Prevalence of Escherichia coli generic and pathogenic in pork meat: systematic review and meta-analysis.

This research aimed to analyze scientific information regarding the prevalence of generic and pathogenic E. coli in the production and supply chain of pork meat, considering different types of samples, places of sampling, and pathotypes using a systematic review and meta-analysis tools. The meta-analysis for the prevalence of generic and pathogenic E. coli was conducted by estimating the effects within subgroups. Data subsets were analyzed using the DerSimonian-Laird method for binary random effects. The average prevalence of generic E. coli in different types of pork meat samples was determined to be 35.6% (95% CI 19.3-51.8), with no significant differences observed between pork meat and carcasses. Conversely, the average prevalence of E. coli pathotypes in samples related to the supply chain of pork meat was found to be 4.7% (95% CI 3.7-5.7). In conclusion, these findings suggest the possibility of establishing an objective threshold for E. coli prevalence as a benchmark for comparison within the meat industry. By utilizing this data, it becomes possible to propose a standardized limit that can serve as a reference point for evaluating and improving processes in the industry.

Porosity determination of Vienna sausages through digital images analysis.

BACKGROUND: This research aimed to determine the porosity and particle size distribution in canned Vienna-type sausages using digital image analysis (DIA) on photographs captured with a digital camera and applying a Monte Carlo simulation. The methodology determined morphometric parameters (area and Feret diameter) by DIA of transverse and longitudinal sections of canned sausages. Those images were previously contrast enhanced, color threshold adjusted, and binarized. Subsequently, the estimation of the pore volume was carried out from the inverse Gaussian distributions of Feret diameter and area, as well as the porosity, using Monte Carlo simulation. RESULTS: The pores had an average Feret diameter of 0.335 mm and an average area of 0.085 mm2 . The highest estimated bivariate kernel density was presented for the smallest pores (around 0.02 mm2 in area and 0.25 mm in diameter). Simulation average values of pore volume, assumed as a cylinder, and porosity were 1.455 mm3 and 0.737 respectively. The average porosity value was consistent with the value experimentally estimated by the indirect method, in concordance with the definition of porosity, which was 0.715, presenting a mean relative percentage error of 3.08% concerning the estimated experimental value as well. CONCLUSION: This research presents interesting perspectives for the quantitative analysis of the microstructure of food and biological materials through a novel, low-cost, reliable, and fast proposal. Moreover, this is the first study to report the porosity determination in canned sausages by DIA. © 2022 Society of Chemical Industry.

Analysis of microbiota structure in cooked ham as influenced by chemical composition and processing treatments: Identification of spoilage bacteria and elucidation on contamination route.

Spoilage in cooked ham is one of the main challenges where microbial contamination can play a fundamental role. This study aimed to characterize pork-cooked ham's microbial community changes among different food production conditions (formulation and processing) using 16S rRNA sequencing and also to investigate the spoilage bacteria in order to elucidate their contamination route. Samples of three pork-cooked ham references with and without post-pasteurization treatment and in contact with the slicing-packaging conveyor belt and slicer and packager surfaces were performed by 16S rRNA gene sequencing. In order to clarify the contamination route, surfaces were sampled by conventional microbiological methods. Results showed that Leuconostoc spp. was the principal genera in spoiled cooked ham and had no relation neither to formulation nor contact with the slicing-packaging conveyor belt. The contamination route found for Leuconostoc spp. was associated with the storage and packaging zone. In addition, the calculated shelf-life decreased to 57.5% independently of the environment interaction minimization when ham casing permeability was changed and linked to contamination of spoilage bacteria during the slicing and packaging process. This research illustrates how the combined approach provides complementary results to implement suggestions in the facility to reduce the cross-contamination with spoilage bacteria. It also generates tools to comprehend and propose transference models understanding the environmental and intrinsic factors related to microbial transfer rate.

Considerations for functional food design based on starch-protein interactions: a systematic review.

This systematic review aims to discuss the considerations in the design of starch-based foods from protein interactions, according to their functional, technological, and nutritional effects. Thereof, a systematic search for articles published in English, without excluding material by year, location, or author. Scopus and PubMed were the databases consulted. The results showed a decrease in gelatinisation, gelation, and viscosity of food matrices and a reduction in hydrolysis and starch digestibility rate by adding protein. Furthermore, found effects from other components such as phenolic compounds. In conclusion, in food design, protein interaction can modulate the starch digestibility rate, which also modifies technological, structural, and nutritional properties, depending on the physicochemical nature of ingredients, the percentage of protein incorporation, and processing conditions.

Systematic Review and Meta-analysis: Salmonella spp. prevalence in vegetables and fruits.

In this study, a systematic review and a meta-analysis were conducted to analyse recent worldwide information about the prevalence of Salmonella spp. in vegetables and fruits to estimate the effect of the different processes such as washing, cutting or disinfection, and place of sampling. A systematic search was conducted for articles from 2014 to 2020 published to date regarding prevalence of Salmonella spp. in vegetables and fruits, without excluding material by location, or author. It was possible to determine eight categories for vegetables and fruits in comparison with the meta-analysis which showed five categories due to data availability. Results showed prevalence for Salmonella spp. of 0.1%, 0.2%, 13.7%, 0.1%, and 0% for fruits, leafy vegetables, mixed vegetables related to ready-to-eat salads (RTE), tubercles, and tomatoes, respectively. Moreover, categories such as fruits, tubercles, and tomatoes as associated with different types of preparations and places of sampling (Retail stores, fresh products wholesale, street markets, distribution centers, farms, and processing plants) did not present a significant combined effect on the prevalence of Salmonella spp. Likewise, leafy, and mixed vegetables showed differences associated with a type of processing, where leafy fresh unprocessed vegetables had a significant positive effect on the prevalence of the pathogen regarding the RTE products. These findings may be useful for the construction of a quantitative model of risk assessment as a means to characterize the differences among the sort of vegetable, fruit, type of processing, and place of sampling.

Assessment of dietary exposure to aflatoxin B1 from corn arepas in Colombia.

The aim of this research was to evaluate dietary exposure to aflatoxin B1 (AFB1) in corn arepas in Colombia. In addition, in this study an assessment considering compliance to the maximum level of AFB1 (4 µg kg-1) for this food was conducted. AFB1 concentration data in corn arepas were obtained from 168 samples. The samples were collected from factories in 16 departments in Colombia. AFB1 was quantified by High-Performance Liquid Chromatography with a fluorescence detector. Consumption data and body weight (b.w.) were measured from the 2005 Colombian National Survey of Nutritional Status. Probabilistic estimates were made by Monte Carlo simulation of dietary exposure and margin of exposure (MOE) segmented by age group. The results showed that 27% of corn arepa samples were contaminated with AFB1, with an average concentration of 15.1 µg kg-1 and a maximum value of 111.1 µg kg-1. The stochastic dietary exposure assessment showed that the age group most exposed was children between 4 and 8 years old (10.014 ng (kg b.w. day)-1). In addition, the MOE values for all age groups were lower than 10,000, indicating a potential risk for consumers. However, in the scenario where AFB1 concentration level complies with the maximum limit of 4 µg kg-1 AFB1, the level of concern could be reduced for the adult population between 14 and 64 years old because the MOE value is above 10,000.

A systematic review of the nutritional implications of military rations.

BACKGROUND: The objective of this study was to assess military rations. Military rations must provide military personnel with suitable nutrition, as high-quality nutrition is crucial for promoting health. AIM: This systematic review provides information regarding the nutritional design of military rations according to energy and protein intake and supplements. METHODS: A systematic search was conducted for articles published to date regarding the nutritional needs involved in a military diet for an active population of either gender, ranging from 18 to 60 years old, without excluding material by year, type of document, location, or author. The pertinent articles found were published from 1994 to 2017. RESULTS: Physical activity and environmental factors directly affect calculating energy needs and carbohydrate intake when designing military rations. However, the results showed no influence on protein, fat and/or sodium intake. Furthermore, the search revealed that military populations have a high intake of dietary supplements; it is thus worth considering their incorporation into campaign rations. CONCLUSION: Military personnel macro- and micro-nutrient needs depend on physical activity and nutrient intake measurement methodologies. The data regarding military personnel dietary supplement consumption indicated that this is a niche worth considering when designing military rations. Research on nutritional needs for military rations could concentrate on optimizing the amount of macro- and micro-nutrients and their biological value, according to physical activity, as well as maintaining their sensory quality, safety and shelf life using different processing technologies.

Effect of Starter Culture and Low Concentrations of Sodium Nitrite on Fatty Acids, Color, and Escherichia coli Behavior during Salami Processing.

The reduction of NaNO2 and safety in meat products have been a concern to the meat industry for the last years. This research evaluated the changes in total fatty acids (TFAs) and myoglobin forms by adding starter culture (Lactobacillus sakei/Staphylococcus carnosus) and 50 ppm of NaNO2 during salami processing. In the postripening stage, the starter culture influenced the concentration of the palmitic, oleic, vaccenic, and γ-linolenic TFAs, whereas the metmyoglobin concentration was lower (which could be related to the antioxidant effect of the starter culture). In this stage, an increase in enthalpy, specific heat, and onset temperature was found when adding starter culture and NaNO2, which is directly related to polyunsaturated TFA. However, when adding just the starter culture without 50 ppm NaNO2, the E. coli population was reduced in 4 log CFU/g. This study proposes the analysis of changes in meat product processing like salami in a holistic form, where the application of starter culture with low nitrite concentrations could be in the meat industry an upward trend for reducing this additive.

Listeria monocytogenes behaviour and quality attributes during sausage storage affected by sodium nitrite, sodium lactate and thyme essential oil.

The effects of the addition of nitrite at 200 ppm (N), sodium lactate 1.5% (L) and thyme essential oil at 100 ppm (T1) on Listeria monocytogenes behaviour and ATPase activity inhibition were evaluated, as well as lipid oxidation through the quantification of malonaldehydes, in sausage stored at 8 ℃ for 41 days and at 30 ℃ for 14 days. The changes in the colour profile were performed during storage time at 8 ℃. Quantitative descriptive sensory analyses were performed after two days at 4 ℃. At 8 ℃, the treatments with the highest inhibition on L. monocytogenes were L and N, without significant differences. In turn, at 30 ℃, the bacterium was most inhibited with treatment L, followed by T1 and N, without significant differences. A 44.1% and 19% inhibition of ATPase activity was detected in L and T1 treatments, respectively. At 8 ℃ and 30 ℃, malonaldehydes content was not different between the treatments. N presented the highest values of a* and concentration of metmyoglobin after 41 days at 8 ℃. The panel detected differences between T1 and N for the aroma in the descriptors spices and herbal.

In vitro modelling of simultaneous interactions of Listeria monocytogenes, Lactobacillus sakei, and Staphylococcus carnosus.

The Jameson effect model describes suppression of microorganism growth as being dependent on non-specific competition. This model was developed for simultaneous growth in a liquid medium and microbial interactions between Listeria monocytogenes, Lactobacillus sakei, and Staphylococcus carnosus with addition of NaNO2 to mimic the manufacturing process of salami for 48 h at 21°C and then for 14 days at 17°C. L. monocytogenes in the presence of L. sakei was inhibited by 2.120 log CFU/mL in the presence of NaNO2, and 1.146 log CFU/mL without NaNO2. Inhibition of L. monocytogenes cocultured with S. carnosus was 2.248 log CFU/mL at 48 h, but after 336 h was not significantly (p>0.05) different from L. monocytogenes in mono-culture. The interspecific competition parameter (ß) <1 indicated that the prevailing competition in co-cultures was intraspecific. Differentiation between 2 bacterial species interactions can be applied for use in starter cultures with pathogenic flora.