Polyphenols are a major class of bioactive phytochemicals whose consumption may play a role in the prevention of a number of chronic diseases such as cardiovascular diseases, type II diabetes and cancers. Phenol-Explorer, launched in 2009, is the only freely available web-based database on the content of polyphenols in food and their in vivo metabolism and pharmacokinetics. Here we report the third release of the database (Phenol-Explorer 3.0), which adds data on the effects of food processing on polyphenol contents in foods. Data on >100 foods, covering 161 polyphenols or groups of polyphenols before and after processing, were collected from 129 peer-reviewed publications and entered into new tables linked to the existing relational design. The effect of processing on polyphenol content is expressed in the form of retention factor coefficients, or the proportion of a given polyphenol retained after processing, adjusted for change in water content. The result is the first database on the effects of food processing on polyphenol content and, following the model initially defined for Phenol-Explorer, all data may be traced back to original sources. The new update will allow polyphenol scientists to more accurately estimate polyphenol exposure from dietary surveys.Database URL: http://www.phenol-explorer.eu

Background/Objectives Polyphenols are plant secondary metabolites with a large variability in their chemical structure and dietary occurrence that have been associated with some protective effects against several chronic diseases. To date, limited data exist on intake of polyphenols in populations. The current cross-sectional analysis aimed at estimating dietary intakes of all currently known individual polyphenols and total intake per class and subclass, and to identify their main food sources in the European Prospective Investigation into Cancer and Nutrition cohort. Methods Dietary data at baseline were collected using a standardized 24-h dietary recall software administered to 36,037 adult subjects. Dietary data were linked with Phenol-Explorer, a database with data on 502 individual polyphenols in 452 foods and data on polyphenol losses due to cooking and food processing. Results Mean total polyphenol intake was the highest in Aarhus-Denmark (1786 mg/day in men and 1626 mg/day in women) and the lowest in Greece (744 mg/day in men and 584 mg/day in women). When dividing the subjects into three regions, the highest intake of total polyphenols was observed in the UK healthconscious group, followed by non-Mediterranean (non-MED) and MED countries. The main polyphenol contributors were phenolic acids (52.5-56.9 %), except in men from MED countries and in the UK health-conscious group where they were flavonoids (49.1-61.7 %). Coffee, tea, and fruits were the most important food sources of total polyphenols. A total of 437 different individual polyphenols were consumed, including 94 consumed at a level [1 mg/day. The most abundant ones were the caffeoylquinic acids and the proanthocyanidin oligomers and polymers. Conclusion This study describes the large number of dietary individual polyphenols consumed and the high variability of their intakes between European populations, particularly between MED and non-MED countries.

Octanol-water partition coefficient (log P) values were determined for flavonoids from the flavone, flavonol, flavanone, and isoflavonoid subclasses. Each flavonoid was dissolved in an octanol-water system and allowed to equilibrate, and then both fractions were analyzed by high-performance liquid chromatography. log P was calculated as log[ratio of the concentration in the octanol phase to the concentration in the aqueous phase at pH 7.4]. The aglycons were more lipophilic than any conjugate. The conjugate moiety had a more significant effect on log P than the aglycon moiety. Quercetin was the least lipophilic aglycon (log P = 1.82 +/- 0.32) and, together with kaempferol (log P = 3.11 +/-0.54), gave the most variable results. The isoflavones genistein and daidzein and the isoflavone metabolite equol gave relatively high log P values (3.04 +/- 0.02, 2.51 +/- 0.06, and 3.20 +/- 0.13, respectively), while glycitein had an unexpectedly low value of 1.97 +/- 0.05. The conjugation characteristics and hydroxylation pattern were the most important determinants of log P in general, and log P was highly variable within the flavonoid subclass. The results are discussed in terms of further understanding of the in vivo fate of the flavonoids as important dietary bioactives.