CERNAS - Artigo em ata de evento científico nacional
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- Miniaturized Solid Phase Extraction Techniques Applied to Natural products: A review.Publication . Rosendo, LM; Brinca, AT; Pires, B; Catarro, G; Rosado, T; Martinho, JP; Guiné, Raquel P. F.; Araújo, ARTS; Anjos, O; Gallardo, E
- Flour from drone broods: A viable alternative?Publication . Correia, Paula; Vouga, C; Coelho, Catarina; Costa, Cristina Amaro Da; Guiné, Raquel P. F.; Gonçalves, Fernando Jorge; C. Goncalves, J.
- Chemical composition of Ruscus aculeatus L. – Preliminary StudiesPublication . Dulyanska, Y; Cruz-Lopes, Luísa; Esteves, Bruno; Barroca, M J; Carvalho, L; Gonçalves, Fernando Jorge; Domingos, Idalina; Ferreira, José; Guiné, Raquel P. F.
- Identifying characteristics of marketing-influenced eating vulnerabilityPublication . Henriques, Carla; Guiné, Raquel P. F.; Matos, Ana; Malva, MadalenaNumerous people’s dietary decisions are influenced by commercial and marketing motiva- tions. Advertising and marketing tactics are in fact intended to pique consumer attention and influence their purchasing decisions. Yong people are known to be particularly vulner- able [1], and it is of interest to identify some other characteristics that may differentiate most vulnerable consumers. In this study, based in a sample of size 11919, collected as part of the project EATMOT [3], marketing motivations in food choices are analyzed through seven items. Factor analysis was applied by country, looking for a factor structure common to all countries. Three items were consistently combined in one factor. The other items were studied individually. Five variables were, then, considered to measure marketing mo- tivations in consumer’s food choices and used in a cluster analysis. Ward’s method, single linkage, and average linkage were three hierarchical techniques that were used; their results were considered as initial solutions for the k-means method. To find an optimal number of clusters, k-means method was applied to 50 bootstrap samples and the similarity of cluster solutions for different numbers of clusters was examined using the rand index [2]. The two cluster solution emerged as an optimal solution, distinguishing consumers more prone to the influence of marketing (Figure 1). Then, using statistical tests and logistic regression analysis, these two clusters were com- pared. For example, consumers of the Notably Motivated cluster were significantly younger (32.7 vs 36.7 years old, p < 0.005), as expected, and this cluster also had a higher per- centage of women (72.2% vs. 70.2%, p=0.016), a higher percentage of single individuals (51.9% vs. 37.9%, p < 0.005), a lower proportion of individuals with university education (58.3% vs. 66.1%, p < 0.005), more consumers living in rural or suburban areas (37.2% vs. 27.6%, p < 0.005), and more consumers without an active professional activity, that is, unemployed, non-working students or retired (43.1% vs.31.1%, p < 0.005). Furthermore, higher BMI and less physical exercise revealed to be associated with a greater chance of belonging to the notably motivated group (p < 0.005). We thus obtained evidence that the propensity for higher levels of commercial and marketing motivations is associated with socio-demographic, anthropometric, behavioural and health related characteristics of the consumer.
- Effect of moisture on the characteristics of hazelnut kernel during storage.Publication . Correia, Paula; Filipe, A.; Ferrão, A. C.; Ramalhosa, E.; Guiné, Raquel P. F.The organoleptic and nutritional quality of hazelnuts during storage can be greatly influenced by environment conditions. The aim of this study was to evaluate the effect of moisture on the physicochemical characteristics of hazelnuts kernel when stored under controlled conditions of temperature (25 °C) and different relative humidity (57.6, 68.9, and 78.6%). To obtain these relative humidities (RH) in the hazelnut storage, the respective salts NaBr, KI, and NH4Cl were used. The following properties were evaluated: moisture, water activity (aw), color, texture, and fat oxidative stability, both in the initial sample and after 1, 2, 4 and 6 months of storage. The results showed that there was a progressive increase over time in moisture and water activity, with growth being most pronounced from 4 months onwards. Moreover, hazelnuts stored at a RH of 78.6%, at 6 months of storage were completely spoiled, making the evaluation of these hazelnuts impossible. The hardness and friability of the hazelnuts decreased over the storage time, with the differences being more pronounced for the samples subjected to higher RH. In general, the color of the skin and core of the fruits varied little over the storage time for all parameters evaluated (L*, a*, b*) and for all RH conditions tested. The hazelnuts stored at a RH of 78,6% can only be preserved until the 4th month, but presenting low oxidative stability, being comparable to the hazelnuts with 6 months at RH of 57,6%, meaning that with a reduction of about 10% of RH it is possible to increase the oxidative stability about 2 months. Thus, it can be concluded that high relative humidities lead to a lower conservation of the quality characteristics of hazelnuts. Moreover, during the 6 months of storage the color of the fruits was little affected for the different RH tested, however all the other evaluated characteristics presented significant alterations, namely the texture and the oxidative stability of the fats.
- Liquefaction optimization of peel of potato Solanum tuberosum L. var Monalisa.Publication . Dulyanska, Y.; Cruz-Lopes, Luísa; Esteves, Bruno; Guiné, Raquel P. F.; Ferreira, José; Domingos, IdalinaThe potato (Solanum tuberosum L.) is native to South America, in the Andes Mountains where it was consumed by native populations 1. According to the Food and Agriculture Organization of the United Nations (FAO), there has been a large increase in potato production in Latin America and Asia, especially China, that in 2018 was the largest producer followed by India. These two countries represented almost a third of the potatoes consumed in the world 1. In Portugal, the most widely planted potato is Solanum tuberosum L. var Monalisa, that is used by potatoes’ processing industry, generating tons of potato peel waste annually. The waste from the potato industry accounts for approximately 27% of total production. The objective of this work was to evaluate the potentiality of potato industrial residues to be liquefied by polyhydric alcohols and the chemical transformations observed in this process with subsequent use to produce polyurethane foams. Potato peel waste (PPW) was dried in an oven, crushed in the Retsch SMI mill and sifted in a vibratory sieve model Retsh 5657 HAAN 1 for 30 minutes. The fractions obtained were > 35 mesh, 35-40 mesh (0.500-0.425 mm); 40-60 mesh (0.425-0.250 mm); 60-80 mesh (0.250-0.180 mm) and 80 mesh (< 0.180 mm). The liquefactions were made in an oil-heated double-shirt reactor with a mixture of glycerol and ethylene glycol 1:1, catalyzed by 3% sulfuric acid. The effect of particle size (<80 mesh at >35 mesh) temperatures (140 oC - 180 oC), ratio material/solvent (1:5, 1:7, 1:10, 1:12) and times (15-60 min) were studied. The Fourier Transform Infrared Spectroscopy by Attenuated total reflection (FTIR-ATR) was used to evaluate the functional groups present in the original sample of PPW, in the liquefied sample and in the solid residue obtained. Liquefaction percentage with increased temperature, time, material/solvent ratio and granulometry is presented (Figure 1). Results show that liquefaction performed at 180 oC with a 1:10 material/solvent ratio, increases along time, reaching a maximum at 60 min. Similarly, liquefactions made during 60 min with a 1:10 material/solvent ratio show that there is an increase in liquefaction yield with the increase in temperature until 180 oC. A higher temperature could increase the liquefaction yield but would lead to a higher energy consumption in the process. There seems to be no significative advantage in increasing material/solvent ratio above 1:7, although the liquefaction yield increases for higher ratios. Granulometry testing shows that the smaller the particle the best is the liquefaction percentage. It was concluded that the best liquefaction yield, of approximately 90%, was obtained with a temperature of 180 oC, for 60 min and particle size <80 mesh for PPW. This material has good properties to be converted in a liquid mixture that can be used later, on the production of polyurethane foams (Figure 1). The PPW spectrum exhibits the common bands for agricultural materials (Figure 2). The main differences between the solid material and the liquefied material is the high OH band with a peak at around 3300 cm-1 for both the original material and the liquefied, while the peak for the solid residue is at higher wavenumbers. The liquefied sample has a considerable higher OH peak than the solid samples, which is probably due to the polyalcohols used for the liquefaction. The band at 1740 cm-1 (non-conjugated C=O bonds) is higher in the solid residue spectrum and smaller in the liquefied material. Similarly Jin et al. 2 observed the absence of C=O groups after the liquefaction of enzymatic hydrolysis lignin. The highest peak in the original and in the liquefied material spectra is the peak at 1100 cm-1 which has been attributed to C–O stretching vibrations in carbohydrates. This is in accordance with several chemical compositions reported for PPW 1. In the liquefied material a new peak appears at around 860 cm-1, which can be due to stretching in the pyranose ring as stated before 3.
- Evaluating phenolic compounds in ethanolic extracts of cherry pitPublication . Dulyanska, Y.; Lima, M. J. Reis; Correia, Paula; Ferreira, Manuela; Fragata, Anabela; Cardoso, Ana Paula; Barroca, Maria João; Silva, A.; Cruz-Lopes, Luísa; Esteves, Bruno; Ferreira, José; Domingos, Idalina; Guiné, Raquel P. F.The climatic conditions in Portugal favoured the adaptation of the cherry tree allowing its cultivation in several regions of the country. Studies made by the Portuguese Bureau of Statistics – INE 1, showed that the Portuguese sweet cherry production has an implemented area of 6,387 ha, producing 9,241 tons of this fruit. Its production extends mainly to two regions: the North (area of 3,099 ha and production of 6,586 tons) and the Centre (3,177 ha and 2,510 tons), while the rest of the country and islands accounts for only 1.6% of the cherry production. There are several varieties of cherry in Portugal, and the most important traditionally cultivated are: “Saco da Cova da Beira”, “Saco do Douro”, “Lisboeta”, “São Julião”, Big Burlat, Maring, Napoleon-big-foot and Big Windsor, being the first four varieties native from Portugal. Cova da Beira is the most important cherry production area in Portugal, either in terms of production volume, or also in area. Additionally, the evolution of technological indicators associated with culture reveals a high degree of specialization of the “new” farms, almost always associated with other fruit crops, which coexist in a very significant number of smaller farms, of a family type, that constitute the historical legacy of cherry production on the hillside north of the Serra da Gardunha. Sweet cherry seeds result from processing sweet cherry for sweets, juices and jams’ production. Generally, seeds are considered a production waste, which gains a strong interest due to the environmental aspects related to waste disposal 2. Additionally, it is well documented that production waste, such as peels, seeds, and pomace, contain high-value bioactive compounds 3. Hence, the present work investigated the extraction of some bioactive compounds from cherry pits that originate from food manufacturing industries. The waste management company Nutrofertil, located in Portugal, namely in the district of Viseu (Tondela), provided the Seeds of Sweet Cherry (SSC) for this study. The seeds were milled and dried for stability and then used for extraction with ethanolic solutions at different percentages (from 50 to 100% water v/v). Variable temperatures were also tested and the extracts were used for quantification of phenolic compounds through spectrophotometric techniques. The material was analysed to verify that it was exempt of hydrocyanic acid. Statistical techniques were used to treat the data: (a) Hierarchical cluster analysis using squared Euclidean distance and average linkage between groups method; (b) Principal component factor analysis with Varimax rotation. The results indicated that extraction at 40 ºC with magnetic stirring and using aqueous solutions of ethanol (water:ethanol ratio = 80:20, % v/v) constitute a separate cluster. Also, extracts obtained with similar conditions but for the temperature of 35 ºC constitute another isolated cluster. Factor analysis revealed a grouping structure with four clearly distinct clusters (Figure 1). Group G1 accounts for the samples with water:ethanol 80:20 (% v/v) and a temperature of 35 ºC, corresponding to the extraction of higher amounts of anthocyanins. Group G3 includes the extractions with 100% water at 70 ºC (G3), with lowest contents of anthocyanins and flavonols. The remaining groups are divergent according to the values of total phenolic compounds. In group G4 are included samples in which were quantified high values for total phenolic compounds, flavonoids, proanthocyanidins, ortho-diphenols and phenolic acids, while G2 corresponds to samples with smaller amounts of those compounds. In conclusion, investigating the extraction potential of different conditions it was allowed to optimize the experimental conditions more favourable to maximize the recovery of certain bioactive compounds, which can have multiple applications as antioxidant substances after rigorous quality control regarding possible concentrations of hydrocyanic acid.
- The impact of extraction temperature and solution concentration on the antioxidant activity of sweet cherry seeds’ extractsPublication . Dulyanska, Y.; Cunha, Margarida; Lima, M. J.; Correia, Paula; Ferreira, Manuela; Fragata, Anabela; Cardoso, Ana Paula; Barroca, Maria João; Silva, A.; Cruz-Lopes, Luísa; Esteves, Bruno; Ferreira, José; Domingos, Idalina; Guiné, Raquel P. F.Sweet cherry seeds, a valuable lignin-cellulose raw material for the production of polyurethane foams 1, are also a significant source of different phenolic compounds 2 and can be a good source of natural antioxidants, which can play an important role in preventing the formation of free radicals and protection against degenerative diseases. Considering sustainability, the main objective of this project was the use of cherry by-products (seeds) to produce extracts rich in antioxidant compounds. In this work, the seed extracts were obtained with the addition of different combinations of ethanolic solution (water:ethanol ratios - 50:50; 60:40; 80:20; 100:0 v:v) and at different temperatures (35, 50, 70 and 80 °C), all under magnetic stirring for 40 minutes. Then, the antioxidant activity of the extracts was evaluated through spectrophotometric methods, using the DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-di-(3-ethylbenzthiazoline sulfonic acid)) radicals, and also the Ferric Reducing Antioxidant Power Assay (FRAP). All measurements were replicated at least in triplicates and were expressed as mg Trolox equivalents per gram (mg TE/g). Statistical analysis was performed using the JAVA software. ANOVA tests show that there is a statistically significant effect of temperature, water percentage and temperature on the antioxidant activity evaluated by the three methods used (p> 0.001 in all tests). The percentage of water is the variable that most contributes to this effect. Individual Post Hoc comparisons show, for all tests, that in general the temperatures induce differences in antioxidant activity, except 70 °C and 80 °C in DPPH and FRAP, and 80 °C and 50 °C in ABTS. Regarding the percentage of water, it was found that all samples are different from each other, except the FRAP, in which no significant differences between 50 and 60% of water were found. In conclusion, no major differences between the ABTS, DPPH and FRAP methods were found. Temperature and percentage of water have a significant effect on the concentration of antioxidant activity in all methods. In that way, the cherry pit is a good by-product to produce extracts with high content of antioxidant activity, being that the 70° C with 50:50 and 60:40 water:ethanol solutions are the most favorable conditions to potentiate the antioxidant activity.
- Estudo Comparativo sobre o consume de produtos alimentares sustentáveis em Portugal e na turquia durante a pandemia de Covid-19Publication . Guiné, Raquel P. F.; Costa, D.; Celik, S.; Florença, Sofia De Guiné E; Ferreira, Manuela; Cardoso, Ana Paula; Cetin, S.; Costa, Cristina Amaro DaResumo: Os sistemas de agricultura biológica são sugeridos para substituir a agricultura convencional de forma a minimizar o impacto ambiental e preservar a biodiversidade. Pretendeu-se investigar as tendências dos consumidores e os hábitos de consumo de alimentos obtidos através da agricultura biológica em Portugal e na Turquia. Foi utilizado um inquérito por questionário online. Para o tratamento de dados, foram utilizadas técnicas estatísticas básicas complementadas com uma classificação em árvore destinada a avaliar a influência de fatores sociodemográficos no conhecimento sobre este tipo de alimentos. Os resultados mostraram que os padrões de consumo são semelhantes em ambos os países, com muitos participantes a consumir alimentos biológicos, especialmente vegetais e frutas, consumindo-os na sua maioria 2 ou 3 refeições por semana. As motivações mais fortes para consumir incluem benefícios para a saúde humana e menores impactos ambientais, enquanto a razão mais substancial para não consumir é o preço. Em ambos os países as pessoas têm bons conhecimentos sobre as vantagens dos alimentos biológicos em relação aos convencionais. Finalmente, a perceção do valor atribuído pela sociedade aos alimentos biológicos foi consideravelmente maior em Portugal. Estes resultados confirmam as tendências atuais dos consumidores para fazer escolhas alimentares mais sustentáveis, motivadas pelo percecionado impacto negativo da agricultura convencional nos ecossistemas e na saúde humana.
- Produção de farinha de larvas e pupas de zângãoPublication . Correia, Paula; Vouga, C.; Coelho, C.; Guiné, Raquel P. F.; Costa, Cristina Amaro DaA técnica da remoção dos quadros de zângão, utilizada no controlo do ácaro Varroa destructor, pode proporcionar uma fonte alternativa de alimento, sendo para isso necessário desenvolver técnicas simples e viáveis de extração e utilização das larvas e pupas. Este trabalho teve como objetivo testar dois métodos de extração, o método de extração a frio e a quente. Após a recolha os quadros foram congelados para garantir a sua conservação. Seguiu-se a extração das larvas e pupas através de métodos de extração a frio e extração quente (imersão em água a ferver). A extração a frio foi realizada manualmente com duas condições: sala fria (61ºC); superfície fria. Os rendimentos de extração variaram entre 62,57,5% e 84,94,0%, respetivamente para a superfície fria e para a extração a quente. Os tempos de extração mais elevado foi para a extração a frio em sala fria (336,342,4 segundos) e o mais baixo para a superfície fria (246,830,1 segundos). As larvas e pupas foram submetidas a dois tipos de desidratação: vaporização e liofilização. A vaporização escureceu demasiado as larvas e pupas não se revelando um bom processo de secagem. Deste modo, a farinha foi produzida a partir da trituração das larvas e pupas secadas por liofilização (até peso constante). Nutricionalmente as farinhas apresentaram-se ricas em proteína e gordura. Este novo produto poderá proporcionar o aumento do rendimento da atividade apícola, benefícios nutricionais e usos na produção de novos produtos à base de farinha de zângão.