Alicyclobacillus spp. in fruit-based products: Isolation, identification, quantitative assessment (SPME/GC-MS) of spoilage compounds and spore's resistance to thermal shocks.

Alicyclobacillus spp. is the cause of great concern for the food industry due to their spores' resistance (thermal and chemical) and the spoilage potential of some species. Despite this, not all Alicyclobacillus strains can spoil fruit juices. Thus, this study aimed to identify Alicyclobacillus spp. strains isolated from fruit-based products produced in Argentina, Brazil, and Italy by DNA sequencing. All Alicyclobacillus isolates were tested for guaiacol production by the peroxidase method. Positive strains for guaiacol production were individually inoculated at concentration of 103 CFU/mL in 10 mL of orange (pH 3.90) and apple (pH 3.50) juices adjusted to 11°Brix, following incubation at 45 °C for at least 5 days to induce the production of the following spoilage compounds: Guaiacol, 2,6-dichlorophenol (2,6-DCP) and 2,6-dibromophenol (2,6-DBP). The techniques of micro-solid phase extraction by headspace (HS-SPME) and gas-chromatography with mass spectrometry (GC-MS) were used to identify and quantify the spoilage compounds. All GC-MS data was analyzed by principal component analysis (PCA). The effects of different thermal shock conditions on the recovery of Alicyclobacillus spores inoculated in orange and apple juice (11°Brix) were also tested. A total of 484 strains were isolated from 48 brands, and the species A. acidocaldarius and A. acidoterrestris were the most found among all samples analyzed. In some samples from Argentina, the species A. vulcanalis and A. mali were also identified. The incidence of these two main species of Alicyclobacillus in this study was mainly in products from pear (n = 108; 22.3 %), peach (n = 99; 20.5 %), apple (n = 86; 17.8 %), and tomato (n = 63; 13 %). The results indicated that from the total isolates from Argentina (n = 414), Brazil (n = 54) and Italy (n = 16) were able to produce guaiacol: 107 (25.8 %), 33 (61.1 %) and 13 (81.2 %) isolates from each country, respectively. The PCA score plot indicated that the Argentina and Brazil isolates correlate with higher production of guaiacol and 2,6-DCP/2,6-DBP, respectively. Heatmaps of cell survival after heat shock demonstrated that strains with different levels of guaiacol production present different resistances according to spoilage ability. None of the Alicyclobacillus isolates survived heat shocks at 120 °C for 3 min. This work provides insights into the incidence, spoilage potential, and thermal shock resistance of Alicyclobacillus strains isolated from fruit-based products.

Transparent, flexible, and eco-friendly starch-based films for reversible optoelectronic noses for food spoilage monitoring in smart packaging.

A reversible optoelectronic nose is presented consisting of ten acid-base indicators incorporated into a starch-based film, covering a wide pH range. The starch substrate is odorless, biocompatible, flexible, and exhibits high tensile resistance. This optical artificial olfaction system was used to detect the early stages of food decomposition by exposing it to the volatile compounds produced during the spoialge process of three food products (beef, chicken, and pork). A smartphone was used to capture the color changes caused by intermolecular interactions between each dye and the emitted volatiles over time. Digital images were processed to generate a differential color map, which uses the observed color shifts to create a unique signature for each food product. To effectively discriminate among different samples and exposure times, we employed chemometric tools, including hierarchical cluster analysis (HCA) and principal component analysis (PCA). This approach detects food deterioration in a practical, cost-effective, and user-friendly manner, making it suitable for smart packaging. Additionally, the use of starch-based films in the food industry is preferable due to their biocompatibility and biodegradability characteristics.

Microbial Composition and Diversity of High-demand Street-vended Foods in Ecuador.

Developing countries such as Ecuador carry a heavy food safety burden but reports on the microbiological quality of their foods are scarce. In this investigation, the microbial diversity of 10 high-risk and mass-consumption street-vended foods including bolones, encebollado, food dressings, ceviche, chopped fruits, fruit juices, fruit salads, cheese, raw chicken, and ground beef in Quito, Guayaquil, and Cuenca, three major population centers in Ecuador, were evaluated using 16S rRNA gene High Throughput Sequencing. In total, 1,840 amplicon sequence variants (ASVs) were classified into 23 phyla, 253 families, 645 genera, and 829 species. In the tested food samples, Proteobacteria and Firmicutes were the most abundant phyla accounting for 97.41% of relative abundance (RA). At genus level, 10 dominant genera were identified: Acinetobacter (12.61% RA), Lactococcus (12.08% RA), Vibrio (8.23% RA), Weissella (7.43% RA), Aeromonas (6.18% RA), Photobacterium (6.32% RA), Pseudomonas (3.92% RA), Leuconostoc (3.51% RA), Klebsiella (3.49% RA), and Cupriavidus (2.86% RA). The highest microbial diversity indices were found in raw chicken, encebollados, fruit salads, and fruit juices from Guayaquil and Cuenca. From sampled foods, 29 species were classified as food spoilage bacteria and 24 as opportunistic pathogenic bacteria. Two groups associated with human diseases were identified, including 11 enteric species and 26 species of fecal bacteria. The occurrence of recognized and opportunistic pathogenic bacteria, as well as enteric and fecal microorganisms, in the street-vended foods indicated extensive risks for the consumers' health. This study demonstrated the application of culture-independent amplicon sequencing in providing a more comprehensive view of microbial safety for street-vended food, which could be a useful tool to facilitate the control of foodborne diseases.

Recent Trends in Active Packaging Using Nanotechnology to Inhibit Oxidation and Microbiological Growth in Muscle Foods.

Muscle foods are highly perishable products that require the use of additives to inhibit lipid and protein oxidation and/or the growth of spoilage and pathogenic microorganisms. The reduction or replacement of additives used in the food industry is a current trend that requires the support of active-packaging technology to overcome novel challenges in muscle-food preservation. Several nano-sized active substances incorporated in the polymeric matrix of muscle-food packaging were discussed (nanocarriers and nanoparticles of essential oils, metal oxide, extracts, enzymes, bioactive peptides, surfactants, and bacteriophages). In addition, the extension of the shelf life and the inhibitory effects of oxidation and microbial growth obtained during storage were also extensively revised. The use of active packaging in muscle foods to inhibit oxidation and microbial growth is an alternative in the development of clean-label meat and meat products. Although the studies presented serve as a basis for future research, it is important to emphasize the importance of carrying out detailed studies of the possible migration of potentially toxic additives, incorporated in active packaging developed for muscle foods under different storage conditions.

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.

Large scale survey of yeasts in frozen concentrated orange juice (FCOJ): Occurrence, diversity, and resistance to peracetic acid.

This study aimed to evaluate the occurrence and diversity of yeasts in frozen concentrated orange juice (FCOJ) and assess the resistance of yeasts to peracetic acid. One thousand five hundred (n = 1500) samples of frozen concentrated orange juice (FCOJ) were analyzed, and 280 yeast strains were isolated and identified. Candida represented 37% of all isolates, and the main species identified were Candida pseudointermedia and C. orthopsilosis. Other yeasts identified were Starmerella, Wickerhamiella, Wickerhamiella, Clavispora, Kodamaea, Meyerozyma, Rhodotorula, Trichosporon, Wickerhamomyces, Kluyveromyces, Hanseniaspora, Saccharomyces, Torulaspora, and Zygosaccharomyces. The exogenous origin of the contamination in FCOJ samples analyzed was shown by the high diversity, corroborated by the Simpson (D) and Shannon (H') indices. From a total of 227 yeasts strains tested, more than 20% were able to withstand peracetic acid concentrations >200 ppm, with emphasis on W. anomalus (300 ppm), W. sergipensis (350 ppm), C. rugopelliculosa (350 ppm), K. marxianus (450 ppm), C. parapsilosis (500 ppm), C. pseudointermedia (500 ppm), W. sorbosivorans (500 ppm), C. boleticola (600 ppm), S. cerevisiae (700 ppm) and C. orthopsilosis (750 ppm). This study adds novel data regarding the occurrence and diversity of yeasts present in FCOJ and their resistance to a chemical compound commonly employed in the sanitization of processing and distribution premises and vehicles. These findings are essential to support the development of measures for proper mitigation of contamination of orange juice towards reducing the risks of spoilage by yeasts during FCOJ transportation/storage or when FCOJ is used as an ingredient.

Synthetic antimicrobial peptides control Penicillium digitatum infection in orange fruits.

Fungal contamination is among the main reasons for food spoilage, affecting food safety and the economy. Among fungi, Penicillium digitatum is a major agent of this problem. Here, the in vitro activity of eight synthetic antimicrobial peptides was assessed against P. digitatum, and their action mechanisms were evaluated. All peptides were able to inhibit fungal growth. Furthermore, atomic force and fluorescence microscopies revealed that all peptides targeted the fungal membrane leading to pore formation, loss of internal content, and death. The induction of high levels of reactive oxygen species (ROS) was also a mechanism employed by some peptides. Interestingly, only three peptides (PepGAT, PepKAA, and Mo-CBP3-PepI) effectively control P. digitatum colonization in orange fruits, at a concentration (50 µg mL-1) 20-fold lower than the commercial food preservative (sodium propionate). Altogether, PepGAT, PepKAA, and Mo-CBP3-PepI showed high biotechnological potential as new food preservatives to control food infection by P. digitatum.

Antimicrobial photodynamic treatment as an alternative approach for Alicyclobacillus acidoterrestris inactivation.

Alicyclobacillus acidoterrestris is a cause of major concern for the orange juice industry due to its thermal and chemical resistance, as well as its spoilage potential. A. acidoterrestris spoilage of orange juice is due to off-flavor taints from guaiacol production and some halophenols. The present study aimed to evaluate the effectiveness of antimicrobial Photodynamic Treatment (aPDT) as an emerging technology to inactivate the spores of A. acidoterrestris. The aPDT efficiency towards A. acidoterrestris was evaluated using as photosensitizers the tetracationic porphyrin (Tetra-Py+-Me) and the phenothiazinium dye new methylene blue (NMB) in combination with white light-emitting diode (LED; 400-740 nm; 65-140 mW/cm2). The spores of A. acidoterrestris were cultured on YSG agar plates (pH 3.7 ± 0.1) at 45 °C for 28 days and submitted to the aPDT with Tetra-Py+-Me and NMB at 10 µM in phosphate-buffered saline (PBS) in combination with white light (140 mW/cm2). The use of Tetra-Py+-Me at 10 µM resulted in a 7.3 ± 0.04 log reduction of the viability of A. acidoterrestris spores. No reductions in the viability of this bacterium were observed with NMB at 10 µM. Then, the aPDT with Tetra-Py+-Me and NMB at 10 µM in orange juice (UHT; pH 3.9; 11°Brix) alone and combined with potassium iodide (KI) was evaluated. The presence of KI was able to potentiate the aPDT process in orange juice, promoting the inactivation of 5 log CFU/mL of A. acidoterrestris spores after 10 h of white light exposition (140 mW/cm2). However, in the absence of KI, both photosensitizers did not promote a significant reduction in the spore viability. The inactivation of A. acidoterrestris spores artificially inoculated in orange peels (105 spores/mL) was also assessed using Tetra-Py+-Me at 10 and 50 µM in the presence and absence of KI in combination with white light (65 mW/cm2). No significant reductions were observed (p < .05) when Tetra-Py+-Me was used at 10 µM, however at the highest concentration (50 µM) a significant spore reduction (≈ 2.8 log CFU/mL reductions) in orange peels was observed after 6 h of sunlight exposition (65 mW/cm2). Although the color, total phenolic content (TPC), and antioxidant capacity of orange juice and peel (only color evaluation) seem to have been affected by light exposition, the impact on the visual and nutritional characteristics of the products remains inconclusive so far. Besides that, the results found suggest that aPDT can be a potential method for the reduction of A. acidoterrestris spores on orange groves.

Inactivation kinetics of beer spoilage bacteria (Lactobacillus brevis, Lactobacillus casei, and Pediococcus damnosus) during acid washing of brewing yeast.

This work aimed to estimate the inactivation kinetic parameters of four potential beer spoilage bacteria (Lactobacillus brevis DSM 6235, Lactobacillus casei ATCC 334, Pediococcus damnosus DSM 20289 and Pediococcus damnosus ATCC 29358) inoculated in brewing yeast submitted to acid washing with purposes of yeast recycle. The experiments were conducted at 4 °C in solutions with pH 1.5, pH 2, and pH 3 adjusted employing 85% phosphoric acid. The acid washing treatment of brewing yeasts in the most common pH used (pH 2.0) demanded almost 50 min for the first decimal reduction (δ) of L. brevis DSM 6235. Sensible strains to acid washing such as P. damnosus DSM 20289 demanded almost 70 min for 4 log reductions to be achieved. On the other hand, pH reduction of the acid washing from 2.0 to 1.5 allowed 4 log reduction of L. brevis DSM 6235) to be obtained in less than 50 min, without ruining brewer's yeast viability. Acid washing in pH 1.5 is a viable method for the inactivation of bacterial contaminants of brewing yeasts. Recycling of brewing yeasts through this approach may contribute to a more sustainable and environmental-friendly industry.

Modeling the inactivation of Lactobacillus brevis DSM 6235 and retaining the viability of brewing pitching yeast submitted to acid and chlorine washing.

This study aimed to model the inactivation of Lactobacillus brevis DSM 6235 while retaining the viability of yeasts during washing brewer's yeast with phosphoric acid and chlorine dioxide. The independent variables in the acid washing were pH (1-3) and temperature (1-9 °C), whereas in the washing with chlorine dioxide, concentration (10-90 mg/L) and temperature (5-25 °C) were assessed. The predictive models obtained for the four response variables γLA, γCl (decimal reduction of L. brevis DSM 6235), Vf/V0LA, and Vf/V0Cl (brewer's yeast viability ratio) were found to have R2 > 0.80 and values of Fcalc > Freference. Then, the models were considered predictive and statistically significant (p < 0.10). Our results indicated that phosphoric acid and chlorine dioxide washing resulted in up to 7 and 6.4 (log CFU/mL) decimal reductions of L. brevis DSM 6235, respectively. On the other hand, the viability of the brewer's yeast ranged from 22.3 to 99.4%. L. brevis DSM 6235 inactivation was significantly influenced by parameters pH(Q) and T°C(Q) when phosphoric acid was applied, and by parameters mg/L(L), mg/L(Q), T°C(Q), and mg/L × T°C when ClO2 was applied. The validation of the models resulted in bias (γLA, 0.93/Vf/V0LA, 0.99 - γCl, 1.0/Vf/V0Cl, 0.99) and accuracy values (γLA, 1.12/Vf/V0LA, 1.01 - γCl, 1.08/Vf/V0Cl, 1.03). The results of this study indicate that it might be possible to decontaminate brewer's yeast through acid and chlorine dioxide washing while keeping its viability. This procedure will result in the reduction of costs and the lower generation of brewer's waste.

Bacteriocin-like inhibitory substance of Pediococcus pentosaceus as a biopreservative for Listeria sp. control in ready-to-eat pork ham.

The growing demand of consumers for synthetic chemical-free foods has increased the search for natural preservatives such as bacteriocins and bacteriocin-like inhibitory substances (BLIS) to give them adequate microbiological safety, sensory characteristics, and shelf life. In this study, the antimicrobial activity of BLIS produced by Pediococcus pentosaceus ATCC 43200 was compared with that of nisin. Lactobacillus sakei ATCC 15521, Listeria seeligeri NCTC 11289, Enterococcus En2052 and En2865, and Listeria monocytogenes CECT 934 and NADC 2045 exhibited larger inhibition halos in BLIS-treated than in Nisaplin-treated samples, unlike Listeria innocua NCTC 11288. In artificially contaminated ready-to-eat pork ham, BLIS was effective in inhibiting the growth of L. seeligeri NCTC 11289 for 6 days (counts from 1.74 to 0.00 log CFU/g) and ensured lower weight loss (2.7%) and lipid peroxidation (0.63 mg MDA/kg) of samples compared with the control (3.0%; 1.25 mg MDA/kg). At the same time, coloration of ham samples in terms of luminosity, redness, and yellowness as well as discoloration throughout cold storage was not influenced by BLIS or Nisaplin taken as a control. These results suggest the potential use of P. pentosaceus BLIS as a biopreservative in meat and other food processing industries.

Purification, characterization, mode of action, and enhanced production of Salivaricin mmaye1, a novel bacteriocin from Lactobacillus salivarius SPW1 of human gut origin

Background: Emergence of antibiotic resistance among pathogenic and food spoilage bacteria such as Staphylococcus aureus, Micrococcus luteus, Streptococcus pyogenes, Streptococcus sanguinis, Streptococcus mutans, Bacillus cereus, and Listeria monocytogenes triggered the search for alternative antimicrobials. An investigation aimed at purifying, characterizing, elucidating the mode of action, and enhancing the production of salivaricin from Lactobacillus salivarius of human gut origin was conducted. Results: Salivaricin mmaye1 is a novel bacteriocin purified from L. salivarius isolated from human feces. It is potent at micromolar concentrations and has a molecular weight of 1221.074 Da as determined by MALDI-TOF mass spectrometry. It has a broad spectrum of antibacterial activity. Salivaricin mmaye1 showed high thermal and chemical stability and moderate pH stability. The proteinaceous nature of salivaricin mmaye1 was revealed by the complete loss of activity after treatment with pepsin, trypsin, α-chymotrypsin, protease, and proteinase. Salivaricin mmaye1 is cell wall associated, and adsorption­desorption of the bacteriocin from the cell wall of the producer by pH modification proved successful. It exhibited a bactericidal mode of action mediated by pore formation. Its biosynthesis is regulated by a quorum sensing mechanism. Enhanced production of salivaricin mmaye1 was achieved in a newly developed growth medium. Conclusions: A novel, cell wall adhering, highly potent bacteriocin with a broad spectrum of inhibitory activity, membrane-permeabilizing ability, and enhanced production in a newly constituted medium has been isolated. It has a quorum sensing regulatory system and possesses interesting physicochemical characteristics favoring its future use in food biopreservation. These findings pave the way for future evaluation of its medical and food applications.

Fungi in cake production chain: Occurrence and evaluation of growth potential in different cake formulations during storage.

This study aimed to determine the prevalence and populations of fungi in cake production chain. Besides, the growth potential of twelve fungal strains in different cake formulations was evaluated. Raw materials from two different batches (n=143), chocolate cakes (n=30), orange cakes (n=20), and processing environment air samples (n=147) were analyzed. Among the raw materials, wheat flour (3.2±0.3 log CFU per g) and corn meal (3.8±0.8 log CFU per g) belonging to batch #1 showed significant higher fungal counts (p<0.05). The fungal counts in the processing environment air reached up to 2.56 log CFU per m3 (p<0.05). The predominant fungi species in the industrialized cakes were Aspergillus flavus (28.15%), Penicillium citrinum (18.45%), Penicillium paxilli (14.56%), and Aspergillus niger (6.8%), which were also detected in the raw materials and processing environment air. Only Penicillium glabrum and Penicillium citrinum showed visible mycelium (>3mm) in the free of preservative cake formulation at 19th and 44th days of storage at 25°C, respectively. Revealing the biodiversity of fungi in ingredients, air and final products, as well as challenging final products with representative fungal strains may assist to implement effective controlling measures as well as to gather data for the development of more robust cake formulations.

Modelo de predicción probabilística de deterioro en jamón de cerdo cocido / Probabilistic prediction model of deterioration of pork cooked ham

Antecedentes: el deterioro del jamón cocido es un proceso complejo que puede manifestarse por alteraciones de tipo microbiológico, fisicoquímico y sensorial, que hasta hoy han sido determinadas por metodologías tradicionales que incluyen largos periodos de seguimiento y un número importante de muestras. Objetivos: en el presente estudio se propuso un modelo para la predicción probabilística del deterioro de jamón cocido, por medio de análisis de componentes principales (ACP) y regresión logística con aproximación bayesiana. Métodos: para realizar el análisis, se evaluaron muestras provenientes de 300 lotes independientes de jamón de cerdo cocido, los cuales se conservaron en cámaras de almacenamiento a temperaturas de 12±1°C. Se determinaron experimentalmente tres tipos de variables: fisicoquímicas (pH, sinéresis, nitritos residuales, porcentaje de ácido láctico), de textura (adhesividad, dureza, trabajo de punción y firmeza instrumental) y microbiológicas (mesófilos aerobios y bacterias acidolácticas) en dos tiempos de medición: 3 y 40 días. Para realizar la creación del modelo se seleccionaron aleatoriamente el 60% de los datos y para la validación el 40% restante. Los datos obtenidos fueron procesados con el paquete estadístico R Core Team 2012. Resultados: los nitritos residuales y la sinéresis fueron las variables más representativas, ya que su distribución, correlación y carga, fueron las más significativas, con mayor poder discriminante del fenómeno de deterioro en los dos momentos de medición. El modelo desarrollado permitió correlacionar los parámetros estudiados y predecir la probabilidad de deterioro del jamón, además de clasificarlo de acuerdo a su estado de calidad. La primera componente principal (CP1) (variables bioquímicas) explicó el 73,3 % de la variación total de los datos, siendo los nitritos residuales y la sinéresis los factores más relacionados con el deterioro. Conclusión: el modelo logístico con aproximación bayesiana permitió obtener la probabilidad de deterioro del jamón cocido, almacenado a 12°C usando parámetros fisicoquímicos. La aplicación del ACP permitió correlacionar y clasificar los factores de deterioro del producto.

Background: the spoilage of cooked ham is a complex process that may be manifested by alterations of microbiological, physicochemical and sensory type, which has been determined by traditional methodologies including long periods of monitoring with a significant number of samples. Objective: in the present study a model for probabilistic prediction of spoilage of cooked ham was proposed by principal component analysis (PCA) and logistic regression with Bayesian approach. Methods: to perform the analysis, independent samples from 300 batches of cooked pork ham were evaluated, which were stored in cold at temperatures 12 ± 1°C. Three types of variables were experimentally determined: physicochemical (pH, syneresis, residual nitrite, lactic acid percentage), texture (adhesiveness, toughness, puncture and instrumental firmness) and microbiological (aerobic mesophilic bacteria and lactic acid bacteria) in two times: 3 and 40 days. To make this model were randomly selected 60% of the data and to validate it the remaining 40%. The obtained data were processed with statistical package R package statistical Core Team 2012. Results: residual nitrite and syneresis were the most representative variables, since its distribution, correlation and loadings were the most significant, more discriminant of the phenomenon of spoilage in the two times of measurement. The developed model allowed correlating the parameters and predicting the spoilage probability of cooked ham, and classifying them according to their quality status. The first principal component (PC1) (biochemical variables) explained 73.3 % of the total variation, the residual nitrite and syneresis were the factors that related the spoilage. Conclusions: the logistic regression model with Bayesian approach allowed obtaining the probability of deterioration of cooked ham, stored at 12°C using physicochemical parameters. Applying the PCA permited to correlate and classify the factors of spoilage.

Occurrence of microrganisms responsable for deterioration of a meat subproduct of low acidity / Ocorrência de microrganismos responsáveis pela deterioração de um produto cárneo de baixa acidez

In the present paper it was studied the cause of contamination of corned beef a meat subproduct of low acidity, were analysed 210 samples. The following agents were searched: Clostridium 3,8%; Bacillus 6,66%; Coliforms 9,52%c; Enterococos 15,71%. Knowing that the present agents of the group Bacillus and Clostridium is a marker of deterioratioyi by subprocessing and the detection of Conforms and Enterococci is an index of leakage from sanitary cans the results obtained allowed to conclude that leakage of sanitary cans is the ynost frequent cause for the putrefactive alterations found in these products.

Procurou-se identificar a causa mais comum da deterioracao da presuntada enlatada, isto é, um sub-processamento ou um vazamento pós-processamento. Para tanto, foram, escolhidos quatro grupos de germes: dois tipicamente esporulados (Bacillus e Clostridium), que refletem muito bem a deterioração por sub-processamento, e dois não esporulados (coliformes e enterococos), habitantes normais do intestino do homem e dos animais e, consequentemente, valiosos índices de contaminação por vazamentos da lata sanitária. Analisados 210 continentes, as porcentagens de ocorrência de positivos foram as seguintes: Bacillus 6,66% a Clostridium 3,80%; coliformes 9,52%; enterococos 15,71%. Os resultados obtidos permitem responsabilizar os vazamentos eventualmente existentes nas latas sanitárias, como principais responsáveis pelas alterações putrefativas de natureza microbiana sofridas pelo alimento analisado.

Occurrence of microrganisms responsable for deterioration of a meat subproduct of low acidity / Ocorrência de microrganismos responsáveis pela deterioração de um produto cárneo de baixa acidez

In the present paper it was studied the cause of contamination of corned beef a meat subproduct of low acidity, were analysed 210 samples. The following agents were searched: Clostridium 3,8%; Bacillus 6,66%; Coliforms 9,52%c; Enterococos 15,71%. Knowing that the present agents of the group Bacillus and Clostridium is a marker of deterioratioyi by subprocessing and the detection of Conforms and Enterococci is an index of leakage from sanitary cans the results obtained allowed to conclude that leakage of sanitary cans is the ynost frequent cause for the putrefactive alterations found in these products.

Procurou-se identificar a causa mais comum da deterioracao da presuntada enlatada, isto é, um sub-processamento ou um vazamento pós-processamento. Para tanto, foram, escolhidos quatro grupos de germes: dois tipicamente esporulados (Bacillus e Clostridium), que refletem muito bem a deterioração por sub-processamento, e dois não esporulados (coliformes e enterococos), habitantes normais do intestino do homem e dos animais e, consequentemente, valiosos índices de contaminação por vazamentos da lata sanitária. Analisados 210 continentes, as porcentagens de ocorrência de positivos foram as seguintes: Bacillus 6,66% a Clostridium 3,80%; coliformes 9,52%; enterococos 15,71%. Os resultados obtidos permitem responsabilizar os vazamentos eventualmente existentes nas latas sanitárias, como principais responsáveis pelas alterações putrefativas de natureza microbiana sofridas pelo alimento analisado.