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The effects of different dipping pretreatments on microwave drying of grapes was studied in a multimode cavity. Grapes pretreated with 2% ethyl oleate in 0.5 % sodium hydroxide (NaOH) solution resulted in comparatively good quality raisins with lowest drying times. Pretreatment with 3% ethyl oleate in 0.5% NaOH solution led to similar product without any major advantage over the former. Grapes treated with 3% ethyl oleate in 2.5% potassium carbonate solution took longer time to dry. Grapes treated with only NaOH solution resulted in raisins of inferior quality in terms of color and appearance. The intelphase mass transfer coeficients also described the effect of these chemical pretreatments. Studies conducted on the effect of washing and time of holding afrer the pretreatment indicated that both of these factors had no influence on drying time. potential of dielectric heating with microwaves (MW) for drying of grapes has been reported (Tulasidas et al. 1993). Several pretreatments have been developed to reduce the drying time of grapes and to enhance the quality of raisins in terms of color and appearance. In most of the pretreatment methods, the fruits are first fumigated with sulphur dioxide to attain a concentration of

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In a 2-year study (1993-94), tomato (Lycopersicon esculentum Mill. `New Yorker') plants grown in a sandy loam soil in field lysimeters were subjected to four water table depth (WTD) treatments (0.3, 0.6, 0.8, and 1.0 m from the soil surface). In 1994, precipitation during the flowering stage was far above average and apparently led to waterlogging in the shallowest WTD treatment, while in the drier year (1993), the deepest WTD treatment suffered from drought stress. In general, over the 2 years, the 0.6-m WTD showed the best yields and largest fruit, while the 1.0-m WTD showed the lowest yields and smallest fruit. However, the incidence of catfacing, cracking, and sunscald was generally higher in the 0.6 m WTD treatment and lower in the 1.0-m WTD treatment. Furthermore, fruit firmness was generally greatest for the two deeper WTD than for the shallower WTD. To strike a balance between yield and quality, a WTD of between 0.6- and 0.8-m is recommended for tomato production on sandy loam soils.

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