Monitoring Volatile Organic Compounds and Aroma Profile of _Robinia pseudoacacia_ L. Honey at Different Storage Temperatures during Shelf Life  
[PERSON]  
1 Department of Veterinary Medicine and Animal Sciences, Universita degli Studi di Milano, Via dell'Universita 6, 26900 Lodi, Italy; [EMAIL_ADDRESS] (P.Y. ); [EMAIL_ADDRESS] (L.C. ); [EMAIL_ADDRESS] (R.R.) [PERSON]  
2 Department of Environmental Science and Policy, Universita degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy; [EMAIL_ADDRESS] (F.B. ); [EMAIL_ADDRESS] (M.G.) [PERSON]  
2 Department of Environmental Science and Policy, Universita degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy; [EMAIL_ADDRESS] (F.B. ); [EMAIL_ADDRESS] (M.G.) [PERSON]  
1 Department of Veterinary Medicine and Animal Sciences, Universita degli Studi di Milano, Via dell'Universita 6, 26900 Lodi, Italy; [EMAIL_ADDRESS] (P.Y. ); [EMAIL_ADDRESS] (L.C. ); [EMAIL_ADDRESS] (R.R.) [PERSON]  
3 Piana Ricerca Consulenza S.r.l., Via Umbria 41, Castell San Pietro Teme, 40024 Bologna, Italy; [EMAIL_ADDRESS]  
[PERSON]  
1 Department of Veterinary Medicine and Animal Sciences, Universita degli Studi di Milano, Via dell'Universita 6, 26900 Lodi, Italy; [EMAIL_ADDRESS] (P.Y. ); [EMAIL_ADDRESS] (L.C. ); [EMAIL_ADDRESS] (R.R.) [PERSON]  
1 Department of Veterinary Medicine and Animal Sciences, Universita degli Studi di Milano, Via dell'Universita 6, 26900 Lodi, Italy; [EMAIL_ADDRESS] (P.Y. ); [EMAIL_ADDRESS] (L.C. ); [EMAIL_ADDRESS] (R.R.) several compounds that are also constituents of organic acids and essential oils used in apiculture for their acaricidal activity, such as formic acid and thymol, respectively [5; 6; 7]. The volatile compound's profile can change during storage as a result of the temperature and the period to which it has been exposed [8]. When honey is heated or stored for a long time, pentoses and hexoses decompose and form undesirable compounds such as furans, mainly furfural and 5-hydroxymethylfurfurral (HMF), that represent the main degradation products of sugars, and their occurrence in foods is usually related to non-enzymatic browning reactions, i.e., Maillard reaction, sugar degradation in an acidic medium, and caramelization. Although not dangerous for humans, HMF is used as an indicator of honey conservation quality, and its concentration must be below 40 mg kg\({}^{-1}\)[9]. Indeed, HMF increases gradually in all kinds of honey during storage, but its production is accelerated with moderate heating (35-40 \({}^{\circ}\)C) for some months or heating at high temperatures for a short time [10]. Beyond the HMF value, also the diastatic index is another important indicator of the freshness and chemical degradation that honey undergoes during storage; in the presence of water, the diastasis enzyme splits the oligosaccharides into simpler compounds, and its activity may be reduced during storage, and modified by denaturation, brought about by heating [11]. The diastatic activity of honey is influenced by the storage and heating conditions and, therefore, represents an indicator of the state of freshness and overheating of honey, considering a minimum of eight Diastase Numbers (DN) expressed in Schade units to be valid, although diastasis has a wide natural variation [9; 11]. The analysis of the volatile compounds detected with different methodologies allows for assessing the aroma and the floral origin of the honey, and also, the appropriate conservation of the product and different chemical analyses can be combined with the use of an electronic nose (e-nose) to analyze the aromatic compounds present in honey [12; 13]. The e-nose can mimic the human sense of smell, and the device consists of multiple sensors that can modify their electrical characteristics in the presence of various volatile compounds. These are non-specific sensors and, therefore, unable to recognize the various substances and return values that are an olfactory imprint.