First report on rare unifloral honey of endemic Moltkia petraea (TRATT.) GRISEB. from Croatia: Detailed chemical screening and antioxidant capacity

JERKOVIC, IGOR;Marijanović, Zvonimir;Zekić, Marina;TUBEROSO, CARLO IGNAZIO GIOVANNI

2017-01-01

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Abstract

Rare Moltkia petraea (Tratt.) Griseb. honey from Croatia was first time characterised. The spectrophotometric assays on CIE L*a*b*Cab*hab° colour coordinates, total phenol content and antioxidant capacity (FRAP, CUPRAC, DPPH• and ABTS•+ assays) determined higher honey values generally close to dark honeys ranges. Headspace solid-phase microextraction (HS-SPME) on two fibres after GC-FID and GC/MS revealed the major compounds 2-phenylacetaldehyde (12.8%; 15.6%), benzaldehyde (11.1%; 10.0%), octane (9.3%; 7.6%), nonane, propan-2-one, pentan-2-one, pentanal and nonanal (4.9%; 14.5%). Ultrasonic solvent extraction (USE) mainly isolated non-specific higher molecular compounds characteristic of the comb environment. Targeted HLPC-DAD analysis of the honey determined higher concentration of phenylalanine (212.08 mg/kg) and lumichrome (16.25 mg/kg) along with tyrosine and kojic acid. The headspace composition (chemical fingerprint) and high concentration of lumichrome can be considered particular for M. petraea honey.