COMPARATIVE EVALUATION AND STUDING OF SOME INDIGENOUS AND INTRODUCED RED GRAPE VARIETIES

Abstract

Azerbaijan is one of the ancient wine-growing country, and it is famous by its rich assortment of local grapes. Historically, in our country well-known brand wines have been prepared from aboriginal red grape varieties. Among them, we can mention branded Kurdamir kagoru, Shamakhi kagoru, Madasa and Khindogni natural wines, etc. wines made from such autochthonous grape varieties won the favor of consumers with their unique physical-chemical and organoleptic characteristics. In line with it, in recent years, to the country introduced a number of valuable grape varieties such as Merlot, Cabernet Sauvignon, Syrah and others. It is actually relevant comparative evaluation of such varieties cultivated in local conditions, including red ones. During the ripening of the studied grape varieties, the amount of sugars ranged between 197 and 265 g/dm3, titratable acids from 4.5 to 7.7 g/dm3, and active acidity between 3.08 and 3.61. The mass concentration of sugars in the Xindogni grape variety was 197 g/dm3 on average. The varieties were in ascending order of the mass concentration of sugars: Madrasa 222 g/dm3, Cabernet-Sauvignon 226 g/dm3, Merlot 240 g/dm3, and Shirvanshahi 265 g/dm3. One of the important indicators determining the quality of raw materials is known to be the sugar-acid potential, in other words, a glucoacidometric index (GAI). In the studied varieties, the GAI varied from 3.0 to 5.7. This index was higher in the Shirvanshahi variety (5.7), medium in Madrasa (4.9) and Cabernet Sauvignon (4.8), and lower in the Xindogni (3.0) and Merlot (3.1) grape varieties. Delphinidin, cyanidin, peonidin, and malvidin anthocyanidins were found in skin hydrolysates. The amount of resveratrol in the skin, seed, and leaf was 0.75-8.25mg/kg, 0.31-5.7mg/kg, and 0.01-0.25mg, respectively, depending on varieties and years. Local grape varieties had a noticeable level of aromatic alcohol content and were not at all inferior to the famous Cabernet Sauvignon grape variety. Aromatic alcohols such as β-phenylethanol, β-phenoxyethanol, and phenylcarbinol were among the compounds of importance for Kagor-type wines. A comparison of their quantity showed that the amount of these compounds in the Madrasa grape variety was more than in the other two grape varieties.

Keywords

• grape
• juice
• skin
• seed
• sugar
• acid
• phenolic compounds
• anthocyanins