Research the drying properties of some grape varieties and obtaining intermediate moisture raisin

Raisin is a nutritionally high food with mineral substances, vitamins and phenolic compounds, and is increasingly demanded throughout the world. In our study, Sultani seedless varieties which are the most commonly used in grape drying are used. These grapes are most widely used during drying process. Dimrit (seedy black), Sergi Karası (seedy black), Rumi (seedy white) and Besni (seedy white) cultivars that are still widely used especially in the southern region, and Reçel grape (seedless black), Tekirdağ Misketi (seedless white), Barış (seedless white) and Tekirdağ Çekirdeksizi (seedless black) cultivars that were rehabilitated and registered by Tekirdağ Viticulture Research Institude and Cengizbey (seedy black) grape varity, that breeding at 2016 was used, too. The physical and chemical properties of these grape varieties, such as their drying properties and their suitability to dryness, their mineral content, their content of phenolic compounds, their total amount of anthocyanins, their antioxidant capacity were investigated. The amount of phenolic substances found at grape varieties; highest one is Besni (15546 mgGAE / kg DM), the lowest one is Sultani seedless (3714 mgGAE / kg DM). In our study, two different drying systems (solar collector drying and laboratory type tray drying systems) were used. Dimit dried in the laboratory drying oven in the shortest time as soon as 13,5 hours, the longest period in the solar collector without dipping potassium carbonate solution Tekirdag cekirdeksizi was dried in 336 hours. The obtained data and the effects of these systems on grape drying were revealed and sensory analysis was performed in the dried grape varieties. According to the sensory analysis, Tekirdağ Misketi and Cengizbey varieties, which were breeding by Tekirdağ Viticulture Research Institute (T.B.A.E.), were the most popular varieties. Also, in our study intermediate moisture product which was dried up to 3 different moisture content (35%, 30%, 25%) with different types of Tekirdag misketi variety was investigated. İntermediate moisture grapes were dried in the open area, in the solar collector drying system and in the laboratory type drying system. Grapes with three different moisture without any application, ethanol pad, anti-microbial substance and thyme extract applications were tried to be maintained in room conditions for 12 months. Intermediate moisture grapes that dried in solar collector and in oven spoilaged later, while the microbial load of those dried in open area was increased.