RESUMO
The banana is a tropical fruit characterized by its composition of healthy and nutritional compounds. This fruit is part of traditional Ecuadorian gastronomy, being consumed in a wide variety of ways. In this context, unripe Red Dacca banana samples and those submitted to different traditional Ecuadorian heating treatments (boiling, roasting, and baking) were evaluated to profile their phenolic content by ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) and the antioxidant activity by ORAC, ABTS, and DPPH assays. A total of sixty-eight phenolic compounds were identified or tentatively identified in raw banana and treated samples, highlighting the content in flavonoids (flavan-3-ols with 88.33% and flavonols with 3.24%) followed by the hydroxybenzoic acid family (5.44%) in raw banana samples. The total phenolic compound content significantly decreased for all the elaborations evaluated, specifically from 442.12 mg/100 g DW in fresh bananas to 338.60 mg/100 g DW in boiled (23.41%), 243.63 mg/100 g DW in roasted (44.90%), and 109.85 mg/100 g DW in baked samples (75.15%). Flavan-3-ols and flavonols were the phenolic groups most affected by the heating treatments, while flavanones and hydroxybenzoic acids showed higher stability against the heating treatments, especially the boiled and roasted samples. In general, the decrease in phenolic compounds corresponded with a decline in antioxidant activity, evaluated by different methods, especially in baked samples. The results obtained from PCA studies confirmed that the impact of heating on the composition of some phenolic compounds was different depending on the technique used. In general, the heating processes applied to the banana samples induced phytochemical modifications. Even so, they remain an important source of bioactive compounds for consumers.
RESUMO
Milk is considered one of the basic raw materials of animal origin; it must present hygienic quality and physical-chemical properties suitable for processing and human consumption. Thus, the ingestion of milk in natura when not properly treated can be characterized as an opportunistic route of transmission of possible microbial pathogens, which can offer risks to public health. The present study aimed the yeast identification, to analyze the thermo-resistance of yeasts isolated from fresh milk, and to trace the susceptibility profile of the isolates to antifungal agents. For this, 23 samples of fresh milk type B, collected by manual or mechanical milking, were stored in collective refrigeration tanks of farms located in the Metropolitan Region of Natal and nearby, State of Rio Grande do Norte (RN), Brazil. Twenty samples of fresh milk commercially traded in the city of Ceará-Mirim RN were also analyzed. The yeasts were quantified by count of colony-forming units (CFU). All isolated species were treated by slow pasteurization (62-64 °C for 30 min) and fast (72-75 °C for 20 s), as well as by boiling (100 °C). Fifty yeast strains were obtained, and the species were identified as Candida tropicalis (28%), Candida parapsilosis (14%), Candida albicans (12%), Candida glabrata (10%), Candida krusei (10%), Kluyveromyces marxianus (10%), Candida guilliermondii (8%), Candida rugosa (2%), Candida orthopsilosis (2%), Pichia manshurica (2%), and Kodamaea ohmeri (2%). Five isolates showed resistance to the antifungal agents tested. Among all the isolates submitted to heat treatment, 80% were resistant to fast pasteurization and 60% to boiling, but none of them resisted the slow pasteurization. The milk collected through mechanical milking and stored in collective cooling tanks, presented higher rates of yeast contamination, compared to milk samples collected by manual milking and kept under the same storage conditions.
Assuntos
Antifúngicos , Termotolerância , Animais , Humanos , Antifúngicos/uso terapêutico , Leite , Temperatura Alta , Pasteurização , Temperatura , Leveduras , Testes de Sensibilidade MicrobianaRESUMO
Heat transfer through a liquid-vapor interface is a complex phenomenon and crucially relevant in heat-removal and cryogenic applications. The physical coupling among confining walls, liquid and vapor phases is very important for controlling or improving cooling rates or condensation efficiency. Surface modification is a promising route, which has been explored to taylor the heat transfer through confined two-phase systems. We use coarse-grained molecular-dynamics simulations to study the heat transfer through a nano-confined liquid-vapor interface as a function of fluid filling. We set up a stationary heat flow through a liquid-vapor interface, stabilized with the liquid in contact with a colder wall and a vapor in contact with a hotter wall. For these physical conditions, we perform extensive simulations by progressively increasing the number of fluid particles, i.e. the channel filling, and measure the fluid distribution in the channel, density, pressure and temperature profiles We also compare the heat flux behavior between a bare-surfaces nano-channel and others where the hot surface was coated with end-grafted polymers, with different wetting affinities and bending properties. We take extreme cases of polymer properties to obtain a general picture of the polymer effect on the heat transfer, as compared with the bare surfaces. We find that walls covered by end-grafted solvophylic polymers change the heat flux by a factor of 6, as compared with bare walls, if the liquid phase is in contact with the polymers. Once the liquid wets the coated wall, the improve on heat flux is smaller and dominated by the grafting density. We also find that for a wall coated with stiff polymers, the jump in heat flux takes place at a significantly lower channel filling, when the polymers' free ends interact with the liquid surface. Interestingly, the morphology of the polymers induces a 'liquid bridge' between the liquid phase and the hot wall, through which heat is transported with high (liquid-like) thermal conductivity.
RESUMO
Rubber (Hevea brasiliensis) is a perennial plant crop grown in many parts of Africa, South East Asia, and South America, especially within the hot and humid climatic regions. Rubber seed, either as feed or food, is a useful raw material to produce edible oil and protein. Despite the huge quantity of rubber seeds produced in Nigeria and its potential as a protein source, rubber seeds still appear neglected and under-utilised as feed/food given its perception as inedible and toxic due to the high concentration of cyanogenic glycoside. Therefore, the quest for effective processing technique(s) that would enhance its food use application is very fitting. This current study was directed to determine the changes in anti-nutrient, phytochemical, and micronutrient contents of different processed rubber seed meals. Specifically, the rubber seeds underwent processing, which employed boiling and the combined action of boiling and fermentation methods that brought about three seed meal flour groups, i.e., raw (RRSM), boiled (BRSM), and fermented (FRSM) seed meals. These were subsequently analysed for anti-nutrient/phytochemical (oxalate, phytate, tannin, phenols, saponin, hydrogen cyanide (HCN), alkaloids, flavonoids, and trypsin inhibitors), and micronutrient (which involved minerals (magnesium, phosphorus, calcium, iron, zinc, potassium, sodium, manganese, lead, and selenium) and vitamin (vitamin B1, B2, B3, C, E, and beta carotene)) contents. The results showed that the processing methods used to achieve the RRSM, BRSM, and FRSM, reduced the anti-nutrients (phytate, tannin, and oxalate) below the acceptable limits, and the HCN below the toxic levels. Importantly, the processing methods herein have not yet succeeded in removing HCN in the (processed) rubber seed meals, but can be seen to be heading toward the right direction. The FRSM obtained significantly lower (p < 0.05) anti-nutrient/phytochemical, but significantly higher (p < 0.05) mineral contents, compared with the other groups (RRSM and BRSM), except for flavonoids that obtained a 30% increase over the BRSM. Some mineral and vitamin contents could be lost in the BRSM compared to the others (RRSM and FRSM) in this study. Additionally, the FRSM obtained higher vitamin contents, after those of RRSM. Overall, the combined action of boiling and fermentation should be recommended for the proper utilisation of rubber seed as food/feed.
RESUMO
The consumption of vegetables in Mexico includes a wide variety of plants that grow naturally as weeds in the fields. The intake of these vegetables is very important in the Mexican diet because these plants supply an important input of nutrients and compounds such as fiber, vitamins, minerals, and antioxidants. Thus, the plants may be universally promoted as healthy. However, there is little information about these vegetables of popular consumption, especially in terms of the nutritional changes caused by boiling. To determine the influence of boiling on five plants of popular consumption in Mexico, the nutritional composition (proximal analysis, dietary fiber, and oxalates), antioxidant compounds (ascorbic acid, phenolics), antioxidant activity (measured by ABTS and DPPH assays), and physicochemical characteristics (water retention capacity, viscosity, color, and SEM) were evaluated. The boiling affected the nutritional composition of plants, mainly soluble compounds as carbohydrates (sugars and soluble fiber), ash, ascorbic acid, and phenolic compounds and caused changes in food hydration and color. Therefore, it is recommended that these plants be consumed raw or with short boiling times and included the cooking water in other preparations to take advantage of the nutrients released in the food matrix. In the future, to complete studies, 3 to 5 min of cooking should be considered to minimize undesirable modifications in terms of the vegetables' composition.
RESUMO
It is largely unknown how processing affects bioactive potential of chickpea proteins to prevent bowel inflammatory diseases. The aim was to investigate the anti-inflammatory activity of protein concentrates from germinated and cooked chickpeas (GC and CC, respectively) and its relationship with protein and isoflavone composition before and after in vitro gastrointestinal digestion and absorption. Anti-inflammatory activity of GC digests was almost 2-fold higher than CC digests (pâ¯<â¯0.05), which was associated to greater content of peptides, formononetin and biochanin A (pâ¯<â¯0.05). Anti-inflammatory activity of phenolic fraction in digests was 7-fold higher than the protein fraction (pâ¯<â¯0.05). The most active peptide fraction from GC digest (IC50â¯=â¯93⯵g/mL) contained a total of 24 peptides derived from legumin and vicilin. In conclusion, this study stands out the potential of germinated chickpea proteins concentrates to exert anti-inflammatory effects in the lower gut which may contribute to the prevention of bowel inflammatory diseases.
Assuntos
Anti-Inflamatórios/metabolismo , Cicer/química , Cicer/crescimento & desenvolvimento , Digestão , Trato Gastrointestinal/fisiologia , Isoflavonas/metabolismo , Peptídeos/metabolismo , Anti-Inflamatórios/farmacologia , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/metabolismo , Genisteína/metabolismo , Germinação , Isoflavonas/farmacologia , Peptídeos/farmacologia , Proteínas de Plantas/químicaRESUMO
Um dos mais relevantes problemas em uma Unidade de Alimentação e Nutrição (UAN), referente a surtos alimentares, é a contaminação cruzada. Desta forma, acredita-se que a esponja de cozinha seja um possível vetor da contaminação microbiológica em alimentos. De fato não existem padrões de tempo de uso para esponjas e este pode ser um problema, pois estas são acondicionadas à temperatura ambiente em meio umedecido rico em matéria orgânica. Além de se conhecer o nível de contaminação microbiológica, é também necessário descobrir qual o melhor método de higienização, a fim de se manter a segurança microbiológica do local, prevenindo assim a contaminação cruzada e consequentemente a ocorrência de um surto de doença transmitido por alimentos. Foram utilizadas esponjas com 24 a 48 horas de uso regular na cozinha de uma UAN hoteleira, estas foram submetidas à contagem microbiológica e aos métodos de desinfecção: imersão em solução de hipoclorito por 15 minutos e em água fervente por 5 minutos. A carga microbiana das esponjas sem higienização analisadas foi de 4,29x105 UFC/cm² (± 1,2x105 UFC/cm²), das tratadas com hipoclorito foi 5,64x103 UFC/cm² (± 1,63x10³ UFC/cm²) e das submetidas à fervura foi 1,1x10-1 UFC/cm² (± 1,26x10-2 UFC/cm²). Diante destas análises é possível afirmar que a esponja é sim um vetor em potencial de contaminação microbiológica e que a imersão em água fervente é o processo de desinfecção mais eficiente, entre os avaliados neste estudo, para reduzir a carga microbiológica de esponjas de cozinha.(AU)
One of the most relevant problems in a unit of food and nutrition, relating to food outbreaks it is cross-contamination. Thus, it is believed that the kitchen sponge is a possible vector of microbiological contamination in food. In fact, there are no time standards for the use of sponges, and this can be a problem because they are stored at room temperature in humidified medium rich in organic matter. In addition to ascertaining the level of microbiological contamination, it is also necessary to find out what is the best disinfectant method in order to maintain the microbiological safety of the site, thus preventing cross-contamination and hence the occurrence of a disease outbreak transmitted by food. Were used sponges with 24 to 48 hours in regular use in the kitchen of a hotel Food Service, these were submitted to microbiological count and disinfection methods: immersion in hypochlorite solution for 15 minutes, and in boiling water for 5 minutes. The microbial load of sponges without cleaning was 4,29 x 105 CFU/cm2 ( ±1,2 105 CFU/cm2) which were treated with hypochlorite was 5,64 x 103 CFU/cm2 (±1,63x103 CFU/cm2) and submitted to boiling was 1,1 x101 CFU/cm2 (±1,26x10-2 CFU/cm2). Considering these results we can conclude that the sponge is a potential vector in microbiological contamination and that immersion in boiling water is the most efficient disinfection process among those evaluated in this study to reduce the microbiological load of kitchen sponges.(AU)
Assuntos
Humanos , Saneamento de Hotéis , Serviços de Alimentação , Poluição Ambiental/análise , Utensílios de Alimentação e Culinária , Desinfecção/métodos , Hipoclorito de Sódio/administração & dosagem , Água Potável/administração & dosagem , Temperatura AltaRESUMO
Um dos mais relevantes problemas em uma Unidade de Alimentação e Nutrição (UAN), referente a surtos alimentares, é a contaminação cruzada. Desta forma, acredita- -se que a esponja de cozinha seja um possível vetor da contaminação microbiológica em alimentos. De fato não existem padrões de tempo de uso para esponjas e este pode ser um problema, pois estas são acondicionadas à temperatura ambiente em meio umedecido rico em matéria orgânica. Além de se conhecer o nível de contaminação microbiológica, é também necessário descobrir qual o melhor método de higienização, a fim de se manter a segurança microbiológica do local, prevenindo assim a contaminação cruzada e consequentemente a ocorrência de um surto de doença transmitido por alimentos. Foram utilizadas esponjas com 24 a 48 horas de uso regular na cozinha de uma UAN hoteleira, estas foram submetidas à contagem microbiológica e aos métodos de desinfecção: imersão em solução de hipoclorito por 15 minutos e em água fervente por 5 minutos. A carga microbiana das esponjas sem higienização analisadas foi de 4,29x105 UFC/cm² (± 1,2x105 UFC/cm²), das tratadas com hipoclorito foi 5,64x103 UFC/cm² (± 1,63x10³ UFC/cm²) e das submetidas à fervura foi 1,1x10-1 UFC/cm² (± 1,26x10-2 UFC/cm²). Diante destas análises é possível afirmar que a esponja é sim um vetor em potencial de contaminação microbiológica e que a imersão em água fervente é o processo de desinfecção mais eficiente, entre os avaliados neste estudo, para reduzir a carga microbiológica de esponjas de cozinha.
Assuntos
Humanos , /análise , Saneamento de Hotéis , Utensílios de Alimentação e Culinária , Serviços de Alimentação , Hipoclorito de Sódio/administração & dosagem , Água Potável/administração & dosagem , Desinfecção/métodos , Temperatura AltaRESUMO
Grapevine leaves (Vitis vinifera L. var. Malvasia Fina and Touriga Franca) under culinary treatment (blanching and boiling at 60, 75 and 90min) were studied for their color, pigments and volatile fraction changes. Blanching and boiling caused a decrease in luminosity and a loss of green coloration in both varieties, while a yellow-brownish color arose. Significant correlations were established between the loss of green color (monochromatic variable a∗) and the total chlorophylls content. The main volatiles in fresh leaves [(Z)-3-hexenal, (Z)-3-hexen-1-ol, and (Z)-3-hexenyl acetate] were drastically reduced by blanching and suppressed by boiling. Other compounds like pentanal and 6-methyl-5-hepten-2 one arose from blanching and boiling. A boiling time of 60min is adequate for the culinary process of grapevine leaves, since the product is considered edible and the pigments and volatile changes are not as drastic as observed at 75 and 90min of boiling.