Modeling the Thermal Inactivation of Monascus ruber Ascospores Isolated from Green Olive (Arauco Cultivar) Storage Brine: An Alternative Strategy to Reduce Antifungal Chemical Agents.

Monascus ruber is an important fungus that causes spoilage in table olives, resulting in the darkening of the brine, the softening of the fruit, increased pH, and apparent mycelial growth. This study aimed to evaluate this resistance, providing a model to determine the optimal processing conditions for mitigating fungal contamination and prolonging shelf life without antifungal agents while optimizing pasteurization to reduce energy consumption. The resistance in brine (3.5% NaCl; pH 3.5) from Arauco cultivar green olives imported from Argentina was assessed. Four predictive models (log linear, log linear + shoulder, log linear + tail, log linear + shoulder + tail) estimated kinetic parameters for each survival curve. Log linear + shoulder + tail provided the best fit for 70 °C and 75 °C, with low RMSE (0.171 and 0.112) and high R2 values (0.98 and 0.99), respectively, while the log linear model was used for 80 °C. Decimal reduction times at 70, 75, and 80 °C were 24.8, 5.4, and 1.6 min, respectively, with a z-value of 8.2 °C. The current regulatory processes are insufficient to eliminate M. ruber at requisite levels, considering reduced antifungal agents.

Inactivation of Salmonella Typhimurium, Escherichia coli, and Staphylococcus aureus in Tilapia Fillets (Oreochromis niloticus) with Lactic and Peracetic Acid through Fogging and Immersion.

This study investigated the antimicrobial effects of lactic acid (LA) (3%) and peracetic acid (PA) (300 ppm) on tilapia fillets (Oreochromis niloticus) by fogging (15 min) or by immersion (2 s) in a pool of Escherichia coli (NEWP 0022, ATCC 25922, and a field-isolated strain), Staphylococcus aureus (ATCC 25923 and a field-isolated strain), and Salmonella Typhimurium (ATCC 13311 and ATCC 14028), as well as the effects on the physicochemical characteristics of the fillets. Fogging was effective and the best application method to control S. Typhimurium regardless of the acid used, promoting reductions of 1.66 and 1.23 log CFU/g with PA and LA, respectively. Regarding E. coli, there were significant reductions higher than 1 log CFU/g, regardless of the treatment or acid used. For S. aureus, only immersion in PA showed no significant difference (p < 0.05). For other treatments, significant reductions of 0.98, 1.51, and 1.17 log CFU/g were observed for nebulized PA, immersion, and LA fogging, respectively. Concerning the pH of the samples, neither of the acids used differed from the control. However, treatments with LA, and fogging with PA, reduced the pH compared to immersion in PA. As for color parameters, L* and a* values showed changes regardless of the acid or method used, resulting in an improved perception of fillet quality. These results indicate that fogging and immersion are alternatives for reducing S. Typhimurium, E. coli, and S. aureus in tilapia fillets.

Milk and Fresh Cheese Quality of Crossbred Cows Supplemented with Phytogenic Additives and Managed under Thermal Stress.

This investigation aimed to assess the physiological parameters and quality of milk and fresh cheeses produced by cows that were housed in paddocks, either with or without shade, and supplemented with a phytogenic additive. Sixteen crossbred cows were allocated in a 4 × 4 Latin square design, dividing them into paddocks with or without shade, and providing or not providing a phytogenic additive in their feed. This resulted in a total of four treatment groups and sixteen experimental plots, each containing four animals, over four periods of 21 days. Various parameters were examined, including haematology, rectal and skin temperature, respiratory rate, milk yield and composition, serum parameters, and cheese yield and quality. It is worth noting that the temperature and humidity, as measured by a black globe thermometer, did not display significant variations between the different environments and exhibited minimal fluctuations throughout the day. Additionally, the supplementation of the phytogenic additive led to a reduction in haematocrit levels (p = 0.011). Furthermore, the analysis showed that whey obtained from cheese production had a higher fat content when cows were without access to shade (p = 0.005). Notably, there was an interaction between factors in relation to the total dry extract content, which was lower when cows had access to shade and received the additive (p = 0.010). In summary, the provision of a phytogenic additive and the presence or absence of shade did not bring about significant changes in milk production and quality or in the yield and quality of fresh cheese.

Biofilm-producing ability of Listeria monocytogenes isolates from Brazilian cheese processing plants.

The persistence of Listeria monocytogenes in food industry environments has been associated to the ability of specific isolates to produce biofilms. This study aimed to evaluate the biofilm production of 85 L. monocytogenes strains previously isolated from samples of cheese, brine and the environment of two cheese processing plants located in São Paulo, Brazil. The L. monocytogenes isolates belonged to serotypes 4b, 1/2b and 1/2c, yielded 30 different pulsotypes by pulsed-field gel electrophoresis (PFGE), and were submitted to biofilm-formation assays on polystyrene microplates and stainless steel coupons incubated statically at 35±0.5°C for 48h. All isolates from different sources showed ability to produce biofilms on polystyrene microplates, from which 21 (24.7%) also produced biofilms on stainless steel. Four isolates (4.7%) belonging to four different pulsotypes were classified as strong biofilms-producers on polystyrene microplates, while isolates belonging to four pulsotypes previously evaluated as persistent had weak or moderate ability to produce biofilms on polystyrene microplates. No relationship between the serotypes or pulsotypes and their biofilm-forming ability was observed. This study highlights the high variability in the biofilm production among L. monocytogenes strains collected from cheese and cheese-production environment, also indicating that strong biofilm-formation ability is not a key factor for persistence of specific isolates in cheese processing plants.

Azeitonas de mesa no Brasil: mercado, tecnologia e aspectos legais / Table olives in Brazil: market, technology and legal aspects

Azeitona de mesa é o produto vegetal fermentado de maior importância no mundo ocidental. Apesar de não possuir produção significativa, o Brasil está entre os dez maiores consumidores de azeitona de mesa do mundo. Para o ano safra 2013/2014 (período entre os dias 01 de outubro até 30 de setembro), estima-se que o país seja o segundo maior importador e o nono maior consumidor do fruto. No entanto, as características do fruto e os principais processos de elaboração de azeitonas de mesa são pouco conhecidos no Brasil. Dessa maneira, este trabalho objetiva realizar um levantamento do mercado, as principais tecnologias utilizadas e os aspectos legais associadas à produção de azeitona de mesa.

Table olives is the greater importance fermented vegetable product in the western world. Despite not having significant production, Brazil is among the ten largest consumers of table olives in the world. For the crop year of 2013/2014 (period between 01 October to 30 September) it is estimated that the country becomes the second largest importer and the ninth-largest consumer of the fruit. However, knowledge about the fruit characteristics and the main processes of elaboration of table olives are scarce. Thus, this research aims to survey the market, main technologies and the associated legal aspects of the production of table olives.