Rita C Alves

Rita C Alves
REQUIMTE/LAQV University of Porto

PhD in Pharmaceutical Sciences, Specialty in Nutrition and Food Chemistry

About

121
Publications
40,381
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3,156
Citations
Additional affiliations
January 2006 - December 2009
University of Porto
Position
  • PhD Student

Publications

Publications (121)
Article
Full-text available
This study investigates the possibility of valorizing coffee silverskin through the recovery of its bioactive compounds using a sustainable extraction method that could be industrially applied. For that, aqueous extracts were prepared using ultrasonic-assisted extraction (laboratorial scale) and, for comparison, a scale-up of the process was develo...
Article
The new trends in drying technology seek a promising alternative to synthetic preservatives to improve the shelf-life and storage stability of food products. On the other hand, the drying process can result in deformation and degradation of phytoconstituents due to their thermal sensitivity. The main purpose of this review is to give a general over...
Chapter
The industrial processing of fruits and vegetables generates a large number of by-products, such as bran, stalk, fibrous material, peel, and seeds. Most of these by-products are discarded, despite being a rich source of many nutrients, such as vitamins, minerals, amino acids and fatty acids, and biologically active compounds, such as phytochemicals...
Article
Natural preservatives were predominantly developed to eliminate the use of synthetic preservatives for food and agriculture industries. Multi-component nanoemulsions (MCN) with significant antibacterial activity should be proper candidates as natural preservatives. This research aimed to formulate a multi-component phospholipid-based nanoemulsion (...
Article
Full-text available
Olive pomace, an olive oil processing byproduct, can be upcycled and meet the current demand for natural and sustainable food ingredients. In this work, a patented process was used to obtain a functional ingredient from different olive pomaces. The nutritional, chemical and antioxi-dant profiles, as well as the antimicrobial activity against S. aur...
Article
Full-text available
Whole sesame seeds and sesame oil, which is obtained after cold pressing the seeds, are foodstuffs globally consumed due to their nutritional characteristics. The press cake that remains from the oil extraction process can be ground to form a defatted flour that can be incorporated into the human diet, contributing to the valorisation of this produ...
Article
Full-text available
PurposeCurrently, monovarietal olive oils are increasingly present on the market and generate large amounts of monovarietal olive pomaces. Considering the high production of this by-product and its bioactive content, it is essential to explore green, reliable, easy-to-go, and low-cost techniques that allow their easy analysis and discrimination. In...
Article
Objectives Nowadays, modern societies are facing two important challenges: (i) demand for healthy foods, due to the increase of chronic diseases; and (ii) reuse food by-products, due to its environmental and economic impacts. Cucumis melo L. is usually consumed as a fruit, but peels and seeds are discarded. The aim of this study was to evaluate the...
Article
Background Coffee is one of the most consumed beverages worldwide due to its appreciated organoleptic characteristics and stimulant effects. It is known that coffee consumption can promote several health benefits. Neurodegenerative diseases are a well-known type of health conditions and a serious health problem, strongly related to the aging of wor...
Article
Full-text available
O planeta está a sofrer alterações cada vez mais rápidas, com consequências devastadoras para a agricultura e as comunidades que a utilizam como principal meio de subsistência. O café é um dos produtos agrícolas mais transacionados e a matéria-prima de uma das bebidas mais consumidas e apreciadas. Porém, o seu cultivo feito em países maioritariamen...
Article
The lipid fraction of seeds from different pine species and populations was studied regarding total lipid content , fatty acid profile and vitamin E composition. The investigated seeds contained a high percentage of lipid (13.6 to 31.5%). L ipid fractions were found to be rich in vitamin E, which varied significantly among species and populations....
Article
Full-text available
The phenolics profile, free amino acids composition, and antioxidant potential of rosemary infusions were studied. Forty-four compounds belonging to nine different groups (hydroxybenzoic acids, hydroxycinnamic acids, flavan-3-ols, flavanones, flavones, phenolic diterpenes, hydroxybenzaldehydes, coumarins, and pyranochromanones) were identified by U...
Article
Background Coffee is the second largest commodity in the world and its market has grown regularly over the last 150 years. During production and processing of coffee beans many by-products are generated such as skin, pulp, mucilage, parchment, silverskin, immature and defective coffee beans. Around 50% of coffee fruit is discard and can contaminate...
Article
Full-text available
The conchocelis life cycle stage of P. dioica represents an unexplored source of bioactive compounds. The aim of this study was to generate and characterise, for the first time, hydrolysates of conchocelis using a specific combination of proteases (Prolyve® and Flavourzyme®). Hydrolysate molecular mass distribution and free amino acid contents were...
Chapter
Food losses and food security have become issues of great public concern. Decreasing food waste should be a priority due to its impact on economic, social, and environmental areas. For the European Union, food security is a critical concern due to the demand for more food, in addition to the sustainable production challenges and equitable food dist...
Article
Full-text available
Food innovation is moving rapidly and comprises new categories of food products and/or ingredients with a natural and ecological origin. Monocultivar olive pomaces, individually or combined, can be a source of natural bioactive compounds suitable for food or cosmetic applications. This work aimed to assess the phenolics content and antioxidant acti...
Article
Porphyra dioica is an Atlantic red seaweed species with economic potential. While its blades are of significant interest in food, feed and cosmetic sectors, little is known about the potential value of conchocelis, the microscopic filamentous sporophytes corresponding to the Porphyra early life stage. The aim of this study was to characterise, for...
Article
Full-text available
Seaweeds are a recognized source of bioactive compounds and techno-functional ingredients. However, its protein fraction is still underexplored. The aim of this study was to determine the total and free amino acid profile and protein content of four seaweeds species (Porphyra dioica, Porphyra umbilicalis,Gracilaria vermiculophylla, and Ulva rigida)...
Article
Full-text available
Enzymatic hydrolysis has been employed to modify protein functional properties and discover new sources of antioxidants. In this study, the effect of different enzymatic treatments on antioxidant activity of Porphyra dioica (blades and protein isolate (PI)) was investigated. Protein nitrogen content of P. dioica blades and PI were 23 and 50% (dry w...
Article
Full-text available
Algae are a complex, polyphyletic group of organisms, affordable and naturally rich in nutrients, but also valuable sources of structurally diverse bioactive substances such as natural pigments. The aim of this work was to evaluate the polar and non-polar pigment contents of different commercial dried algae (brown: Himanthalia elongata, Undaria pin...
Article
Porphyra sp. is one of the most cultivated and commercially valuable species, recognized for its high protein content (up to 47% dry weight) and complete amino acids profile. Based on these characteristics, P. dioica produced in an integrated multitrophic aquaculture system was selected for this study. The aim was to evaluate the effect of in vitro...
Article
Silverskin, the main coffee roasting by-product, is rich in fiber, protein and antioxidants. Its protein fraction was studied regarding total, protein and non-protein nitrogen content. Amino acids were analysed after automated on-line derivatization. The method showed to be precise (<6.9%) and accurate (recoveries using a certified reference materi...
Article
The antioxidant potential and phenolic profile of infusions prepared with cherry stems from different commercial brands were studied. The phenolic profile of each infusion was characterized by UHPLC-ESI-QTOF-MS and 44 phenolic compounds belonging to eight distinct classes (hydroxybenzoic acids, hydroxycinnamic acids, phenylpropanoic acids, flavan-3...
Article
Full-text available
Oilseeds from five native plant species with edible potential from the Brazilian Caatinga semi-arid region (Diplopterys pubipetala, Barnebya harleyi, Croton adamantinus, Hippocratea volubilis, and Couroupita guianensis) were investigated regarding their mineral contents. The minerals, Na, K, Ca, Mg, Fe, Cu, Cr, Al, were analyzed by high-resolution...
Article
Olive pomace, a wet semi-solid paste that remains after olive oil extraction, is a major waste of the process and its recovery is mandatory due to its phytotoxicity when rejected directly into the soil. Innovative applications have been studied, but simple and reliable methods that fulfil the gap between the recovery of compounds and their use by i...
Article
Background Macroalgae are a natural source of valuable compounds for different applications. Despite the high protein content (up to 47%) and complete essential amino acid profile in some species, their protein fraction is still relatively underexplored. Besides the potential as alternative protein sources, macroalgae can also provide bioactive pep...
Poster
Full-text available
Olive oil consumption and processing is increasing in Portugal and worldwide. Along with its production, several by-products are generated such as olive mill wastewaters and olive pomace (OP). The type of by-product produced depends on the method applied to obtain olive oil: three or two-phase system. In the three-phase system, water is added to th...
Article
This study analyzes the lipid composition and the oxidative stability of oils of Sapindaceae and Meliaceae seeds. The oil content ranged from 14.7% (Guarea guidonia) to 30.1% (Allophylus puberulus and Paullinia elegans). Ten fatty acids were identified in seed oils. Guarea guidonia seeds accumulated mainly oleic (44.9%) and linoleic (24.1%) acid, w...
Article
Introduction: The production of food by-products is a major problem nowadays, and their valorization as food ingredients for the development and formulation of new food products has increased. Every year’s tons of melon (Cucumis melo L.) seeds are discarded. This by-product is a good source of oil and has an interesting fatty acids profile [1–3 De...
Article
Coffee silverskin is the major by-product of coffee roasting. Among all the coffee by-products, it is a relatively stable product due to its low moisture content. Currently, silverskin is used as direct fuel (e.g. firelighters), for composting and soil fertilization. As it is a natural source of several bioactive compounds that can be extracted and...
Article
Olive pomace is a semi-solid paste resulting from the two-phase olive oil production, being the most significant waste generated by this agro-industry. Olive pomace is reported as an environmental hazard due to its high content in phenolic compounds (phytotoxic). Nevertheless, these compounds, when recovered, can have impactful actions in different...
Article
Olive pomace is a major output of olive oil processing. This by-product is a valuable source of bioactive compounds with well-recognized benefits for human health and well-being. In this work, the proximate composition and the profiles of vitamin E (HPLC-DAD-FLD), fatty acids (GC-FID) and phenolics (HPLC-DAD-FL/MSn) were determined. Additionally, a...
Article
Background: Nowadays food wastes are a major concern. On the other hand, the demand for natural beneficial compounds to human health is increasing. Melon (Cucumis melo L.) is a very appreciated fruit, consumed all over the world, that contains large amounts of seeds and peel, which up to now are discarded. These by-products contain phytochemical co...
Article
The aim of this study is to evaluate hardy kiwi (Actinidia arguta L.) leaves, a crop waste, as a source of bioactive compounds with potential application in different industries, such as food industry. For this study, a new, green and sustainable extraction technique was employed: Multi-Frequency Multimode Modulated Technology. The total phenolic a...
Article
Nowadays, daily food supplementation regarding the improvement of physical and mental performance is a growing trend in sport practitioners, young students and active people. Food supplements are foodstuffs, labeled under food law and not obliged to safety assessments before their commercialization. Several products are commercialized claiming ergo...
Article
Full-text available
Coffee silverskin, the major coffee-roasting by-product, is currently used as fuel and for soil fertilization. However, there are several studies reporting silverskin as a good source of bioactive compounds that can be extracted and further used by cosmetic industry. Its high antioxidant potential may be due to the synergistic interaction of chloro...
Chapter
The world consumption of coffee generates large amounts of by-products. However, the use of these wastes for animal feed has not been possible due to the presence of antiphysiological and antinutritional factors, such as tannins and caffeine. Nevertheless, coffee silverskin (CS), spent coffee grounds (SCGs), coffee husks, and immature/defective cof...
Chapter
This chapter describes the steps involved in coffee processing from the field to the cup and the respective generation of by-products along the chain. The chemical composition of coffee husks, pulp, immature, and defective beans, coffee silverskin, and spent coffee grounds is detailed and methods for the sustainable management of these by-products...
Article
Full-text available
Aging is a natural and progressive declining physiological process that is influenced by multifactorial aspects and affects individuals' health in very different ways. The skin is one of the major organs in which aging is more evident, as it progressively loses some of its natural functions. With the new societal paradigms regarding youth and beaut...
Article
Olive fly (Bactrocera oleae R.) is the most harmful pest of olive trees (O. europaea) affecting fruit development and oil production. Olive fruits have characteristic phenolic compounds, important for plant defense against pathogens and insects, and with many biological activities, contributing to the high value of this crop. In this study, olives...
Article
Medicinal plants have been used since ancient times and emerge nowadays as an alternative for synthetic products, due to their richness in bioactive compounds. Achillea millefolium L., commonly known as yarrow, belongs to the Asteraceae family being found in meadows, pathways, crop fields and homegardens. In the present work, commercial and wild sa...
Article
Full-text available
Portuguese honeys (n = 15) from different botanical and geographical origins were analysed regarding their quality parameters (diastase activity, hydroxymethylfurfural content, moisture and pH), colour (L∗ a∗ b∗) and antioxidant profile (total phenolics content, total flavonoids content, DPPH∗ scavenging activity, and ferric reducing power). The sa...
Article
Coffee chaff is a major coffee roasting by-product that could be valued as a source of antioxidants. In the present work, we compared classic, but optimized, solid-liquid extraction conditions with a new concept, namely, the Multi-frequency Multimode Modulated (MMM) vibration technique. The extracts obtained by both methods were analysed and compar...
Article
Herbs have been used from ancient times for infusion preparation based on their potential health effects. In particular, the consumption of Hibiscus sabdariffa L., Crataegus spp. and Panax spp. has been largely associated to cardiovascular benefits. In this work, the label information of 52 herbal products for infusion preparation containing the re...
Article
Full-text available
A randomized controlled trial was conducted to assess the effects of exercise plus pharmacotherapy on monoamine neurotransmitters (dopamine, noradrenaline, adrenaline, serotonin) and cortisol levels. A total of 26 women with clinical depression were randomly assigned to one of the two groups: aerobic exercise plus pharmacotherapy or only pharmacoth...
Article
Coffee silverskin (a coffee roasting by-product) contains high amounts of dietary fibre (49% insoluble and 7% soluble) and protein (19%). Potassium (∼5 g/100 g), magnesium (2 g/100 g) and calcium (0.6 g/100 g) are the major macrominerals. The vitamin E profile of silverskin comprises α-tocopherol), β-tocopherol, ɣ-tocopherol, δ-tocopherol, β-tocotr...
Article
Background The nutritional properties of grapes (Vitis vinifera L.) and derived-grape products are known for a long time. To produce those food products, the agro-industry generates great amounts of by-products. The re-use of these undervalued materials is challenging because it represents an attractive opportunity to convert them into value-added...
Article
Bactrocera oleae, an olive fruit fly, is a major olive pest in Algeria. In this study, olives of two Algerian cultivars (Limli and Rougette de Métidja) with different degrees of infestation by the Bactrocera oleae fly (0%, not attacked; 100%, all attacked; and real %) were analysed. The influence of this pest on individual phenolic compounds (HPLC-...
Article
The extraction of Ara h 6 (a peanut allergen) from a complex chocolate-based food matrix was optimized by testing different temperatures, extraction times, and the influence of additives (NaCl and skimmed milk powder) in a total of 36 different conditions. Analyses were carried out using an electrochemical immunosensor. Three conditions were select...
Article
Plant tissue and organ culture has been extensively used from the beginning of the XX century for the study and comprehension of some primary biological mechanisms such as morphogenesis. However, with the increasing demand of the market for novel products derived from plants, in vitro culture became a reliable technique for the mass production of p...
Article
This comprehensive review points out the major developments on the recovery of bioactive compounds of olive by-products, intending innovative food applications and enhanced technological functions. Nutritional and sensorial factors influencing consumers' acceptance are also discussed. Besides being an economic burden for producers, olive oil by-pro...
Article
Nine plant infusions were assessed in terms of their polyphenolic compounds and antioxidant capacity properties by performing a “battery” of assays. Bioactive compounds (total phenolic and flavonoid content) were measured using spectrophotometric procedures and the total antioxidant capacity was determined by DPPH-RSA, FRAP and DNA-based biosensor...
Article
Smoothies are blended beverages that could contain fruit pulp, fruit juice, vegetables, yoghurt, milk, or honey. These beverages are typical examples of the food industry reply to the increase awareness of consumers for healthier foods with simple ingredients and clean labels. As emerging products, different profiling studies are needed to ensure t...
Chapter
Acrylamide is a heat-generated food toxicant, usually found in processed carbohydrate-rich foods, that represents a potential health hazard for humans. It is formed via the Maillard reaction between asparagine and reducing sugars during food processing. In coffee, acrylamide is formed during the early stages of bean roasting and, after that, its co...
Article
Full-text available
Elephant foot yam (Amorphophallus paeoniifolius (Dennst.) Nicolson) is an underground, unbranched deciduous plant that produces a large tubercle (rhizome) with recognized health effects. In this study, the influence of solvent nature (water, water/etanol (1:1) and absolute ethanol) and processing type (fresh, lyophilized and boiled) on the antioxid...
Article
A vitamin E extraction method for rainbow trout flesh was optimized, validated and applied in fish fed commercial and Gracilaria vermiculophylla-supplemented diets. Five extraction methods were compared. Vitamers were analyzed by HPLC/DAD/fluorescence. A solid-liquid extraction with n-hexane, which showed the best performance, was optimized and val...
Article
A voltammetric biosensor for Ara h 6 (a peanut allergen) detection in food samples was developed. Gold nanoparticle-modified screen-printed carbon electrodes were used to develop a sandwich-type immunoassay using two-monoclonal antibodies. The antibody-antigen interaction was detected through the electrochemical detection of enzymatically deposited...
Article
Full-text available
Over the years, food industry wastes have been the focus of a growing interest due to their content in high added-value compounds. A good example of this is olive oil by-products (OOBP), which retain a great amount of phenolic compounds during olive oil production. Their structure and biological properties justify their potential use as antioxidant...
Article
Full-text available
The phenolic profile and antioxidant activity of three endemic Laurus sp. from Portugal were analysed. Dried leaves of L. nobilis L., L. azorica (Seub.) Franco, and L. novocanariensis Rivas Mart., Lousã, Fern. Prieto, E. Días, J. C. Costa & C. Aguiar, collected in the mainland and in the Azores and Madeira archipelagos, respectively, were used to p...