Investigation of the traditional organic vinegars by UV–VIS spectroscopy and rheology techniques

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2021-02, Vol.246, p.118987, Article 118987
• Main Authors: Yalçın, O., Tekgündüz, C., Öztürk, M., Tekgündüz, E.
• Format: Article
• Language: English
• Subjects: Absorbance spectra; Organic acids; Organic vinegar; Phenolic compounds; Rheology; UV–Vis spectroscopy; Viscosity
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2020.118987

Optical, rheological and metabolic properties of the apple, hawthorn, artichoke, grape, rosehip and blackberry organic vinegar produced by deep culture method (handmade traditional method) were analysed using UV–Vis spectroscopy and rheology techniques. Flow behaviours for all samples were analysed in the shear rate range of 10−3 to 103 1/s and in frequency range of 10−3 to 103rad/s, respectively. Absorption spectra for six organic vinegars was observed two peaks around 215 and 285nm due to the presence of phenolic compounds and organic acids such as acetic. The effects of optical transitions of organic molecules on the absorption coefficient values for vinegars were determined. Optical energy band gaps of all samples were found to be consistent with Planck's radiation approach known as Rayleigh-Jeans law and Tauc law. The rheological/flow properties of the all vinegars were found to be relevant with non-Newtonian flow behaviour and Ostwald-de Waele model. From the results of optical and rheological analysis, which determines the quantity and quality characteristics of all organic vinegars, it was concluded that these vinegars are in a level that people can drink easily. [Display omitted] •Traditional (deep culture) method was used in the production of organic vinegars.•Optical spectra of all organic vinegars were investigated by the UV–Vis spectroscopy.•Flow behaviours (diagrams) of all samples were characterized by rheology technique.•Rheological properties of all vinegars were related to non-Newtonian flow behaviour.•It was predicted that organic vinegars would be beneficial to human health.