Novel Urinary Biomarkers of Orange Juice Consumption, Interindividual Variability, and Differences with Processing Methods.

Untargeted metabolomics identified urinary biomarkers able to discriminate between the intake of fresh hand-squeezed and industrially processed orange juices. Processing led to an upregulation in the excretion of hydroxy-polymethoxyflavone sulfates, abscisic acid, and sinapic acid 4'-glucuronide. The demethylated polymethoxyflavone metabolites were produced with a significant interindividual variability suggesting that they could originate from gut microbiota metabolism. No correlation between the excretion levels of flavanone and polymethoxyflavone metabolites was observed, showing that gut microbiota metabolism differences could be behind the interindividual variability. Subjects with a high excretion level of hesperetin conjugates could be low or high polymethoxyflavone excretors. Flavanone phase II metabolites were primarily glucuronides, while those of demethylated polymethoxyflavones were mainly sulfates. A comparative study with the available demethylated polymethoxyflavone standards suggested that the metabolites produced in humans could be tentatively 4'-hydroxy- and/or 3'-hydroxy-polymethoxyflavone sulfates. This study is the first to describe the bioavailability and metabolism of citrus juice polymethoxyflavones in humans.

Encapsulation and micronization effectively improve orange beverage flavanone bioavailability in humans.

The effect of hesperidin encapsulation and particle size reduction on hesperetin bioavailability was assessed after the intake of orange flavanone beverages. Hesperidin micronization (5.1 µm) increased flavanone's bioavailability 2-fold compared to conventional hesperidin (32.8 µm). Gum Arabic encapsulated hesperidin, with enhanced dispersion in water, also showed increased bioavailability despite having a higher particle size than conventional hesperidin (74.2 µm), showing that flavanone dispersion also enhances its bioavailability. The bioavailability of micronized hesperetin was also evaluated to overcome the need for gut microbiota rhamnosidase hydrolysis. When volunteers were stratified for their flavanone excretion capability, differences among treatments were better observed. The treatments used to increase solubility and decrease particle size to facilitate the interaction with intestinal cells and gut microbiota enhanced bioavailabilty especially in high (9.2 ± 1.5 mg) and medium (5.5 ± 0.3 mg) flavanone excretors. On the contrary, micronized hesperetin bioavailability was particularly high in the case of low excretors (4.3 ± 0.6 mg), showing that the low excretion in these volunteers should be associated with the lack of the appropriate microbiota to release hesperetin from hesperidin. Not all of the low excretors, however, reached the excretion levels of high excretors when hesperetin was supplied, suggesting that differences in intestinal transporters of the volunteers could also affect the flavanone excretion rates observed.

Volunteer stratification is more relevant than technological treatment in orange juice flavanone bioavailability.

The effect of two technological treatments on orange juice flavanone bioavailability in humans was assessed. Processing affected flavanone solubility and particle size of the cloud. Volunteers were stratified in high, medium, and low urinary excretion capabilities. Flavanones from high-pressure homogenized juice showed better absorption than those of conventional pasteurized juice in high excretors. These differences were not observed in medium and low excretors. High flavanone excretors took advantage of the high-pressure homogenization juice attributes (smaller cloud particle size) and showed an improved absorption/excretion. Stratification of the individuals by their excretion capability is more relevant than technological treatments in terms of flavanone bioavailability. This stratification should be considered in clinical studies with citrus juices and extracts as it could explain the large interindividual variability that is often observed.