Browsing by Author "Viegas, Olga"
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- An eco-friendly approach for analysing sugars, minerals, and colour in brown sugar using digital image processing and machine learningPublication . Alves, Vandressa; Santos, Jeferson M. dos; Viegas, Olga; Pinto, Edgar; Ferreira, Isabel M.P.L.V.O.; Lima, Vanderlei Aparecido; Felsner, Maria L.Brown sugar is a natural sweetener obtained by thermal processing, with interesting nutritional characteristics. However, it has significant sensory variability, which directly affects product quality and consumer choice. Therefore, developing rapid methods for its quality control is desirable. This work proposes a fast, environmentally friendly, and accurate method for the simultaneous analysis of sucrose, reducing sugars, minerals and ICUMSA colour in brown sugar, using an innovative strategy that combines digital image processing acquired by smartphone cell with machine learning. Data extracted from the digital images, as well as experimentally determined contents of the physicochemical characteristics and elemental profile were the variables adopted for building predictive regression models by applying the kNN algorithm. The models achieved the highest predictive capacity for the Ca, ICUMSA colour, Fe and Zn, with coefficients of determination (R2) ≥ 92.33 %. Lower R2 values were observed for sucrose (81.16 %), reducing sugars (85.67 %), Mn (83.36 %) and Mg (86.97 %). Low data dispersion was found for all the predictive models generated (RMSE < 0.235). The AGREE Metric assessed the green profile and determined that the proposed approach is superior in relation to conventional methods because it avoids the use of solvents and toxic reagents, consumes minimal energy, produces no toxic waste, and is safer for analysts. The combination of digital image processing (DIP) and the kNN algorithm provides a fast, non-invasive and sustainable analytical approach. It streamlines and improves quality control of brown sugar, enabling the production of sweeteners that meet consumer demands and industry standards.
- Exploring geographical influences on physicochemical characteristics of honey: the Montesinho Natural Park scenarioPublication . Soares, Sónia; Magalhães, Leandro; Moreira, Manuela M.; Rede, Diana; Fernandes, Virgínia Cruz; Viegas, Olga; Pinto, Edgar; Almeida, Agostinho; Azevedo, Rui; Delerue-Matos, CristinaIn recent years, there has been a substantial increase in the global consumption of honey, driven by the high demand for natural products that offer health benefits. Consequently, consumers show a preference for honey, recognised for its superior quality, namely honey with a Protected Designation of Origin (PDO) or honey produced in protected areas, as it is associated with superior attributes and characteristics. Portugal is one of the leading countries in the production of PDO honey, with Montesinho Natural Park (MNP) being an excellent example of high-quality Portuguese honey, known for its distinctive attributes. However, environmental threats pose a double challenge, leading to a decline in honey production and compromising its overall quality. This study aimed to assess the specific physicochemical parameters and nutritional characteristics of MNP honey and investigate their correlation with the different locations of apiaries. MNP honey samples (n=13) were obtained from local producers or purchased at supermarkets. Standard physicochemical parameters, such as 5-hydroxymethylfurfural, diastase activity, moisture and ash content, free acidity, electrical conductivity and pH, were determined according to honey legislation. Additionally, colour parameters, protein, low-molecular-weight carbohydrates (mono- and disaccharides), and mineral content were determined. The results obtained were consistent with the requirements outlined in the legislation and those described in the literature. The results suggest that geographical factors within the park and boundaries do not contribute to variations in the analysed parameters. A significant level of homogeneity was evident in all parameters evaluated among the MNP honey samples. This is the first comprehensive study of the physicochemical properties of honey from various apiaries within the MNP.
- Exploring two food composition databases to estimate nutritional components of whole mealsPublication . Silva, Marta; Ribeiro, Mafalda; Viegas, Olga; Martins, Zita E.; Faria, Miguel; Casal, Susana; Pinto, Edgar; Almeida, Agostinho; Pinho, Olívia; Ferreira, Isabel M.P.L.V. O.The integration of foodomics data to explain the impact of diet on health requires a precise knowledge of nutrients composition of complex meals. This work assesses the adequacy of two food composition databases (FCDBs) for calculation of nutritional composition of whole meals, compared to the golden standard “lab chemical analyses” and search for predictive models to overcome some limitations of FCDBs. Six meals were designed by integrating healthy foods in a meal based on the “Western diet” pattern. The nutritional composition of each meal was i) chemically determined; ii) retrieved from the Portuguese food composition table (TCAP) and from iii) United States Department of Agriculture database (USDA). Compared to chemical analyses, both FCDBs significantly (p < 0.05) overestimate the amount of Na and vitamin B6; TCAP also overestimate the amount of Ca (p < 0.05), while USDA overestimate energy, fat, available carbohydrates, P, and Fe. Linear regression analyses were used to adjust nutrient values based on TCAP and USDA. Predictive models from both FCDBs were successfully obtained for reliable estimation of protein, PUFA, available carbohydrates, total carbohydrates, sugars, Zn, β-carotene, vitamin E, riboflavin, and niacin in meals with a given uncertainty, which is provided by the respective correction factors. Those predictive models are limited to the range of theoretical values of meals studied.
- Impact of food replacements within a meal in the nutrients profile and quality indicesPublication . Silva, Marta; Ribeiro, Mafalda; Viegas, Olga; Martins, Zita; Casal, Susana; Mendes, Eulália; Faria, Miguel; Pinto, Edgar; Ferreira, Isabel MPLVO; Pinto, EdgarModern societies are increasingly prone to chronic noncommunicable diseases linked with inadequate nutrition. Knowledge about macronutrients balance, micronutrient deficiencies, bioactive and harmful compounds is the starting point of a holistic approach concerning the effects of ingestion of a whole meal in human health.
- Nutritional characterization of Strychnos madagascariensis fruit flour produced by Mozambican communities and evaluation of Its contribution to nutrient adequacyPublication . Chemane, Sandra S. I.; Ribeiro, Mafalda; Pinto, Edgar; Pinho, Susana C. M.; Martins, Zita Sá; Almeida, Agostinho; Ferreira, Isabel M. P. L. V. O.; Khan, Maida; Pinho, Olívia; Casal, Susana; Viegas, OlgaThe indigenous fruit Strychnos madagascariensis is usually processed to flour, called nfuma, being highly consumed during staple food shortage. This study aimed to evaluate the nutritional composition of nfuma and its nutrient adequacy. Flours from four districts of Mozambique were analyzed using AOAC methods for proximate composition, HPLC for sugar, amino acids (AA), vitamin E and carotenoids and ICP-MS and FAAS for minerals. The results showed that nfuma stands out for its high content of fat (26.3–27.8%), mainly oleic acid, fiber (>6%), vitamin E (6.7 to 8.0 mg/100 g) and carotenes (2.2 to 2.6 mg/100 g). The main amino acids of nfuma protein were Arg, Asp and Glu, and Lys was the limiting one. The mineral composition reveals K (~1200 to 1700 mg/100 g) as the main macromineral followed by Mg > Ca > Na. The main trace element was Mn (~4 mg/100 g) followed by Fe > Zn > Cu > Cr > Co. Aluminum (~3 mg/100 g) was the main non-essential element and Rb, Ni, Sr, Ba, V, Cd were also quantified. Assuming the daily consumption of 50 g, nfuma provides 82% of Vitamin A dietary reference value for toddlers, while the consumption of 100 g contributes to 132% and 60% of Mn and vitamin A DRV for adults, respectively. Despite the nutritional advantages of nfuma, this flour can be a source of Ni, highlighting the importance of the study of good practices in its preparation to decrease the exposure to non-essential elements.
- Salt replacement by Salicornia ramosissima to reduce biogenic amines formation in fishPublication . Ramos, Ana Gabriela; Viegas, Olga; Pinto, Edgar; Ferreira, Isabel M.P.L.V.O.Salicornia ramosissima is frequently used as a salt replacer due to its high salt content. Its richness in phenolics, organic acids, minerals, and fiber make it an interesting natural preservative. The impact on biogenic amines formation from replace salt by seasoning fish products with salicornia has not been explored. Biogenic amines (BA), including histamine (HIM), cadaverine (CAD), putrescine (PUT), 2-phenylethylamine (2-FEN), tryptamine (TRI) and tyramine (TIR) are a group of undesirable compounds that can arise in foods, such as fish during its shelflife. Their consumption by susceptible individuals can lead to poisoning, especially histamine [1]. Therefore, reduction of their formation during shelf-life of fish products is of major relevance. The objective of this work was to explore the possibility of using Salicornia ramosissima in the formulation of fish hamburgers (salmon and hake) to replace salt seasoning (1%) and protect against biogenic amines formation. Biogenic amines were analysed by reverse phase HPLC with fluorescence detector, after acid extraction and derivatization with dansyl chloride. On the day of fish acquisition (day 0), salmon presented 5.0, 1.7 and 1.2 mg/kg of HIM, PUT and CAD, respectively and hake presented 8.3, 0.6 and 0.3 mg/kg of HIM, PUT and CAD, respectively. In both fishes tryptamine was detected but not quantified (< 0.487 mg/kg) and 2-FEN and TIR were not detected. On day 2, a considerable increase of all BA was observed in salmon burgers (∑BA control salmon = 257 mg/kg). The salicornia seasoning led to a mild inhibition of BA formation in those hamburgers, without statistical significance (∑BA 226 mg/kg). On days 5 and 8, a considerable increase in BA continued to be observed. However in hake, on day 2, the increase in BA was negligible (∑BA control: 12.6 mg/kg), and no significant effects could be observed by the addition of salicornia (7.9 mg/kg). However, on day 5 (∑BA control = 56.0 mg/kg), a significant reduction (p < 0.05) of the total BA content was observed in the hamburgers seasoned with salicornia (∑BA = 42.6 mg/kg), especially by inhibition of cadaverine formation (38.2 mg/kg vs 18.0 mg/kg). By day 8, the ∑BA of the control burgers increased to 117 mg/kg, whereas in burgers with salicornia BA content was similar to that observed on day 5 (42.9 mg/kg). Salicornia salt was not able to significantly prevent BA formation in salmon samples. Contrary to hake burgers, in which a strong inhibition of total BA was observed on days 5 (~ 50%) and 8 (~ 80%), this effect being greater than that observed by the addition of salt (~ 20% on day 8), and especially observed in cadaverine.
- Unveiling the geographical influence on honey's physicochemical profile: a case study from Montesinho Natural ParkPublication . Soares, Sónia; Magalhães, Leandro; Moreira, Manuela M.; Rede, Diana; Fernandes, Virgínia Cruz; Viegas, Olga; Pinto, Edgar; Almeida, Agostinho; Azevedo, Rui; Delerue-Matos, CristinaIn recent years, global honey consumption has significantly increased due to the rising demand for natural products with health benefits. Consumers are particularly drawn to honey recognized for its superior quality, such as Protected Designation of Origin (PDO) honey or honey produced in protected areas, which is associated with distinctive characteristics. Portugal stands among the top producers of PDO honey, with Montesinho Natural Park (MNP) being a notable example of high-quality Portuguese honey. Despite its reputation, environmental challenges threaten both honey production and quality in this region. This study aims to evaluate the physicochemical parameters and nutritional characteristics of honey from MNP and investigate the correlation between these properties and the geographical location of the apiaries. Honey samples (n=13) were collected from local producers and supermarkets. Standard physicochemical parameters, including 5-hydroxymethylfurfural (HMF), diastase activity, moisture and ash content, free acidity, electrical conductivity, and pH, were analysed following honey legislation guidelines. Additional parameters, such as colour, protein content, low-molecular-weight carbohydrates, and mineral composition, were also assessed. The findings indicate that all honey samples complied with legal standards and align with previously published data, showing a high degree of homogeneity across the physicochemical properties analysed. Principal Component Analysis (PCA) revealed that parameters such as colour, HMF, and specific minerals (Mg, Ca, K, Mn, Sr, Cu, Ba) contributed to the clustering of honey samples, suggesting that geographical variations among apiary locations might influence these properties. However, these differences do not affect the overall quality of the PDO honey produced in MNP. This study represents the first comprehensive characterization of honey from different apiaries within MNP. While the results demonstrate the consistency and quality of MNP honey, further research is necessary to explore the relationship between geographic origin and quality under varying environmental conditions. These insights could be valuable for maintaining sustainable beekeeping practices in the region and preserving the unique attributes of MNP honey.
- Whole meals nutritional composition: comparison between experimental and theoretical dataPublication . Ribeiro, Mafalda; Silva, Marta; Viegas, Olga; Martins, Zita; Casal, Susana; Mendes, Eulália; Pinto, Edgar; Faria, Miguel A.; Ferreira, Isabel MPLVO; Pinto, EdgarInformation concerning food composition is essential in public health and nutrition. Chemical analyses are the most accurate methodologies for the assessment of food composition, however, these procedures are very expensive and time-consuming. Therefore, food composition data has been compiled in databases to facilitate the access and manipulation of information. Although food composition databases (FCDB) are vital tools, they have some limitations.