Food Biotechnology
Amir Shafiee Dastgherdy; Hamdollah Moshtaghi; Mojtaba Bonyadian
Abstract
IntroductionMicrobial safety and quality of raw animal products, particularly chicken meat, are among the critical concerns in the food production and distribution chain. Chicken meat holds a significant place in the dietary patterns of many populations due to its high nutritional value, easy accessibility, ...
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IntroductionMicrobial safety and quality of raw animal products, particularly chicken meat, are among the critical concerns in the food production and distribution chain. Chicken meat holds a significant place in the dietary patterns of many populations due to its high nutritional value, easy accessibility, and affordable price. However, the presence of pathogenic microorganisms like Salmonella spp. and Campylobacter spp. in chicken carcasses is a major cause of foodborne illnesses, affecting millions of people worldwide annually. According to the World Health Organization (WHO), Campylobacter jejuni and Salmonella enterica are among the leading bacterial agents responsible for human gastroenteritis, with contaminated poultry products being their primary source. Slaughterhouses represent critical control points within the protein supply chain, playing a pivotal role in either the dissemination or mitigation of microbial contamination. Therefore, the adoption of innovative technologies for effective microbial load reduction at early processing stages is essential for enhancing food safety and reducing reliance on chemical preservatives in later distribution stages.In recent years, there has been increased interest in applying non-chemical and non-thermal methods to control microbial contamination. Techniques such as the application of ice powder for thermal shock, ozone as a potent disinfectant and oxidizing agent, lactic acid as a natural organic acid, and pulsed electric fields (PEF) as an emerging non-thermal technology have gained prominence. These approaches effectively reduce pathogenic microbial loads without compromising the physical or sensory qualities of meat products. They are particularly promising in lowering resistant microbial populations and extending the shelf life of meat products.Considering the limitations of conventional thermal or chemical methods in preserving product quality and meeting the growing consumer demand for safer and more naturally processed products, the present study aimed to evaluate and compare the efficacy of four non-chemical methods such as ice powder, ozone, lactic acid, and pulsed electric fields in reducing the total microbial count, Salmonella, and Campylobacter contamination on chicken carcasses. Material and MethodsThis experimental study was conducted on 150 samples collected from a total of 450 broiler chicken carcasses at an industrial poultry slaughterhouse in Najafabad County, Esfahan Province, Iran. To assess microbial control methods and improve hygienic conditions in the slaughtering process, treatments included immersion in water containing ice powder at 0 and 10 °C, lactic acid at concentrations of 0.5% and 1%, ozonated water at 1 and 2 ppm, pulsed electric fields applied at 60 volts with frequencies of 100 and 200 MHz, and combinations of these four methods at the specified concentrations. Treatment durations were set at 5 and 10 min for all groups. Following treatment, samples were taken from the carcass surfaces, and total microbial counts, Salmonella, and Campylobacter populations were enumerated according to Iranian National Standard methods. Data were statistically analyzed using one-way ANOVA and means were compared by Tukey’s test at a 95% confidence level.Results and DiscussionThe results of this study demonstrated that most examined treatments significantly reduced the microbial contamination of chicken carcasses compared to the control (P<0.05). Among the treatments, lactic acid and the combined method particularly at their highest tested levels, exhibited the greatest effectiveness in reducing total microbial counts and Campylobacter populations, highlighting the synergistic potential of combined interventions for improved pathogen control. The use of ice powder showed the least effect in reducing the microbial contamination of poultry carcasses. However, as observed, the combined method successfully reduced the total bacterial count, Campylobacter and Salmonella by 97%, 91% and 95%, respectively, compared to the control. The findings of this study revealed that the examined treatments led to a significant reduction in the total bacterial count and Campylobacter at 5 and 10 minutes (P<0.05). However, increasing the treatment duration from 5 to 10 minutes did not result in a further significant reduction of these bacteria (P>0.05). Nevertheless, a 5-minute treatment already reduced more than half of the Salmonella population, and extending the treatment time to 10 minutes resulted in an even greater reduction in Salmonella (P<0.05). This finding aligns with Carvalho et al. (2022), who reported that the antibacterial activity of organic acids against meat pathogens increases up to a saturation point, beyond which extended exposure yields minimal additional efficacy.ConclusionThe findings of this study indicate that the application of treatments such as lactic acid, pulsed electric field, ozonated water, and ice powder can significantly reduce the microbial load of poultry carcasses within a short period. These interventions offer promising alternatives to conventional thermal treatments or the use of harsh chemical preservatives. Moreover, the results highlight the critical importance of precise control over parameters such as treatment time, concentration, and intensity, which significantly influence the overall antimicrobial efficacy. In summary, the present study not only confirms the practical applicability of these methods for enhancing the microbial safety of poultry meat but also demonstrates that the strategic combination of physical and chemical technologies with optimized exposure times can effectively control microbial contamination in slaughterhouses and meat processing operations without compromising product quality.Funding Sources This work was financially supported by the Faculty of Veterinary Medicine, Shahrekord University.
Food Biotechnology
Elnaz Mehrabi; Mojtaba Bonyadian; Aziz A. Fallah
Abstract
IntroductionRecently, the use of new packaging materials and natural additives for improving the durability and preservation of foods has been increasingly considered. Edible coatings containing plant extracts lead to increase the shelf life of food, do not cause environmental contamination, and do not ...
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IntroductionRecently, the use of new packaging materials and natural additives for improving the durability and preservation of foods has been increasingly considered. Edible coatings containing plant extracts lead to increase the shelf life of food, do not cause environmental contamination, and do not endanger the health of the consumer. Fish is a food rich in amino acids, vitamins and minerals, and polyunsaturated fatty acids, especially omega-3, which has made it more and more popular in the human diet. However, the presence of a significant amount of polyunsaturated fatty acids as well as easily digestible proteins has turned fish into a highly perishable commodity. Fresh seafood spoils rapidly due to the enzymatic and bacterial activities that occur after death, as well as the spoilage caused by the oxidation of polyunsaturated fatty acids and the high concentration of hematin compounds and metal ions of fish muscle, such as iron, and their pH which is close to neutral. Therefore, the use of natural coatings that can increase the shelf life of food and attract the consumers should be given more attention. Iran is the largest fishery producer in the region, thus, providing new methods to increase the shelf life of these products until the time of consumption can guarantee the safety and be effective in the economic prosperity of this industry. Therefore, the present study was designed to investigate the effect of chitosan coating along with the volatile oil of ginger plant on the shelf life of salmon fillets stored in refrigerator to reduce microbial growth, reduce chemical reactions, and increase the storage life of salmon fillets in refrigerator. Material and MethodsRainbow trout fish with an approximate weight of 600 grams were purchased from the market. Fish were washed with sterile distilled water, and cut into 60-gram pieces after separating the head and tail and eviscerating. The prepated fish were randomly divided into 4 groups. The control group was without any treatment but the treatment groups were immersed in chitosan containing different concentrations of Ginger essential oils. All the samples were kept in zipped bags at refrigerator (4°C) for 15 days. Microbial tests (Mesophilic, Psychrophilic, Coliform, and Lactic acid bacteria count), chemical tests (pH, TVN, TBARS), and sensory tests (color, smell, taste, texture, and overall acceptance) were performed on days 1, 4, 7, 12 and 15. The data obtained from the microbial and chemical tests were analyzed by one-way analysis of variance and the data obtained from the sensory tests were analyzed by the Kruskal-Wallis test in Sigma Stat 4 statistical software, considering P<0.05. Results and Discussion The results of bacterial tests showed that chitosan coating with ginger essential oil had a significant effect on reducing the growth of mesophilic, coliform, lactic acid bacteria and psychrophilic bacteria compared to the control and chitosangroups during 15 days of storage in the refrigerator (P<0.05). During the storage period, chitosan-treated groups containing 1.5% and 0.75% of ginger volatile oil had the best microbial quality in terms of mesophilic bacteria, Psychrophilic bacteria, lactic acid- bacteria, and coliforms. Also, in samples immersed in chitosan coating with ginger essential oil, the pH, TVN and TBARS values at the end of the storage period were significantly lower than the control and chitosan group (P<0.05). The results showed that pH, TVN, and TBARS did not exceed the defined standard for fish meat at the end of the storage period in the groups treated with ginger volatile oil. Sensory characteristicsindicated that the groups treated with chitosan coating containing ginger essential oils showed better sensory characteristics in terms of color, taste, smell, texture, and overall acceptance than the control and chitosan groups during the storage period (P<0.05). ConclusionBased on the results of the present study using the chitosan coating combined with ginger volatile oils has antimicrobial and antioxidant properties, which can reduce the oxidation of fats and microbial loads, while maintaining the organoleptic quality and increasing the shelf life of fish meat at refrigerator temperature. In comparison between treated groups, the use of chitosan along with 0.75% volatile oil of ginger is recommended, because by using a smaller amount of volatile oil, the microbial, chemical, and organoleptic properties can be kept at the standard level until the 15th day. Acknowledgments The authors are grateful to Shahrekord University's Research Vice-Chancellor for supporting this project.
