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Aims@#Shelf-life estimation, determination and validation of frozen food are essential in hazard analysis and critical control points (HACCP) and can be done by adopting an accelerated shelf-life (ASL) study to reduce the time and cost of a long-lasting experiment. This study aims to determine the microbial shelf-life of frozen crispy chicken curry puffs (FCCCP). @*Methodology and results@#An ASL study was performed at varying temperatures of -18 °C, -8 °C, 2 °C and 12 °C for 12 weeks. Samples were also maintained at -18 °C for 12 months for the shelf-life study. Along the studies, microbiological growth (total plate count, yeast and mould count, Salmonella), pH and moisture content were analysed periodically. Findings from the ASL study indicated that storage at 2 °C and 12 °C led to an increase in microbiological growth. Yeast and mold count (YMC) had the highest correlation and was used to estimate the shelf-life using the Arrhenius equation. The estimated shelf-life of FCCCP was 30.5 months at -18 °C, 6.86 months at -8 °C, 1.72 months at 2 °C and 0.47 months at 12 °C. The Q10 was 4.45, 3.99 and 3.62 at -18 °C to -8 °C, -8 °C to 2 °C and 2 °C to 12 °C, respectively. All samples were within the microbiological limit throughout the storage period in the actual shelf-life study. Salmonella was not detected in any of the studies.@*Conclusion, significance and impact of study@#These findings provide valuable data for frozen food small and medium enterprises (SMEs) to verify product shelf-life during HACCP application. It can serve as a reference in the shelf-life determination of frozen foods under inappropriate temperature conditions along the cold chain.
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This study was carried out to assess the influence of post-mortem processing methods on quality and shelf life of two breeds of sheep meat. A total of twelve sheep, six each from Balami and Ouda (two prominent breed of Sheep in Nigeria) were weighed, slaughtered and allotted to three processing methods which are scalding, singeing and skinning in a completely randomized experimental design in a 2 × 3 factorial arrangement (2 breeds and 3 post-mortem processing methods). The carcass characteristics, primal cuts, physico-chemical properties, sensory and microbial counts were assessed. The results showed that Ouda breed gave the highest (p<0.05) dressing % (36.43%), preferred (p<0.05) primal cuts in rounds (15.13%), Marbling score, lipid profile (Total cholesterol, LDL), and Lipid peroxidation, Balami sheep was however rated higher (p<0.05) in juiciness, tenderness and overall acceptability. The Scalded sheep had the highest dressing % (35.45%), with preferred marbling score (5.80), and microbial counts. The scalded samples were also the lowest (p<0.05) for crude Fiber, CF, total cholesterol (276.40 mg/dL) and LDL (183.89 mg/dL). Minimal exudate loses (cooking loss and drip loss) were recorded in singeing samples and was rated highest (p<0.05) with organoleptic properties. The microbial and fungi loads increased with the storage days. Conclusively, Ouda breed and Scalding method of post-mortem dressing gave the preferred values for optimum nutrients and shelf-life of sheep meat.
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Pickle from native desi chicken meat was prepared and stored at room temperature (32±5ºC) in polyethylene teraphthalate (PET) bottles. The samples were evaluated for physico-chemical parameters, microbial quality and sensory attributes at regular intervals of 0, 5, 15, 30, 45,60, 75 and 90 days of storage. Non significantly increase in pH values were observed with increasing storage period and value remained below 5.0 up to 60 days of storage period. Non significantly increase in titrable acidity (% acetic acid) and free fatty acids (as % oleic acid) values were observed with increasing storage period. However, significantly decreased in moisture (%) values were observed with increasing storage period. A significant (P<0.05) and progressive increase in Thiobarbituric Acid (TBA) values (mg malonaldehyde / kg) were observed with increasing storage period and increase in TBA values between 0 and 60 days of storage did not turn out to be statistically significant. Microbiological counts were nonsignificantly increased between day 0 to 60, thereafter significantly (P<0.05) increased with the advancement of storage period and throughout the storage period, all microbial counts were within the acceptable limits. Sensory evaluation scores indicate that native desi chicken meat was very acceptable up to 60 days of storage and thereafter native desi chicken meat pickle was moderately acceptable between 60 to 90 days of storage at room temperature (32±5°C)
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Palms are considered as familiar strangers. Various studies reported that the genus Phoenix was mostly cultivated,traditionally used plants as medicine, and also as an ornamental plant. In this present study, preliminary phytochemicalanalysis, the study of microscopical structures and the chemical constituents of Phoenix pusilla root was evaluated.Transverse Section of P. pusilla root was studied by sectioning the two different thickness roots and also powdermicroscopy was carried out. Non-polar, volatile constituents of crude ethanolic extract of root were analyzed byGC–MS. Primary and secondary metabolites quantification revealed that the carbohydrate content and total phenolicsconcentration were higher than the other metabolites. The physicochemical analysis showed the moisture content was3.78 ± 0.54, the ash content value was 2.46 ± 0.95, and the crude fiber content was higher than protein, fat content.Microscopy study showed the presence of unique tracheids. Metabolite profiling revealed the presence of 96 differentconstituents and more than 10 found to have biological importance. Pharmacognostic study is an important step ofresearch which reveals about shelf-life of the drug, adulterations, etc.
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Objective: In the present study, an attempt was made to assess the shelf life of the Snuhi latex which is frequently used in fresh condition for the preparation of Ksharasutra, a medicated thread, used in Ayurveda. Methods: The latex of E. antiquorum, E. caducifolia, E. nivulia and E. tirucalli were collected individually and stored in air tight glass vials during the month of May, 2018. Physical attributes like Colour, odour, appearances, pH and microbial load of all four samples were assessed as per standard protocol. Assessment was made every day, 9 AM, for 7 d in room temperature and for 10 d in refrigerated samples. Results: Result shows that, pH range (start-end day) was 4.25-5.18, 4.79-5.12, 4.48-4.76 and 4.40-5.42 in case of E. antiquorum, E. caducifolia, E. nivulia and E. tirucalli at room temperature. It was found that, Aspergillus niger was found in Euphorbia antiquorum, Euphorbia caducifolia whereas Candida albicans was found in Euphorbia tirucalli latex in fungal culture on the 7th day after collection, when the samples were stored at room temperature. All the samples were free from microbial growth up to 10thday when stored at 4-5 °C in a refrigerator. Conclusion: Temperature, and moisture affects the quality of fresh snuhi latex. The latex remains free from microbial growth up to six days in room temperature and up to 10 d under at refrigerated temperature (4-5 °C).
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The storage stability study was conducted for precooked breast fillets T1 (without post-mortem ageing, T2 (PM ageing for 4 h at room temp) and T3 (PM ageing for 24 h at refrigeration temp). Nutritional profiles were evaluated on 0 day and 15th day of aerobic storage. The samples were also evaluated for physico-chemical, microbiological and sensory parameters at 5 days interval up to 20 days. Moisture content decreased significantly (P≤0.05) from 0 day to 20th day of storage. The overall protein content was significantly lower at 20 day of storage as compared to fresh sample. Fat content showed slight decrease in T1, T2 and T3 during storage period. pH values were increased with the increase of storage intervals but after 10th day onwards the values showed decreasing trends. T3 showed least Warner Bratzler shear force value (W-BSFV) but values were decreased non-significantly. Overall thiobarbituric acid reactive substances (TBARS) values were increased with the increase of storage time, and accordingly amongst the different treatments, overall TBARS values in breast fillets were also differed significantly. Peroxide value (PV) showed significantly increasing trends for T1, T2 and T3 with advancement of storage days. Highest overall free fatty acids (FFA) content was observed for T3. T2 and T3 showed significantly higher overall titrable acidity than T1. Titrable acidity range was between 18 to 20%. Changes in microbiological quality were observed with the increase of storage days. However, these only the values of standard plate count (SPC) were much lower than the permissible limits of FSSAI for meat products. However, overall acceptability scores of breast fillets decreased significantly up to 20th day of storage period. The breast fillets of T3 sample had significantly higher overall acceptability score.
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Aim: The aim of the present study was to evaluate the retting of jute (Corchorus olitorius L. and C. capsularis L.) using the endospores of microbial consortium of three strains of Bacillus pumilus with extended shelf-life. Methodology: Endospore and vegetative cells of Bacillus pumilus were tested for viability by introducing them into different temperature, pH, UV radiation and antibiotics. Laboratory, as well as field-trials of jute retting was performed with 6 and 18-months-old endospores and vegetative cells of Bacillus pumilus with estimation of enzymatic activities for comparison of their retting efficiency. Results: Endospores of Bacillus pumilus recorded very high colony forming unit (109 to 108ml-1) compared to their vegetative cells (106 to 104ml-1) after 6 to 18 months of their preservation. Endospores also showed higher resistance to temperature, pH, UV irradiation and antibiotic than their vegetative forms. High colony forming unit and higher release of pectinolytic and xylanolytic enzymes during retting of jute by endospores resulted in complete of jute retting in 10 days with good quality jute fibre compared to talc based formulation. Interpretation: It can be concluded from the study that endospores remained highly efficient in rejuvenating higher CFU and quantitatively larger pool of enzymes to accelerate retting of jute after prolonged preservation. Therefore, the endospores of Bacillus pumilus can be used cost effectively in place of their talc based formulation for higher shelf life of the product, faster retting and better fibre quality of jute.
Résumé
O objetivo deste estudo foi verificar a influência do tempo de armazenamento na qualidade microbiológica, físico-química e sensorial do pescado caranha (Piaractusmesopotamicus). Os pescados foram estocados em gelo durante zero, sete, 14, 21 e 28 dias e submetidos às contagens de micro-organismos mesófilos, psicrotróficos, coliformes a 35ºC e 45ºC, Salmonella sp. e estafilococos coagulase positiva. Foram realizadas análises de temperatura, pH, acidez, bases voláteis, proteínas, lipídeos, cinzas, umidade, prova de cocção, bem como análise sensorial. As contagens de mesófilos, psicrotróficos, coliformes a 35ºC e 45ºC aumentaram com o tempo de armazenamento. A presença de Salmonella sp. não foi constatada, enquanto a contagem de estafilococos coagulase positiva foi de <10 (est) UFC/g em todos os períodos de estocagem. Observou-se, ainda, que o tempo de armazenamento apresentou influência em todas as variáveis físico-químicas, exceto para temperatura. Na análise sensorial, foi constatado um aumento linear do índice de qualidade (IQ) ao longo do armazenamento, e a rejeição ocorreu aos 14 dias.(AU)
The objective of this study was to verify the influence of storage time on the microbiological, physical-chemical, and sensorial quality of the fish (Piaractusmesopotamicus). The fish were stored on ice for 0, 7, 14, 21, and 28 days and submitted to counts of mesophilic, psychrotrophic, coliform microorganisms at 35ºC and 45ºC, Salmonella sp. and coagulase positive staphylococci. Analyzes of temperature, pH, acidity, volatile bases, proteins, lipids, ashes, humidity, cooking test, as well as sensorial analysis were performed. Counts of mesophiles, psychrotrophic, coliforms at 35°C and 45°C increased with storage time. The presence of Salmonella sp. was not observed, whereas the coagulase positive Staphylococcus count was <10 (est) CFU/g in all storage periods. It was also observed that the storage time had influence on all physical-chemical variables, except for temperature. In the sensorial analysis, a linear increase of the quality index (IQ) was verified throughout the storage and the rejection occurred at 14 days.(AU)
Sujets)
Animaux , Pêcheries , PerciformesRésumé
A farinha de mandioca fermentada é um alimento típico da região amazônica brasileira e sua produção ocorre com as seguintes etapas: colheita, descascamento, fermentação (tubérculos são imersos em um tanque com água ou córrego), lavagem, trituração, prensagem, moagem e torrefação. A farinha de mandioca é uma fonte importante de carboidratos na Amazônia, especialmente pelas pessoas de baixa renda. Neste trabalho estudou-se o comportamento físico-químico e microbiológico da farinha de mandioca fermentada comercializada em um mercado de rua e em supermercado. Para tal, 36 quilogramas de farinha de mandioca fermentada foram adquiridos e mantidos sob as mesmas condições ambientais do mercado de rua e do supermercado. Durante dois meses, as amostras foram analisadas quanto à umidade, cinzas acidez total titulável, pH e atividade de água. Os resultados mostraram que o pH e a acidez total titulável foram estáveis, mas a umidade e a atividade de água mudaram e aumentaram significativamente (p>0,05).(AU)
Sujets)
Humains , Manihot/microbiologie , Manihot/composition chimique , Stockage des aliments , Farine/analyse , Brésil , Échantillons AlimentairesRésumé
Por sua composição, o leite é considerado um dos alimentos mais completos em termos nutricionais e por essa mesma razão constitui um excelente meio para proliferação de micro-organismos patogênicos. A pasteurização, quando feita de forma correta, visa acabar com esses micro-organismos, mas quando o leite é produzido em condições higiênicas inadequadas ou é mal conservado nos pontos de venda pode se transformar em um veículo para transmissão de doenças. Este trabalho teve como objetivo avaliar a segurança microbiológica, durante o período de validade, do leite pasteurizado produzido em um laticínio da cidade de Januária-MG. Foram analisadas amostras de leite pasteurizado no primeiro e no último dia de validade. Foram realizadas contagens de micro-organismos mesófilos aerofílicos, bactérias coliformes totais e a 45°C, bactérias psicrotróficas e enterobactérias. Nenhuma amostra apresentou contaminação por bactérias psicrotróficas. Foram encontradas contagens de micro-organismos coliformes totais e coliformes a 45°C acima dos valores máximos permitidos pela legislação brasileira, representando um risco para a saúde dos consumidores.
Sujets)
Humains , Lait/microbiologie , Date de Validité des Produits , Stockage des aliments , Pasteurisation , Conservation aliments/normes , Échantillons Alimentaires , Contamination des aliments/analyse , Aliments Réfrigérés , ColiformesRésumé
Shelf-life estimation is the core of stability tests and critical to the final label claim on the package of new drug.Firstly,this paper depicts the methods of ICH Q1E for shelf-life estimation,compares it to the counterpart in the newest version of Chinese Pharmacopeia (Ch.P 2015,IV-9001),and proves its compliance.Secondly,this paper also unfolds the latent assumptions and hinged limitations of the quantitative methods in the guidelines.Finally,the empirical distributions of the shelf-life estimators are obtained via Monte-Carlo simulation to facilitate better understanding of properties of the estimators.It is shown that the approach that takes the average as final shelf-life estimate is likely to further underestimate the true shelf-life comparing to the ICH Q1E approach,and hence puts the manufacturers in unnecessary disadvantage.
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Este trabalho teve como objetivo estabelecer a melhor temperatura para a conservação de melões ‘Louis‘. Os frutos foram armazenados sob condição de ambiente (22±2°C e 80±5% UR), sob refrigeração (3±1°C e 80±5% UR; 6±1°C e 80±5% UR; e 9±1°C e 80±5% UR) e avaliados quanto à coloração e firmeza da polpa, teores de sólidos solúveis, acidez titulável, atividade das enzimas peroxidase, polifenoloxidase, poligalacturonase e pectinametilesterase e perda de massa fresca. Os melões ‘Louis‘ armazenados a 22°C apresentaram maior redução nos teores de sólidos solúveis e acidez titulável, além de apresentarem maior atividade da enzima poligalacturonase, com conservação por até 18 dias. Os frutos armazenados a 6°C mantiveram a qualidade comercial durante 25 dias de armazenamento, apresentando os maiores teores de sólidos solúveis e menor atividade das enzimas peroxidase e poligalacturonase.
This research aimed to establish the best temperature for the conservation of ‘Louis‘ melons. Fruit were stored under ambient condition (22°C and 80% RH) and under refrigeration (3°C - 80% RH, 6°C - 90% RH e 9°C - 80% RH) and evaluated for color and resistance of pulp, soluble solids, titratable acidity content, peroxidase, polyphenol oxidase, polygalacturonase and pectin methyl esterase activity and weight loss. ‘Louis‘ melons at 22°C showed greater reduction in soluble solids and titratable acidity content, and had higher activity of the enzyme polygalacturonase, culminating in conservation for 18 days. Melons stored at 6°C preserved the shelf-life for 25 days, showed the highest soluble solids and lower activity of peroxidase and polygalacturonase.
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El aislamiento Pseudomonas fluorescens Ps006 demostró alto potencial para ser usado como principio activo de un bioinsumo, por su capacidad para producir biosurfactantes, actividad solubilizadora de fósforo y antagonista ante diferentes fitopatógenos. Por tal razón, el presente trabajo tuvo como objetivos desarrollar y caracterizar un prototipo de formulación a base de P. fluorescens Ps006, estable bajo condiciones de almacenamiento. Inicialmente se caracterizó el principio activo y se seleccionaron los auxiliares de formulación compatibles con el mismo, evaluándose la estabilidad de su mezcla con tres soportes sólidos, a dos humedades diferentes (10% y 20%) durante tres meses de almacenamiento a temperaturas de 8, 18 y 28 ± 2 °C. El principio activo demostró actividad antagonista in vitro sobre cuatro fitopatógenos y la temperatura y la humedad afectaron su estabilidad durante el almacenamiento. A los prototipos de formulación más estables en cuanto a viabilidad y actividad biocontroladora se les evaluó su estabilidad en presencia y ausencia de oxígeno y de protectores de membrana. Se seleccionó el soporte S1 al 20% de humedad mezclado con el principio activo sin adición de protectores de membrana y almacenado en presencia de oxígeno, por ser el tratamiento más estable durante seis meses de alamacenamiento a tres temperaturas, con pérdidas de viabilidad inferiores al 5%.
The isolation Pseudomonas fluorescens PS006 demonstrated high potential to be used as an active ingredient of a bioprodut, because its capacity to produce biosurfactants, its phosphorus solubilizing activity and its antagonistic activity over different phytopathogens. For this reason, the present work had as objectives to develop and characterize a formulation prototype based on P. fluorescens PS006, stable under storage conditions. Initially the active ingredient was characterize and compatible formulation auxiliaries, were selected evaluating the stability of its mixture with three solid diluents at two different moistures (10% and 20 %) during three months of storage at temperatures of 8, 18 and 28 ± 2 °C. The active ingredient showed in vitro biocontrol activity over four phytopathogens and temperature and humidity affected its stability during storage. Stability of the most stable formulation prototypes in terms of viability and biocontrol activity was evaluated in presence and absence of oxygen and membrane protectors. Support S1 with 20% of moisture mixed with the active ingredient without addition of membrane protectors and stored in presence of oxygen, was selected as the most stable treatment during six months of storage at three temperatures, with viability losses lower than 5%.
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Os subprodutos da indústria de frutas possuem alta qualidade nutricional, de forma que sua transformação em ingredientes para aplicação em produtos alimentícios é de grande importância. No presente estudo, foram avaliados os efeitos da substituição total da gordura em pães de forma através da utilização de fibra de casca de laranja (0 a 5%), um subproduto industrial. A adição da fibra de laranja foi combinada ao uso de α-amilase (10 a 50ppm), através de um planejamento experimental fatorial completo 22. Para fins de comparação, foi elaborada uma formulação controle, sem fibras, sem enzimas e com 2% de gordura. A qualidade dos pães foi avaliada através de análises de vida útil (por índice de retrogradação, DSC), volume, cor, atividade de água e análise sensorial. A fibra de laranja, associada ao uso de enzimas, contrapôs os possíveis efeitos negativos causados pela ausência da gordura, para as concentrações de fibra e enzima estudadas, permitindo a obtenção de pães isentos de gordura e com fibras. A presença de 2,5% de fibra de laranja combinada ao uso de 30ppm de α-amilase gerou um pão com volume 23% maior ao alcançado pela amostra controle e com índice de aceitação em torno de 80%.
Food industry byproducts have high nutritional quality, so that its transformation into ingredients for use in food products is of great importance. This study aimed to analyze the effects of total fat replacement in loaf bread, by adding orange peel fiber (0-5%), an industrial byproduct. The use of citrus fiber was combined with the addition of α -amylase (10 to 50ppm), by using a complete experimental factorial design (22). A formulation containing 2% of fat, without citrus fiber and enzyme was used as control. The breads quality was measured by analyzing shelf life (by Retrogradation Index determination), volume, crumb color, water activity and sensorial parameters. The citrus fiber in association with the addition of α-amylases neutralized the potential negative effects that the removal of fat could cause, considering the ranges of fiber and enzyme studied, allowing to obtain fat-free breads with fibers. The presence of 2.5% of citrus fiber combined with the use of 30ppm of α-amylase increased the volume of breads by 23%, comparing with the control formula, and had an acceptance index of around 80%.
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Introduction. The safety and effi cacy of fi nished pharmaceutical products depend on its stabilityattribute. Stability requirements were included for fi rst time in Good manufacturing practice standardMNS 5524:2014. The pharmaceutical manufacturer is responsible to conduct stability studies and tosubmit the report as part of marketing authorization documentation.Purpose of the study. The purpose of this study is to conduct ongoing stability study of the mostlyproduced domestic medicine to monitor the product over its shelf-life.Materials and Methods. As a material used 2 locally produced Paracetamol (Acetaminophen INN) 500mg tablets (local manufacturer (LM) 1 with batch number 271110, LM 2 with batch number 441110). Asa method we used shelf-life specifi cation: Mongolian national standard of Paracetamol 500 mg tablets,MNS 4358:2007. Testing frequency was at 0 time (when tablets were produced) and at 12, 24 and 36months (study was covered the shelf-life).Results. In frame of this study we defi ned the most produced product as Paracetamol (AcetaminophenINN) 500 mg tablets. From the LICEMED- medicines registration record we found 8 tablets, containingAcetaminophen in 500 mg. Two of them were produced locally. These two products were involved inongoing stability study. Testing results showed that no any stability issues over the defi ned shelf life.Discussion. The shelf life was defi ned as 36 months, initially by manufacturers before productsregistered. After a marketing authorization has been granted, the stability of the fi nished pharmaceuticalproducts should be monitored according to a continuous appropriate program that should be permittedthe detection of any stability issue associated with the formulation in the container closure system inwhich it is marketed.Conclusions. After 36 months, testing results were in acceptable limits, selected products wereremaining their quality over the shelf-life.
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Background: The microbiological and chemical processes are the main responsible for deterioration of fresh fish. Therefore, it is essential to avoid these processes by applying good manufacturing practices during fish handling, distribution and storage. Objective: The aim of this paper was to evaluate the physico-chemical and microbial changes in commercial tilapia (Oreochromis niloticus) during cold storage in order to establish the shelf life since its arrival at the supermarket. Methods: 27 aquacultured tilapia specimens were analyzed at 0, 2, 4, and 7 days of storage at 4ºC. Measurements of texture, color, water holding capacity, total volatile basic nitrogen (TVB-N), thiobarbituric acid index, ATP-related compounds, as well as microbial analyses were carried out. Results: The TVB-N content was high at the beginning of the study, remaining stable during the storage. Lipid oxidation of samples was minimum, so this process did not contribute to the fish spoilage. It was observed the breakdown of inosine-5'- monophosphate (IMP) into Ino (inosine), and Ino into Hx (hypoxantine). The texture parameters and colour underwent changes as a consequence of the fish spoilage. Low microbial counts were observed at day 0, but Enterobacteriaceae and mesophilic counts gradually increased throughout storage. Conclusions: The K1 -value showed the progressive spoilage of the fish during the cold storage. The decrease of hardness and firmness confirmed the loss of quality throughout the time of study. The low microbial counts at the beginning of the study demonstrated the good quality of the tilapia; however, the increase of the mesophilic counts at the end of the studied period showed that tilapia was not fit for human consumption at day 7.
Antecedentes: Los procesos microbiológicos y químicos son los principales responsables del deterioro del pescado fresco. Por tanto, es esencial evitar estos procesos aplicando buenas prácticas de fabricación durante la manipulación, distribución y almacenamiento del pescado. Objetivo: El objetivo de este trabajo fue evaluar los cambios físico-químicos y microbiológicos en tilapia comercial (Oreochromis niloticus) durante el almacenamiento refrigerado con el fin de establecer la vida útil desde su llegada al supermercado. Métodos: 27 especímenes de tilapia fueron analizados a día 0, 2, 4 y 7 de almacenamiento a 4 ºC. Se llevaron a cabo medidas de textura, color, capacidad de retención de agua, nitrógeno básico volátil total (N-BVT), índice del ácido tiobarbitúrico, compuestos relacionados con el ATP, así como análisis microbianos. Resultados: El contenido en N-BVT fue alto al principio del estudio, siendo estable durante el almacenamiento. La oxidación lipídica de las muestras fue mínima, por lo que este proceso no contribuyó al deterioro del pescado. Se observó la degradación de inosina-5'- monofosfato (IMP) a Ino (inosina), y de Ino a Hx (hipoxantina). Los parámetros de textura y color sufrieron cambios como consecuencia del deterioro del pescado. Se observaron bajos recuentos microbianos a día 0, pero los recuentos de Enterobacteriaceae y de mesófilos aumentaron gradualmente durante el almacenamiento. Conclusiones: El valor K1 mostró el deterioro progresivo del pescado durante el almacenamiento en refrigeración. La disminución de dureza y firmeza confirmó la pérdida de calidad a lo largo del tiempo de estudio. Los bajos recuentos microbianos al principio del estudio demostraron la buena calidad de la tilapia; sin embargo, el aumento de los recuentos de mesófilos al final del periodo estudiado mostraron que la tilapia no era adecuada para el consumo humado a día 7.
Sujets)
Humains , Cichlides , Phénomènes chimiques , Phénomènes microbiologiques , Management par la qualitéRésumé
Objective:To observe the effect of storage period of three experimental dentin self-etching primers on the shear bond strength.Methods:Three experimental primers with 2-hydroxyethyl methacrylate (HEMA)or N-methacryloyl glycine (NMGly)as a hydrophilic monomer and 1 0-methacryloxydecyl dihydrogen phosphate(MDP)or N-methacryloyl-2-aminoethylphosphonic acid (NMEP) as an acid monomer,were designed.Immediately after preparation of the samples of MDP-HEMA,MDP-NMGly and NMEP-NMGly, the primers were stored at 40 ℃for 0,6 and 1 4 weeks.At the end of each storage period,the shear bond strength of resin to dentin(n=1 4)and the pH value of the primers were measured.Results:After storage at 40 ℃ for 1 4 weeks,the shear bond strength of MDP-HEMA decreased from (1 7.61 ±1 .56)MPa to (7.53 ±1 .76)MPa;however the bond strenth of MDP-NMGly and NMEP-NMGly did not decrease;most of the specimens of MDP-HEMA and MDP-NMGly exhibited an interfacial failure of the resin from the dentin sur-face;however NMEP-NMGly exhibited a cohesional failure of the dentin and/or resin.The SEMimages showed a separation of resin and dentin of MDP-HEMA and MDP-NMGly had storaged at 40 ℃for 1 4 weeks;while the interface of NMEP-NMGly did not change.Con-clusion:The NMEP-NMGly primer has noticeably higher hydrolytic stability than the MDP-HEMA and MDP-NMGly primers.
Résumé
Leites fermentados por Lactobacillus rhamnosus e Lactobacillus fermentum, isolados de queijos artesanais, foram produzidos e avaliados quanto às características físico-químicas e microbiológicas durante 45 dias de estocagem a 8-10ºC. Análises sensoriais foram realizadas aos 15 e 60 dias. Ambos os leites fermentados apresentaram contagens adequadas das bactérias láticas, superiores a 108 UFC/g, durante toda a estocagem. As médias das análises físico-químicas e microbiológicas dos produtos durante a estocagem foram iguais e todos atenderam às especificações da legislação brasileira. Melhores resultados de avaliações sensoriais (P<0.05) foram aos 15 dias de estocagem. Leites fermentados por L. fermentum obtiveram melhor aceitação sensorial aos 60 dias de estocagem, quando apresentavam acidez titulável inferior à encontrada no leite fermentado por L. rhamnosus. Portanto, a utilização dessas culturas pode ser viável para a elaboração de novos leites fermentados, que apresentariam prazo de validade de 45 dias de estocagem sob refrigeração.(AU)
Sujets)
Lait , Stockage des aliments/méthodes , Aliments fermentés/analyse , LactobacillusRésumé
Este trabalho objetivou estudar a cinética de degradação de suco integral manga Ubá por testes acelerados e estimar sua vida-de-prateleira a 25°C. Para isso, amostras do produto foram armazenadas em estufas tipo BOD a 25, 35 e 45°C, providas de iluminação (650lux) 24 horas por dia. As características físico-químicas que mais influenciaram na qualidade do produto foram as coordenadas de cor (L* e ∆E*) e a concentração de vitamina C. A alteração da cor seguiu o modelo cinético de ordem zero, sendo verificado um escurecimento dos produtos mantidos a 35°C e 45°C, enquanto que a degradação da vitamina C foi mais bem explicada pelo modelo de primeira ordem. Houve correlação significativa entre a concentração de vitamina C e os valores de L* e ∆E* (P<0,01), sugerindo que a degradação dessa vitamina influenciou no escurecimento do produto. Uma vida-de-prateleira de 190 dias foi estimada para o suco integral de manga, a 25°C, utilizando a concentração de vitamina C como parâmetro de qualidade.
This research aimed to study the kinetic of whole mango juice cv. 'Ubá' degradation using accelerated assays and estimate its shelf-life at 25°C. The products were stored in BOD incubator at 25°C (control), 35°C and 45°C (accelerated conditions), provided with 24 hours a day 650lux lighting. Physico-chemical properties that most influenced the quality of the product were the color coordinates (L* and ∆E*) and the vitamin C content. It was found that zero order kinetic model was the best fit to variations in the values of L* and ∆E*, which showed browning of products stored under higher temperatures. There were significant correlations between changes in vitamin C content and changes in values of L* and ∆E*, suggesting that the degradation of this vitamin contributed to darkening of the product. Shelf-life of 190 days was estimated for whole mango juice stored at 25°C, using vitamin C content as the limiting quality.
Résumé
The effects of natural fermentation on the stability or shelf life of adhesives produced from starch of two cassava varieties (Manihot utilissima and Manihot palmate) were studied. It was observed that the HCN content of the Manihot utilissima reduced from 35.74±0.11 mg/kg for unfermented starch sample to 6.93±0.25 mg/kg after 5 days of fermentation (p = 0.037), while the sample’s pH increased from 4.60±0.05 to 6.89±00 respectively. However, the reduction in HCN concentration and corresponding increase in pH for manihot palmate were only marginal, as the concentration of HCN in the starch reduced from 2.49±0.12 to 0.89±0.26 while the pH increased from 6.02±0.04 to 6.35±0.05 after five days of fermentation. The viscosity test conducted at room temperature for a period of 30 days to determine the stability or shelf of the produced adhesives show that adhesives produced from unfermented Manihot utilissima starch sample as well as samples of that cassava variety fermented for only 1 day have longer shelf-life as exemplified by the relative stable low viscosity of the adhesive over the 30 days test period with a highly significant effect, (p = 0.018). The drying time of Manihot utilissima was significantly high at 7.1±0.01 minutes (p = 0.041) and remained relatively stable for the 30 days storage time. The results therefore show that the higher the cassava starch acidity the lower its viscosity, the higher its drying time and the longer its shelf-life.