbers increased significantly (p<0.05) from 1.1 x 103 to 7.9 x 107 cfu.g?. When comparing dried and fresh samples, a significant (p<0.05) difference, except for the air-dried samples, was found. Interestingly following six weeks of storage, the sun dried samples showed a significant difference (p<0.05) compared to the other dried samples. Moreover, there was no significant difference (p>0.05) between air-drying, vacuum drying, freeze drying and modified atmosphere on the Staphylococcus spp. count.
This study indicates that Penicillium spp., Cladosporium spp., and Aspergilllus
samples and they survived the drying processes. Quality attribute values, such as expressed juice and pH were significantly affected by the drying methods. The freeze-dried muscle sample showed the lowest pH (p<0.05), and the highest expressed juice (p<0.05). Regarding the PV results, freeze-drying gave the highest value, while air-drying gave the lowest value and no
ant difference between sun drying and MA drying was observed. Finally, the findings of this study have practical importance to the meat industry in developing dried meat products using different drying methods.
