Effect of irradiation of frozen meat/fat trimmings on microbiological and physicochemical quality attributes of dry fermented sausages

Meta-analysis of the effects of gamma irradiation on chicken meat and meat product quality

Background and Aim

Irradiation is one of the most effective microbial decontamination treatments for eliminating foodborne pathogens and enhancing chicken meat safety. The effect of gamma irradiation on the overall quality of chicken meat and its products must be observed to provide a comprehensive explanation to the public. This meta-analysis examined the effects of gamma irradiation on the oxidation parameters, microbial activity, physicochemical characteristics, sensory parameters, and nutrient quality of chicken meat and meat products.

Materials and Methods

We conducted a literature search using various search engines (Scopus®, PubMed®, and Google Scholar®) with "irradiation," "gamma," "chicken," and "meat" as keywords. Gamma irradiation treatment was set as a fixed effect, and the difference between experiments was set as a random effect. This study used a mixed-model methodology. After evaluation, we selected 43 articles (86 studies) for inclusion in the database.

Results

Gamma irradiation significantly increased (p < 0.01) thiobarbituric acid-reactive substance levels on days 0, 7, and 14 of storage. Gamma irradiation reduced total aerobic bacteria, coliforms, Salmonella, yeast, and mold activity (p < 0.01). According to our meta-analysis, 21.75 kGy was the best dose for reducing total aerobic bacteria. On day 0, gamma irradiation did not affect the color parameters (L*, a*, b*). However, a significant difference (p < 0.01) was noted for a* and b* parameters between the control and irradiation treatments at 7 and 14 days. Although irradiation treatment was less consistent in sensory parameters, overall acceptability decreased on days 0, 7, and 14 after storage (p < 0.05). Regarding nutrient composition, gamma irradiation reduced moisture content and free fatty acid (FFA) content (p < 0.05). Although irradiation significantly reduces the microbial population, it increases the oxidation of chicken meat and its products. Irradiation decreases FFA content and overall acceptability, but it does not affect flavor, tenderness, juiciness, or cooking loss.

Conclusion

Gamma irradiation positively reduces the microbial activity in chicken meat and its products but increases the oxidation parameters. Although gamma irradiation does not alter the flavor, tenderness, juiciness, or cooking loss, gamma irradiation can reduce the FFA content and overall acceptability.

Quality of pork after electron-beam irradiation: A meta-analysis study

Background and Aim

Irradiation has become a preferred method for pork preservation in recent years. Electron-beam irradiation is notably recognized for its feasibility and safety among various irradiation methods. This meta-analysis study aims to elucidate the impact of electron-beam irradiation on oxidation parameters, color, sensory attributes, and microbiological conditions in pork.

Materials and Methods

A total of 79 data from 22 articles were aggregated into an extensive database. The irradiation dose ranged from 0 to 20 kGy in this current meta-analysis. The observed parameters encompassed oxidation, color, sensory attributes, and microbiological conditions. A mixed-model approach was used to perform the meta-data analysis, in which irradiation dose was treated as fixed effects and distinct studies (articles) as random effects.

Results

Electron-beam irradiation resulted in an increase in thiobarbituric acid-reactive substances levels and peroxide-oxygen value of pork (p < 0.01). Conversely, total volatile-base-nitrogen values (p < 0.05) were observed. Following irradiation, the pH value, lightness (L*), redness (a*), and yellowness (b*) remained unaffected. Pork color tended to decrease after irradiation treatment (p = 0.095 and p = 0.079, respectively) at 7 and 14 days of storage. The irradiation process resulted in an increase in the values of texture and juiciness parameters (p < 0.05). However, electron-beam irradiation resulted in decreased overall acceptability (p = 0.089). In terms of microbiological status, electron-beam irradiation led to a reduction in the populations of Salmonella (p < 0.01), Escherichia coli (p < 0.01), Listeria monocytogenes (p < 0.05), and coliforms (p < 0.05) at 7 and 14 days of storage.

Conclusion

Electron-beam irradiation enhances lipid peroxidation in porcine meat. The color of the meat remained unchanged after treatment. However, with regard to sensory properties, electron-beam irradiation showed a tendency to decreased overall acceptability. Most microbiological parameters decreased following electron-beam irradiation.

Effect of Various Doses of Electron Beam Irradiation Treatment on the Quality Characteristics of Vacuum-Packed Dry Fermented Sausage during Refrigerated Storage

In this study, we investigated the effect of electron beam irradiation on the physicochemical, microbiological, and sensory attributes of dry fermented sausage during 8 weeks of refrigerated storage at 4°C. The five doses of e-beam irradiation applied were: 0 kGy (control) and 1, 2, 3, and 4 kGy. All the experimental treatments led to a significant decrease in pH values during the storage period of 60 days (P<0.05). The 2-kGy treatment caused a significant (P<0.05) decrease in pH value, bacterial growth (total plate count, Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli), and thiobarbituric acid-reactive substances values than other irradiated fermented sausage batches during the study. Irradiation did not affect the water activity value of the fermented sausage samples. For color characteristics, 3 kGy exhibited significantly lower (P<0.05) L* (lightness) values than other irradiation treatments. A similar trend of significantly lower (P<0.05) a* (redness) and b* (yellowness) values was observed in all irradiated treatments than in the control. All the treatments showed no significant differences (P>0.05) in scores in sensory attributes (color and sourness); however, fermented sausage irradiated with 3 kGy had the highest sensory characteristics (overall acceptability) at the end of the storage period. In conclusion, 1, 2, and 3 kGy irradiation treatments can be beneficial for inhibiting lipid oxidation, controlling microbial growth, and maintaining sensory attributes of fermented sausage during storage, thereby enhancing their food safety and shelf stability.

Quality and Lactic Acid Bacteria Diversity of Pork Salami Containing Kimchi Powder

We investigated the quality properties and bacteria diversity of pork salami containing homemade kimchi powder (KP). Pork salamis were manufactured with commercial starter culture (control), and 1% KP (KP1), 3% KP (KP3), and 5% KP (KP5). The salami was fermented and aged for 2 days and 56 days, respectively. The pH and A_W values of salamis with KP were significantly lower than that of the control (p<0.05). The 2-thiobarbituric acid reactive substance values of all salamis with KP increased but were below 0.2 mg MDA/kg. Salamis with KP, decreased the L* value, but increased the a* and b* values (p<0.05). The Lactobacillus count was significantly higher in the salamis with KP than in the control by day 14 (p<0.05). The number of Leuconostoc was higher in salamis with KP than in the control and was the highest in salamis in KP1. The KP1 protected lipid oxidation and showed low TBARS value of pork salami compared to the control. This study demonstrates that KP can improve pork salami properties and can serve as a potential natural compounds for fermented meat prodcuts like Metzgerei.

Health and Safety Considerations of Fermented Sausages

Fermented sausages are highly treasured traditional foods. A large number of distinct sausages with different properties are produced using widely different recipes and manufacturing processes. Over the last years, eating fermented sausages has been associated with potential health hazards due to their high contents of saturated fats, high NaCl content, presence of nitrite and its degradation products such as nitrosamines, and use of smoking which can lead to formation of toxic compounds such as polycyclic aromatic hydrocarbons. Here we review the recent literature regarding possible health effects of the ingredients used in fermented sausages. We also go through attempts to improve the sausages by lowering the content of saturated fats by replacing them with unsaturated fats, reducing the NaCl concentration by partly replacing it with KCl, and the use of selected starter cultures with desirable properties. In addition, we review the food pathogenic microorganisms relevant for fermented sausages(Escherichia coli,Salmonella enterica,Staphylococcus aureus,Listeria monocytogenes,Clostridium botulinum, andToxoplasma gondii)and processing and postprocessing strategies to inhibit their growth and reduce their presence in the products.

Use of mild irradiation doses to control pathogenic bacteria on meat trimmings for production of patties aiming at provoking minimal changes in quality attributes

The objectives of the present work were to assess the use of moderate doses of gamma irradiation (2 to 5 kGy) and to reduce the risk of pathogen presence without altering the quality attributes of bovine trimmings and of patties made of irradiated trimmings. Microbiological indicators (coliforms, Pseudomonas spp and mesophilic aerobic counts), physicochemical indicators (pH, color and tiobarbituric acid) and sensory changes were evaluated during storage. 5 kGy irradiation doses slightly increased off flavors in patties. Two pathogenic markers (Listeria monocytogenes and Escherichia coli O157:H7) were inoculated at high or low loads to trimming samples which were subsequently irradiated and lethality curves were obtained. Provided that using irradiation doses ≤2.5 kGy are used, reductions of 2 log CFU/g of L. monocytogenes and 5 log CFU/g of E. coli O157:H7 are expected. It seems reasonable to suppose that irradiation can be successfully employed to improve the safety of frozen trimmings when initial pathogenic bacteria burdens are not extremely high.

Safety and quality of ready-to-eat dry fermented sausages subjected to E-beam radiation

The inactivation kinetics in the death of Listeriainnocua NTC 11288 (more radioresistant than five different strains of Listeriamonocytogenes) and Salmonella Enterica serovar Enteritidis and S. enterica serovar Typhimurium by E-beam irradiation has been studied in two types of vacuum-packed RTE dry fermented sausages ("salchichon" and "chorizo") in order to optimize the sanitation treatment of these products. A treatment of 1.29kGy was calculated to reach the food safety objective (FSO) according to the "zero tolerance" criterion for the three strains. No irradiation treatment was necessary to meet the 10(2)c.f.u./g microbiological criterion for L. monocytogenes. Dry fermented sausages treated with ⩽2kGy had negligible sensory (appearance, odour and taste) modifications. Therefore, this treatment produces safe dry fermented sausages with similar sensory properties to the non-irradiated product.