Contribution to the characterisation of honey-based Sardinian product abbamele: Volatile aroma composition, honey marker compounds and antioxidant activity

Sardinian abbamele is a typical product obtained from the honey recuperation from combs (traditional procedure) or by concentration of the honey diluted in water (industrial procedure). Seven abbamele samples were obtained to study the volatiles’ composition, the presence of honey marker compounds and their relationship with the production procedures. The long thermal treatment applied in abbamele production caused very high (1007.0–4405.8 mg/kg) HMF content (HPLC-DAD), while glucose and fructose amounts were quite similar to the honey ones (HPLC-RI). Total antioxidant activity (FRAP assay) of the samples ranged between 13.3 and 71.2 mmol Fe2+/kg, while antiradical activity (DPPH assay) ranged between 3.8 and 23.3 mmol TEAC/kg. Such high antioxidant values were linearly correlated with total phenol amount (1297.8–4469.5 mg GAE/kg) determined by Folin–Ciocalteau method. Thermally derived furan derivatives and terpenes were abundant among the headspace volatiles (HS-SPME), particularly limonene (0.5–76.0%) that probably originated from citrus rinds’ addition during abbamele production. GC and GC–MS analyses of USE isolates revealed HMF predominance as well as the honey marker compounds (if/when existing) such as methyl syringate (up to 49.2%), marker of Asphodelus microcarpus honey. High isophorone percentage (up to 30.9%) determined by HS-SPME followed by minor percentage of 4-ketoisophorone and norisoprenoids in one sample indicated Arbutus unedo L. honey use in the production. HPLC-DAD analysis confirmed the presence of specific honey markers: two samples showed high methyl syringate concentrations (150.4–120.1 mg/kg) while homogentisic acid and other specific markers of A. unedo honey were found in one sample. The compared GC–MS and HPLC-DAD data proved to be useful to obtain information about the use of specific honey in the production and to verify citrus addition.