Efeito da secagem por ar quente na cor e propriedades nutricionais de duas variedades de castanha (Castanea sativa Mill.)

O objetivo do nosso trabalho foi avaliar o efeito da secagem por ar quente, realizada num secador de tabuleiros a 50 °C (convecção forçada), nas propriedades físicas e nutricionais de castanha laminada ao longo do tempo de secagem (0, 4, 6 e 10 horas). Verificou-se um aumento na variação total de cor (ΔE) ao longo da desidratação. Contudo, esta mudança de cor não foi visualmente percetível. As alterações na composição nutricional também foram pouco significativas, mesmo após 10 horas de secagem. A variabilidade entre variedades foi maior do que a observada ao longo da secagem para cada variedade, sugerindo que o processo de desidratação não alterou significativamente as propriedades nutricionais da castanha. Devido ao seu baixo teor calórico (cerca de 367 kcal/100 g produto), reduzido teor de gordura e um interessante teor em fibras, além de não conter glúten, a castanha laminada apresenta-se como um excelente snack.A Teresa Delgado agradece à FCT pela bolsa de Doutoramento (SFRH/BDI82285/2011). Os autores agradecem ao CIMO (PEst-OEI AGR/UI0690/2011 ), ao REQUIMTE (PEst-CIEQBILA0006/2013) e ao POCTEP - Programa Cooperação Transfronteiriça Espanha-Portugal pelo apoio financeiro através do Projeto "REDI AGROTEC - Red transfi·onteriza Espana Portugal de experimentaci ón y transferencia para e! desanollo dei sector agropecuario y agroindustrial".info:eu-repo/semantics/publishedVersio

How Agronomic Factors Affects Olive Oil Composition And Quality

Olive oil is one of the most popular vegetable oils worldwide but several factors might affect its quality and composition, from the tree to the spoon. Olive oil quality and composition is mainly influenced by olive fruit characteristics, and therefore all aspects that influence their development have a crucial effect on olive products. Those factors include the selection of olive cultivar, its cultivation, degree of crop intensification and production systems, agricultural practices, including irrigation and fertilization, olive pests and diseases management, all these factors clearly defining the composition of olive fruits and the inherent quality and properties of olive products. In the last decades, huge modifications in olive tree cultivation have been observed, related essentially with two great factors: development of olive cultivations in new producing areas and crop intensification in traditional producing areas. Generally, most agronomic factors, including crop density, farming system, irrigation and fertilization, have no substantial effects on fresh olive oil quality parameters and classification. Nevertheless, a considerable incidence of olive pests and diseases can easily take fresh olive oils to the lampante category. In opposition, all agronomic factors seem to influence olive oil composition. Antioxidants are the main affected components, with a crucial effect on olive oil sensorial attributes, bioactive and nutritional properties, as well as its oxidative stability. In present chapter the influence of diverse agronomic factors on olive fruits and olive oils production, composition and quality, is reviewed and discussed, giving special importance to olive farming-systems, fertilization and irrigation, as well as the incidence of olive pests and diseases.info:eu-repo/semantics/publishedVersio

Comparison of different drying methods on the chemical and sensory properties of chestnut (Castanea sativa M.) slices

The aim of this work was to determine the effect of hot-air convective drying (D), osmotic dehydration (OD), osmotic dehydration + drying (OD + D) and freeze-drying (FD) on chemical and sensorial characteristics of chestnut slices. Proximate composition, sugars, organic acids and lipid profiles were determined along 60 days of storage. Immediately after production, D and FD samples had similar proximate compositions, both with higher fat and protein contents than the osmodehydrated ones, the latter with increased sucrose contents. FD was the method that better preserved starch, amylose, ascorbic and citric acid molecules at day 0, while D originated samples with higher glucose and fructose contents. Along storage, the major variations were observed on organic acids: ascorbic acid decreased on all methods, while fumaric acid increased. Only small variations were observed on the fatty acids and vitamin E profiles and amounts. All samples presented similar and good overall sensorial acceptance with the exception of D. FD was the method that better preserved the sensorial characteristics until 60 days of storage, while D only preserved freshness until 15 days and OD + D until 30 days. In general terms, the most adequate and accepted preservation methods to apply to chestnuts would be FD and OD + D.Teresa Delgado acknowledges the Fundação para a Ciência e Tecnologia (FCT) for the financial support through the PhD grant—SFRH/BD/82285/2011 and REQUIMTE through the UID/QUI/50006/2013 project. The authors are also grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013).info:eu-repo/semantics/publishedVersio

Efeito do armazenamento da azeitona na qualidade de azeites elementares da Cv. Cobrançosa.

O objectivo do trabalho que se apresenta foi avaliar a influência do armazenamento da azeitona na qualidade do azeite, uma vez que esta ainda é uma prática usual na região de Trás-os-Montes. O presente estudo decorreu na campanhas de 1997/1998 e 1998/1999 tendo incidido respectivamente em 4 e 5 lotes de azeitonas da Cv. Cobrançosa que foram laborados em 3 tempos distintos (To- I dia após colheita; T7-7 dias após colheita; T14 - 14 dias após colheita). Os parâmetros químicos avaliados foram a acidez, o índice de peróxido, a absorvência no ultravioleta e a resistência à oxidação. Nos azeites da campanha de 1997/1998 foram ainda avaliados os teores em polifenóis totais e esteróis. Na campanha de 1998/1999 foi também avaliado o teor em tocoferóis. À excepção do índice de peróxido todos os parâmetros avaliados evidenciam diferenças significativas com o armazenamento da azeitona. Os valores de acidez, K270' estigmasterol, eritrodiol e uvaol sofrem incrementos com o armazenamento. Pelo contrário os valores de K232, resistência à oxidação, polifenóis totais, -sitosterol e tocoferóis apresentaram reduções significativas

Composição em ácidos gordos e vitamina E de óleos de sementes de uvas de dez castas portuguesas

O presente estudo teve como objetivo avaliar a vitamina E (tocoferóis e tocotrienóis) e os ácidos gordos em óleos de semente de uva de dez castas portuguesas com o intuito de aumentar o potencial e valorizar a exploração destes resíduos industriais. Os resultados mostraram que os óleos de semente de uva são uma fonte potencialyde -tocotrienol (499- 1575 mg/kg), a-tocoferol (85,5-244 mg/kg) e a -tocotrienol (69-319 mg/kg), sendo o ytocotrienol o mais comum. No que diz respeito à composição dos ácidos gordos, o linole ico (C 18:2cc), oleico (C 18: I ), palmítico (C 16:0) e esteárico (C 18:0) foram os predominantes. Os óleos de semente de uva demonstraram ser uma boa fonte de ácidos gordos polinsaturados (PUF A) (63,64-73,53%), enquanto os ácidos gordos monoinsaturados (MUF A) e saturados (SFA) variaram entre 14,19-2 1,29 e 11 ,64-1 4,94%, respetivamente. Em suma, o presente trabalho demonstrou que os óleos extraídos a partir de sementes de castas de uvas portuguesas apresentam uma composição adequada para poderem ser incorporados em outros produtos alimentares. O presente estudo teve como objetivo avaliar à vitamina E (tocoferóis e tocotrienóis) e os ácidos gordos em óleos de semente de uva de dez tradicionais castas portuguesas - Aragonês, Cornifesto, Marufo, Periquita, Tinta Barroca, Tinta Carvalha, Touriga Cão, Touriga Francesa, Touriga Nacional e Trincadeira Preta, com o intuito de aumentar o potencial e valorizar a exploração destes resíduos industriais. Os resultados mostraram que os óleos de semente de uva são uma boa fonte de γ-tocotrienol (499-1575 mg/kg), α-tocoferol (85,5-244 mg/kg) e α-tocotrienol (69-319 mg/kg), sendo γ-tocotrienol o mais comum. No que diz respeito, a composição dos ácidos gordos o linoleico (C18:2cc), oleico (C18:1), palmítico (C16:0) e esteárico (C18:0) foram os mais predominantes. Os óleos de semente de uva demonstraram ser uma boa fonte de ácidos gordos polinsaturados (PUFA) (63,64 -73,53%), enquanto que os ácidos gordos monoinsaturados (MUFA) e saturados (SFA) variaram entre 14,19-21,29 e 11,64-14,94%, respectivamente. Segundo, as análises de cluster realizadas aos ácidos gordos e vitamina E obtiveram-se quatro grupos homogéneos. Em suma, o presente trabalho demonstrou que as sementes de castas tradicionais de uvas portuguesas podem ser reutilizas e seus óleos incorporados em outros produtos alimentares, tendo em conta os compostos detectados que são referidos na literatura como tendo efeitos positivos na saúde humana

Effect of Drying on Color, Proximate Composition and Drying Kinetics of Sliced Chestnuts

In the present work, dried sliced chestnuts (Judia and Longal varieties), product with an increased shelf life, low calorie and gluten-free contents, were prepared. The effect of air convective drying on the drying kinetics, color and proximate composition of sliced chestnuts was evaluated. Even though significant differences in nutritional composition were found between both varieties at the beginning, the drying behaviors were similar; however, Judia dried at a slightly faster rate than Longal. The use of Page, two-term, and modified Henderson and Pabis models fitted well the experimental data (adjusted R 2 > 0.999). With drying, slight variations in color were observed for both varieties and only moisture content decreased significantly. The obtained product retained all chemical composition, and due to the low caloric value (367 kcal/100 g product), low fat and gluten-free contents of chestnut slices, this can be an interesting substitute to other high-calorie snacks available in the market. Practical Applications: The chestnut fruit is increasingly popular among consumers. The fruit is usually sold fresh or frozen while smaller fruits are generally rejected by industries. So, it is very important to find alternatives to valorize these fruits. Moreover, consumers search for healthy and easy-to-consume food. Chestnut follow these requisites, being a nut with interesting properties due to its low fat content, high levels of starch (sugar of slow absorption) and significant amounts of fibers. Furthermore, it is a gluten-free nut, ideal for celiac patients. On the other hand, the majority of snacks in the market are rich in fat and are made from wheat flour. So, the development of snacks based on chestnut would be innovative. This study intends to provide information on the effect of drying on color, nutritional composition and drying kinetics of sliced chestnut in order to obtain a healthy and low-calorie content snack.Teresa Delgado acknowledges the Fundação para a Ciência e Tecnologia (FCT) for the financial support through the PhD grant – SFRH/BD/82285/2011, CIMO through the Project PEst-OE/AGR/UI0690/2014, REQUIMTE through the Project PEst-C/EQB/LA0006/2013 and POCTEP – Programa de cooperação Transfronteiriça Espanha – Portugal through the Project RED/AGROTEC – Experimentation network and transfer for development of agricultural and agro industrial sectors between Spain and Portugal.info:eu-repo/semantics/publishedVersio

Avaliação das propriedades nutricionais e sensoriais de snacks de castanha (Castanea sativa Mill.)

Aiming to increase the market offer of chestnut based products, for both increased economical return and shelf life, different preservation methods were tested on sliced chestnut. Hot air convective drying, osmotic dehydration, and freeze-drying, followed by both sensorial and chemical analysis (proximate composition, free sugars, organic acids and lipid profiles) during a storage period of up to 60 days were performed. Freeze-dried was the method that better preserved samples freshness, particularly regarding starch and ascorbic, but lipid oxidation after 60 days was higher. Osmotic dehydration followed by oven drying provided the highest sensorial scored samples, with increased lipid protection at expenses of sugar incorporation. In opposition, oven dried samples were less accepted from the sensorial point of view, despite the low composition variability. Along storage, the major variations were observed on the ascorbic acid contents, requiring more effective measures to prevent it. Both freeze-drying and osmotic dehydration followed by hot air convective drying are good methods to reduce chestnut losses associates with its natural perishability, while increasing market offer of healthy snacks.info:eu-repo/semantics/publishedVersio

Influence of sustained deficit irrigation and foliar kaolin application on almond kernel composition

Deficit irrigation and kaolin foliar application are agronomic practices that have been demonstrated to improve productivity and physiological response in almond trees but there is no consistent information on the effects on the kernel composition. The objective of this study was to evaluate the effect of different Sustainable Deficit Irrigation (SDI) strategies and kaolin application on some physicochemical composition of the cv Ferragn`es almond (Prunus dulcis (Mill.) D.A. Webb). A randomized block design with five treatments was developed: nonirrigation (NI), non-irrigation with foliar kaolin application (NI+K), full irrigation (FI), and two levels of SDI receiving 70% and 35% of evapotranspiration (SDI75 and SDI35). Pomological parameters, volatile profile and oil composition were analyzed. SDI effect on kernel weight was reduced against full irrigation (FI) but substantially improved in comparison with the rainfed treatments (NI and NI+K). Irrigation treatments showed a lower volatile compounds concentration in comparison with rainfed treatment. The fatty acid composition of the oil was significantly affected, with all the irrigated treatments having higher oleic acid contents than the rainfed treatments, and therefore an expected increased shelf life. Kaolin application had no positive effects on the nonirrigated trees, other than an apparent increase in the total volatiles, a tendency also observed in the NI. Moderate water stress levels (SDI35) improved the synthesis of tocopherols compared to NI, FI and SDI70, which could be related to the adaptation of the almond tree to drought. SDI35 is therefore regarded as a very interesting approach, with significant improvements in comparison with non-irrigated trees, and a clear saving on water against full irrigation without significant pomological and chemical alterations.The authors acknowledge the financial support of Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020), SusTEC (LA/P/0007/2021) and LAQV (UIDB/ 50006/2020 and UIDP/50006/2020). David Barreales thanks FCT for the Ph.D. grant SFRH/BD/139393/2018. This manuscript is part of David Barreales’s Ph.D. thesis. The authors thank to the Cooperativa Agrícola de Alfandega da F´e, Crl. for allowing this research activity in its almond orchards.info:eu-repo/semantics/publishedVersio

Organic acid profile of chestnut (Castanea sativa Mill.) as affected by hot air convective drying

The objective of the present work was to evaluate the effect of hot air convective drying on the organic acid profile of chestnut. An extractive method, with internal standard, followed by HPLC-UV was validated, allowing the quantification of malic, ascorbic, citric, and fumaric acids with good precision and accuracy. Fresh chestnuts presented differences between varieties. The thermal process caused equivalent losses of ascorbic acid on both varieties, but higher losses of malic acid in Longal. Furthermore, fumaric acid contents increased on both varieties. Therefore, hot air convective drying affected the organic acid composition of chestnut slices, and this effect was varietal dependent.info:eu-repo/semantics/publishedVersio

Effect of hot air convective drying on sugar composition of chestnut (Castanea sativa Mill.) slices

The main objectives of the present work were as follows: (a) to develop an analytical procedure to quantify free sugars on chestnuts based on green-chemistry principles and (b) to evaluate the effect of hot air convective drying (50 °C along 10 hr) on the carbohydrate profile of sliced chestnuts (Longal and Judia varieties). The analytical method allowed the quantification of several sugars in chestnut extracts, with low detection limits and good precision. In fresh, Judia variety had higher sucrose, fructose, and glucose contents than Longal, together with amylose. Nevertheless, when applying hot air convective drying to chestnut slices, a significant increase in fructose contents was observed with time, particularly after 10 hr drying in Longal variety. Nonetheless, a significant increase in glucose content was observed on both varieties, probably related to starch thermal hydrolysis. Practical applications: An environment-friendly methodology for free sugars quantification, based on ethanol/water extraction (green solvents), ion-exchange high-performance liquid chromatography separation with water as mobile phase, and evaporative light scattering detection, was developed. The method allowed the quantification of raffinose, sucrose, glucose, and fructose in chestnut extracts, with detection limits of 6 μg for sucrose and 0.3 μg for other sugars. Good precision was achieved with intra-day and inter-day coefficients of variation below 5%. Regarding chestnuts' drying, hot air convective drying might be applied to chestnut slices but it may induce modifications on the carbohydrate composition of the samples, particularly when long drying periods are applied, requiring some attention because it might induce both visual and sensory changes.Fundação para a Ciência e Tecnologia (FCT), Grant/Award Number: SFRH/BD/ 82285/2011; REQUIMTE, Grant/Award Number: UID/QUI/50006/2013; Foundation for Science and Technology (FCT, Portugal) and FEDER, Grant/Award Number: UID/AGR/00690/2013info:eu-repo/semantics/publishedVersio