Browsing by Author "Casal, Susana"
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- Espresso coffee residues: a valuable source of unextracted compoundsPublication . Cruz, Rebeca; Cardoso, Maria M.; Fernandes, Luana; Oliveira, Marta; Mendes, Eulália; Baptista, Paula; Morais, Simone; Casal, SusanaEspresso spent coffee grounds were chemically characterized to predict their potential, as a source of bioactive compounds, by comparison with the ones from the soluble coffee industry. Sampling included a total of 50 samples from 14 trademarks, collected in several coffee shops and prepared with distinct coffee machines. A high compositional variability was verified, particularly with regard to such water-soluble components as caffeine, total chlorogenic acids (CGA), and minerals, supported by strong positive correlations with total soluble solids retained. This is a direct consequence of the reduced extraction efficiency during espresso coffee preparation, leaving a significant pool of bioactivity retained in the extracted grounds. Besides the lipid (12.5%) and nitrogen (2.3%) contents, similar to those of industrial coffee residues, the CGA content (478.9 mg/100 g), for its antioxidant capacity, and its caffeine content (452.6 mg/100 g), due to its extensive use in the food and pharmaceutical industries, justify the selective assembly of this residue for subsequent use.
- 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.
- Fish Oil Enzymatic Esterification for Acidity ReductionPublication . Mata, Teresa M.; Correia, Daniela; Andrade, Soraia; Casal, Susana; Ferreira, Isabel M. P. L. V. O.; Matos, Elisabete; Martins, António A.; Caetano, NídiaThe reduction of the fish oil acidity is a significant problem in the rendering industry, as the oil’s range of applications and market value strongly depend on this parameter. In particular, the lower the acidity, the larger the oil’s market value. This work aims to study the potential of enzymatic esterification for reducing the fish oil acidity, by converting the free fatty acids into esters. Thus, four commercial lipases were used and a parametric study was performed to identify the best operating conditions, varying the reaction temperature, enzyme/oil mass ratio and alcohol/FFA mass ratio. All experiments were performed in duplicate with a very good reproducibility of results. Results showed that Lipozyme TL 100L contributed to greater acidity reduction (75% from an initial acid value of 10–14 mg KOH/g oil) for esterification at 40 °C, using ethanol 96% v/v, enzyme/oil and alcohol/FFA mass ratios of 0.01 and 3.24 w/w, respectively, reaching 3.13 mg KOH/g oil of final acid value or 1.57% FFA content. The reaction kinetics were also studied and it was found that a second order rate law as a function of the alcohol and oil concentrations is more adequate, with 35.44 kJ/mol of activation energy and 1.94 × 103 L mol− 1 min− 1 of pre-exponential factor. In conclusion, this work shows that the enzymatic esterification to reduce the fish oil acidity is technically feasible, increasing its market value.
- 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.
- Improvement of vegetables elemental quality by espresso coffee residuesPublication . Cruz, Rebeca; Morais, Simone; Mendes, Eulália; Pereira, José A.; Baptista, Paula; Casal, SusanaSpent coffee grounds (SCG) are usually disposed as common garbage, without specific reuse strategies implemented so far. Due to its recognised richness in bioactive compounds, the effect of SCG on lettuce’s macro- and micro-elements was assessed to define its effectiveness for agro industrial reuse. A greenhouse pot experiment was conducted with different amounts of fresh and composted spent coffee, and potassium, magnesium, phosphorous, calcium, sodium, iron, manganese, zinc and copper were analysed. A progressive decrease on all lettuce mineral elements was verified with the increase of fresh spent coffee, except for potassium. In opposition, an increment of lettuce’s essential macro-elements was verified when low amounts of composted spent coffee were applied (5%, v/v), increasing potassium content by 40%, manganese by 30%, magnesium by 20%, and sodium by 10%, of nutritional relevance This practical approach offers an alternative reuse for this by-product, extendable to other crops, providing value-added vegetable products.
- Intra- and interspecific mineral composition variability of commercial instant coffees and coffee substitutes: contribution to mineral intakePublication . Oliveira, Marta; Casal, Susana; Morais, Simone; Alves, Cláudia; Dias, Filipa; Ramos, Sandra; Mendes, Eulália; Delerue-Matos, Cristina; Oliveira, M. Beatriz P. P.The present paper reports the amount and estimated daily mineral intake of nine elements (Ca, Mg, K, Na, P, Fe, Mn, Cr and Ni) in commercial instant coffees and coffee substitutes (n = 49). Elements were quantified by high-resolution continuum source flame (HR-CS-FAAS) and graphite furnace (HR-CS-GFAAS) atomic absorption spectrometry, while phosphorous was evaluated by a standard vanadomolybdophosphoric acid colorimetric method. Instant coffees and coffee substitutes are rich in K, Mg and P (>100 mg/100 g dw), contain Na, Ca and Fe in moderate amounts (>1 mg/100 g), and trace levels of Cr and Ni. Among the samples analysed, plain instant coffees are richer in minerals (p < 0.001), except for Na and Cr. Blends of coffee substitutes (barley, malt, chicory and rye) with coffee (20–66%) present intermediate amounts, while lower quantities are found in substitutes without coffee, particularly in barley. From a nutritional point of view the results indicate that the mean ingestion of two instant beverages per day (total of 4 g instant powder), either with or without coffee, cannot be regarded as important sources of minerals to the human diet, although providing a supplementation of some minerals, particularly Mg and Mn in instant coffees. Additionally, and for authentication purposes, the correlations observed between some elements and the coffee percentage in the blends, with particular significance for Mg amounts, provides a potential tool for the estimation of coffee in substitute blends.
- 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.
- Nutritional value and influence of the thermal processing on a traditional Portuguese fermented sausage (alheira)Publication . Campos, Sílvia D.; Alves, Rita C.; Mendes, Eulália; Costa, A. S. G.; Casal, Susana; Oliveira, M. Beatriz P. P.Alheiras are a traditional, smoked, fermented meat sausage, produced in Portugal, with an undeniable cultural and gastronomic legacy. In this study, we assessed the nutritional value of this product, as well as the influence of different types of thermal processing. Alheiras from Mirandela were submitted to six different procedures: microwave, skillet, oven, charcoal grill, electric fryer and electric grill. Protein, fat, carbohydrate, minerals, NaCl, and cholesterol contents, as well as fatty acid profile were evaluated. The results show that alheiras are not hypercaloric but an unbalanced foodstuff (high levels of proteins and lipids) and the type of processing has a major impact on their nutritional value. Charcoal grill is the healthiest option: less fat (12.5 g/100 g) and cholesterol (29.3 mg/100 g), corresponding to a lower caloric intake (231.8 kcal, less 13% than the raw ones). Inversely, fried alheiras presented the worst nutritional profile, with the highest levels of fat (18.1 g/100 g) and cholesterol (76.0 g/100 g).
- Octopus Lipid and Vitamin E Composition: Interspecies, Interorigin, and Nutritional VariabilityPublication . Torrinha, Álvaro; Cruz, Rebeca; Gomes, Filipa; Mendes, Eulália; Casal, Susana; Morais, SimoneOctopus vulgaris, Octopus maya, and Eledone cirrhosa from distinct marine environments [Northeast Atlantic (NEA), Northwest Atlantic (NWA), Eastern Central Atlantic, Western Central Atlantic (WCA), Pacific Ocean, and Mediterranean Sea] were characterized regarding their lipid and vitamin E composition. These species are those commercially more relevant worldwide. Significant interspecies and interorigin differences were observed. Unsaturated fatty acids account for more than 65% of total fatty acids, mostly ω-3 PUFA due to docosahexaenoic (18.4−29.3%) and eicosapentanoic acid (11.4− 23.9%) contributions. The highest ω-3 PUFA amounts and ω-3/ω-6 ratios were quantified in the heaviest specimens, O. vulgaris from NWA, with high market price, and simultaneously in the lowest graded samples, E. cirrhosa from NEA, of reduced dimensions. Although having the highest cholesterol contents, E. cirrhosa from NEA and O. maya from WCA have also higher protective fatty acid indexes. Chemometric discrimination allowed clustering the selected species and several origins based on lipid and vitamin E profiles.
- Revalorization of spent coffee residues by a direct agronomic approachPublication . Cruza, Rebeca; Mendes, Eulália; Torrinha, Álvaro; Morais, Simone; Pereira, José Alberto; Baptista, Paula; Casal, SusanaSpent coffee grounds (SCG) represent a high-volume food waste worldwide, and several reuse approaches have been attempted. Herein, a greenhouse field experiment was carried out by cultivating Batavia lettuce with 5%, 10%, 15%, 20% and 30% (v/v) espresso SCG directly composted in the soil. Healthy vegetables were obtained for all treatments, without yield loss for up to 10% SCG. A progressive increment of green color intensity with increasing SCG content was observed, corroborated by the increase of their photosynthetic pigments (chlorophylls and carotenoids). Furthermore, total ascorbic acid and tocopherols showed statistical significant increases (p < 0.001) between control and all tested groups. Marked variations of nutritionally relevant minerals, particularly potassium, phosphorous and sodium were also revealed at higher percentage treatments (20% and 30%). This approach constitutes a clean, direct, simple and cost-effective measure to produce value-added vegetables, while reducing food waste disposal.