Drying of plums to prunes is an important postharvest processing step, as it results in a product with higher nutrient density, increased shelf life, and significantly greater antioxidant and fiber content. However, due to the waxy layer present on the plums surface having low permeability toward moisture, plum dries very slowly which is an energy-demanding process. Therefore, to breakdown waxy layer on the surface and enhancement of skin moisture diffusivity, two genotypes (V91074 and V95141) of Yellow European Plums (YEPs) were dipped in 1% (w/ v) of Ascorbic Acid (AA), Citric Acid (CA), and Potassium Metabisulfite (KMS) solution for 1 min at 40°C. The pretreated YEPs were dried at three different temperatures (50°C, 60°C, and 70°C) until a final moisture content of approximately 30% (wet basis) was reached. It was observed that treated samples (AA and KMS) dried faster as compared to untreated samples, except for CA treatment where no significant difference in drying time was observed. One model cannot be selected for describing the thin layer drying characteristics of YEPs. Five out of 11 models used were found to be a perfect fit for genotype V91074 and genotype V95141, respectively. Pretreatment had a significant effect on effective moisture diffusivity (D eff ). D eff for untreated and treated plum samples ranged between 4.6 × 10 −11 to 8.6 × 10 −11 (m 2 /s) and 4.9 × 10 −11 to 9.1 × 10 −11 (m 2 /s). The drying temperature had a significant effect on phenolic content and antioxidant activity, whereas no significant effect of pretreatment was observed.

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Maize (Zea mays L.) cultivation during the winter is a new cropping practice in North India. In this cropping system, maize has slow seedling growth associated with low winter temperatures. If the crop can be grown in a nursery during this slow‐growth period and then transplanted, the crop duration in the main field is shortened. Therefore, the present study was conducted to determine if maize could be successfully transplanted to the field. Other objectives were to evaluate the effect of seedling age, and date and method of transplanting. Experiments were done in the field during two or three winter seasons at two locations. Among the transplanting treatments, 40‐d‐old seedlings transplanted on 24 December and 60‐d‐old seedlings on 16 January resulted in the highest grain yields. Grain yields from these transplantings were 92 to 94% (5314–5402 kg ha−1) of the yield of the crop direct seeded on 9 November (5743 kg ha−1), the optimum sowing time. Grain yield was significantly reduced when younger (up to 20 d) or older (up to 80 d) seedlings were used, with drastic reduction in the latter case. Transplanting of 60‐d‐old seedlings on 24 December and 80‐d‐old seedlings on 16 January yielded only 10 to 12% as compared with the best transplantings. Delayed transplanting (6 February) also decreased grain yield. The comparisons between methods, transplanting on the southern slope of the east‐west ridge or on a flat seed bed, showed that the former improved grain yield. The present study indicates that maize can be successfully produced by transplanting 40‐d‐old seedlings on 24 December and 60‐d‐old seedlings on 16 January, and that transplanting should preferably be done on the ridged seedbed.

Yellow European Plums (YEPs) are a rich source of phenolic compounds and antioxidants, which can be obtained using microwave‐assisted extraction (MAE). During this study, two MAE experiments were performed to optimize MAE extraction parameters and the MAE process using YEPs. The first experiment was to determine the influence of independent variables such as solvent concentration (20, 60, and 100 %) and solid‐to‐solvent ratio (0.05, 0.1, and 0.15 g/mL), on the yield of total phenolic content (TPC) and antioxidant activity (1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and ferric ion reducing antioxidant power (FRAP)), for ethanol and methanol, during MAE. Using a response surface methodology, the optimized extraction parameters for MAE were then found to be 60 % ethanol at a solid‐to‐solvent ratio of 0.1 g/mL. Using the optimized parameters from the first experiment, the second experiment evaluated the effect of microwave temperature (50, 60, 70 °C) and duration (5, 10, and 15 min) on TPC, DPPH, and FRAP, using a face‐centered central composite design. Individual phenolic compounds, including ascorbic acid, neochlorogenic acid, and chlorogenic acid, were quantified using high performance liquid chromatography. In the second experiment, it was observed that time and temperature had a significant (p ≤ 0.05) effect on the extraction of phenolic compounds from four genotypes of YEPs. However, due to their diverse phenolic composition, there was not one optimal operating time and temperature suitable for all genotypes.

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