Determination of Polyphenolic Compounds by Ultra-Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry and Antioxidant Capacity of Spanish Subtropical Fruits

Abstract

In an analysis of the seven types of subtropical fruits most consumed and produced in southern Spain, UPLC-ESI-MS/MS was used to quantify 14 phenolic species: five hydroxycinnamic acids, seven hydroxybenzoic acids and two flavonoids (quercetin and naringenin). In each case, in addition, antioxidant capacity was determined by FRAP, ABTS and DPPH. Of these fruits, carambola (or starfruit) presented the highest levels of phenolic compounds, cherimoya (custard apple) and kiwi were the richest in non-flavonoid phenolic compounds and papaya had the highest levels of the flavonoids studied.Higher mean values were recorded in home-grown fruits than in imported varieties by ABTS and DPPH methods. Persimmon's antioxidant capacity was well above that of the other fruits, according to our analyses.

Differences in the Phenolic Profile by UPLC Coupled to High Resolution Mass Spectrometry and Antioxidant Capacity of Two Diospyros kaki Varieties

“…Comparing these values (using a simulate analytical method with other studies of our group) [ 29 ] mainly with tropical fruits, much higher levels of hydroxybenzoic acids and especially gallic acid (0.953 mg/100 g) are clearly observed in the Rojo Brillante variety. Three types of fresh fruit were compared with this variety of persimmon and were found to have compatible high tannin content (epicatechin gallate and epigallocatechin gallate): cherimoya 0.0735 mg/100 g, papaya 0.0341 mg/100 g, and pitaya 0.0546 mg/100 g. These compounds are commonly called catechins and form a group of bioactive compounds with strong antioxidant capacity involved in many oxidative stress-based chronic diseases.…”

“…According to the aforementioned study on tropical fruits [ 29 ] the antioxidant capacity for the Rojo Brillante variety, measured by the ABTS method, was superior to avocado (5455 µmol/g), mango (4889 µmol/g), papaya (4221 µmol/g) and carambola (2271 µmol/g) but lower than that of cherimoya (52,142 µmol/g), and kiwi (45,627 µmol/g). According to Park et al (2015), the antioxidant capacity of persimmon is higher than that of banana, grape, grapefruit, and lemon, but lower than that of strawberry, apple pulp, kiwi, and mangosteen [ 44 ].…”

“…The method used for sample treatment was described by Moreno-Montoro et al [ 30 ] with some changes described by Esteban-Muñoz et al [ 29 ], which used diethyl ether instead of acidic methanol to extract phenolic compounds from different fruit matrixes. An amount of 20 mL of diethyl ether was briefly added to persimmon (100 g of homogenized pulp) and the resulting solution was frozen at −20 °C for 24 h. Then, the mixture was centrifuged for 10 min at 9000 rpm.…”

“…An UPLC-QTOF-MS method [ 31 , 32 ] was used to identify the different polyphenols with some modifications described by Esteban-Muñoz et al [ 29 ].…”

“…However, such analytical platforms have not yet been used to analyze phenolic compounds in persimmon fruit. In this study a extraction technique coupled to an UPLC-QTOF-MS high-resolution mass spectrometer was used, having previously been tested by Esteban-Muñoz et al [ 29 ] on other fruits.…”