Vol.:(0123456789) 1 3 European Food Research and Technology https://doi.org/10.1007/s00217-019-03355-4 ORIGINAL PAPER Mono‑ and di‑glucoside anthocyanins extraction during the skin contact fermentation in hybrid grape varieties T. Roman 1  · L. Barp 1  · M. Malacarne 1  · T. Nardin 1  · G. Nicolini 1  · R. Larcher 1 Received: 14 June 2019 / Revised: 5 August 2019 / Accepted: 10 August 2019 © Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract In this work, the anthocyanins’ profle of two hybrid grape varieties—Cabernet Carbon and Prior—grown in two experi- mental plots in Trentino (Northern Italy) was investigated during 2016 and 2017 harvests. The focus was on the mono- and di-glycoside anthocyanins extraction during the fermentative maceration. It was optimized an HPLC-DAD method, which allows the separation and quantifcation of mono- and di-glucoside anthocyanin forms (non-esterifed, acetylated, and p-coumaroylated) in a single chromatographic run. Furthermore, an HPLC-DAD/HQOMS approach was used to confrm the compound identifcation. The skin contact fermentation was conducted for 7 days at 24 °C, punching down manually the cap twice a day. Must samples were collected every 24 h. As expected, every anthocyanin showed an initial net extraction phase described by a frst-order kinetic, followed by a decrease until the end of the maceration. The analysis of the accumulation rate showed a faster increase of the di-glucoside anthocyanins concentration compared to the corresponding mono-glucoside, due to their richness in the initial grapes. Moreover, the di-glucosides concentration at the end of the alcoholic fermentation underwent a three times minor percentage decrease with respect to the maximum reached. This paper intend to improve the knowledge of the kinetics of each anthocyanin form during the maceration step, providing information about the behavior of di-glucoside compounds, never investigated before in terms of accumulation and percentage decrease. Keywords Mono- and di-glucoside anthocyanins · HPLC-DAD · Hybrid grape varieties · Anthocyanins extraction kinetic Introduction Anthocyanins are a class of phenolic compounds responsible for the red color of grapes and wines. Malvidin (MV), cya- nidin (CY), peonidin (PN), petunidin (PT) and delphinidin (DP) are the most important anthocyanidins in wine and are diferentiated by the substituent groups present in the B-ring. Any kind of plant has a distinctive anthocyanin profle [1, 2]. Grapes belonging to Vitis vinifera varieties are character- ized by anthocyanins with the aglycone bonded to a sugar molecule, typically glucose, through a glycosidic bond in position 3′ (3-O-monoglucoside anthocyanins). Despite the varying concentrations of these compounds among grape varieties, malvidin-3-O-glucoside (MV-3-glc) is generally the most abundant anthocyanin, representing more than 40% of the total in some cultivars [3]. Anthocyanins with a second glucose molecule in position 5′ (3,5-O-diglucoside anthocyanins) characterize instead some non-V.vinifera grapes; thus, the presence of di-glucosidic anthocyanins can be normally used to detect interspecifc hybrid grapes [2, 4–6]. For most of red grape varieties, anthocyanins are syn- thesized exclusively in the grape skins and continue to accumulate in the vacuoles of the upper cellular layers from veraison throughout the ripening process [3]. During mac- eration in red winemaking, anthocyanins are fast extracted, through a difusive process, in the frst days of skin con- tact [7]. The maximum concentration reached during this phase is determined by the adsorption–desorption equilib- rium between grapes and wine [8]. Then the concentration decreases slowly due to diferent factors, such as adsorption mechanisms with the wall cell of yeasts or precipitation after fxation with solid parts of the grapes, or involvement into chemical reactions as oxidation, condensation with catechins or cycloaddition with yeast metabolites [3, 7, 9–11]. Several analytical method have been developed during years aiming to identify and quantify as many anthocyanins * L. Barp laura.barp@fmach.it 1 Technology Transfer Center, Edmund Mach Foundation, San Michele All’adige, Italy