H. C., KRISHNA,FOUSHANJE., AHMAD SHAFIQ,K. R., VASUDEVA,T. H., SHANKARAPPA,S., BHUVANESWARI,G. K., RAMEGOWDA,2021-01-082021-01-082018-06UHS15PGM697https://krishikosh.egranth.ac.in/handle/1/5810159580Fresh grapes contain about 80 per cent moisture which promotes microbial spoilage and early deterioration of shelf-life. Drying is a common method to convert fresh grapes into raisins which has high nutritive values and longer shelf life. Study was carried out to standardize the effect of pretreatment viz., treating grapes with combination of K2CO3 with ethyl oleate oil and olive oil, hot water treatment and no dipping along with three drying methods such as cabinet tray dryer, solar tunnel dryer and open sun drying on raison production and evaluate its drying time, sensory attributes, nutritive quality and microbial load using factorial CRD design. Pretreated, grapes were dried until the moisture level was reduced below 16 per cent. The results from interaction effects of pretreatments and drying methods indicate that raisins pretreated with ethyl oleate oil 1.5 per cent + K2CO3 3 per cent and dried in cabinet tray dryer took minimum drying time (26.08 h) with least non-enzymatic browning (0.049), highest carbohydrate (79.42 g 100 g-1), soft texture, (4.91 N) minimum titratable acidity (1.80%) and crud fiber (1.11 g 100 g-1) but sun dried raisins without dipping pretreatment took maximum drying time (169 h), highest NEB (0.836), lower level of carbohydrates (74.48 g 100 g-1) and hard texture (6.44 N). Grapes dipped in emulsion of ethyl oleate and olive oil along with potassium carbonate and dried in cabinet tray dryer had uniform and superior light green color and recorded highest sensory score, while, raisins prepared by same pretreatment showed golden brown color under solar tunnel dryer and dark brown appearance under open sun drying. Microbial safety conditions of prepared raisin were as per the codex standards in all condition of drying and pretreatments.EnglishThesis