Quantitative Determination of Allergenic 5-Alk(en)ylresorcinols in Mango (Mangifera indica L.) Peel, Pulp, and Fruit Products by High-Performance Liquid Chromatography

Abstract

Despite a number of serious case reports of mango dermatitis, no attempts at the identification and quantification of allergenic 5-alk(en)ylresorcinols in mango fruits have so far been made. Therefore, total alk(en)ylresorcinol content and relative homologue composition in 13 mango peel samples and 7 samples of mango pulp were determined by HPLC and LC-MS/MS analyses. Furthermore, mango puree and nectar prepared on pilot plant scale were also analyzed and compared with commercially available thermally preserved products. Depending on cultivar, alk(en)ylresorcinol contents ranged from 79.3 to 1850.5 mg/kg of dry matter (DM) in mango peels and from 4.9 to 187.3 mg/kg of DM in samples of mango pulp. The profile of alk(en)ylresorcinols was found to be highly characteristic, with an average homologue composition of C15:0 (6.1%), C15:1 (1.7%), C17:0 (1.1%), C17:1 (52.5%), C17:2 (33.4%), C17:3 (2.4%), C19:1 (2.1%), and C19:2 (0.8%). Mango puree samples prepared from peeled and unpeeled fruits revealed contents of 3.8 and 12.3 mg/kg of fresh weight, respectively. Content and homologue composition were not significantly affected during puree processing and thermal preservation. In nectar samples prepared from peeled and unpeeled fruits, contents of 1.4 and 4.6 mg/L, respectively, were found.

Resistance of industrial mango peel waste to pectin degradation prior to by‐product drying

“…, 2009). Compared to twelve other mango cultivars, peels of ‘Kaew’ fruit were reported to be comparatively rich in alk(en)ylresorcinols (1.4 g kg −1 of peel dry matter; Knödler et al. , 2009), which play a role in plant disease resistance (Hassan et al.…”

“…On a relatively large part of the peel waste surface, wax layers and the thickness of the cuticle initially still act as physical barriers. Additionally, minor antimicrobial effects might still emanate from polyphenolics like gallotannins and alk(en)ylresorcinols present in mango peels even at consumption ripeness of the fruit (Berardini et al, 2004;Engels et al, 2009;Kno¨dler et al, 2009). Compared to twelve other mango cultivars, peels of 'Kaew' fruit were reported to be comparatively rich in alk(en)ylresorcinols (1.4 g kg )1 of peel dry matter; Kno¨dler et al, 2009), which play a role in plant disease resistance (Hassan et al, 2007).…”

“…Additionally, minor antimicrobial effects might still emanate from polyphenolics like gallotannins and alk(en)ylresorcinols present in mango peels even at consumption ripeness of the fruit (Berardini et al, 2004;Engels et al, 2009;Kno¨dler et al, 2009). Compared to twelve other mango cultivars, peels of 'Kaew' fruit were reported to be comparatively rich in alk(en)ylresorcinols (1.4 g kg )1 of peel dry matter; Kno¨dler et al, 2009), which play a role in plant disease resistance (Hassan et al, 2007). Because of the enhanced flexibility, the observed tolerance of intermediate storage is important for a future exploitation of peel waste from mango processing on smaller industrial scales, where immediate peel drying may impose considerably higher logistic and economic investment than on large scale with completely continuous processing and waste stabilisation.…”

A novel approach to authenticity control of whole grain durum wheat (Triticum durum Desf.) flour and pasta, based on analysis of alkylresorcinol composition

“…Mass spectrometric conditions have been reported in detail in a recently published study (Knödler et al, 2008). Individual compounds were identified by their retention times and UV and mass spectra (Knödler et al, 2008) and quantified using a calibration curve of the corresponding standard compound (Knödler, Reisenhauer, Schieber, & Carle, 2009). …”

Present Status and Perspectives on the Use of Alkylresorcinols as Biomarkers of Wholegrain Wheat and Rye Intake

“…Barley has a much larger proportion of C25 : 0 compared to the other cereals, though overall has much lower total AR concentrations (40–110  μ g/g versus 300–1500  μ g/g for wheat and rye) [9, 16–18]. ARs are not found in appreciable concentrations in other food plants, though homologues C15 : 0, C17 : 1, and C17 : 2 have been found in mango flesh at low concentrations (4–17 mg/kg fresh weight) [19]. Estimates for average daily intake range from 12 mg in the United Kingdom to nearly 40 mg in Finland [20], though this may underestimate intakes at the low end of the range as the small amounts present in white wheat flour were not accounted for [16].…”