Agroclimatic characterization, aromatic composition and sensory profile of wines from Torontel grapes (Vitis vinifera L.) grown under warm climate and arid conditions (Ica, Peru)

Abstract

Torontel (Vitis vinífera L.) is an autochtonous Peruvian grape variety¹ issuing from the crossing between Listan Prieto and Muscat of Alexandria, which were introduced to South America by Spanish missionaries in the 16th century. While traditionally used to produce Pisco (an emblematic Peruvian spirit), some wineries are exploring the production of still and sparkling wines with this grape variety. However, little is known about its oenological potential, its sensory profile and agroclimatic characteristics. In order to bridge these gaps, this project studied the agronomical characteristics of Torontel grapes grown during 3 years (2023 – 2026) in the Ocucaje district (Ica valley, Peru), as well as the aroma composition and sensory profile of their wines. According to the results obtained, Ocucaje, which is a desert coastal region located 35 km from the Pacific Ocean at 310 masl, can be considered a very warm region (Winkler Region V), with a warm climate (HI+2) and temperate nights (IF-1)², and alluvial alkaline soils of medium to low fertility. Under these agroecological conditions, Torontel grapes had medium to high yield (18400 kg/ha), medium-sized conical-cylindrical bunches (360 g) with moderate compactness levels. Berries were broad ellipsoid, with medium skin thickness, greenish yellow through golden skin color and muscat aroma. Wines were made with these grapes and analysed by gas chromatography coupled to a flame ionization detector (GC-FID) as well as gas chromatography mass spectrometry (GCMS) to evaluate their aroma composition^3,4. The main compounds detected were 1-propanol, 1-butanol, isobutanol, acetaldehyde, 2- and 3-methyl-1-butanol, ethyl lactate and ethyl acetate, as well as a range of terpenes (nerol, geraniol and ß-citronellol), esters (ethyl hexanoate, ethyl octanoate, ethyl decanoate, ethyl 2-phenylacetate, diethyl succinate and hexyl acetate) and volatile phenols (4-vinylguaiacol and 4-vinyl phenol). The wines were described as having a fruity and floral sensory profile⁵. This work describes for the first time the agronomical and aromatic characteristics of Torontel, an interesting white grape variety with muscat aroma capable of growing in warm and arid environmental conditions.

References

¹ Mendoza, K., Aliquó G., Prieto, J.A., Blas, R., Flores, J., Casas, A., Grados, M., Aybar, L., Torres, M.R. (2022) Prospection and identification of traditional-heritage Peruvian grapevine cultivars (Vitis vinifera L.) from Ica and Cañete valleys. Vitis 61, 47–51.

² Tonietto J, Carbonneau A (2004) A multicriteria climatic classification system for grape-growing regions worldwide. Agric Meteorol 124: 81−97.

³ Sorrentino, A., Boscaino, F., Cozzolino, R., Volpe, M., Ionata, E., Guerriero, S., Picariello, T., & La Cara, F. (2013). Characterization of Free Volatile Compounds in Fiano Wine Produced by Different Selected Autochthonous Yeasts. Chemical Engineering Transactions, 32, 1837-1842. https://doi.org/10.3303/CET1332307

⁴ Oria, I. (2016). Estudio preliminar de la composición volátil y sensorial de las variedades blancas autorizadas en la DOCa. Rioja. Trabajo fin de grado. Universidad de La Rioja.

⁵ Aragón-García, F., Ruíz-Rodríguez, A., & Palma, M. (2021). Changes in the Aromatic Compounds Content in the Muscat Wines as a Result of the Application of Ultrasound during Pre-Fermentative Maceration. Foods, 10(7), 1462. https://doi.org/10.3390/foods10071462