Oil-in-water emulsion loaded with optimized antioxidant blend improved the shelf-life of trout (Oncorhynchus mykiss) fillets: a study with simplex-centroid design.

This study aimed to obtain optimized mixture with three essential oils (EOs) for maximum antioxidant activity through the augmented simplex-centroid mixture design and evaluate the effect of this optimized blend on total aerobic psychrotrophic count (TAPC), lipid and protein oxidation, instrumental color parameters and texture profile in rainbow trout fillets at refrigerated storage for nine days. Considering the DPPH and FRAP assays, the ideal EO blend was 66% lemongrass and 34% oregano. During refrigerated storage, this blend at 2000 ppm was equally effective as BHT (100 ppm) (p > 0.05), mitigating the discoloration (a* and b*), lipid, and protein oxidation in 38.83%, 12.95%, 76.13%, and 35.13%, respectively, besides shows greater effectiveness for preserving texture changes (p < 0.05) and extending the shelf life in 13 h. The lemongrass + oregano EO blend reveals a promising natural alternative to enhance the quality of rainbow trout fillets under refrigerated storage. Furthermore, the multiresponse optimization showed to be a strong ally in enabling the use of these EOs by food industries.

Effect of Aloe vera gel coating on organoleptic and nutritional quality of minimally processed carrot.

Demand for fresh vegetables has led to development studies in postharvest area mainly focused on minimizing and look for alternatives to chemical additives for food preservation. The use of natural derived edible coatings emerges as a promising alternative for maintaining quality of vegetables. The objective of this study was to evaluate the effect of Aloe vera gel in minimally processed carrot during postharvest storage. Samples with different degrees of processing were immersed in Aloe vera gel, packaged polyolefin bags, and stored in refrigerated chambers at 5 °C for 12 days. Different organoleptic and quality parameters were evaluated. In general, the samples treated with Aloe vera gel showed less quality loss and a lower increment in the bleaching index. Moreover, sensory analysis allowed to establish that carrots processed in slices and shredded and coated with the gel had a more flavorful taste and higher moisture content. Aloe vera treatment did not influence the microbiological growth of bacteria and fungi during storage. Regarding nutritional quality, the treated samples showed a higher accumulation or lower degradation of phenols, flavonoids, and carotenoids, probably generating in this way, a higher antioxidant capacity in these samples. Finally, Aloe vera gel treatment did not influence sugar dynamics in any of the samples. It can be concluded that the treatment with Aloe vera gel allows maintaining a better organoleptic and nutritional quality of carrots with different degrees of processing during refrigerated storage.

Improving bitter pit prediction by the use of X-ray fluorescence (XRF): A new approach by multivariate classification.

Bitter pit (BP) is one of the most relevant post-harvest disorders for apple industry worldwide, which is often related to calcium (Ca) deficiency at the calyx end of the fruit. Its occurrence takes place along with an imbalance with other minerals, such as potassium (K). Although the K/Ca ratio is considered a valuable indicator of BP, a high variability in the levels of these elements occurs within the fruit, between fruits of the same plant, and between plants and orchards. Prediction systems based on the content of elements in fruit have a high variability because they are determined in samples composed of various fruits. With X-ray fluorescence (XRF) spectrometry, it is possible to characterize non-destructively the signal intensity for several mineral elements at a given position in individual fruit and thus, the complete signal of the mineral composition can be used to perform a predictive model to determine the incidence of bitter pit. Therefore, it was hypothesized that using a multivariate modeling approach, other elements beyond the K and Ca could be found that could improve the current clutter prediction capability. Two studies were carried out: on the first one an experiment was conducted to determine the K/Ca and the whole spectrum using XRF of a balanced sample of affected and non-affected 'Granny Smith' apples. On the second study apples of three cultivars ('Granny Smith', 'Brookfield' and 'Fuji'), were harvested from two commercial orchards to evaluate the use of XRF to predict BP. With data from the first study a multivariate classification system was trained (balanced database of healthy and BP fruit, consisting in 176 from each group) and then the model was applied on the second study to fruit from two orchards with a history of BP. Results show that when dimensionality reduction was performed on the XRF spectra (1.5 - 8 KeV) of 'Granny Smith' apples, comparing fruit with and without BP, along with K and Ca, four other elements (i.e., Cl, Si, P, and S) were found to be deterministic. However, the PCA revealed that the classification between samples (BP vs. non-BP fruit) was not possible by univariate analysis (individual elements or the K/Ca ratio).Therefore, a multivariate classification approach was applied, and the classification measures (sensitivity, specificity, and balanced precision) of the PLS-DA models for all cultivars evaluated ('Granny Smith', 'Fuji' and 'Brookfield') on the full training samples and with both validation procedures (Venetian and Monte Carlo), ranged from 0.76 to 0.92. The results of this work indicate that using this technology at the individual fruit level is essential to understand the factors that determine this disorder and can improve BP prediction of intact fruit.

Respuesta en poscosecha de frutos de agraz (Vaccinium meridionale Swartz) a almacenamiento en dos tipos de plástico / Postharvest response of berry fruits (Vaccinium meridionale Swartz) to storage in two types of plastic

RESUMEN La planta de agraz (Vaccinium meridionale Swartz) es una especie nativa de arándano de Colombia y su fruto es una baya globosa con propiedades nutraceúticas, debido a su excelente fuente de antioxidantes, utilizado como ingrediente para la preparación de alimentos. El objetivo del estudio fue evaluar las propiedades físico químicas del fruto, almacenado durante 12 días, a 2°C y 90% de HR. Se evaluaron frutos en dos estados de madurez: rompimiento de color, estado inmaduro (asociado al color rojo) y completamente pigmentado (100% pigmentación morado), los frutos fueron puestos en bolsas hechas de polietileno biorientado y polipropileno monoorientado. Los resultados muestran que los frutos inmaduros preservaron los sólidos solubles totales, cuando se mantuvieron en polipropileno monoorientado, mientras los sólidos solubles totales, se incrementaron significativamente en los frutos maduros almacenados en polipropileno monorientado, afectando el metabolismo del fruto y las reservas de carbohidratos. El pH disminuyó en todos los tratamientos; entre los 6 y 12DDT, coincidiendo, a su vez, con el aumento de la acidez total titulable durante el mismo periodo.

ABSTRACT 'Agraz' (Vaccinium meridionale Swartz) is a native blueberry from Colombia, being the fruit a globose berry, with nutraceutic quality due to an excellent source of antioxidants and is used as an ingredient for food preparation. The objective of this study was to evaluate the physical-chemical properties of fruits stored during 12 days, at a temperature of 2°C and a relative humidity of 90%. Fruits with two stages of ripeness, color break, an immature state (associated with red color), and fully pigmented (100% purple pigmentation) were stored, packaged in two different plastics recipients, one bioriented polyethylene and the other mono-oriented polypropylene. The results indicate that immature fruits demonstrated a prolonged preservation of the total soluble solids, when combined with the mono-oriented polypropylene packaging, otherwise TSS were significantly increased in mature fruits, packaged in mono-oriented polypropylene, affecting fruit metabolism and carbohydrate reserve. The pH diceased in all treatments, between 6 to 12 days after treatment, coinciding in turn, with the increase in total titratable acidity during the same period.

Microstructural characteristics and gastro-small intestinal digestion in vitro of potato starch: Effects of refrigerated storage and reheating in microwave.

The objective of our study was to evaluate paste clarity, retrogradation (syneresis %), thermal characteristics and kinetics of glucose release during in vitro gastro-small intestinal digestion of freshly cooked and refrigerated potato starch. Freshly cooked starch pastes had a paste clarity of 71%, which decreased to 35.4% whereas syneresis (%) increased after 7days of refrigerated storage. The X-ray and thermal characteristics of native, retrograded and microwave reheated starch samples differed significantly from each other. For the freshly cooked starch pastes, ∼88% starch hydrolysis was observed at the end (150min) of digestion under simulated gastro-small intestinal conditions that decreased to ∼70% for the 7day stored pastes. The hydrolysis (%) of refrigerated pastes increased to 86% and 92% after one and two cycles of microwave reheating, respectively. These results contribute to the understanding of starch retrogradation in relation to starch digestion.

Nutritional and sensory quality during refrigerated storage of fresh-cut mints (Mentha×piperita and M. spicata).

The effect of storage time on quality attributes of refrigerated fresh-cut mints (Mentha×piperita and M. spicata) was studied. Atmosphere composition, respiratory activity, weight loss, surface colour, total chlorophyll, carotenoids, browning potential, total phenols, flavonoids, radical-scavenging activity, ascorbic acid and essential oil yield and composition were analysed. Respiratory activity of peppermint and spearmint samples diminished moderately (42% and 28%, respectively) after 21days at 0°C. A slight modification of the internal atmosphere was achieved. Surface colour, chlorophyll, carotenoid and antioxidant compounds remained almost constant. The yield of essential oil did not change or it showed an apparent increase after 21days at 0°C, depending on plant growth stage. The characteristic flavour components of peppermint (menthone and menthol) increased, while the contents of the main constituents of spearmint essential oil showed minor variations after storage. The conditions assayed for packaging and storing fresh-cut mints were adequate to achieve a relatively long shelf life and they retained their antioxidant properties.

Composition, antioxidant capacity and quality of yellow passion fruit during storage / Composição, atividade antioxidante e qualidade do maracujáamarelo durante armazenamento

In this work, the contents of phenolic compounds, B-carotene, ascorbic acid and antioxidant activity (DPPH and TEAC methods) were determined in the yellow passion fruit juice during storage at 5 and 24 C, at intervals of 10 days. The fruit quality during storage was determined, and the parameters weight loss, wrinkles, skin color and pathogenic degradation index were used. Samples of fruit at maturity stage with the skin color predominantly green were used for the tests. The results showed that total phenolic compounds, B-carotene and antioxidant activity of the yellow passion fruit juice were not affected by storage temperature and the content of total phenolic compounds of the juice increased with storage time. It as demonstrated that the effects of high temperature during storage is much more evident and impacting the appearance of the fruit, which in the nutritional quality of the juice. The antioxidant activity of juice, expressed in kidnapping DPPH decreased during storage. Based on the microbiological quality, the shelf life of yellow passion fruit was extended to 20 days in refrigerated storage.

Neste trabalho, os conteúdos de compostos fenólicos totais, B-caroteno, ácido ascórbico e a atividade antioxidante (pelos métodos DPPH e TEAC) foram determinados no suco do maracujá-amarelo durante o armazenamento a 5 e 24 ºC, em intervalos de 10 dias, durante 40 dias. A qualidade dos frutos foi determinada durante o armazenamento, tomando como parâmetros as variáveis perda de massa, enrugamento, cor da casca e o índice de degradação por patógenos. Amostras de frutos em estádio de maturação com a cor da casca predominantemente verde, em início de amarelecimento, foram utilizadas nos ensaios. Os teores de compostos fenólicos totais e B-caroteno, e a atividade antioxidante do suco do maracujá-amarelo não foram influenciados pela temperatura de armazenamento. O conteúdo de compostos fenólicos totais do suco aumentou com o tempo de armazenamento. Os efeitos da temperatura de armazenamento foram mais evidentes e impactantes na aparência do fruto do que na qualidade nutricional do suco. A atividade antioxidante do suco, expressada em seqüestro do radical DPPH, diminuiu durante o armazenamento. Com base na qualidade microbiológica, a vida útil do maracujáamarelo se estendeu até 20 dias no armazenamento refrigerado.

Composition, antioxidant capacity and quality of yellow passion fruit during storage / Composição, atividade antioxidante e qualidade do maracujáamarelo durante armazenamento

 In this work, the contents of phenolic compounds, B-carotene, ascorbic acid and antioxidant activity (DPPH and TEAC methods) were determined in the yellow passion fruit juice during storage at 5 and 24 C, at intervals of 10 days. The fruit quality during storage was determined, and the parameters weight loss, wrinkles, skin color and pathogenic degradation index were used. Samples of fruit at maturity stage with the skin color predominantly green were used for the tests. The results showed that total phenolic compounds, B-carotene and antioxidant activity of the yellow passion fruit juice were not affected by storage temperature and the content of total phenolic compounds of the juice increased with storage time. It as demonstrated that the effects of high temperature during storage is much more evident and impacting the appearance of the fruit, which in the nutritional quality of the juice. The antioxidant activity of juice, expressed in kidnapping DPPH decreased during storage. Based on the microbiological quality, the shelf life of yellow passion fruit was extended to 20 days in refrigerated storage. 

Neste trabalho, os conteúdos de compostos fenólicos totais, B-caroteno, ácido ascórbico e a atividade antioxidante (pelos métodos DPPH e TEAC) foram determinados no suco do maracujá-amarelo durante o armazenamento a 5 e 24 ºC, em intervalos de 10 dias, durante 40 dias. A qualidade dos frutos foi determinada durante o armazenamento, tomando como parâmetros as variáveis perda de massa, enrugamento, cor da casca e o índice de degradação por patógenos. Amostras de frutos em estádio de maturação com a cor da casca predominantemente verde, em início de amarelecimento, foram utilizadas nos ensaios. Os teores de compostos fenólicos totais e B-caroteno, e a atividade antioxidante do suco do maracujá-amarelo não foram influenciados pela temperatura de armazenamento. O conteúdo de compostos fenólicos totais do suco aumentou com o tempo de armazenamento. Os efeitos da temperatura de armazenamento foram mais evidentes e impactantes na aparência do fruto do que na qualidade nutricional do suco. A atividade antioxidante do suco, expressada em seqüestro do radical DPPH, diminuiu durante o armazenamento. Com base na qualidade microbiológica, a vida útil do maracujáamarelo se estendeu até 20 dias no armazenamento refrigerado.

Avaliação da qualidade da lagosta (Panulirus argus. Latreille 1804) inteira armazenada em gelo / Qual ity assessment of whole lobster (Panulirus argus Latreille 1804) stored in ice

A lagosta tem papel de destaque no setor pesqueiro nacional, sendo o principal recurso pesqueiro da região Nordeste e 95% desta produção destina-se ao mercado internacional. O grau de frescor do pescado é um dos aspectos mais importantes para determinar a qualidade do pescado, e frequentemente se recorre a métodos sensoriais, físicos, bioquímicos e microbiológicos. O objetivo deste trabalho foi avaliar a qualidade da lagosta inteira armazenada em gelo através do Método de Índice de Qualidade (MIQ), que permite a determinação rápida e eficiente do grau de frescor do pescado. Os pontos de deméritos foram designados aos atributos sensoriais selecionados de acordo com sua importância. Durante o armazenamento foram realizadas determinações do Nitrogênio das Bases Voláteis Totais (NBVT), pH e análises microbiológicas (Coliformes Termotolerantes, Salmonella spp. e Staphylococcus aureus). O Índice de Qualidade (IQ) variou de zero (máximo frescor) a 14 (perda total do frescor) atingindo o limite de aceitabilidade para consumo (IQ = 6,3), o que equivale a um período de 7 dias. O valor do N-BVT variou de 19,69 a 29,63 mg 100g-1, e o pH variou de 6,91 a 7,03 no primeiro e 17º dia de armazenamento, respectivamente. Os resultados microbiológicos atenderam aos padrões microbiológicos estabelecidos pela legislação brasileira.

The lobster has an important role in the national fisheries sector, the main fishing resourc e in the Northeast and 95% of this production is intended for the international market. The seafood freshness degree is one of the most important in determining the seafood quality, and often uses a sensorial, physical, biochemical and microbiological methods. The objective of this study was to evaluate the whole lobster quality stored on ice through the Quality Index Method (QIM), which allows rapid and efficient determination of the seafood freshness. The demerits points were assigned to the sensory attributes selected according to their importance. During storage the total volatile bases nitrogen (TVB - N), pH and microbiological (fecal coliform, Salmonella spp. and Staphylococcus aureus ) were made. The Quality Index (IQ) ranged from zero (maximum freshness) to 14 (total loss of freshness) reached the acceptable limit for consumption (IQ = 6.3), which corresponds to a period of 7 days. The value of the TVB - N ranged from 19.69 to 29.63 mg 100g - 1 , and the pH ranged from 6.91 to 7.03 in the first and 17th day of storage, respectively. The microbiological results met the microbiological standards e stablished by Brazilian legislation.

Evaluation of culture media for counts of Bifidobacterium animalis subsp. lactis Bb 12in yoghurt after refrigerated storage / Avaliação de meios de cultura para contagem de Bifidobacterium animalis subsp. lactis Bb 12em iogurte após a estocagem refrigerada

The agar RCPB pH5 has been considered a good alternative for counts of Bifidobacterium in yoghurt. However, during the refrigerated storage of yoghurt it is extremely difficult to count this microorganism due to the size of the colonies, which are so small they require the aid of a stereoscope to count them. Another agar, MRS-LP, has been also recommended for counts of Bifidobacterium in the presence of yoghurt bacteria. This study evaluated the supplementation of RCPB pH5 agar with dehydrated liver extract and the salts KH2PO4, K2HPO4, FeSO(4)7H2O, MnSO4H2O and MgSO(4)7H2O, aiming at improving the differentiation of Bifidobacterium in yoghurt after refrigerated storage, and also evaluated the selective count of Bifidobacterium in yoghurt using the agar MRS-LP. The agar MRS-LP presented the same cell recovery as non-fortified RCPB pH5 agar, used as a standard medium, thus being considered a good option for counts of Bifidobacterium in yoghurt. The fortified RCPB pH5 also presented the same recovery as the standard RCPB pH5 medium, however, the addition of dehydrated liver extract to the RCPB pH5 agar considerably increased the size of the Bifidobacterium colonies after refrigerated storage, making differentiation of the colonies much easier and reliable when compared to the standard non-fortified RPCP pH5. The addition of the salts (KH2PO4, K2HPO4, FeSO(4)7H2O, MnSO4H2O and MgSO(4)7H2O) had no influence on the performance of the RCPB pH5 agar.

O meio RCPB pH5 tem sido considerado uma boa opção para a contagem de Bifidobacterium em iogurte. Entretanto, durante a estocagem refrigerada do iogurte é extremante difícil a contagem deste microrganismo devido ao pequeno diâmetro desenvolvido pelas colônias de Bifidobacterium neste meio, sendo que a sua contagem somente se torna possível com o auxílio de um estereoscópio. Outro meio, MRS-LP, também tem sido recomendado para a contagem de Bifidobaterium em iogurte. Este estudo avaliou a suplementação do meio RCPB pH5 com extrato de fígado desidratado e com os sais KH2PO4, K2HPO4, FeSO(4)7H2O, MnSO4H2O e MgSO(4)7H2O, visando melhorar a diferenciação de Bifidobacterium em iogurte durante a estocagem refrigerada e também avaliou a contagem seletiva de Bifidobacterium em iogurte usando o meio MRS-LP. O meio MRS-LP apresentou a mesma recuperação de células que o meio RCPB pH5, usado como padrão, após 30 dias de estocagem refrigerada do iogurte, sendo considerado uma boa opção para a contagem de Bifidobacterium em iogurtes durante a estocagem refrigerada. O meio RCPB pH5 fortificado também apresentou a mesma recuperação de células de Bifidobacterium que o meio padrão RCPB pH5; entretanto, a adição de extrato de fígado desidratado aumentou consideravelmente o diâmetro das colônias de Bifidobacterium, tornando a diferenciação destas bastante fácil e confiável quando comparadas à sua diferenciação no meio RCPB pH5 sem a fortificação. A adição dos sais (KH2PO4, K2HPO4, FeSO(4)7H2O, MnSO4H2O e MgSO(4)7H2O) não exerceu influência no desempenho do meio RCPB pH5.

Evaluation of culture media for counts of Bifidobacterium animalis subsp. lactis Bb 12in yoghurt after refrigerated storage.

The agar RCPB pH5 has been considered a good alternative for counts of Bifidobacterium in yoghurt. However, during the refrigerated storage of yoghurt it is extremely difficult to count this microorganism due to the size of the colonies, which are so small they require the aid of a stereoscope to count them. Another agar, MRS-LP, has been also recommended for counts of Bifidobacterium in the presence of yoghurt bacteria. This study evaluated the supplementation of RCPB pH5 agar with dehydrated liver extract and the salts KH2PO4, K2HPO4, FeSO47H2O, MnSO4H2O and MgSO47H2O, aiming at improving the differentiation of Bifidobacterium in yoghurt after refrigerated storage, and also evaluated the selective count of Bifidobacterium in yoghurt using the agar MRS-LP. The agar MRS-LP presented the same cell recovery as non-fortified RCPB pH5 agar, used as a standard medium, thus being considered a good option for counts of Bifidobacterium in yoghurt. The fortified RCPB pH5 also presented the same recovery as the standard RCPB pH5 medium, however, the addition of dehydrated liver extract to the RCPB pH5 agar considerably increased the size of the Bifidobacterium colonies after refrigerated storage, making differentiation of the colonies much easier and reliable when compared to the standard non-fortified RPCP pH5. The addition of the salts (KH2PO4, K2HPO4, FeSO47H2O, MnSO4H2O and MgSO47H2O) had no influence on the performance of the RCPB pH5 agar.

Evaluation of culture media for counts of Bifidobacterium animalis subsp. lactis Bb 12in yoghurt after refrigerated storage

The agar RCPB pH5 has been considered a good alternative for counts of Bifidobacterium in yoghurt. However, during the refrigerated storage of yoghurt it is extremely difficult to count this microorganism due to the size of the colonies, which are so small they require the aid of a stereoscope to count them. Another agar, MRS-LP, has been also recommended for counts of Bifidobacterium in the presence of yoghurt bacteria. This study evaluated the supplementation of RCPB pH5 agar with dehydrated liver extract and the salts KH2PO4, K2HPO4, FeSO(4)7H2O, MnSO4H2O and MgSO(4)7H2O, aiming at improving the differentiation of Bifidobacterium in yoghurt after refrigerated storage, and also evaluated the selective count of Bifidobacterium in yoghurt using the agar MRS-LP. The agar MRS-LP presented the same cell recovery as non-fortified RCPB pH5 agar, used as a standard medium, thus being considered a good option for counts of Bifidobacterium in yoghurt. The fortified RCPB pH5 also presented the same recovery as the standard RCPB pH5 medium, however, the addition of dehydrated liver extract to the RCPB pH5 agar considerably increased the size of the Bifidobacterium colonies after refrigerated storage, making differentiation of the colonies much easier and reliable when compared to the standard non-fortified RPCP pH5. The addition of the salts (KH2PO4, K2HPO4, FeSO(4)7H2O, MnSO4H2O and MgSO(4)7H2O) had no influence on the performance of the RCPB pH5 agar.

O meio RCPB pH5 tem sido considerado uma boa opção para a contagem de Bifidobacterium em iogurte. Entretanto, durante a estocagem refrigerada do iogurte é extremante difícil a contagem deste microrganismo devido ao pequeno diâmetro desenvolvido pelas colônias de Bifidobacterium neste meio, sendo que a sua contagem somente se torna possível com o auxílio de um estereoscópio. Outro meio, MRS-LP, também tem sido recomendado para a contagem de Bifidobaterium em iogurte. Este estudo avaliou a suplementação do meio RCPB pH5 com extrato de fígado desidratado e com os sais KH2PO4, K2HPO4, FeSO(4)7H2O, MnSO4H2O e MgSO(4)7H2O, visando melhorar a diferenciação de Bifidobacterium em iogurte durante a estocagem refrigerada e também avaliou a contagem seletiva de Bifidobacterium em iogurte usando o meio MRS-LP. O meio MRS-LP apresentou a mesma recuperação de células que o meio RCPB pH5, usado como padrão, após 30 dias de estocagem refrigerada do iogurte, sendo considerado uma boa opção para a contagem de Bifidobacterium em iogurtes durante a estocagem refrigerada. O meio RCPB pH5 fortificado também apresentou a mesma recuperação de células de Bifidobacterium que o meio padrão RCPB pH5; entretanto, a adição de extrato de fígado desidratado aumentou consideravelmente o diâmetro das colônias de Bifidobacterium, tornando a diferenciação destas bastante fácil e confiável quando comparadas à sua diferenciação no meio RCPB pH5 sem a fortificação. A adição dos sais (KH2PO4, K2HPO4, FeSO(4)7H2O, MnSO4H2O e MgSO(4)7H2O) não exerceu influência no desempenho do meio RCPB pH5.