Effect of Lactobacillus coryniformis FZU63 on the flavor quality of black tea beverage / 生物工程学报

The tea beverages will be endowed with distinct aroma and taste, as well as various biologically active compounds including probiotic factors, when fermented with lactic acid bacteria (LAB). However, at present, few studies on the dynamics of flavors in tea soup at different fermentation stages were conducted. In this study, the composition of monosaccharides, aromatic components, free amino acids, and organic acids were measured, when the black tea beverages were fermented with Lactobacillus coryniformis FZU63 which was isolated from Chinese traditional kimchi. The results indicated that monosaccharides including glucose, fructose, mannose and xylose in black tea beverages are the main carbon sources for fermentation. In addition, the abundance of aromatic compounds in black tea soup are increased significantly at different fermentation stages, which endow the fermented black tea soup with fruit aroma on the basis of flowery and nutty aroma. Moreover, some bitter amino acids are reduced, whereas the content of sweet and tasty amino acids is elevated. Furthermore, the levels of lactic acid, malic acid, citric acid and other organic acids are accumulated during the fermentation. Additionally, sensory evaluation displays that black tea beverage is acquired with comprehensive high-quality after being fermented for 48 h. This study provides a theoretical basis to steer and control the flavor formation and quality of the fermented tea beverages during LAB fermentation.

Survey of molds, yeast and Alicyclobacillus spp. from a concentrated apple juice productive process

Bacteria and molds may spoil and/or contaminate apple juice either by direct microbial action or indirectly by the uptake of metabolites as off-flavours and toxins. Some of these microorganisms and/or metabolites may remain in the food even after extensive procedures. This study aim to identify the presence of molds (including heat resistant species) and Alicyclobacillus spp., during concentrated apple juice processing. Molds were isolated at different steps and then identified by their macroscopic and microscopic characteristics after cultivation on standard media at 5, 25 and 37ºC, during 7 days. Among the 19 isolated found, 63% were identified as Penicillium with 50% belonging to the P. expansum specie. With regards to heat resistant molds, the species Neosartorya fischeri, Byssochlamys fulva and also the genus Eupenicillium sp., Talaromyces sp. and Eurotium sp. were isolated. The thermoacidophilic spore-forming bacteria were identified as A. acidoterrestris by a further investigation based on 16S rRNA sequence similarity. The large contamination found indicates the need for methods to eliminate or prevent the presence of these microorganisms in the processing plants in order to avoid both spoilage of apple juice and toxin production.

Contaminação fúngica de plantas medicinais utilizadas em chás / Fungal contamination of medicinal plants used in teas

Este trabalho teve como objetivo avaliar a qualidade microbiológica quanto à presença de fungos filamentosos em ervas do tipo Peumus boldus Molina (Boldo), Pimpinella anisum L. (erva-doce) e Matricaria chamomilla L. (Camomila) comercializadas na cidade de Campina Grande (Paraíba). Nove amostras de cada planta foram analisadas, totalizando 27 amostras, obtidas aleatoriamente nas feiras livres e barracas informais da cidade. Cada 10 g de amostra foram suspensas em 90 mL de solução salina 0,89% estéril, obtendo-se o concentrado, a partir do qual foram realizadas diluições sucessivas. A seguir, uma alíquota de 0,1mL de cada diluição foi semeada em placas de Petri contendo Ágar Sabouraud Dextrose, as quais foram incubadas à temperatura ambiente por cinco a dez dias. Após este período foram contadas as colônias fúngicas presentes e realizados seus respectivos microcultivos para identificação através de microscópio óptico. Foram encontrados fungos toxigênicos como Aspergillus sp., Penicillium sp. e Fusarium sp., estando o primeiro presente em todas as amostras avaliadas. Também foram identificados os fungos Exophiala sp. E Fonsecaea sp., que possuem importância clínica, podendo causar micose. A forma como estas plantas são armazenadas para comercialização e a falta de fiscalização torna questionável a qualidade das plantas comercializadas para obtenção de chás, o que pode comprometer a saúde do consumidor ao utilizar esses produtos na forma de Chá.

The aim of this study was to assess the microbiological quality, with regard to the presence of filamentous fungi, of the tea herbs Peumus boldus Molina (boldo leaf), Pimpinella anisum L. (anise) and Matricaria chamomilla L. (wild chamomile) marketed in the city of Campina Grande (Paraiba State, Brazil). Nine samples of each plant, totaling 27 samples, were randomly collected in street markets and informal stalls in the city. In the laboratory, 10 g of each sample was ground and suspended in 90 mL of 0.89% sterile saline solution, affording the concentrate from which serial dilutions were obtained. Aliquots of 0.1 mL of each dilution were spread on plates of Sabouraud Dextrose Agar, which were then incubated at room temperature for five to ten days. After this period, the fungal colonies were counted, their morphology was analyzed and subcultures were made on slides for identification by optical microscope. Toxigenic fungi such as Aspergillus sp., Penicillium sp. and Fusarium sp. were found, the first being present in all plant samples. The fungi Exophiala sp. and Fonsecaea sp., which are clinically significant as they can cause mycoses, were also identified. The method of storing these plants before sale and the lack of inspection raise questions about the quality of the marketed herbs, suggesting that the health of the consumer who uses these products to make tea could be harmed.

Microbiological, technological and therapeutic properties of kefir: a natural probiotic beverage

Kefir is a fermented milk beverage produced by the action of bacteria and yeasts that exist in symbiotic association in kefir grains. The artisanal production of the kefir is based on the tradition of the peoples of Caucasus, which has spread to other parts of the world, from the late 19th century, and nowadays integrates its nutritional and therapeutic indications to the everyday food choices of several populations. The large number of microorganisms present in kefir and their microbial interactions, the possible bioactive compounds resulting of microbial metabolism, and the benefits associated with the use this beverage confers kefir the status of a natural probiotic, designated as the 21th century yoghurt. Several studies have shown that kefir and its constituents have antimicrobial, antitumor, anticarcinogenic and immunomodulatory activity and also improve lactose digestion, among others. This review includes data on the technological aspects, the main beneficial effects on human health of kefir and its microbiological composition. Generally, kefir grains contain a relatively stable and specific microbiota enclosed in a matrix of polysaccharides and proteins. Microbial interactions in kefir are complex due to the composition of kefir grains, which seems to differ among different studies, although some predominant Lactobacillus species are always present. Besides, the specific populations of individual grains seem to contribute to the particular sensory characteristics present in fermented beverages. This review also includes new electron microscopy data on the distribution of microorganisms within different Brazilian kefir grains, which showed a relative change in its distribution according to grain origin.

Calidad microbiológica de alimentos remitidos a un laboratorio de salud pública en el año 2009 / The microbiological quality of food sent to a public health laboratory in 2009

Objetivo Analizar la calidad Microbiológica de alimentos provenientes de los Municipios de Santander, procesados por el Laboratorio Departamental de Salud Pública durante el año 2009. Materiales y Métodos Se analizó la calidad microbiológica de los alimentos remitidos al LDSP de Santander durante el año 2009 mediante la recopilación de los reportes emitidos por la institución y la realización de un análisis estadístico de 763 muestras de alimentos provenientes de 76 municipios del departamento. Se analizó la información por municipio en los programas estadísticos Minitab versión 15 y Statistica versión 8.0 donde se organizó la información por categorías alimentarias y se analizaron las frecuencias en cada municipio durante el periodo de enero a diciembre del 2009 Resultados Se evidenció que de los 763 registros de alimentos el 45,2 % (n=345) presentaron contaminación bacteriana, observándose una mayor frecuencia de estos eventos en los municipios de Barichara, Barrancabermeja, Floridablanca, Girón, Socorro y Valle de San José con el 33,6 % (n=116) del total de muestras afectadas. Los principales alimentos que presentaron parámetros fuera de norma fueron los alimentos preparados con un total de 160 muestras remitidas, de las cuales 80 presentaron alteraciones lo que corresponde al 50 %, seguido de las bebidas como jugos y refrescos con un 48,3 %, los lácteos 47,9 % y los cárnicos 40,7 %. Conclusiones En las muestras remitidas al LDSP se encontró un alto índice de contaminación alimentaria durante el año 2009, información útil para la planeación de acciones preventivas dentro de los programa de vigilancia del LDSP.

Objective Testing the microbiological qualityof foodsamples from municipalities in theSantander department which were processed bythePublicHealth Laboratory(PHL) in 2009. Materialsand Methods The microbiological quality of food samples sent to the Santander PHL in 2009 was analysed by collecting reports issued by the institution and conducting a statistical analysis of 763 food samples from 76 municipalities in the department. Minitab statistical software (version 15) and Statistica (version 8.0) were used for analysing the information by municipality; this information was organised by food category and adverse incident frequency was analysed in each municipality from January to December 2009. Results It was seen that 45.2 % (n=345) of 763 food records had bacterial contamination; there was a greater frequency of these events in the municipalities of Barichara, Barrancabermeja, Floridablanca, Girón, Socorro and Valle de San Jose accounting for 33.6 % (n=116) of all affected samples. The main foods that had non-standard parameters were prepared foods (160 samples submitted), of which 80 had alterations in quality (50 %), followed by drinks like fruit juice and soft drinks (48.3 %), dairy products (47.9 %) and meat (40.7 %). Conclusions A high rate of food contamination was found in the samples sent to PHL during 2009; this information is useful for planning preventative action within the ongoing PHL surveillance programme.

Bebida mista à base de goiaba (Psidium guajava L.) e palma forrageira (Opuntia fícus-indica): desenvolvimento e aceitabilidade / Mixed drink consisting of guava (Psidium guajava. L) and forrageira palm (Opuntia fícus-indica): development and acceptability

Atualmente, na indústria de bebidas, uma alternativa para aumentar o valor nutritivo ou mesmo desenvolver novos sabores tem sido a mistura de produtos na formulação de bebidas mistas. Este trabalho teve como objetivo o desenvolvimento de uma bebida mista de palma forrageira e goiaba. Foram avaliadas quatro formulações com diferentes concentrações de palma e de sólidos solúveis, mantendo-se constante a concentração de goiaba. As formulações foram submetidas à caracterização química (pH, sólidos solúveis, acidez titulável, vitamina C), avaliação sensorial (sabor, cor, corpo e aceitação global) e análises microbiológicas (coliformes totais e termotolerantes, Salmonella e Estaphylococcus aureus). Todas as formulações foram bem aceitas sensorialmente e não apresentaram diferença significativa (p<0,5) entre elas, estando o nível de aceitação entre "gostei ligeiramente" e "gostei moderadamente" para todos os atributos avaliados. A bebida mista formulada apresentou-se dentro dos parâmetros químicos e microbiológicos fixados pela legislação brasileira, exceto para o pH, o qual se apresentou acima do ideal para produtos industrializados. Em relação às análises microbiológicas, nenhuma das formulações apresentou presença de microrganismos. Os resultados mostraram que o produto elaborado encontra-se de acordo com os padrões de identidade e qualidade para bebidas e com uma boa aceitação sensorial, tornando-se um produto com potencial para industrialização.

Nowadays, in the beverage industry, the mixture of products became an alternative to increase the nutritional value or even to develop new flavors in the formulation of mixed drinks. The objective of this work was to develop a mixed drink of forrageira palm with guava. Four formulations with different palm concentrations and soluble solids were evaluated, keeping the concentration of guava stable. The products were submitted to chemical characterization (pH, soluble solids, titratable acidity, vitamin C) sensory evaluation (flavor, color, body and global acceptance) and microbiological analysis (total coliforms and thermotolerants, Salmonella and Estaphylococcus aureus). All the samples were well accepted in the sensory aspect and did not present any significant difference (p<0,5) among them. And the level of acceptance ranged from "I liked it slightly." to "I liked it moderately." for all the evaluated features. The formulated mixed drink was according to the chemical and microbiological patterns set by Brazilian laws, except for the pH that was above the ideal level for industrialized products. In respect of the microbiological analysis, none of the formulations presented microorganisms. The results showed that the elaborated product is in accordance with the identity and quality standards established for beverages. It also has a good sensory acceptance, which makes it a product with high potential for industrialization.

Characterization of the antiyeast compound and probiotic properties of a starter lactobacillus plantarum DW3 for possible use in fermented plant beverages

Lactobacillus plantarum DW3 produced antifungal compounds that inhibited the growth of Rhodotorula mucilaginosa DKA, contaminating yeast in fermented plant beverages (FPBs) and various potential human pathogens. Phenyllactic acid (PLA) identified by gas chromatography- mass spectrometry (GC-MS) was produced at 31 mg/L PLA in MRS medium and 5 mg/ml inhibited growth of the target yeast in vitro by 90 percent. Other inhibitors were also present but not specifically identified. Results of in vitro tests showed that DW3 also had probiotic properties as it survived various human biological barriers resistance to pH 3, bile salts, growth without vitamin B12 and the presence and absence of oxygen. Its inhibitory effect against food borne pathogenic bacteria and spoilage organisms was higher than that found for a commercial strain Lactobacillus casei R. An acute oral toxicity test on ICR mice at a high single dose of either 10(9) and 10(12) cells per mouse for 14 days showed that DW3 had no adverse effect on the general health status and there was no evidence of bacteremia. Mice fed DW3 had a reduced weight gain compared to the control. No significant difference (p > 0.05) was found for the spleen weight index (SWI) among the treatment and control groups whereas there was a significant difference (p < 0.05) for the liver weight ratio (LWR) in a group fed with 10(12) cells per mouse when compared with the control group.

Linden flower (Tilia spp.) as potential vehicle of Clostridium botulinum spores in the transmission of infant botulism / El té de tilo como vehículo potencial de esporas de Clostridium botulinum en la transmisión del botulismo infantil

Infant botulism is an intestinal toxemia caused principally by Clostridium botulinum. Since the infection occurs in the intestinal tract, numerous food products have been investigated for the presence of C. botulinum and its neurotoxins. In many countries, people use linden flower (Tilia spp) tea as a household remedy and give it to infants as a sedative. Therefore, to help provide a clear picture of this disease transmission, we investigated the presence of botulinum spores in linden flowers. In this study, we analyzed 100 samples of unwrapped linden flowers and 100 samples of linden flowers in tea bags to determine the prevalence and spore-load of C. botulinum. Results were analyzed by the Fisher test. We detected a prevalence of 3% of botulinum spores in the unwrapped linden flowers analyzed and a spore load of 30 spores per 100 grams. None of the industrialized linden flowers analyzed were contaminated with botulinum spores. C. botulinum type A was identified in two samples and type B in one sample. Linden flowers must be considered a potential vehicle of C. botulinum, and the ingestion of linden flower tea can represent a risk factor for infant botulism.

El botulismo del lactante es una toxiinfección causada, principalmente, por Clostridium botulinum. Debido a que esta infección ocurre en el tracto intestinal, la presencia de esta bacteria y sus neurotoxinas ha sido investigada en numerosos alimentos. En muchos países se utiliza el té de tilo (Tilia spp.) como sedante natural, el que se administra incluso a los lactantes. A fin de contribuir al esclarecimiento de la transmisión de esta enfermedad, se investigó la prevalencia y la carga de esporas botulínicas en esta hierba. Se analizaron 100 muestras de tilo comercializado a granel y 100 muestras de tilo industralizado en “saquitos”. Los resultados de prevalencia fueron analizados por el test de Fisher y la carga de esporas por la técnica del número más probable. Se halló una prevalencia de esporas de C. botulinum del 3% en el tilo comercializado a granel, con una carga de 30 esporas/100 g de hierba. En tanto, ninguna de las muestras en saquitos acusó la presencia del patógeno. Se identificaron tres cepas de C. botulinum, dos tipo A y una tipo B. En virtud de estos resultados, el tilo podría considerarse un potencial vehículo de esporas de C. botulinum y la administración de sus infusiones a menores y lactantes, un riesgo para la transmisión de la enfermedad.

Perfil microbiológico do caldo de cana comercializado na cidade de São Luís, MA / Microbiological profile of the sugar cane juice commercialized in the city of São Luís, MA

O consumo de caldo de cana como refresco tem aumentando nos últimos anos devido ao seu alto valor energético e à procura por uma alimentação nutritiva e saudável. A extração do caldo de cana é feita de forma artesanal favorecendo, assim, altos índices de contaminação. Com o objetivo de avaliar as condições higiênico-sanitárias do caldo de cana comercializado na cidade de São Luís/MA, analisando-se 30 amostras de caldo de cana in natura, durante os meses de maio a outubro de 2004, adquiridas em estabelecimentos comerciais da cidade de São Luís, Maranhão. Realizou-se pesquisa para a presença de: Escherichia coli, Bacillus cereus e Salmonella sp., segundo a metodologia descrita pelo Compendium of Methods for the Microbiológical Examination of Foods (APHA, 2001). Os resultados mostraram que do total de 30 amostras analisadas, 23 (76,6 por cento) apresentaram contaminação por Escherichia coli, 6 (20,0 por cento) por Salmonella sp. E 2 (6,6 por cento) por Bacillus cereus, caracterizando esse alimento como um potencial veiculador de bactérias causadoras de toxinfecções alimentares para os consumidores.

Estudo da vida-de-prateleira de bebidas elaborada pela mistura de garapa parcialmente clarificada-estabilizada e suco natural de maracujá / Shelf-life study of a beverage elaborate by blend of partially clarified-stabilized sugar-cane juice and natural passion fruit juice

O objetivo desta pesquisa foi estudar a vida-de-prateleira de produto elaborado com garapa, parcialmente clarificada-estabilizada, e suco de maracujá (5 por cento). A mistura foi adicionada de antioxidante, conservante e espessante em concentrações pré-estabelecidas. Após pasteurização, o produto foi resfriado, embalado em garrafas de polietileno tereftalato(PET) e armazenado sobrefrigeração pelo período de um mes. Foram realizadas determinações microbiológicas (Contagem Padrão, Contagem de Bolores e Leveduras, Coliformes Totais e Fecais), físico-químicas (pH, ºBrix, acidez, relação Brix/Acidez, teor de ácido ascórbico, turbidez), e sensoriais. Os resultados da análise sensorial considerados os mais relevantes para a pesquisa, indicaram que o produto (mistura de garapa parcialmente clarificada-estabilizada com suco de maracujá pode ser elaborado, pois as condições do porcesso permitiram a manutenção da qualidade microbiológica e sensorial. O teor de ácido ascórbico manteve-se em bom nível até o final da estocagem, com perda de apenas 20 por cento em relação ao teor adicionado

Evaluación microbiológica y fisicoquímica de néctares pasteurizados elaborados con pulpa de tomate de árbol (Cyphomandra betaceae Sendth) / Microbiological and physicochemical evaluation of pasteurized nectar elaborated with tree tomato (Cyphomandra betaceae Sendth)pulp

Tree tomato (Cyphomandra betaceae Sendth) is a species from high tropical regions. In Venezuela, it is cultivate at the Andean and Aragua state but its consumption is restricted as fruit-fresh, though it a nutritious and industrial potential due its provitamin A content. In this research four nectars were elaborated in proportion I L pulp/4 L of water (1:4) and addition of ascorbic acid (I: 0 per cent; II: 0.5 per cent; III: 1.0 y IV: 1.5 per cent). The nectars were pasteurized (60 degrees C for 30 min), tuned into amber bottle, and stored under refrigeration conditions (7.0 +/- 1.0 degrees C). Weekly during 21 days the mesophilic bacteria, molds, yeasts, total coliforms (MPN/mL), pH, degree Brix, acidity, total carotenoids, vitamin C and total sugars were evaluated. The mesophilic bacteria content was < 200 UFC/mL for every formulation on the first day the evaluation, molds and yeasts were < 10 UFC/mL and the total coliforms (NPN/mL) < 3 until the third evaluation. No significant differences (P > 0.05) were founded on: pH. degree Brix and total sugars. Significant differences (P < 0.05) were founded in vitamin C and total carotenoids content. Sensorial analysis did not show significant differences between formulations for the smell and flavor attributes, when the color was discriminate during the evaluations. The formulation I (without acid ascorbic) had more preference due its color. In conclusion, the nectars showed useful life of 14-21 days under refrigeration condition storage due to the adequate physicochemical and microbiological quality of the product.

Comparative behaviour of yeast strains for ethanolic fermentation of culled apple juice.

The culled apple juice contained (% w/v): nitrogen, 0.036; total sugars, 11.6 and was of pH 3.9. Saccharomyces cerevisiae NCIM 3284, Pichia kluyeri and Candida krusei produced more ethanol from culled apple juice at its optimum initial pH 4.5, whereas S. cerevisiae NCIM 3316 did so at pH 5.0. An increase in sugar concentration of apple juice from natural 11.6% to 20% exhibited enhanced ethanol production and improved fermentation efficiency of both the S. cerevisiae strains, whereas P. kluyveri and C. krusei produced high ethanol at 11.6% and 16.0% sugar levels, respectively. Urea was stimulatory for ethanol production as well as fermentation efficiency of the yeast strains under study.

Enteropathogenic Escherichia coli in raw and cooked food.

A total of 402 Escherichia coli isolates were obtained from a variety of food samples and screened for enteropathogenic E. coli (EPEC). Screening was carried out using 15 specific monovalent antisera from Murex Diagnostic Limited. A total of 19 E. coli isolates were serotyped as EPEC. The EPEC strains were shown to belong to 8 serotypes. Eight out of 19 EPEC strains belonged to serotype 018C:K77 (B21). Seventeen out of 19 of the EPEC strains were isolated from cooked food. The presence of E. coli in cooked food is an indicator of fecal contamination and a sign of unhygienic food handling. The presence of EPEC in food could be a potential source of food-borne outbreak. Hygiene training for every food-handler is a necessity.