Cristina García-Viguera

Flavanols and Anthocyanins in Cardiovascular Health: A Review of Current Evidence

Nowadays it is accepted that natural flavonoids present in fruits and plant-derived-foods are relevant, not only for technological reasons and organoleptic properties, but also because of their potential health-promoting effects, as suggested by the available experimental and epidemiological evidence. The beneficial biological effects of these food bioactives may be driven by two of their characteristic properties: their affinity for proteins and their antioxidant activity. Over the last 15 years, numerous publications have demonstrated that besides their in vitro antioxidant capacity, certain phenolic compounds, such as anthocyanins, catechins, proanthocyanidins, and other non coloured flavonoids, may regulate different signaling pathways involved in cell survival, growth and differentiation. In this review we will update the knowledge on the cardiovascular effects of anthocyanins, catechins and proanthocyanidins, as implied by the in vitro and clinical studies on these compounds. We also review the available information on the structure, distribution and bioavailability of flavanols (monomeric catechins and proanthocyanidins) and anthocyanins, data necessary in order to understand their role in reducing risk factors and preventing cardiovascular health problems through different aspects of their bioefficacy on vascular parameters (platelet agregation, atherosclerosis, blood pressure, antioxidant status, inflammation-related markers, etc.), myocardial conditions, and whole-body metabolism (serum biochemistry, lipid profile), highlighting the need for better-designed clinical studies to improve the current knowledge on the potential health benefits of these flavonoids to cardiovascular and metabolic health.

Natural bioactive compounds of Citrus limon for food and health.

Citrus genus is the most important fruit tree crop in the world and lemon is the third most important Citrus species. Several studies highlighted lemon as an important health-promoting fruit rich in phenolic compounds as well as vitamins, minerals, dietary fiber, essential oils and carotenoids. Lemon fruit has a strong commercial value for the fresh products market and food industry. Moreover, lemon productive networks generate high amounts of wastes and by-products that constitute an important source of bioactive compounds with potential for animal feed, manufactured foods, and health care. This review focuses on the phytochemistry and the analytical aspects of lemon compounds as well as on the importance for food industry and the relevance of Citrus limon for nutrition and health, bringing an overview of what is published on the bioactive compounds of this fruit.

Phytochemical evidence for the botanical origin of tropical propolis from Venezuela

Abstract The phenolic compounds present in 38 propolis samples produced in tropical Venezuela by imported Apis mellifera and five indigenous species of stingless bees, and seven propolis samples from different temperate regions were analysed by HPLC. The different tropical propolis generally showed a single phenolic profile characterized by the occurrence of polyprenylated benzophenones as major components. Flavonoids were present in only a few samples, and in each case they were found to be lipophilic methylated 6-oxygenated flavones (eupatorin, hispidulin, 5-hydroxy-6,7,3′,4′-tetramethoxyflavone, etc.). Generally, no correlations between the composition of tropical propolis and the place of collection or the bee species were found. However, propolis from temperate areas contained flavonoids (with an unsubstituted ring B) as the main phenolic components (pinobanksin, pinobanksin 3-acetate, pinocembrin, chrysin, galangin and tectochrysin). These analyses confirmed that the source of the phenolics found in propolis produced in temperate regions was different Populus species of section Aigeiros (Salicaceae). The resins exuded by the flowers of Clusia minor and C. major (Guttiferae) contained the polyprenylated benzophenones found in the majority of the propolis studied, suggesting that this is the main source for propolis in tropical Venezuela.

Betalains in the era of global agri-food science, technology and nutritional health

Natural pigments from plants are of growing interest as substitutes for synthetic dyes in the food and pharmaceutical industry and they increase their added value if they possess positive effects on health. These pigments can be added as such if they are in the legal authorized lists of additives or can be added as phytochemical-enriched plant extract achieving the original product, which has received it, the new nomenclature of functional food. In this way, we comprise on this review a wide point of view of a group of natural pigments known as betalains. From a chemical point of view, betalains are ammonium conjugates of betalamic acid with cyclo-DOPA (betacyanins, violet) and aminoacids or amines (betaxanthins, orange or yellow), which are compounds present in our diet. Besides and taking into account that one type of betalain, betanin is approved as food colorant (E-162) by the European Union and that enlarges the specific weight of these compounds in the diet, we have evolved an overview from the biosynthesis, technology and promoting production, industrial uses as pigments up to physiological and nutritional biovailability or biological and health-promoting properties of betalains for accessible information to industrials, researchers and consumers.

Natural Bioactive Compounds from Winery By-Products as Health Promoters: A Review

The relevance of food composition for human health has increased consumers’ interest in the consumption of fruits and vegetables, as well as foods enriched in bioactive compounds and nutraceuticals. This fact has led to a growing attention of suppliers on reuse of agro-industrial wastes rich in healthy plant ingredients. On this matter, grape has been pointed out as a rich source of bioactive compounds. Currently, up to 210 million tons of grapes (Vitis vinifera L.) are produced annually, being the 15% of the produced grapes addressed to the wine-making industry. This socio-economic activity generates a large amount of solid waste (up to 30%, w/w of the material used). Winery wastes include biodegradable solids namely stems, skins, and seeds. Bioactive compounds from winery by-products have disclosed interesting health promoting activities both in vitro and in vivo. This is a comprehensive review on the phytochemicals present in winery by-products, extraction techniques, industrial uses, and biological activities demonstrated by their bioactive compounds concerning potential for human health.

Rapid and Comprehensive Evaluation of (Poly)phenolic Compounds in Pomegranate (Punica granatum L.) Juice by UHPLC-MSn

The comprehensive identification of phenolic compounds in food and beverages is a crucial starting point for assessing their biological, nutritional, and technological properties. Pomegranate (Punica granatum L.) has been described as a rich source of (poly)phenolic components, with a broad array of different structures (phenolic acids, flavonoids, and hydrolyzable tannins) and a quick, high throughput, and accurate screening of its complete profile is still lacking. In the present work, a method for UHPLC separation and linear ion trap mass spectrometric (MSn) characterization of pomegranate juice phenolic fraction was optimized by comparing several different analytical conditions. The best solutions for phenolic acids, anthocyanins, flavonoids, and ellagitannins have been delineated and more than 70 compounds have been identified and fully characterized in less than one hour total analysis time. Twenty-one compounds were tentatively detected for the first time in pomegranate juice. The proposed fingerprinting approach could be easily translated to other plant derived food extracts and beverages containing a wide array of phytochemical compounds.

The use of acetone as an extraction solvent for anthocyanins from strawberry fruit

The use of acetone as an extraction solvent for anthocyanins from strawberry has been investigated. The results are compared with those obtained with classical acidified aqueous or methanolic solvents, the use of which gives rise to difficulties concerning sample concentration and filtration for further high-performance liquid chromatographic analysis. The use of acetone allows an efficient and more reproducible extraction, avoids problems with pectins, and permits a much lower temperature for sample concentration. The method has been applied to the analysis of anthocyanins from four varieties of strawberry (Camarosa, Oso Grande, Chandler and Tudla) used for the industrial production of jam in Spain. The variety Camarosa was richest in anthocyanins; approximately 10% of the anthocyanins present in fresh fruit was lost during the freezing process. Copyright

Colour and anthocyanin stability of red raspberry jam

Anthocyanin and colour stability of red raspberry jams made from two different varieties (‘Zeva’ and ‘Heritage’) were analysed during 6 months, stored at three temperatures (20, 30 and 37°C). Also the influence of freezing the fruit, previously to jam manufacture, was evaluated. Different anthocyanin composition was detected for both cultivars and while ‘Zeva’ fruit had a higher total anthocyanin content, Heritage variety produced jams with a higher redness hue. The development of browning was directly related to storage temperature but not to thawing or the variety of fruit used.

Simultaneous identification of glucosinolates and phenolic compounds in a representative collection of vegetable Brassica rapa.

Brassica raparapa group is widely distributed and consumed in northwestern Spain. The consumption of Brassica vegetables has been related to human health due to their phytochemicals, such as glucosinolates and phenolic compounds that induce a variety of physiological functions including antioxidant activity, enzymes regulation and apoptosis control and the cell cycle. For first time in Brassica crops, intact glucosinolates and phenolic compounds were simultaneously identified and characterized. Twelve intact glucosinolates, belonging to the three chemical classes, and more than 30 phenolic compounds were found in B. rapa leaves and young shoots (turnip greens and turnip tops) by LC-UV photodiode array detection (PAD)-electrospray ionization (ESI). The main naturally occurring phenolic compounds identified were flavonoids and derivatives of hydroxycinnamic acids. The majority of the flavonoids were kaempferol, quercetin and isorhamnetin glycosylated and acylated with different hydroxycinnamic acids. Quantification of the main compounds by HPLC-PAD showed significant differences for most of compounds between plant organs. Total glucosinolate content value was 26.84 micromol g(-1) dw for turnip greens and 29.11 micromol g(-1) dw for turnip tops; gluconapin being the predominant glucosinolate (23.2 micromol g(-1) dw). Phenolic compounds were higher in turnip greens 51.71 micromol g(-1) dw than in turnip tops 38.99 micromol g(-1) dw, in which flavonols were always the major compounds.

Growing Hardier Crops for Better Health: Salinity Tolerance and the Nutritional Value of Broccoli

To evaluate the variations in the nutritional components of a broccoli cultivar under saline stress, two different NaCl concentrations (40 and 80 mM) were assayed. Glucosinolates, phenolic compounds, and ascorbic and dehydroascorbic acids (vitamin C) were analyzed by HPLC, and mineral composition was determined by ICP spectrophotometry. Qualitative differences were observed for several bioactive compounds depending on the plant organ and the intensity of the salt stress. Glucosinolate content showed the most significant increase in the florets; phenolic compounds also increased in the florets, whereas no variation in the vitamin C content was observed as a result of the saline treatments. The mineral composition of the edible parts of the inflorescences remained within the range of the recommended values for human consumption. Overall, the nutritional quality of the edible florets of broccoli was improved under moderate saline stress.