Abstract This study aimed to investigate the antimicrobial activity of kefir fermented fruit by-products against strains of Alicyclobacillus spp., and determine their chemical characterization and antioxidant activity. According to the results, extracts fermented for a longer period (72 h) showed greater inhibition, and the extract of acerola by-product fermented for 72 h achieved the best results. For all strains, the Minimal Inhibitory Concentration (MIC) was 0.78%, except for A. acidocaldarius subsp. rittmannii, (1.56%). The same applies to the Minimal Bactericidal Concentration (MBC), in which 1.56% of the extract was capable of inactivating A. cycloheptanicus and A. acidocaldarius. In addition, damages to the structure of the microorganisms caused by the extracts were detected by Scanning Electron Microscopy. Metabolite identification through liquid chromatography (UHPLC-Qtof-MS) showed that the fermented extracts had a greater number of compounds compared to the non-fermented ones, such as glucuronic, succinic and glutaric acids. In conclusion, the extracts of fruit by-products showed to have bioactive properties, such as antibacterial potential and antioxidant activity against the Alicyclobacillus strains tested in this study, not to mention the value added by the use of a food by-product.

RESUMO: O objetivo deste trabalho foi elaborar e caracterizar mortadelas a partir de aparas da filetagem (corte em “V” do filé) de tilápia do Nilo, de forma a possibilitar a agregação de valor a este subproduto do processo de filetagem. Foram elaboradas três mortadelas, sendo uma com 100% de aparas da filetagem de tilápia, outra contendo 100% de carne de frango e a terceira com 100% de carne suína. As mortadelas foram caracterizadas quanto à microbiologia, composição química, cálcio, colágeno, pH, Aw, cor, textura e custo de formulação. As mortadelas estavam dentro dos padrões microbiológicos recomendados. A mortadela de tilápia apresentou maiores teores de umidade, cinzas, cálcio e colágeno, maior pH e menor atividade de água quando comparada às demais espécies. A mortadela de tilápia apresentou menor luminosidade, maior croma a* e croma b* intermediário às demais. A textura foi melhor para as mortadelas de tilápia, quanto a dureza, gomosidade e mastigabilidade, cujos valores foram menores. A mortadela de frango teve maior índice de aceitação, porém, a de tilápia também foi elevado, enquanto de suíno todos os atributos avaliados receberam as piores notas. A mortadela de tilápia do Nilo é uma inovação tecnológica que pode ser introduzida no setor alimentício com bom valor nutricional e bom índice de aceitação.

ABSTRACT: The objective of this research was to elaborate and characterize mortadella using fillet residues (‘V’-cut fillet trim) of Nile tilapia, in order to add value to this by-product of the filleting process. Three mortadellas were made, one with 100% tilapia fillet trimmings, another containing 100% chicken meat and the third with 100% pork meat. Mortadellae were characterized in terms of microbiology, chemical composition, calcium, collagen, pH, Aw, colour, texture and formulation cost. Mortadella was within the recommended microbiological standards. Tilapia mortadella had higher levels of moisture, ash, calcium and collagen, higher pH and lower water activity when compared to other species. The tilapia mortadella had lower brightness, higher chroma a * and intermediate chroma b *, compared with the others. The texture of tilapia mortadella was better in terms of hardness, gumminess and chewability, the values of which were lower. The chicken mortadella had a higher acceptance rate; however, that of tilapia was also high, while all evaluated attributes of pork received the worst grades. Nile tilapia mortadella is a technological innovation that can be introduced into the food sector with good nutritional value and a good acceptance index.

RESUMO: O objetivo deste estudo foi avaliar o efeito da carga microbiana inicial, temperatura e tempo de contato na formação de biofilme de Alicyclobacillus acidoterrestris em aço inoxidável e borracha natural de qualidade alimentar utilizando suco de laranja como meio de cultura. A baixa carga inicial de A. acidoterrestris (2 log UFC/mL) levou à formação de biofilme na superfície do aço inoxidável após 48 h de contato a 28 ºC e após 24 h a 45 ºC, e na superfície natural de borracha de qualidade alimentar após 48 h de contato nas duas temperaturas. A alta carga microbiana inicial (5 log UFC/mL) levou à formação de biofilme em aço inoxidável após 4 h de contato a 28 °C e 45 °C, enquanto o biofilme foi formado em borracha natural de qualidade alimentar após 8 h de contato a 28 °C e 4 h a 45 °C. A carga microbiana também afetou a presença de esporos no biofilme, o que foi observado em ambas as superfícies apenas com altas cargas iniciais de A. acidoterrestris.

ABSTRACT: The objective of this study was to evaluate the effect of the initial microbial load, temperature and contact time on the biofilm formation of Alicyclobacillus acidoterrestris on stainless steel and natural food-grade rubber using orange juice as culture medium. The low initial load of A. acidoterrestris (2 log CFU/mL) led to biofilm formation on the stainless steel surface after 48 h of contact at 28 ºC and after 24 h at 45 ºC, and on natural food-grade rubber surface after 48 h of contact at both temperatures. The high initial microbial load (5 log CFU/mL) led to biofilm formation on stainless steel after 4 h of contact at 28 °C and 45 °C, while biofilm was formed on natural food-grade rubber after 8 h of contact at 28 °C and 4 h at 45 °C. The microbial load also affected the presence of spores in biofilm, which was observed on both surfaces only at high initial loads of A. acidoterrestris.

Abstract This study evaluated the chemical composition, fatty acid profile, technological quality, sensory profile and microbiological characteristics of rolls with inclusion of 0, 5, 10 and 15% meal prepared with tilapia carcasses. Moisture and carbohydrate content were linearly reduced (P < 0.05) with increasing inclusion of tilapia meal, but a linear increase (P < 0.0001) was observed in protein (9.91 to 14.30%) and ash (1.74 to 4.65%) content. Lipids and calorific value of the rolls were not affected (P > 0.05) by inclusion levels, but 15% tilapia meal resulted in greater amount of polyunsaturated fatty acids (4.63%) in relation to 0% inclusion (4.46%). There was a linear increase (P < 0.0001) in the firmness of the breads (3.65 to 13.17N) and a linear decrease (P < 0.001) in volume and specific volume. Sensory attributes showed a negative linear effect (P < 0.01), with acceptance rates ranging from 85.24% (0% inclusion) to 70.57% (15% inclusion). It can be concluded that the inclusion of 5 to 15% tilapia meal in roll is effective to increase the protein, mineral matter, polyunsaturated fatty acids and the firmness of the roll, in addition to reducing carbohydrates and volume. Considering the reduction in sensory acceptance, it is recommended to use up to 10% tilapia meal in rolls.

ABSTRACT The present study evaluated the antibacterial and antibiofilm activity of carvacrol against Salmonella Typhimurium. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined and the time-kill curve and scanning electron microscopy (SEM) were performed to evaluate antibacterial activity. Antibiofilm activity was evaluated by quantifying total biomass using crystal violet assay, and metabolic activity was determined using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The action of carvacrol against preformed biofilm on polypropylene and stainless steel was also evaluated by colony counting and SEM. The MIC and MBC was 312 µg mL-1. Carvacrol at MIC and 2 x MIC eliminated cells after 6 and 1 h of treatment, respectively, as exhibited in the time-kill curve. The greatest reduction in biofilm biomass and metabolic activity was 1,719 OD550 and 0,089 OD550 respectively, both at 4 x MIC of carvacrol. In carvacrol treated biofilms of S. Typhimurium on polypropylene, a reduction of 5.12 log was observed with 4 x MIC, while on stainless steel, carvacrol at 4 x MIC reduced bacterial counts by 5 log. The results showed that carvacrol exhibits antibacterial activity and can be used as an alternative for the control of S. Typhimurium biofilms.

Abstract The aim of this study was to develop a lasagna pasta enriched with dried mix of tuna (30%) and tilapia (70%) and formulate ready lasagna with enriched pasta. Lasagna pasta was elaborated with increasing levels (0, 5, 10 and 15%) of dried mix. Moisture, lipids and calories were not different between the inclusion levels; crude protein and ash increased linearly, carbohydrates reduced linearly, according to increasing levels of inclusion. There was an increase in n-3 and n-6 fatty acids with the inclusion of mix in lasagna. Between lasagna prepared with different sauces (tuna, chicken and bolognese), and pasta with 15% mix, it was observed that tuna lasagna had lower moisture content and higher protein, lipids, ash, carbohydrates and calories. All lasagna showed optimal sensory acceptance, indicating that the inclusion of 15% dried mix of tilapia and tuna in the pasta is feasible to improve the nutritional composition of lasagna.

Resumo O objetivo deste trabalho foi desenvolver massas de pizza com diferentes níveis de inclusão de farinha de atum (Tunnus spp.). Para a produção da farinha de atum, foram utilizados troncos de atum sem nadadeiras, cozidos por uma hora, prensados, moídos e desidratados por 24 horas a 60 °C. Foram elaboradas massas de pizza sem inclusão (0%) ou com inclusão de 5, 10, 15 e 20% de farinha de atum, sendo estas inclusões calculadas com base na quantidade de farinha de trigo. A farinha de atum e as diferentes massas foram analisadas quanto aos teores de umidade, proteína bruta, lipídeos totais, cinzas e carboidratos, além do valor calórico e do perfil de ácidos graxos. Análises microbiológica e sensorial foram realizadas nas massas de pizza. A crescente inclusão de farinha de atum resultou em aumento do teor de proteína bruta (10,89 a 18,94%), de lipídeos totais (4,63 a 5,89%) e de cinzas (2,54 a 3,54%) nas massas, sem influenciar no teor de umidade e no valor calórico. A inclusão de farinha de atum aumentou linearmente a quantidade de ácidos graxos da série n-3 nas massas, com aumento de 1,56 para 5,93 g/kg, em 20% de inclusão de farinha de atum. A relação entre ácidos graxos poli-insaturados e saturados da farinha de atum e das massas variou entre 1,21 e 1,85. A análise microbiológica demonstrou que as massas foram produzidas em condições adequadas de higiene. Observou-se que a inclusão de 5 a 20% de farinha de atum na massa de pizza não interferiu significativamente (p>0,05) nos parâmetros de aroma, sabor, impressão global e intenção de compra. Concluiu-se que a inclusão de 5 até 20% de farinha de atum é eficaz para melhorar o valor nutritivo e o perfil de ácidos graxos de massa de pizza.

Abstract The aim of this study was to develop pizza dough with different levels of tuna meal (Tunnus spp.). In order to produce tuna meal, tuna torsos without fins were used, cooked for 1 hour, pressed, milled and dehydrated for 24 hours at 60 °C. Pizza dough was produced without (0%) or with the addition of 5, 10, 15 and 20% of tuna meal, calculated based on the quantity of wheat flour. The tuna meal and different pizza pastries were analyzed for moisture content, crude protein, total lipids, ash, carbohydrates, caloric value and fatty acid profiles. Microbiological and sensory analyses were also carried out on the pizza pastries. The increasing addition of tuna meal resulted in gains in the crude protein (10.89 to 18.94%), total lipid (4.63 to 5.89%) and ash (2.54 to 3.54%) contents of the pizza pastries, not influencing the moisture content or caloric value. The inclusion of tuna meal linearly increased the quantity of n-3 series fatty acids in the pizza pastry, from 1.56 to 5.93 g/kg with the addition of 20% tuna meal. The ratio between the polyunsaturated and saturated fatty acids in the tuna meal and pizza pastries varied from 1.21 to 1.85. The microbiological analyses showed that the pizza pastries were produced under proper hygiene conditions. It was also observed that the addition of 5 to 20% of tuna meal to the pizza pastry did not significantly (p>0.05) alter the parameters of aroma, flavor, overall impression and purchase intention. It was therefore concluded that the addition of 5 to 20% tuna meal is effective in improving the nutritional value and fatty acid profile of pizza pastry.

A contaminação de alimentos por patógenos entéricos é uma das principais causas de doenças diarréicas em todo o mundo, resultando em altas taxas de morbidade e mortalidade e perdas econômicas significativas. As bactérias são importantes agentes de doenças de origem alimentar, particularmente Escherichia coli diarreiogênicas. O presente estudo teve como objetivo avaliar a diversidade genética e a resistência a antimicrobianos de E. coli isoladas de leite pasteurizado, processados em 21 laticínios na região noroeste do Paraná - Brasil. Os 95 isolados de E. coli foram submetidos a testes de suscetibilidade aos antimicrobianos de acordo com as recomendações do Clinical and Laboratory Standards Institute e avaliados genotipicamente por ERIC-PCR (Enterobacterial Repetitive Intergenic Consensus - Polymerase Chain Reaction). O principal perfil de resistência encontrado entre os isolados foi resistência à cefalotina (55,78%). ERIC-PCR revelou alta diversidade genética, agrupando os 95 isolados bacterianos em 90 diferentes perfis genotípicos. Estes resultados mostraram uma população heterogênea de E. coli em amostras de leite produzido na região noroeste do Paraná e a necessidade de boas práticas na manipulação de todo o processamento de leite pasteurizado, a fim de reduzir o risco de doenças transmitidas por alimentos.

Food contamination caused by enteric pathogens is a major cause of diarrheal disease worldwide, resulting in high morbidity and mortality and significant economic losses. Bacteria are important agents of foodborne diseases, particularly diarrheagenic Escherichia coli. The present study assessed the genetic diversity and antimicrobial resistance of E. coli isolates from pasteurized milk processed in 21 dairies in northwestern State of Parana, Brazil. The 95 E. coli isolates were subjected to antimicrobial susceptibility testing according to the recommendations of the Clinical and Laboratory Standards Institute and assessed genotypically by Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR). The highest rate of resistance was observed for cephalothin (55.78%). ERIC-PCR revealed high genetic diversity, clustering the 95 bacterial isolates into 90 different genotypic patterns. These results showed a heterogeneous population of E. coli in milk samples produced in the northwestern region of Paraná and the need for good manufacturing practices throughout the processing of pasteurized milk to reduce the risk of foodborne illnesses.

O objetivo deste trabalho foi avaliar a qualidade microbiológica e a vida útil de filés de tilápia-do-nilo, submetidos a diferentes métodos de defumação e condições de armazenamento. Foram utilizados dois processos de defumação (a frio ou a quente), em filés com ou sem pigmentação. Os produtos foram armazenados sob refrigeração ou congelados, e monitorados por 28 dias para avaliação da vida útil. Os filés congelados foram monitorados continuamente por 146 dias, apenas para a análise de ácido tiobarbitúrico (TBA). Defumação a quente e a frio reduziram a quantidade de coliformes, respectivamente em 99,78% e 97,80%. O armazenamento do produto sob refrigeração permitiu a redução de 99,73% dos coliformes, e o armazenamento sob congelamento os reduziu em 99,83%. Os valores encontrados de coliformes fecais estiveram dentro do limite permitido. Os valores de TBA nos filés atingiram o máximo no 14o dia de armazenamento. Os valores de TBA nos tratamentos sob refrigeração foram superiores aos daqueles sob congelamento e, também, em filés defumados a frio, em comparação aos defumados a quente. O processo de defumação a quente, com posterior armazenamento sob congelamento, é a técnica mais apropriada para assegurar qualidade e maior período de vida útil para os filés de tilápia-do-nilo, independentemente do processo de pigmentação.

The objective of this work was to evaluate the microbiological quality and shelf life of Nile tilapia fillets subjected to different smoking methods and storing conditions. Two smoking processes (cold or hot) were used in fillets with or without pigmentation. Products were stored under refrigeration or freezing, and monitored continually for 28 days for evaluation of their shelf life. Frozen fillets were monitored for 146 days for analysis of thiobarbituric acid (TBA) only. Hot- and cold-smoking reduced the coliform quantity, respectively, by 99.78% and 97.80%. Product storage under refrigeration allowed a 99.73% coliform reduction, and storage under freezing reduced them by 99.83%. Fecal coliform values were within the allowed limits. TBA values in fillets reached their maximum on the 14th storage day. TBA values were higher in treatments under refrigeration storage than in those under freezing, as well as in cold-smoked fillets in comparison to the hot-smoked ones. Hot-smoked process, followed by refrigeration storage, is the most adequate technique to ensure quality and a larger shelf life for Nile tilapia fillets, regardless of pigmentation process.

Objetivou-se caracterizar peles de tilápia-do-nilo, conservadas por congelamento e salga a seco, visando à extração de gelatina em processo batelada. Após a filetagem, as peles foram descarnadas e distribuídas em dois lotes. Um dos lotes foi congelado a -18 ºC por sete dias e o outro foi salgado e mantido a 25 ºC por sete dias. As peles foram lavadas, pesadas e pré-tratadas em solução de H2SO4 a10N (pH 3,0), na proporção de 1:6 (pele:água) por uma hora a 24 ºC. Extraiu-se a gelatina em banho-maria a 50 ºC por uma hora e retirou-se uma amostra para análise do perfil molecular. O restante foi congelado a -18 ºC. Foram realizadas análises físico-químicas das peles e das gelatinas líquidas, do perfil molecular com as gelatinas e análises microbiológicas das peles. As peles congeladas e salgadas apresentaram, respectivamente, 78,13 e 76,46% de umidade; 18,16 e 19,59% de proteína bruta; 2,26 e 1,90% de extrato etéreo e 1,44 e 2,06% de cinzas. Nas gelatinas líquidas extraídas das peles congeladas e salgadas, a umidade foi de 97,68 e 96,08%, o conteúdo de proteína bruta de 3,18 e 4,12%, de extrato etéreo 0,29 e 0,18% e de cinzas de 2,31 e 3,03%, respectivamente. Os valores da força de gel e viscosidade foram maiores para a gelatina de peles salgadas (200 g e 19,02mPas) em comparação à gelatina de peles conservadas pelo congelamento (12,7 g e 9,16mPas). O perfil molecular foi menor na gelatina extraída a partir de peles congeladas, portanto houve perda de β e γ-componentes, que indica grande degradação do colágeno decorrente do método de conservação.

The objective was to characterize Nile tilapia skins, freeze- and dry salt dry-preserved to extract gelatins by batch processing. After filleting, the skins were separated from the meat and distributed into two lots: In one, skins were frozen for 7 days (-18 ºC); and in the other, skins were salted for seven days (25 ºC). The skins were rinsed, weighed and pretreated in H2SO4 a10N solution (pH 3.0), at a 1:6 (skin/water) ratio for 1 h at 24 ºC. Gelatin was extracted in water bath at 50 ºC for 1 h, and a sample was removed for molecular profiling; the rest was frozen at -18 ºC. Physical-chemical analyses were carried out on the skins and liquid gelatins, the molecular profile was obtained from the gelatins, and the skins underwent microbiological analyses. Frozen and salted skins showed, respectively: 78.13% and 76.46% moisture, 18.16% and 19.59% crude protein, 2.26% and 1.90% ether extract, and 1.44% and 2.06% ash, respectively. For the liquid gelatins extracted from frozen and salted skins, moisture was 97.68% and 96.08%, crude protein was 3.18% and 4.12%, ether extract was 0.29% and 0.18%, and ash was 2.31% and 3.03%, respectively. Gel strength and viscosity values were higher for salted skins gelatin (200 g and 19.02 mPas) compared with freeze-preserved skins gelatin (12.7 g and 9.16 mPas). The molecular profile was lower in gelatin extracted from frozen skins, which indicates loss of β and γ-components, which indicates considerable collagen decay from that preservation method.

O objetivo deste estudo foi analisar o perfil de resistência à antimicrobianos, de Salmonella isoladas de 21 amostras provenientes de pacientes com sintomatologia de gastroenterite. Verificou-se que S. enteritidis foi o sorotipo com maior prevalência. Estas cepas mostraram-se sensíveis à maioria dos antimicrobianos testados, no entanto, as cepas S. typhimurium e S. enterica subsp. enterica sorotipo 4,5,12:i:-, mostraram-se resistentes à vários antimicrobianos. Vigilância e um monitoramento eficiente, para diminuir a resistência antimicrobiana em microrganismos que causam infecções veiculadas por alimentos, devem ser prioridade para a saúde pública.

The purpose of this study was to analyse the profile of antimicrobial resistance among 21 strains of Salmonella isolated from patients with gastroenteritis symptom. It was observed that S. enteritidis was the serotype prevalent. These strains were sensitive to the majority of the antimicrobials tested, however, high resistance was observed in S. typhimurium and S. enterica subsp. enterica serotype 4,5,12:i:-. Surveillance and an efficient monitoring should be priority for the public health for the containment of antimicrobial resistance in foodborne infections.