Percorrer por autor "Rodrigues, Christian Teixeira"
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- Chemical, physical and bioactive properties of different cultivars of potatoes (solanum tuberosum L.) and their peelsPublication . Rodrigues, Christian Teixeira; Carocho, Márcio; Barros, LillianThe development of environmentally friendly products has been the main agenda of the 21st century. One of the main focuses is the recycling of products from the food processing industries. For some decades now, the by-products of the food industry have been converted into energy and other value-added products. Potatoes are the fourth most important food in the world, however their by-products, namely their peels contain nutrients and molecules of interest, being candidates for applications such as food preservatives, colorants or nutritional matter for other foods. In this work, 29 pulps and skins of potato varieties were studied. Nutritional value, soluble sugar content, organic acids, antioxidant activity by the TBARS method and antimicrobial activity were determined. They were also pH, water activity, texture and color of potato skins and pulps. Due to the large number of different samples, there was a lot of overlapping of ratings. Thus, a linear discriminant analysis was used to group potatoes according to the values obtained for each analysis. Thus, the potatoes were grouped into 5 groups that approximated them by region. Overall, the potatoes and peels seem to show bioactive molecules that could be exploited, as well as colorants that could be used in the food industry. Furthermore, the diversity of the 29 potato varieties shows that this vegetable is very different and adapted to different climates, which shows in their intrinsic properties.
- Nutritional and antioxidant characterization of the peel of 10 species of coloured potatoesPublication . Oliveira, Izamara; Rodrigues, Christian Teixeira; Heleno, Sandrina A.; Petropoulos, Spyridon Α.; Alexopoulos, Alexios; Carocho, Márcio; Ferreira, Isabel C.F.R.; Barros, LillianThe use of by-products from the food agro-industry reduces production costs, increases the total use of food and reduces the impact that these by-products may cause when disposed of in the environment. In this way, some potato by-products are used and transformed into food ingredients, such as peelings. Thus, innovative measures are needed to stimulate the full reuse of these foodstuffs, since, whenever possible, the final waste should become raw material for a new process, constituting a second transformation, leading to the reuse of all the raw materials of the potato industry. In this sense, the aim of this work was to carry out a study aimed at peeling ten potato species to which the nutritional parameters were carried out. The samples were from different countries, grown in Greece and obtained under optimal consumption conditions. A total nutritional characterization of the twenty-nine potato peels was performed, as well as of the individual organic acids and soluble sugars. The antioxidant activity was carried out using the thiobarbituric acid reactive substances (TBARS) assay. According to the results obtained, the sample Peru Blue (1.57 ± 0.05 g/100g) obtained the highest value for crude fat, followed by Blaue Hindelbank (1.12 ± 0.13 g/100g); while the sample Blaue Hermans Blaue presented the lowest value (0.33 ± 0.01 g/100g). For protein, Fleuer Bleue (9.5 ± 0.2 g/100g), Blaue Hindelbank (8.9 ± 0.1 g/100g), Pink of Bolivia (9.3 ± 0.5 g/100g), Purple from Congo or Congo (8.9 ± 0.6 g/100g) and Blue from Peru (9.1 ± 0.3 g/100g) were not significantly different from each other and showed the lowest value, while Highland Burgundy Red (12.6 ± 0.1 g/100g) showed the highest value. The ash content showed statistical differences among the results, with the highest content found in Pink of Bolivia (8.0 ± 0.2 g/100g) and the lowest for Fleuer Bleue (1.3 ± 0.1 g/100g). In terms of energy there was also a difference between the results with lower values for Pink of Bolivia (373 ± 1 Kcal) and Purple from Congo (375.8 ± 0.4 Kcal) and higher for Fleuer Bleue (398 ± 1 Kcal). Two soluble sugars were identified and quantified, namely fructose and glucose. For fructose the values were highest for Fleuer Bleue (3.29 ± 0.11 g/100g) and lowest for Highland Burgundy Red (0.04 ± 0.02 g/100g), also, glucose showed lower values compared to fructose, the lowest content being quantified for Purple Fiesta (0.516 ± 0.052 g/100g) and the highest for Blue from Peru (1.07 ± 0.07 g/100g). Three organic acids were quantified, namely oxalic, malic and citric acids. Oxalic acid was highest for Hermans Blaue (2.394 ± 0.015 g/100g) and lowest for Purple Fiesta (0.91 ± 0.02 g/100g). Malic content was found highest for Purple Fiesta (3.12 ± 0.017 g/100g) and lowest for Purple from Congo or Congo (0.213 ± 0.003 g/100g DW). For citric acid, two potato samples showed higher values, namely Purple Fiesta (2.8 ± 0.2 g/100g) and Blaue Hindelbank (2.9 ± 0.1 g/100g) and two other potato samples showed lower values, namely Highland Red Fiesta (1.53 ± 0.03 g/100g) and Blaue Hermans (1.57 ± 0.01 g/100g). The antioxidant activity carried out using TBARS showed similar values for five of the 10 potatoes analysed, Highland Burgundy Red (343.4 ± 8.7 μg/mL), Violet Queen (328.4 ± 11.9 μg/mL), Purple Fiesta (305.7 ± 8.0 μg/mL), Blaue Hindelbank (366. 7 ± 12. 7 μg/mL), Pink of Bolivia (369.5 ± 12.7 μg/mL) and Blue from Peru (323.7 ± 3.5 μg/mL) showed the lowest EC50 concentrations while Blue Star (740.9 ± 33.9 μg/mL) and Fleuer Bleue (692.1 ± 13.3 μg/mL) showed the highest concentrations. This work showed that potato peel has an interesting nutritional profile and can be used to enrich other foods. Furthermore, future work will be carried out on antimicrobial activities, and cytotoxicity.
- Nutritional characterization, ph and antioxidant activity of the pulp of 29 color-fleshed potatoesPublication . Oliveira, Izamara; Rodrigues, Christian Teixeira; Heleno, Sandrina A.; Petropoulos, Spyridon Α.; Alexopoulos, Alexios; Carocho, Márcio; Ferreira, Isabel C.F.R.; Barros, LillianPotatoes (Solanum tuberosum L.) is one of the most important food sources for humans due to their high production and nutritional quality, allowing various culinary uses, from domestic cooking to processing into chips and other ready-to-eat snacks. In this work, 29 color-fleshed varieties of potatoes were studied by analyzing their pH, nutritional profile (moisture, nutritional contents of fat, protein, carbohydrates and ash) and antioxidant activity through the thiobarbituric reactive acid substances (TBARS) assay. The samples were classified by a one-way analysis of variance using Tukey's test as post-hoc analysis for homoscedastic samples and Tamhane T2 for no homoscedastic ones, using a significance of 0.05 in both cases. According to the results obtained for nutritional values, protein showed statistically significant differences, with the Lilly Rose variety having the lowest content (1.173 g/100 g) and Highland Burgundy Red having the highest protein content (2.813 g/100 g). Considering crude fat, no significant differences were sought between the 29 varieties. The ash content showed significant differences among varieties, with Lilly Rose having the lowest content (0.509g /100 g) and Highland Burgundy Red having the highest content (1.9 g/100 g). For total carbohydrates few significant differences were detected, with variations being sought only for Blaue Ajanhuiri (13.835 g/100 g) and Highland Burgundy Red (23.302 g/100 g). Moisture was classified in three significantly different groups with Highland Burgundy Red showing the lowest moisture content at 71.86 g/100 g and Lilly Rose the highest, at 83.163 g/100 g. The pH analysis showed statistical variations among the varieties, with the Blaue Neuseeländer having the lowest pH value (pH=5.839) and the Blaue St. Galler the highest (pH=6.331). For the TBARS assay, only the five potatoes (pulp) with highest antioxidant activity were selected for analysis, and, apart from Schwarzer Teufel, the rest of the four potatoes cultivars showed no significant differences among each other. The antioxidant activity (EC50) of Schwarzer Teufel was 0.37 mg/mL Overall, the results showed a similarity in nutritional values among the tested potato varieties, indicating that beyond their interesting and appealing colors, they also possess valuable nutritional parameters with low variations among the varieties. Furthermore, the Schwarzer Teufel variety showed a very high antioxidant activity compared to the rest of the tested cultivars. Further studies are being performed to analyze the color of these potatoes, as well as bioactivities and chemical composition analyses of their pulp and skin.
- Perfil nutricional e actividade antioxidante da polpa de 29 batatas coloridasPublication . Oliveira, Izamara; Rodrigues, Christian Teixeira; Heleno, Sandrina A.; Petropoulos, Spyridon Α.; Alexopoulos, Alexios; Carocho, Márcio; Ferreira, Isabel C.F.R.; Barros, LillianNeste trabalho realizou-se um estudo de 29 variedades de batatas coloridas através das análises do pH e perfil nutricional (humidade, gordura, proteínas, hidratos de carbono, cinzas), e ainda a sua atividade antioxidante através do ensaio de inibição da peroxidação lipídica de substâncias reativas ao ácido tiobarbitúrico (TBARS).
- Physical properties of 29 colored potato varietiesPublication . Oliveira, Izamara; Ueda, Jonata Massao; Rodrigues, Christian Teixeira; Heleno, Sandrina A.; Petropoulos, Spyridon Α.; Alexopoulos, Alexios; Carocho, Márcio; Barros, Lillian; Ferreira, Isabel C.F.R.The use of different varieties of potatoes ( Solanum tuberosum L.) with different colors may be appealing to consumers, namely in terms of their visual appearance, allowing their use as “chips” and other ready-to-eat snacks. This work studied the physical properties of 29 varieties of colored potatoes, analyzing their external color and the different dimensions of texture. The external color was measured with a portable colorimeter, analyzing the CIELab color space according to the L* (lightness), a* (red-green) and b* (blue-yellow) coordinates. The texture was determined using a “texture profile analysis” assay allowing the classification of their hardness, adhesiveness, springiness, cohesiveness and resilience. The samples were classified through an analysis of variance using Tukey’s test as a post-hoc, and finally were subjected to a linear discriminant analysis for further discrimination based on the studied parameters. According to the obtained results, the color of the potatoes showed significant statistical differences, although many of the samples were related to each other. The sample with the darkest color was “Blaue veltlin” variety, with an L* of 27.8, whereas the sample with the lightest colour was “Blaue ajanhuiri” variety. In terms of the values of parameter a* the cultivar with the greenest tone was also the “Blaue ajanhuiri”, while the one closer to the red quadrant was "Purple from Peru”. Finally, the analysis of parameter b* showed that “Blaue Neuseeländer” sample was the one with the highest blue tone and “Purple fiesta” the one with the highest intensity of yellow. Regarding the different texture dimensions, the samples showed homogenous values. All samples revealed no statistical difference for springiness, whereas regarding adhesiveness, the sample “Purple from Congo” was the most adhesive at -144 g/sec and “Linzer blaue” the less adhesive at -15 g/sec. Concerning the hardness parameter, “Blaue Anneliese” and “Blaue neuseeländer” were the samples with the hardest and softest texture, respectively. In addition, the most cohesive sample was “Pink from Bolivia”, whereas the least cohesive one was “Linzer blaue”. Chewiness had three different levels of significant difference with “Blaue Anneliese” being the least chewy and “Black princess” the most, while for resilience, the least resilient were “Pink from Bolivia” and “Hermanns blaue” and the most resilient was “Linzer blaue”. In terms of the linear discriminant analysis, the first two of five functions described 84.8% of variability (function 1 – 72.0%, function 2 – 12.8%), while the varieties that presented the highest variability were “Lilly rose”, “Red salad potato”, “Purple from Peru”, “Königspurpur” and “Highland burgundy”. In conclusion, the presented results showed a great variability among the tested potato varieties indicating that these could dictate the different uses of the final food product.