The bioequivalence of two commerical blackcurrant extracts and the effect of caffeine on the appearance of blackcurrant polyphenolics in blood plasma in healthy participants.

INTERVENTION: This is a double‐blind, three‐arm repeated measures crossover study that will allow us to evaluate the bioequivalence of anthocyanins in human plasma following the consumption of two commercial blackcurrant extracts. Additionally, we seek to determine the effect of co‐consuming caffeine with blackcurrant powder on the bioavailability of anthocyanins in human blood plasma. Prospective participants who have passed the study’s inclusion/exclusion criteria will be asked to attend a familiarisation session where they will meet with the study’s principal investigator. During this session, the study’s principal investigator (research scientist, PhD) will explain the purpose of the study and what is expected from them as a participant. They give potential participants a copy of the information sheet and health questionnaire for them to take home and complete. Recruited participants will be required to complete all three treatment interventions of this study: (1) spray‐dried blackcurrant powder, (2) spray‐dried blackcurrant powder + caffeine and (3) anthocyanin‐enriched blackcurrant extract. The order at which participants will consume the treatments will be randomised. Participants will be instructed to refrain from consuming a list of food, drinks and dietary supplements containing anthocyanins 24 hours before their trial day. On each trail day, participants will be given a standardised breakfast bar to consume with water to have for breakfast 2 hours before the beginning of the trial. On the first trial day, participants will be given their allocated blackcurrant treatment to consume with 250 mL of water as quickly as possible. All blackcurrant treatments will contain a dose of anthocyanins relative to each participant’s bodyweight (3.2 mg total anthocyanins/k CONDITION: Nutrient absorption; ; Nutrient absorption Other ‐ Research that is not of generic health relevance and not applicable to specific health categories listed above PRIMARY OUTCOME: Plasma anthocyanin concentrations will be measured in blood samples collected from all participants at the same timepoints on all trial days.[This will be measured from blood samples collected at 0, 1, 2, 4 and 6 hours after treatment consumption during each trial day using validated in‐house high performance liquid chromatography (HPLC) methods.] SECONDARY OUTCOME: Blood glucose levels[On each trial day, blood glucose levels will be measured from an aliquot of venous blood samples collected at 0, 1, 2, 4 and 6 hours after treatment consumption. Glucose will be measured using "point‐of‐test" biosensors.] INCLUSION CRITERIA: Healthy individuals (male or female) 18 – 55 years who are able to provide written consent to participate in this study will be selected from this study.