Ana F. Vinha

Angolan Cymbopogon citratus used for therapeutic benefits: Nutritional composition and influence of solvents in phytochemicals content and antioxidant activity of leaf extracts

Folk medicine is a relevant and effective part of indigenous healthcare systems which are, in practice, totally dependent on traditional healers. An outstanding coincidence between indigenous medicinal plant uses and scientifically proved pharmacological properties of several phytochemicals has been observed along the years. This work focused on the leaves of a medicinal plant traditionally used for therapeutic benefits (Angolan Cymbopogon citratus), in order to evaluate their nutritional value. The bioactive phytochemical composition and antioxidant activity of leaf extracts prepared with different solvents (water, methanol and ethanol) were also evaluated. The plant leaves contained ∼60% of carbohydrates, protein (∼20%), fat (∼5%), ash (∼4%) and moisture (∼9%). The phytochemicals screening revealed the presence of tannins, flavonoids, and terpenoids in all extracts. Methanolic extracts also contained alkaloids and steroids. Several methods were used to evaluate total antioxidant capacity of the different extracts (DPPH·, NO·, and H₂O₂ scavenging assays, reducing power, and FRAP). Ethanolic extracts presented a significantly higher antioxidant activity (p<0.05) except for FRAP, in which the best results were achieved by the aqueous extracts. Methanolic extracts showed the lowest radical scavenging activities for both DPPH· and NO· radicals.

Development and evaluation of an HPLC/DAD method for the analysis of phenolic compounds from olive fruits

A new HPLC/DAD methodology for separating nine phenolic compounds is described. This methodology is applied to the definition of qualitative and quantitative profiles of three Portuguese olive fruit cultivars (Cobrançosa, Madural and Verdeal). Two different extraction methods were needed for the complete definition of their profiles, one of them including a Sep-pack C18 cleaning step. The chromatographic separation was achieved using a Spherisorb ODS2 (25.0×0.46 cm; 5 μm, particle size) column. The solvent system used was a gradient of water-formic acid (19:1) and methanol, with a flow rate of 0.9 mL/min. The detection limit values for phenolic compounds were between 0.04 and 4.32 μg/mL and the method was precise. As a general rule, the recovery values were high. This technique can also be useful in the discrimination of Portuguese olive fruit cultivars.

A New Age for Quercus spp. Fruits: Review on Nutritional and Phytochemical Composition and Related Biological Activities of Acorns

The current global food system must adapt to the expected growth of world population (about 9 billion individuals by 2050). This adaptation will probably include an increased consumption of edible wild foods, due to their richness in micronutrients and bioactive compounds, besides providing a cost-effective and sustainable way of improving caloric food security. A striking example of such natural matrices is the Quercus genus, which has the additional advantage of being widespread throughout the Northern Hemisphere. In a traditional sense, Quercus fruits (acorns) were mainly used in animal feeding, despite their potentially important role on the rural economy. But this preconception is changing. In fact, their nutritional value, high contents in phytochemical compounds, biological activity (such as antioxidant, anticarcinogenic, and cardioprotective properties) and use in the treatment of specific diseases (such as atherosclerosis, diabetes, or Alzheimers disease) have raised the interest in integrating acorns into the human diet. Accordingly, this comprehensive overview was designed to provide an evidence-based review of the literature, with the objective to achieve useful conclusions regarding the nutritional properties, methodologies of extraction, identification, and characterization of a wide variety of bioactive compounds and scientifically validated bioactivities in Quercus species worldwide. The industrial by-products from acorn oil extraction or flour production are also included. Data regarding the analytical techniques, individual compounds, and their bioactivities, are organized in tables. The reported data are discussed and directions for further investigations are suggested, highlighting the use of acorns in food, nutraceutical, and pharmaceutical applications.

State of the art in coffee processing by-products

Abstract 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 are addressed, as well as legislative frameworks and policy recommendations. Although coffee by-products have a high potential of application in different fields, more integrated strategies with the involvement of coffee producers, industries, academic institutions, governmental and nongovernmental organizations are still needed to convert coffee by-products into really profitable substrates.

Nutritional, chemical and antioxidant/pro-oxidant profiles of silverskin, a coffee roasting by-product

Coffee silverskin (a coffee roasting by-product) contains high amounts of dietary fibre (49% insoluble and 7% soluble) and protein (19%). Potassium (∼5g/100g), magnesium (2g/100g) and calcium (0.6g/100g) are the major macrominerals. The vitamin E profile of silverskin comprises α-tocopherol, β-tocopherol, ɣ-tocopherol, δ-tocopherol, β-tocotrienol, ɣ-tocotrienol, and δ-tocotrienol. The fatty acid profile is mainly saturated (C16:0 and C22:0), but the total amount of fat is low (2.4%). Caffeine (1.25g/100g), chlorogenic acid (246mg/100g), and 5-hydroxymethylfurfural (5.68mg/100g) are also present in silverskin. Total phenolics and flavonoids are partially responsible for the in vitro antioxidant activity. Silverskin extracts protected erythrocytes from oxidative AAPH- and H2O2-induced hemolysis, but at high concentrations a pro-oxidant effect on erythrocyte morphology was observed.

Pre-meal tomato (Lycopersicon esculentum) intake can have anti-obesity effects in young women?

Abstract The effect of pre-meal tomato intake in the anthropometric indices and blood levels of triglycerides, cholesterol, glucose, and uric acid of a young women population (n = 35, 19.6 ± 1.3 years) was evaluated. During 4 weeks, daily, participants ingested a raw ripe tomato (∼90 g) before lunch. Their anthropometric and biochemical parameters were measured repeatedly during the follow-up time. At the end of the 4 weeks, significant reductions were observed on body weight (−1.09 ± 0.12 kg on average), % fat (−1.54 ± 0.52%), fasting blood glucose (−5.29 ± 0.80 mg/dl), triglycerides (−8.31 ± 1.34 mg/dl), cholesterol (−10.17 ± 1.21 mg/dl), and uric acid (−0.16 ± 0.04 mg/dl) of the participants. The tomato pre-meal ingestion seemed to interfere positively in body weight, fat percentage, and blood levels of glucose, triglycerides, cholesterol, and uric acid of the young adult women that participated in this study.

Natural pigments and colorants in foods and beverages

Abstract Color is perhaps the single most important product-intrinsic sensory cue when it comes to setting our expectations regarding the likely taste and flavor of food and beverage. The replacement of artificial colorants by natural alternatives is becoming increasingly important in the European Union, United States, and other parts of the world. The food and beverage industries are fueled by consumer demand for natural plant-derived alternatives generally as well as by several scientific reports on the potential harmfulness of synthetic food colorants. However, when applying plant pigments to food and beverage, their limited stability needs to be considered. Due to health concerns associated with the application of synthetic colorants, modern food processing aims at stabilizing genuine pigments (e.g., by adding polyphenols with anthocyanins, or pyranoanthocyanins as natural colorants and coloring foodstuffs, respectively), which exhibit superior stability and high consumer acceptance. This chapter highlights the high potential of some polyphenolic compounds as food colorants providing red, yellow-orange, and blue hues. Besides coloring properties, the presented novel pigment sources are characterized by assumed health-promoting properties, suggesting their additional use as functional food ingredients.

Hardy kiwifruit leaves (Actinidia arguta): An extraordinary source of value-added compounds for food industry

The present study reports for the first time the identification and quantification of phenolic compounds, the antioxidant and antimicrobial activities as well as the in vitro radical scavenging activity and intestinal cell effects of A. arguta leaves extracts. Extractions were carried out under water, water:ethanol (50:50) and ethanol. The highest antioxidant activity were obtained in alcoholic extract (IC50 = 53.95 ± 3.09 μg/mL for DPPH; 6628.42 ± 382.49 µmol/mg dry weight basis for FRAP) while the phenolic profile confirmed by HPLC analysis revealed highest amounts of phenolic acids (hydroxycinnamic acid derivatives) and flavonoids (flavan-3-ol and flavonols derivatives). An excellent scavenging activity against reactive oxygen and nitrogen species were determined for all extracts as well as no adverse effects on Caco-2 and HT29-MTX cells in concentrations below 100 μg/mL and 1000 μg/mL, respectively. These results highlight the potentialities of hardy kiwi leaves valorization.

Nutrigenomics and polyphenols

Abstract Nutrients can act as dietary signals, influencing genes, and protein expression and, subsequently, metabolite production. The diversity in the individual genetic profile affects nutrient requirements, metabolism, and responses to dietary interventions. Humans have developed the ability to extract and combine food nutrients, altering the way they naturally exist and unbalancing the composition of food. Therefore, nutrition is not anymore “a way to fuel the body” but rather something much more complex and deeply entangled with the specific genetic features. Nutrigenomics emerges as the science that provides a molecular genetic understanding on how common dietary chemicals affect health. The interaction between genes and dietary chemicals, namely polyphenols, is the main objective of this chapter as well as the major progresses in polyphenols–gene interaction of specific food groups. The recent international initiatives related with nutrigenomics and the developing personalized nutrition are also presented and discussed.