ABSTRACT
The stability of betalains (Bet) encapsulated in cryogels made with a mixture of albumin (ALB) and albumin-pectin (ALB-PEC) as wall materials were evaluated during storage at 32% and 83% relative humidity (RH) at several different temperature conditions (4 °C, 30 °C and 40 °C). The retention of betalains (betanin + isobetanin) and phenolic compounds and the antioxidant activity were determined by high-performance liquid chromatography, the Folin-Ciocalteu method and radical ABTS*+ capture methodology. The color parameters and images of the encapsulated betalains were obtained. Cryogels prepared with ALB at 32% RH and at 4 °C provided betanin and isobetanin retention of 72% and 82%, with half-life times of 108 and 165 days, respectively. The antioxidant activity and phenolic compounds showed retention greater than 70% during storage at 32% RH at all temperatures. Cryogels prepared with ALB-PEC also conferred high retention percentages of phenolic compounds at 83% RH, but this high RH caused a significant decrease in the retention of betalains. Both ALB and ALB-PEC improved betalain stability during storage compared with the extracts without encapsulating. Therefore, cryogels could be used as protection matrices for betalains.
ABSTRACT
ABSTRACT: This research evaluated the influence of blanching on osmotic dehydration in sucrose solutions of papaya of Formosa cultivar. The characterization of invertase present in the fruits was also done. Blanching possibly caused damages to the cellular structure resulting in higher water loss, sugar gain and, thus, effective diffusion coefficients than fresh papayas during osmotic dehydration. The invertase extracted from papaya pulp presented optimum temperature of 45 °C and optimum pH of 4.8. Considering the low production cost of papaya and the invertase characteristics, the fruit shows to be a potential source for the referred enzyme extraction.
RESUMO: O objetivo desse trabalho foi avaliar a influência do branqueamento na desidratação osmótica de mamão Formosa em soluções de sacarose. A caracterização da invertase presente nos frutos também foi realizada. O branqueamento possivelmente danificou a estrutura celular do vegetal resultando em maior perda de água, ganho de açúcar e, consequentemente, maior coeficiente de difusão do que os mamões frescos após a desidratação osmótica. A invertase extraída da polpa do mamão apresentou temperatura ótima de 45 °C e pH ótimo de 4.8. Considerando o baixo custo de produção do mamão e as características da invertase, essa fruta apresenta-se como potencial fonte de extração da enzima.
ABSTRACT
The grape is an important fruit regarding economic and health benefit parameters, because of its large consumption around the world and their bioactive phenolic compounds. The drying process of BRS Morena grapes, whether pre-treated or not with olive oil for producing raisins, resulted in qualitative and quantitative changes in their phenolic composition (anthocyanins, flavonols, stilbenes, hydroxycinammic acid derivatives, flavan-3-ols and proanthocyanidins). The raisins with the pre-treatment preserved more anthocyanins and proanthocyanidins than the raisins not pre-treated. Moreover, the total dehydration time accelerated by approximately 40% in the raisins pre-treated. Therefore, the production of raisins of BRS Morena grapes pre-treated with olive oil as a natural surfactant constitutes an interesting process from both the industrial and health points of view, because of the remarkable reduction in the processing time and the preservation of high concentrations of flavonoids, which have important claims to health benefits from biological activities.
Subject(s)
Desiccation , Fruit/chemistry , Phenols/analysis , Vitis/chemistry , Anthocyanins/analysis , Chromatography, High Pressure Liquid/methods , Flavonoids/analysis , Flavonols/analysis , Plant Extracts/chemistry , Proanthocyanidins/analysis , Stilbenes/analysisABSTRACT
With the objective of utilizing agro-industrial by-products and enhancing the quality attributes of dehydrated fruits, this study evaluated the effects of edible pectin-based coatings containing disintegrated guava by-products (up to 50% concentration) and drying temperatures (46-74 °C) on the drying kinetics and nutritional properties of dried red guava. Coatings were applied to guava slices prior to hot-air drying. A central composite rotatable design was used to optimize carotenoid and phenolic compound retention. The effects of the edible coating compositions combined with the drying temperatures affected the effectiveness of the film as a barrier to carotenoid oxidation. Total phenolic compound retention, however, was affected only by temperature. Responses were simultaneously optimized, and high carotenoid and total phenolic retentions were obtained at approximately 60 °C with 25% by-product concentration. The effective water diffusivities were mainly affected by temperature. Consequently, the coatings improved nutritional quality without having a major impact on drying times.
ABSTRACT
Jambolan [Syzygium cumini (L.)] berries are a popular fruit in Brazil, renowned for their high phenolic compound (PC) content. These PCs have antioxidant, antibacterial, and other characteristics that may be beneficial to human health. The objective of the study was to evaluate the quantitative and qualitative changes of the main phenolic compounds (PCs) (anthocyanins, flavonols, and hydrolysable tannins) in the jambolan fruit, the produced fruit juice, and in the corresponding dehydrated powders obtained by foam mat drying (60, 70, and 80°C) and lyophilization (control). The PCs were analyzed using high-performance liquid chromatography with a diode array detection coupled with an electrospray ionization mass spectrometry (HPLC-DAD-ESI-MSn). Juice production resulted in a more pronounced degradation of anthocyanins than flavonols, and facilitated the extraction of hydrolysable tannins. Elevation of the dehydration temperature negatively impacted the anthocyanin content of the products; on the other hand, the flavonols and hydrolysable tannins were more sensitive to oxidation and heating time during dehydration, respectively, than dehydration temperature. In summary, it can be concluded that processing at 70°C is most suitable, in light of the least loss of nutritional quality of the product with processing time. This study directly informs further investigations into preparation of high-quality jambolan fruit products.
Subject(s)
Antioxidants/analysis , Food Handling/methods , Fruit and Vegetable Juices/analysis , Fruit/chemistry , Phenols/analysis , Syzygium/chemistry , Anthocyanins/analysis , Chromatography, High Pressure Liquid , Desiccation , Flavonols/analysis , Hydrolyzable Tannins/analysis , Nutritive Value , Powders , Spectrometry, Mass, Electrospray Ionization , Tandem Mass Spectrometry , Temperature , Time FactorsABSTRACT
O objetivo do presente trabalho foi avaliar a influência do branqueamento em água quente, da desidratação osmótica em solução de sacarose e da aplicação de cobertura comestível de pectina na cor e atividade de água de fatias de mamão Formosa, após secagem convectiva. Nos experimentos iniciais, com base em planejamento fatorial, avaliou-se a influência da concentração da solução desidratante e do tempo de desidratação osmótica na cor e atividade de água de fatias frescas e branqueadas de mamão. Não foram verificadas alterações significativas na cor das amostras nos intervalos estudados. Encontrou-se expressão para a atividade de água das frutas branqueadas desidratadas osmoticamente. Posteriormente avaliou-se a influência do branqueamento, da desidratação osmótica, da aplicação de cobertura comestível e de combinações entre esses pré-tratamentos na cor e atividade de água das fatias de mamão após secagem convectiva. Verificou-se que o branqueamento não representou pré-tratamento vantajoso para a manutenção da cor e para a redução da atividade de água das frutas secas. As frutas frescas desidratadas osmoticamente com ou sem aplicação de cobertura comestível apresentaram os melhores resultados.
