Measuring the total microbial count of cow minced meat with the conventional method and comparing the result with standard limits is one of the routine tests. Achieving the results of total microbial count in minimum time is really important for confidence from the hygi More
Measuring the total microbial count of cow minced meat with the conventional method and comparing the result with standard limits is one of the routine tests. Achieving the results of total microbial count in minimum time is really important for confidence from the hygienic quality of products. So impedance- splitting method as a new technique for this purpose was considered in order to receive the results in less time and as soon as possible. The main purpose of the study was to evaluate the correlation between impedance detection times (IDT in hrs), total microbial population (log CFU/g), total volatile nitrogen (TVN) and pH of minced meat. Totally 80 minced meat samples were collected and examined for the total microbial count by reference and impedance - splitting methods, also total volatile nitrogen and pH were measured based on the recommendations of Iran's Standard Institute and Industrial Investigation. Then the calibration curves of methods and their equations were obtained by using Excel software. The calibration curves of methods were elaborated for total microbial count and impedance detection time, demonstrating a good correlation between the two methods in mince neat samples equal to %93/39. Also according to the calibration curves, the correlation between impedance detection time and total volatile nitrogen in all of the samples was equal to %69.8. Also, the correlation between total microbial count and pH was equal to %71/4. According to the aforementioned correlation values, the impedance technique could be only recommended as an alternative method in evaluating the microbial load of the minced meat.
Manuscript profile
Synthetic preservatives have been used as food additives to extend shelf life of foods, but they are strictly regulated due to toxicological concerns and some health problems. So it is increasingly attractive to find out effective and nontoxic measures (e.g. use of natu More
Synthetic preservatives have been used as food additives to extend shelf life of foods, but they are strictly regulated due to toxicological concerns and some health problems. So it is increasingly attractive to find out effective and nontoxic measures (e.g. use of natural antimicrobial agent) to delay microbial spoilage. Nisin is a bacteriocin that it is the only bacteriocin permitted for use in foods. And rosemary is one of the medicinal plants. In this study the effect of antibacterial property of various concentration of rosemary extract alone (3 and 4 mg/ml), and with nisin (7 µg/ml nisin + 1.5 mg/ml RE and 8 µg/ml nisin + 2 mg/ml RE) against Staphylococcus aureus in minced meat were assessed throughout 14 days of storage at 4±1˚C. Leaves and stems of rosemary after drying in the shade were soaking in pure ethanol and alcoholic extract was obtained. The minimum inhibitory concentration (MIC) of RE and nisin were determined against S. aureus using the agar dilution method. Assessment of microbial parameters (total plate count and S. aureus count) was carried out in 0, 1, 3, 7 and 14 days. The data were statistically significant (P<0.05). The results reveals that treatment with both concentrations of RE showed significantly lower microbial indexes in comparison with controls, but treatment with both preservative (nisin & RE) had better results and results were statistically significant (P<0.05). As a consequence, using of RE with nisin was better than of RE alone.
Manuscript profile
This study aimed to study the effect of tarragon and savory essential oils on the shelf life of minced beef. Appropriate concentrations of tarragon and savory essential oils were determined by sensory and microbial tests and mixed with minced beef. The treatment and con More
This study aimed to study the effect of tarragon and savory essential oils on the shelf life of minced beef. Appropriate concentrations of tarragon and savory essential oils were determined by sensory and microbial tests and mixed with minced beef. The treatment and control samples weighing about 100g were packaged in polyethylene containers and stretched films. Microbial, physicochemical and sensory assessments were performed on the samples every day for five days. The results showed that the trend of increasing aerobic mesophilic bacteria in control samples was significantly different (P <0.05) from the second day until the end of the five-day storage period. Similar results were observed for psychrotrophs and coliforms. From the day thee, the pH difference in the control and treatment groups was significant (P <0.05). Peroxide value, total volatile nitrogen content as well as sensory properties of tarragon and savory treatments had almost similar results. Nonetheless, from the third to the fifth day there was a significant difference (P <0.05) between the control and treatment groups. It seems that the use of tarragon and savory essential oils can retain the population of spoilage bacteria below the allowable level, for up to four and five days, respectively. It was concluded that tarragon and savory essential oils can be used as natural antimicrobial/antioxidants to improve the sensory properties of minced meat.
Manuscript profile
Sanad
Sanad is a platform for managing Azad University publications
