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In this study the potential of Fourier Transform Mid-Infrared (FT-MIR) spectroscopy to predict the sensory score of traditional balsamic vinegar (TBV) of Reggio-Emilia was investigated. The composition of two hundred commercial TBV samples was analysed and the sensory scores, ranging from 133 to 306 points, were evaluated by a certified panel of master experts (reference method). Partial least squares (PLS) regression, obtained from selected pre-processing signal techniques, was used for multivariate calibration to relate the sensory score to the MIR spectra. Performance of different models was compared in terms of coefficient of correlation (r) and root mean square error of cross-validation (RMSECV). The overall best prediction results were obtained using second order derivative with autoscaling and mean-centering of spectral data with the correlation coefficient of 0.889 and 0.885, respectively. It was concluded that the MIR spectroscopy is suitable for rapid instrumental screening of TBV sensory quality.

In this study, six enological tannins (T1–T6) from different source were analysed by selected analytical techniques, including UV–Vis, FTIR, NMR, SEC, LC-MS/MS and electronic nose. Moreover, the samples were tested for their antioxidant activity. Spectra and chromatograms are considered as a fingerprint with a pattern that is distinctive for a given type of sample. In particular, tannins showed the maximum UV–Vis absorbance (λmax) at 273–280 nm, the inflection point (λmin) at 247–264 nm, and the ratio λmax/λmin was 1.03, 1.35, 1.67, 1.36, 2.15, 2.02 for tannin T1–T6, respectively. The FTIR analysis of tannins showed the presence of most important absorption bands at 1522, 1453, 1380, 1350, 1328, 1286, 1210, 1148 and 1044 cm−1. Besides, SEC and NMR analysis allowed to sort the tannins according to their average DP as follows: T1 > T2 = T4 > T3 > T6 = T5. Based on this multiple techniques approach three condensed tannins (sample T3, T5 and T6) were clearly identified, together with two mixtures of hydrolysable tannins (sample T1 and T2), whereas one sample (T4) showed a peculiar pattern different from the commercial tannin commonly used in enology.

The monomeric and polymeric pigments of 20 young red wines were analysed using most recent of the approaches available for phenolics measurements in wine, including: (i) HPLC with silica-based reversed-phase, (ii) HPLC with polymeric-based reversed-phase columns, (iii) the spectrophotometric Adams’ tannin and polymeric pigments assay, (iv) the Boulton’s copigmentation assay, and (v) the Somers’ unbleached polymeric color assay. Moreover, a modification of an existing HPLC method, i.e. the addition of SO2 to the mobile phases, allowed the unbleached polymeric pigments to be analysed by HPLC for the first time. The wines displayed a variation in their color density at 520 nm that ranged by 10-fold, and included wines made from Pinot noir, Merlot, Cabernet sauvignon, Cabernet franc, Sangiovese, Cagnulari and Cannonau grapes. The total color of wines was an aggregate number of three components: copigmentation (8–30%), total free anthocyanins (24–35%), and polymeric pigment (35–63%). Cross-comparison between the selected method was performed and discussed. In particular, the polymeric pigments estimated by HPLC with polymeric-based reversed-phase column were in good agreement with the result of the reversed-phase C18 column (R2 = 0.9703) and the sum of small and large polymeric pigments estimated by the Adams’ assay (R2 = 0.9511). The level of copigmentation can be almost completely described by the levels of monomeric pigments (R2 = 0.9464) and not by the tannin content as has often been suggested (copigmentation vs tannin: R2 = 0.4827).

The quality of wine is mainly determined during the alcoholic fermentation that gradually transforms the grape juice into wine. Along this process the yeast goes through several stressful stages which can affect its fermentative ability and industrial performance, affecting wine quality. Based on their actual application on industrial winemaking, commercial Saccharomyces cerevisiae strains (EC1118, QA23, VIN7 and VL3) were used. They were inoculated in batch laboratory fermentations in a model wine solution for evaluating the production of reactive oxygen species (ROS) during the yeast’s alcoholic fermentation. For first time total hydroperoxides were determined by FOX-1 assay to follow ROS generation. The total hydroperoxides accumulated along the 10 days of fermentation peaked up to 10.0 μM in yeast EC1118, of which 1.3 μM was hydrogen peroxide (H 2 O 2 ). The FOX-1 based analytical approach herein presented is a valuable tool for the quantification of ROS oxidative damage during winemaking.

The modern fruit juice industry needs their products to be characterized by high-quality attributes to meet consumers’ expectation. In this view, the composition of 26 Italian commercial apricot juices obtained from organic, integrated and conventional agriculture was analysed for carbohydrates, organic acids, amino acids, phenolic compounds and furanic compounds by high-performance liquid chromatography (HPLC). The content of 5-hydroxymethylfurfural in apricot juices (range 0.1–18 mg/l) was within the regulatory limit of 20 mg/l. The lack of furanic compounds in apricot fresh fruits confirmed their importance as quality markers of heating condition during processing and storage of fruit juices. Univariate analysis disclosed some significant differences among the composition of the apricot juices in terms of glucose, fructose, malic acid, glycine, chlorogenic acid, rutin, and a ∗ -parameter (redness). Principal component analysis on chemical composition of apricot juices resulted in two principal components (PCs) that accounted for 66% of the total variance. Organic apricot juices showed some separation from the other juices, whereas a lack of distinction between integrated and conventional juices appeared.

The compositions of three peach juices obtained from the cultivars Redhaven, Suncrest and Maria Marta, respectively, were studied. The fruits were grown in the Emilia-Romagna region (Italy). The juices were characterised by pH, CIE L *, a *, b * colour values, soluble solids, individual carbohydrates, organic acids, and phenolic compounds. Univariate analysis disclosed some significant differences among the compositions of the varietal peach juices. Principal component revealed clear group structures in the data matrix, the most relevant variables being glucose, fructose, sorbitol, malic acid, L * and b *-values. Suncrest peach juice was clearly distinguished from Redhaven and Maria Marta juices.

High performance anion-exchange chromatography (HPAEC), coupled with pulsed amperometric detection (PAD), was used to identify and quantify oligogalacturonic acids (OGAs) in strawberry juice. This method allowed good separation and detection of OGAs with degree of polymerization (DP) ® MAX enzyme, for 2 h at 45°C, produced juice with by far the highest concentration of OGAs. Moreover, treatment with Grindamyl Pectinase ™ LM was also extended to 4 and 6 h to measure the time course of pectinase activity and verify the stability of OGA. This enzyme generated high levels of pectin breakdown products proportionately with time (monitored up to 6 h) and increased the total level of OGAs with DP ⩾4 units from 78 to 771 mg/l. ©