Improvement Of Microbiological Quality Research Articles

Impactos causados ​​por el COVID-19 en industrias cárnicas ubicadas en el Distrito Federal y Goiás

The SARS-CoV-2 virus, responsible for COVID-19, spreads more easily in crowded places, including slaughterhouses and meat processing factories, which employ over 560,000 workers in Brazil. However, there is still limited information on how the pandemic has affected meat processing plants in the Federal District and Goiás. Therefore, this study aimed to determine the main operational and structural changes adopted for disease control. The study involved the participation of 15 micro, small, and medium-sized companies, which together employ more than 1,500 workers in cattle, poultry, and swine slaughterhouses, meat processing units, and distribution centers. The study material was obtained through an online questionnaire directed at technical managers, agricultural inspectors, quality control teams and industry managers. The questions focused on potential structural and operational changes that occurred during this period, human resources and employee health, product logistics, and microbiological quality of the produced food. The statistical analysis revealed that 93% of the factories developed contingency plans. Among the changes implemented, 40% introduced a 1-meter distance between workstations, 33.3% increased the frequency of Sanitation Standard Operating Procedures (SSOPs), and 27% modified the layout of workstations to avoid face-to-face contact. Approximately 80% of the companies reported confirmed cases of COVID-19, with the majority (66.7%) choosing to isolate suspected employees and providing them paid medical leave (86%). Regarding finished products, there were challenges in customer delivery (71.4%), while 26.7% of the companies showed an improvement in microbiological quality. No establishments needed to close for procedure revisions related to pandemic control. The contingency plans followed Joint Ordinance nº 19/2020 (MAPA/MS/ME) and primarily aimed to ensure social distancing. However, promoting distance between workstations proved challenging due to the internal organization of meat factories. The pandemic recommendations did not replace existing legal obligations, and companies had to further emphasize their responsibility toward public health.

Application of Lytic Bacteriophages and Their Enzymes to Reduce Saprophytic Bacteria Isolated from Minimally Processed Plant-Based Food Products-In Vitro Studies.

The aim of this study was to isolate phage enzymes and apply them in vitro for eradication of the dominant saprophytic bacteria isolated from minimally processed food. Four bacteriophages-two Enterobacter-specific and two Serratia-specific, which produce lytic enzymes-were used in this research. Two methods of phage enzyme isolation were tested, namely precipitation with acetone and ultracentrifugation. It was found that the number of virions could be increased almost 100 times due to the extension of the cultivation time (72 h). The amplification of phage particles and lytic proteins was dependent on the time of cultivation. Considering the influence of isolated enzymes on the growth kinetics of bacterial hosts, proteins isolated with acetone after 72-hour phage propagation exhibited the highest inhibitory effect. The reduction of bacteria count was dependent on the concentration of enzymes in the lysates. The obtained results indicate that phages and their lytic enzymes could be used in further research aiming at the improvement of microbiological quality and safety of minimally processed food products.

Effect of Processing Treatment and Modified Atmosphere Packing on Carrot's Microbial Community Structure by Illumina MiSeq Sequencing.

The aim of this study was to analyze the microbiome of carrot (Daucus carota subsp. sativus) subjected to minimal pre-treatment (rinsing in organic acid solution) and packaging in a high-oxygen modified atmosphere, and then stored for 17 days under refrigeration conditions (4 °C). The highest levels of bacteria in the carrot microbiome were characterized, at almost 78%, by bacteria belonging to the Enterobacteriaceae and Pseudomonadaceae families. Rinsing in a solution of ascorbic and citric acids resulted in the improvement of microbiological quality in the first day of storage. However, the use of a high-oxygen modified atmosphere extended the shelf life of the minimally processed product. Compared to carrots stored in air, those stored in high oxygen concentration were characterized by a greater ratio of bacteria belonging to the Serratia and Enterobacter genera, and a lower ratio belonging to the Pseudomonas and Pantoea genera. Moreover, the β-biodiversity analysis confirmed that the oxygen concentration was the main factor influencing the differentiation of the metabiomes of the stored carrots. The bacterial strains isolated from carrots identified by molecular methods were mostly pathogenic or potentially pathogenic microorganisms. Neither the minimal pre-treatment nor packaging in high-oxygen atmosphere was able to eliminate the threat of pathogenic bacteria emerging in the product.

Effect of Lactobacillus plantarum and Staphylococcus xylosus on flavour development and bacterial communities in Chinese dry fermented sausages

The use of starter cultures helps to improve the quality and safety of traditional meat products. In this study, the effects of Lactobacillus plantarum R2 and Staphylococcus xylosus A2 inoculation on microbial community, lipolysis, proteolysis, and volatile compounds in Chinese dry fermented sausages were investigated. Culture-dependent and culture-independent high-throughput sequencing) methods were employed to evaluate the bacterial communities. Results showed that the total contents of free fatty acids (FFAs) and free amino acids (FAAs) were increased by inoculating the starter cultures, especially a mixed culture. A significant decrease in pH and water activity was observed in the inoculated sausages (p < 0.05). Moreover, the inoculation treatment enhanced the competitiveness of dominant bacteria and inhibited the growth of unwanted bacteria. This was beneficial to promote the release of FFAs and FAAs and to prevent the formation of off-flavours and rancidity. Thus, the flavour development in the inoculated dry fermented sausages was attributed to the improvements in microbiological quality.

Improvement of microbiological quality of hen egg powder using gamma irradiation

Eggs and their products such as desserts, confectioneries, bakery mixes, mayonnaise and many convenience foods have been implicated in food-borne disease outbreaks due to microorganism contamination. The effect of gamma irradiation on the presence of microorganisms in egg powder was investigated. Egg powder samples were exposed to several doses of irradiation: 0, 5, 10 and 15 kGy and stored for up to 12 months at ambient temperature (25 oC). Results indicated that the total viable count (TVC) (5.56 log10 cfu g-1), total coliform counts (TCC) (6.46 log10 cfu g-1) and mold and yeast counts (MYC) (9.12 log10 cfu g) in un-irradiated (control) samples of egg powder were higher than the maximum limits (4.88, 2.00 and 1.70 log10 cfu g-1, respectively). Application of the higher doses (10 and 15 kGy) decreased the TVC, TCC and MYC of the egg powder samples to less than 1 log10 cfu g-1 and the counts remained almost constant during storage for 12 months. D10 values for Escherichia coli and Salmonella typhimurium were 0.714 and 0.278 kGy, respectively. Gamma irradiation treatment could be chosen on the basis of preliminary microbiological tests including TVC, TCC and MYC and help improve the hygienic quality by killing and reducing the microorganisms that might be present inside of egg powder to meet national and international standards.

Improvement of microbiological quality, antioxidant content and shelf life of jujube (Ziziphus mauritiana cv. BAU Kul) fruit by gamma irradiation

Postharvest loss of inherently perishable fruits is a matter of serious concern for the farmers and traders. Reduction of postharvest loss is one of the key components for ensuring food security. A study was carried out to reduce the postharvest loss of BAU Kul, an improved variety of jujube fruit (Ziziphus mauritiana), by using gamma irradiation. Different doses of gamma irradiation (0.5, 1.0 and 1.5 kGy) was applied to the jujube fruit samples and the microbiological quality, antioxidant content and shelf life of those fruits were evaluated. Gamma irradiation initially caused significant reduction of the total heterotrophic bacteria, coliform as well as yeast and mold counts. However, the counts increased in both irradiated and non-irradiated fruit samples with the passage of storage period but the increment was significantly less in the 1.5 kGy irradiated samples. Irradiation played active role in the enhancement of total phenolics and flavonoids contents. The concentration of these antioxidants remained higher in irradiated samples in comparison to non-irradiated control samples throughout the storage period. However, the ascorbic acid content decreased gradually with the increase of radiation dose and storage period. The overall acceptability of the fruit samples was determined by the taste-taking panelist. The irradiated (1.0 and 1.5 kGy) fruits were acceptable up to 8 days whereas control and 0.5 kGy irradiated fruits lost their acceptability during storage. The study revealed that 1.5 kGy irradiation can improve microbiological quality and extend the shelf life of jujube fruits (cv. BAU Kul) without significant loss of overall antioxidant content and sensory attributes.

The effect of carrageenan and gelatine hydrosols incorporated with acidic electrolysed water on surface microbiota and quality changes on pork meat

SummaryThe aim of the study was to determine antimicrobial efficiency of carrageenan and gelatine hydrosols containing acidic electrolysed water (AEW) on surface microbiota of meat and evaluate possible quality changes in raw meat after treatment with experimental AEW‐containing hydrosols. Microbiological examination of meat samples covered with AEW‐containing hydrosols (total number of microorganisms, yeast and moulds, and psychrotrophs) was performed. To evaluate quality changes, haem pigments, colour, thiobarbituric acid‐reactive substances (TBARS), antioxidant capacity and preliminary sensory evaluations were performed. Treatment with AEW‐containing hydrosols causes improvement in microbiological quality of meat samples. The treatment with AEW‐containing hydrosols significantly influenced the variability of myoglobin forms of tested meat samples. Changes in L*a*b* colour parameters were found and favourably affected sensory evaluation of meat quality, especially for samples treated with AEW and gelatine‐containing hydrosols. The TBARS values of all AEW–sols‐treated samples were in the range of 0.30–0.39 mg malondialdehyde kg−1. Radical scavenging (DPPH) and reducing ability (FRAP) assays confirmed that process of electrolysis significantly improved antioxidant activity of modified meat samples compared to treatment with hydrosols containing nonelectrolysed salt solutions. Obtained results suggest that hydrosols incorporated with AEW may be used for food preservation because of their antimicrobial activity and positive impact on quality factors of raw meat.

Removal of Emerging Waterborne Pathogens and Pathogen Indicators by Pilot‐Scale Conventional Treatment

The goal of this project was to evaluate the removal of emerging pathogens and pathogen indicators by pilot‐scale coagulation, flocculation, sedimentation, and granular media filtration. The emerging pathogens included Cryptosporidium parvum oocysts, Encephalitozoon intestinalis spores, Escherichia coli O157:H7, and Aeromonas hydrophila. Bacteriophage MS2 and turbidity were used as pathogen indicators. This work revealed that some emerging pathogens were removed much more effectively than others. A. hydrophila was removed more effectively than C. parvum, and E. intestinalis spores and E. coli O157:H7 were the least effectively removed. For the water tested in this study, the results suggest that a change in filter effluent turbidity requirements from 0.5 to 0.3 ntu would not achieve a significant improvement in the reliability of pathogen removal. However, by setting filter effluent turbidity goals below 0.2 ntu, significant improvements in microbiological quality could be obtained. In general, the pilot‐plant data suggest that good removal of both turbidity and natural organic matter (NOM) decreases the risk of achieving poor emerging pathogen removal. In other words, optimizing the coagulation process for reduction of turbidity and NOM would improve removal of emerging pathogens.

Have changes to meat and poultry food safety regulation in Australia affected the prevalence of Salmonella or of salmonellosis?

During the 1990s, there was radical change in regulation of meat and poultry hygiene in Australia, and Australian Standards were developed for each sector of the meat industry. Systems for industry/government co-regulation and company-employed meat inspection were introduced based on company HACCP programs approved and audited by the Controlling Authority. However, in the 5 years since regulatory changes took full effect, rates of salmonellosis have not decreased (surveillance and reporting systems have remained unchanged). Using statistics gathered by the National Enteric Pathogens Surveillance Scheme, an attempt was made to link Salmonella serovars isolated from meat and poultry with those causing salmonellosis. Two periods were studied, 1993/1994, before regulations were introduced, and 2000/2001, when regulations should be having an effect. For red meat, the same serovars were prominent among the top 10 isolates both before and after regulation, and there was little linkage with salmonelloses. For poultry, frequently isolated serovars differed pre- and post-regulation, however, in both periods there was some linkage between serovars isolated from poultry and those causing salmonelloses. Using published and unpublished survey data, it was concluded that there had been improvements in microbiological quality of red meat and poultry over the same timeframe as regulatory changes. That these improvements apparently have not carried through to reduced case-rates for salmonellosis may be due to numerous causes, including lack of control in the food processing, food service and home sectors. The present paper illustrates difficulties faced by governments in measuring public health outcomes of changes to food hygiene regulation.

Chemical sprays as a method for improvement in microbiological quality and shelf-life of fresh sheep and goat meats during refrigeration storage (5–7°C)

The shelf-life of meats from freshly slaughtered sheep and goat carcasses at 5–7 °C was extended after spraying (pressure 3 kg/cm 2) the carcasses with solution ‘B’ containing potassium sorbate, sodium acetate, sodium citrate, sodium lactate each at 2.5% and sodium chloride at 5% (prepared w/v in potable water), when compared with solution ‘A’ (without potassium sorbate). Solution B treatment inhibited Bacillus spp. to minimum and were not detected up to sixth day. It extended the lag phase of all organisms including psychrotrophes (pseudomonads) and reduction of differential counts in sheep and goat meat were noted throughout the refrigerated storage. On sixth day (control) and seventh day (solution “A treated”) meat samples developed off odour and discoloration with total viable count (TVC)>10 7 cfu/g. Solution B treated meat samples showed no spoilage at seventh or eighth day, indicating an extended shelf-life of 3 and 2 days when compared with control and solution A treated meat, respectively.

Preservation of Fish Cutlet (Pangasius pangasius) at Ambient Temperature by Irradiation

Development of gamma irradiation preservation of ready-to-eat, commercially prepared fish cutlet and improvement of microbiological quality were studied. Studies on the shelf life extension by a combination of irradiation and ascorbic acid treatments of fish cutlets prepared at the laboratory and commercial scale have also been conducted. Cutlets prepared at the laboratory scale according to selected formulation and irradiated at a dose of 5 kGy could extend the shelf life up to 5 weeks at room temperature. In commercially prepared fish cutlets, maximum shelf life extension observed was 14 days for samples treated with 5 kGy of irradiation and stored at ambient temperature on the basis of combined microbiological, chemical, and organoleptic evaluation. The microbiological quality of the commercially prepared fish cutlets revealed the unhygienic conditions of the place where the fish was prepared and the unhygienic storage conditions and temperatures. As a result, the chemical and irradiation treatments were not effective in extending the shelf life of the cutlets under the storage condition used in this study compared with that of the laboratory scale–prepared cutlets.

Irradiation of Chewable Tobacco Mixes for Improvement in Microbiological Quality

Microbiological quality of chewable tobacco mixes traditionally known as “Gutkha” was studied. The microbiological analysis of 15 samples analyzed revealed high bacterial and fungal counts. The total viable counts were in the range of 1.8 × 104 to 7.2 × 104 CFU g−1 and the yeast and mold count from 3.6 × 103 to 7.1 × 104 CFU g−1. The proteolytic and lipolytic counts were 9 × 102 to 2.6 × 103 CFU g−1 and 2.6 × 103 CFU g−1, on an average, respectively. Lecithinase-positive Staphylococcus aureus was found in 2 of the 15 samples analyzed; the counts were up to 3.4 × 103 CFU g−1. Coliform and Salmonella spp. were found to be absent. Aflatoxins B1, B2, and G2 were found to be present in all the samples. These samples were exposed to gamma radiation (60Co) at 1-, 2-, 3-, 5-, 10-, and 25-kGy doses. The decrease in total viable count and fungal count was noticed with increase of radiation dose. The 3-kGy dose was observed to be the sterilization dose for Gutkha. At this dose no survival of organisms was noticed and no revival was observed during postirradiation storage at room temperature for 6 months.

Influence of low dose irradiation on the quality of fresh buffalo meat stored at 0–3°C

The effect of low dose irradiation on the microbiological, chemical and sensory qualities of fresh buffalo meat stored at 0–3°C was studied. Meat slices packed in polyethylene bags subjected to 2·5 kGy dose had a shelf-life of 4 weeks with acceptable sensory score, low total volatile basic nitrogen values and remarkable improvement in microbiological quality. Irradiated meat was completely free of Pseudomonas spp. and Enterobacteriaceae throughout storage. In contrast, the unirradiated control meat spoiled within 2 weeks.

The Examination of Foods for Enterobacteriaceae using a Test of the Type Generally Adopted for the Detection of Salmonellae

Summary: In countries that have recently increased their bacteriological inspection of foods, many products have shown considerable improvement in microbiological quality; simultaneously, however, discrepancies between salmonella and coli‐aerogenes tests, especially on dehydrated and frozen foods, have tended to become more frequent. These discrepancies have been eliminated by applying the following measures: incorporating glucose in culture media so as to reveal all Enterobacteriaceae; placing reliance on growth rather than gas formation so as to avoid missing anaerogenic organisms, and, especially, examining quantities of foods commensurate with those used in salmonella tests.For this purpose a procedure is recommended in which 10 g of well homogenized food are enriched in 100 ml of buffered brilliant green‐bile‐glucose broth, with no attention being paid to gas formation; the enrichment cultures are then streaked on to MacConkey's glucose agar. Single colonies so obtained are tested for fermentative attack on glucose and may be further examined for other characteristics. The same enrichment fluid can be used for the so‐called ‘nonselective pre‐enrichment’ of samples of food containing salmonellae impaired by periods spent in conditions of low water activity, low pH, etc.

Bacteriological standards for perishable foods. Manufactured meats.

The unrestricted growth of micro-organisms in meat products leads to spoilage and therefore it is necessary to consider whether meat products should be made to conform to microbial. standards. This question raises many problems which can be solved only in the distant future. However, an understanding of the rôle of micro-organisms in the manufacture of meat products suggests that in the immediate future it is possible to effect a considerable improvement in micro-biological quality. In order to achieve this result, education and advisory services will play an important part. It is important that pathogenic bacteria should be excluded from meat products, but it must be appre ciated that this problem concerns only a few of the micro-organisms which may adversely effect meat products. Furthermore, it is difficult to convince many of those concerned in food production that traditional methods should be improved if our arguments are related solely to the prevention of food-poisoning. The opinions expressed in this paper are those of the author and are not necessarily those of the Ministry of Food.