69 research outputs found
(Poly)phenolic content and profile and antioxidant capacity of whole-grain cookies are better estimated by simulated digestion than chemical extraction
It is widely recognized that the biological effects of phytochemicals cannot be attributed to the native compounds present in foods but rather to their metabolites endogenously released after intake. Bioavailability depends on bioaccessibility, which is the amount of the food constituent that is released from the matrix in the gastrointestinal tract. The use of chemical extraction to evaluate the content and profile of phytochemicals does not mirror the physiological situation in vivo, and their bioaccessibility should be considered while assessing their nutritional significance in human health. The current study was designed to compare the (poly)phenolic profile and content and antioxidant capacity of whole-grain (WG) cookies using chemical extraction and a more physiological approach based on simulated digestion. Three types of organic WG cookies (made with durum, Italian khorasan, or KAMUT\uae khorasan wheat) were considered, either fermented by Saccharomyces Cerevisiae or sourdough. Although the flour type and the fermentation process influenced the release of phytochemicals from the cookie matrix, in almost all samples, the simulated digestion appeared the most efficient procedure. Our results indicate that the use of chemical extraction for evaluation of the phytochemicals content and antioxidant capacity of food could lead to underestimation and underline the need for more physiological extraction methods
Honey, a Gift from Nature to Health and Beauty: A Review
Benefits of honey are contributed by the composition of its elements such as glucose, fructose, glucose oxidase, vitamins and phenolic compounds. For health, honey can be used to treat wounds due to the antibacterial activity conferred by the hydrogen peroxide produced by glucose oxidase in honey. Anti-inflammatory, anti-oxidant, deodorizing and tissue regeneration activities in honey also help in the wound healing process. It can also be an alternative sweetener for diabetic patients to ensure compliance to a healthy diet. Moreover, honey exerts several effects such as lowering low density lipids and increasing high density lipids, thus reducing risk of atherosclerosis. In terms of beauty, honey can be used on skin and hair. It moisturizes skin through its natural humectant properties contributed by high contents of fructose and glucose. Honey treats acne on the skin due to its antibacterial activity, anti-inflammatory action and tissue repair. The hair can benefit from honey in such a way that the hair has abundance, and becomes easier to comb. However, there have not been as many studies regarding the use of honey in skin in comparison to its use for health. Therefore, future studies on honey could research its use, action and benefits in both cosmetics and dermatology
Inflation Targeting in Financially Stable Economies: Has it been Flexible Enough?
The events surrounding the financial crisis and recession of 2008-2009 required significant policy responses by central banks. For formal inflation targeters (IT) a natural question arises about whether IT frameworks were flexible enough to address this unprecedented policy environment. In this paper we tackle this question by assessing the policy responses to the crisis of nine IT central banks that did not face systemic problems in their banking or financial systems. We first document substantial deviations of actual policy responses from prescriptions of conventional monetary policy reaction functions, beginning in the second half of 2008. Although several explanations for the deviations are offered, highlighting the extreme challenges at the time, we can more easily reconcile the findings with a decline in the persistence of monetary policy, again, in all cases. Second, we document the banks´ non-monetary-policy measures adopted at the time, and estimate their impact on local money markets (both in local currency and US dollars) and on exchange rates. While these measures helped broadly to normalize markets, firm conclusions on the effectiveness of specific measures are elusive, owing to the difficulty in comparing the different mix of measures adopted across countries and the significant heterogeneity in specific economies´ responses to these non-monetary policy measures.Los eventos que rodearon la crisis financiera y la recesión de 2008-2009 exigió a los bancos centrales tomar importantes medidas de política. En las economías con un régimen formal de metas de inflación, surge naturalmente la pregunta de si tales regímenes mostraron la suficiente flexibilidad para lidiar con desafíos sin precedentes. Este documento aborda esta interrogante evaluando cómo reaccionaron a la crisis los bancos centrales de nueve economías con metas de inflación cuyos sectores bancarios y financieros no sufrieron problemas sistémicos. En primer lugar documentamos desviaciones sustanciales de las respuestas de política aplicadas de lo que prescriben las funciones de reacción de la política monetaria convencional, a partir del segundo semestre del 2008. Aunque se ofrecen diversas explicaciones para dichas desviaciones, subrayando la gravedad de los problemas, nos resulta más fácil conciliar las conclusiones con una disminución de la persistencia de la política monetaria, en los nueve casos. En segundo lugar, documentamos las medidas de política no monetaria que adoptaron los respectivos bancos centrales, y estimamos su impacto en los mercados monetarios locales (tanto en moneda local como en dólares) y en el tipo de cambio. Aunque, en general, estas medidas ayudaron a normalizar los mercados, no podemos sacar conclusiones definitivas sobre la eficacia de las medidas específicas, dada la dificultad de comparar los distintos paquetes de medidas adoptadas en cada país y la alta heterogeneidad de las respectivas respuestas de cada economía a estas medidas de política no monetaria
Flavonoid Occurrence, Bioavailability, Metabolism, and Protective Effects in Humans: Focus on Flavan-3-ols and Flavonols
Flavonoids are profusely abundant in the human diet and might be responsible for the advantages ascribed to dietary regimens rich in plant foods. Notwithstanding the evidence from epidemiological and cohort studies, an unambiguous and exhaustive pattern has not yet emerged regarding the mechanisms underlying their food-related health properties. It is now increasingly evident that the sole direct action of substances available in planta is not sufficient to fully explain the benefits of polyphenol-rich dietary habits. To elucidate this conundrum, a better comprehension of the interplay between human and microbial metabolism and dietary polyphenols is needed. This chapter provides a detailed overview of the current knowledge on bioavailability and in vivo biotransformation of two widespread classes of flavonoids: flavonols and flavan-3-ols. According to data collected, these substances are not always endowed with the highest bioactivities in vivo, and a deeper knowledge of their metabolites is needed to properly assess their overall contribution to human health and to single out substances to be monitored for the exhaustive profiling of flavonoid bioavailability
Absorption and metabolism of milk thistle flavonolignans in humans
This study evaluated the absorption and metabolism of milk thistle flavonolignans silychristin, silydianin, silybin and isosilybin isomers (all together known as silymarin) in humans. Fourteen volunteers consumed an extract of milk thistle and urine was collected up to 48 hours after consumption. Thirty-one metabolites were identified in urine by means of HPLC-MS/MS, monoglucuronides being the most common excreted form, followed by sulphate-glucuronides and diglucuronides, respectively. The excretion of monoglucuronides peaked 2 hours after consumption, whereas sulphate-glucuronide and diglucuronide excretion peaked at 8 hours. The bioavailability of milk thistle flavonolignans was 0.45 ± 0.28% (mean ± SD). In conclusion, milk thistle flavonolignans are extensively modified after ingestion and recovered in urine as sulpho- and glucuronyl-conjugates, indicating a strong affinity for hepatic phase II enzymes. All future studies (in vitro and in vivo) dealing with the effects of milk thistle should start by considering the modification of its flavonolignans after ingestion by humans
Phenolic Composition, Caffeine Content and Antioxidant Capacity of Coffee Silverskin
Coffea arabica silverskin (CSS), the inner fruit layer surrounding coffee beans, was analyzed for its (poly)phenolic and caffeine content by means of liquid chromatography-tandem mass spectrometry and evaluated for its antioxidant properties by means of the Folin-Ciocalteu and FRAP methods. The most abundant quantified phenolics were caffeoylquinic acids, with the 5- and 3-isomers being the most relevant (199 mg/100 g and 148 mg/100 g, respectively). The three caffeoylquinic acid isomers reached a total concentration of 432 mg/100 g, corresponding to 74% of the total chlorogenic acids detected in CSS. The level of the three feruloylquinic acids detected was 143 mg/100 g, corresponding to 23%, and the two identified coumaroylquinic acids plus the two caffeoylquinic acid lactones were only marginally contributing to the final figure (only 3% of total hydroxycinnamates). No unconjugated phenolic add was detected. Caffeine content in CSS was equal to 10 mg/g of product, 3.5 times lower than most coffee brews. The total antioxidant capacity (TAC) of CSS was 139 mmol Fe2 /kg, a value similar to those of valuable sources of food antioxidants like dark chocolate, herbs and spices. Besides its potential as a food supplement, CSS may represent an innovative functional ingredient exploitable to increase the TAC of a wide range of food products. (C) 2013 Elsevier Ltd. All rights reserved
Antiglycative and antioxidative properties of coffee fractions
In this work the inhibitory activity of coffee low molecular weight compound (LMWC) and high molecular weight compound (HMWC) fractions against in vitro advanced glycation end products (AGEs) formation was investigated. The HMWC fraction was characterized for its content in total phenolic groups, proteins and carbohydrates. The chlorogenic acids of LMWC fraction were identified by liquid chromatography coupled with tandem mass spectrometry. HMWC inhibited bovine serum albumin glycation by acting as radical scavenger and Fe-chelator in the post-Amadori phase of the reaction and by inhibiting dicarbonyl reactive compounds production during glucose autoxidation. LMWC fraction was able to inhibit protein glycation and dicarbonyl reactive compounds formation more than HMWC fraction. Chlorogenic acids are the main responsible for the antiglycative activity of LMWC fraction. This study clearly shows that coffee contains molecules with in vitro antiglycative activity and in particular chlorogenic acids are of particular interest for their known bioavailability in vivo
Fingerprint of enological tannins by multiple techniques approach
In this study, six enological tannins (T1–T6) from different source were analysed by selected analytical techniques, including UV–Vis, FTIR, NMR, SEC, LC-MS/MS and electronic nose. Moreover, the samples were tested for their antioxidant activity. Spectra and chromatograms are considered as a fingerprint with a pattern that is distinctive for a given type of sample. In particular, tannins showed the maximum UV–Vis absorbance (kmax) at 273–280 nm, the inflection point (kmin) at 247–264 nm, and the ratio kmax/
kmin was 1.03, 1.35, 1.67, 1.36, 2.15, 2.02 for tannin T1–T6, respectively. The FTIR analysis of tannins showed the presence of most important absorption bands at 1522, 1453, 1380, 1350, 1328, 1286, 1210, 1148 and 1044 cm-1. Besides, SEC and NMR analysis allowed to sort the tannins according to their
average DP as follows: T1 > T2 = T4 > T3 > T6 = T5. Based on this multiple techniques approach three condensed tannins (sample T3, T5 and T6) were clearly identified, together with two mixtures of hydrolysable tannins (sample T1 and T2), whereas one sample (T4) showed a peculiar pattern different from the commercial tannin commonly used in enology
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