Table 1 List of studies reporting candidate biomarkers for pome fruit consumption
From: Food intake biomarkers for apple, pear, and stone fruit
Dietary factor | Study design | Number of subjects | Analytical method | Biofluid | Discriminating metabolites/candidate biomarkers | Primary reference(s) |
|---|---|---|---|---|---|---|
Apple | ||||||
Apple (24-h recalls, 58.7 ± 113.5 g/day+) | Observational study | 53 (31 women, 22 men) | HPLC-MS | Urine (spot and 24 h) | • Phloretin • Other non-specific polyphenol metabolites | [40] |
Apple (FFQ and food diaries, 47 (3–140)g/day*) | Observational study | 119 (all women) | HPLC-ESI-MS | Urine (24 h) Plasma | • Phloretin • Other non-specific compound | [42] |
Apple (24-h recall, 61 (0–317) g/day*) | Observational study: 5 months of free access to fruit basket in working place. | 79 | HPLC-ESI-MS | Urine (24 h) | • Phloretin • Other polyphenols for other fruits | [41] |
Apple and pear (24-h recalls, 228 ± 239 g/day+) | Observational study | 481 | Untargeted HPLC-TOF-MS | Urine (24 h) | • Phloretin glucuronide • Other non-specific epicatechin metabolites | [17] |
40 g of lyophilized apples: polyphenol-rich vs polyphenol-poor apples | Double-blind, randomized cross-over trial, 4-week periods | 30 (all men) | LC-MS | Morning spot urine | • Phloretin | [47] |
25 g of unripe apple processed in powder | Randomized cross-over study (two 1-day interventions: (1) 50 g OGTT and (2) 50 g OGTT+ 25 g apple powder) | 6 (all women) | LC-MS | Urine (0 h, 0-2 h, 2–4 h) | • Phloretin • Phloretin glucuronide | [45] |
1 L cloudy apple juice | Kinetics intervention, single dose | 11 (healthy ileostomy subjects) | HPLC-DAD; HPLC-ESI-MS/MS | Ileostomy fluid (0 h, 1 h, 2 h, 4 h, 6 h, and 8 h) | • Phloretin 2′-O-xyloglucoside • Phloretin 2′-O-glucuronide • Phloretin • Other non-specific polyphenol metabolites | [46] |
0.7 L of apple smoothie | Single dose, kinetic study | 10 (healthy ileostomy persons) | HPLC-DAD and HPLC-MS/MS | Ileostomy fluid (0 h, 1 h, 2 h, 4 h, 6 h, and 8 h) | • Phloretin 2′-O-xyloglucoside • Phloretin 2′-O-glucuronide (and isomers) • Phloretin • Other non-specific polyphenol metabolites | [95] |
1 kg of apple (organic vs conventional) | Randomized, cross-over single-dose study (2 experimental days, 1 per intervention) | 6 (all men) | HPLC-MS | Plasma (0 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 9 h, 12 h, 24 h) | • Phloretin | [43] |
500 g/day apple for 4 weeks (organic vs conventional vs no apple) | Double-blind, randomized parallel study (3 interventions: (1) organic apple, (2) conventional apple, (3) control) | 43 (all men) | HPLC-MS | Plasma (day 0 and day 28 24 h after last intake of fruit) | • Phloretin | [43] |
Apple (low: 200 ± 10 g, medium: 400 ± 10 g and high: 790 ± 10 g consumption) | Acute parallel study with three groups | 30 (14 women, 16 men) | HPLC-ESI-QTrap | Urine (0 h, 0–2 h, 2–4 h, 4–6 h, 6–8 h, 8–10 h, 10–12 h, 12–14 h, 14–16 h, 48 h morning spot, 72 h morning spot, 96 h morning spot) | • Phloretin • Other non-specific polyphenol metabolites | [48] |
Pear | ||||||
Pear (0.6 g/kg/h) vs Banana (0.6 g/kg/h) vs water (3 ml/kg/h) | Cross-over, randomized controlled trial (3 experimental days, 1 per intervention) | 20 (all men) | Untargeted UPLC-QTOF-MS | Plasma (T0, immediately after cycling, 1.5 h after cycling trial and 21-h post exercise) | • Arbutin • Hydroquinone sulfate • Other non-specific compounds (sugars, polyphenol microbial metabolites) | [64] |
Pear (1 fruit, as part of a high Hydroquinone diet) | Controlled Intervention study (3 experimental days, 1 per intervention: high hydroquinone meal with pear, low hydroquinone and acetaminophen) | 4 (2 women, 2 men) | GC-ED | Plasma (30, 60, 120 min after meal) Urine (2-h interval collection in a 8-h period after meal) | • Conjugated hydroquinone | [65] |