New Insights Into the Biological Activity Evaluation of Mango Juices Processed by Sustainable Emerging Technologies

The human intervention study has been designed with the aim to study the effect of a usual dietary intake of a commercial HPP mango juice on phenolic and carotenoid compounds bioavailability and health-related biomarkers. Due to mango juice is obtained from a pulp puree, the high viscosity of this product makes it necessary to mix it with water or other fruit juice for consumption. Thus, the commercial mango juice is not actually composed of 100% mango. For the present study, it has been selected a commercial HPP mango juice whose composition is mango puree 20% and orange juice 80%. A commercial HPP orange juice 100% elaborated with the same process will be consumed by the participants as control juice after be diluted. Subjects will be instructed to dilute the commercial HPP orange juice with water to match the content of orange juice in both groups. A 28-day feeding trial (randomized cross-over controlled clinical trial) will be conducted to study the effect of a usual dietary intake of commercial HPP mango juice [mango puree (20%)-orange juice (80%)] or control juice [water (20%)-HPP orange juice (80%)] on phenolic and carotenoid metabolite profiles and cardiometabolic health biomarkers. To date, no human intervention studies have been conducted to assess the health effects of ingesting commercial HPP-treated mango juices.

Recruitment of study participants. The inclusion criteria will be: individuals with body mass index [BMI] 25-29.9, aged 18-50, plasma total cholesterol levels 180-235 mg/dL, and plasma retinol concentration in the upper tertile of the normal reference range (20-60 µg/dL). Subjects will be recruited at the Human Nutrition Unit (HNU), Institute of Food Science, Technology and Nutrition (ICTAN). The study will be advertised at the campus of Universidad Complutense de Madrid (UCM), on the webpage of ICTAN-CSIC and through different social media. All participants will attend a familiarization session before beginning the study. The exclusion criteria will be: use of medication/food supplements to lower blood cholesterol, chronic disease, such as high blood pressure, diabetes, and heart disease; pregnancy or lactation; smoking habits; alcohol consumption above recommendations; allergy to mango or orange fruit.

Study design and dietary intervention. The participants will receive oral and written information about the study and provide written consent. This study will be a randomized cross-over controlled clinical trial. Approval by the Ethics Committee for Clinical Research of the University Hospital Puerta de Hierro Majadahonda, Spain has been obtained. To avoid sex and gender bias, men and women will be recruited. Subjects will be randomly to either the HPP mango juice group or the control juice group. Each intervention period will last 4 weeks and will be separated by a 4-week wash-out period. During each intervention period, participants will be instructed to consume 500 mL of juice/day in two doses, 250 mL in the morning and 250 mL in the afternoon. Daily dose of juice (500 mL) and duration of intervention (4 weeks) have been selected based on our previous human intervention studies and literature studies, both compatible with a usual dietary intake. Three visits to HNU at ICTAN will be required by the study protocol: the initial screening, at Week 0 (day 0-Baseline), and Weeks 2 (day 14), and 4 (day 28). Participants will be fasted overnight. On study visit days to HNU at ICTAN, fasting blood samples will be drawn, urine and faeces samples will be collected. It is planned that a total of 30 individuals will be recruited to obtain outcome significant differences. The primary outcome variable for sample size calculation has been the modification in the plasma CRP levels (as inflammation biomarker). In particular, power calculations have been based on a 30% reduction in CRP levels following previous nutritional clinical trials in subjects consuming fruit juices containing mango, orange or similar. A sample size of 30 has been calculated as sufficient to detect this change with 95% power and an alpha value of 0.05, using published variances of this parameter. Blood samples will be drawn and collected on days 0, 14, and 28 of the study. Urine and faeces will be collected the same days of blood sample collection and stored at -80 °C until analysis.

The following determinations will be performed at different periods: anthropometric measurements and blood pressure, dietary analysis; phenolic and carotenoid compounds analysis in plasma/serum/urine, carotenoid compounds analysis in serum and faeces, lipid profile and biochemistry markers, inflammatory and vascular injury biomarkers and metabolic hormones, oxidative stress biomarkers, and antioxidant enzyme activities and plasma antioxidant activity.