The application of chemometrics, a widely used science in food studies (and not only food studies) has begun to increase in importance with chemometrics being a very powerful tool in analyzing large numbers of results. In the case of honey, chemometrics is usually used for assessing honey authenticity and quality control, combined with well-established analytical methods. Research related to investigation of the quality changes in honey due to modifications after processing and storage is rare, with a visibly increasing tendency in the last decade (and concentrated on investigating novel methods to preserve the honey quality, such as ultrasound or high-pressure treatment). This review presents the evolution in the last few years in using chemometrics in analyzing honey quality during processing and storage. The advantages of using chemometrics in assessing honey quality during storage and processing are presented, together with the main characteristics of some well-known chemometric methods. Chemometrics prove to be a successful tool to differentiate honey samples based on changes of characteristics during storage and processing.

The reaction of Cu²⁺ acetate monohydrate with 2-[N,N′-bis(carboxymethyl)aminomethyl]-4-carboxyphenol (H₄cacp), 2-[N,N-bis(carboxymethyl)aminomethyl]hydroquinone (H₄cah) and the dinucleating 2,5-bis[N,N-bis(carboxymethyl)aminomethyl]hydroquinone (H₆bicah) in water results in the formation of several Cu²⁺ species, which are in dynamic equilibrium in aqueous solution and their stability is pH dependent. A systematic crystallographic study of these species was pursued, resulting in the characterization of most of the species. Additional techniques were employed to characterize the molecules in the solid state (infrared spectroscopy) and in solution (UV-vis spectroscopy and electrochemistry). These measurements show that the Cu²⁺ ions are ligated mainly to the iminodiacetate at pH < 6, exhibiting only weak interactions with the phenol oxygen. At pH > 6, the phenol oxygen was deprotonated and dinuclear-bridged species, from the phenolate oxygen complexes exhibiting a Cu^{2 +} ₂O₂ core, were isolated. The coordination environment around the copper ions varies between trigonal bipyramidal, tetragonal pyramidal and distorted octahedral geometries. The two unpaired electrons of the Cu²⁺ ions are found to be antiferromagnetically coupled. A survey of the magnetic and structural properties of the dinuclear phenoxide bridged Cu²⁺ complexes shows that the strength of the antiferromagnetic coupling is linearly dependent on the Cu–O_phenolate bond lengths, at bond distances below 1.98 Å. The effect of the Cu–O–Cu angles on the magnetic properties of the complexes is also discussed.