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The hot air convective drying characteristics of blanched tomato (Lycopersicon esculantum L.) slices have been investigated. Drying experiments were carried out at four different temperatures (50, 60, 65 and 70 °C). The effect of drying temperatures on the drying behavior of the tomato slices was evaluated. All drying experiments had only falling rate period. The average effective diffusivity values varied from 0.5453 × 10(-9) to 2.3871 × 10(-9) m(2)/s over the temperature range studied and the activation energy was estimated to be 61.004 kJ/mol. In order to select a suitable form of the drying curve, six different thin layer drying models (Henderson-Pabis, Page, Diamante et al., Wang and Singh, Logarithmic and Newton models) were fitted to the experimental data. The goodness of fit tests indicated that the Logarithmic model gave the best fit to experimental results, which was closely followed by the Henderson-Pabis model. The influence of varied drying temperatures on quality attributes of the tomato slices viz. Hunter color parameters, ascorbic acid, lycopene, titratable acidity, total sugars, reducing sugars and sugar/acid ratio of dried slices was also studied. Slices dried at 50 and 60 °C had high amount of total sugars, lycopene, sugar/acid ratio, Hunter L- and a-values. Drying of slices at 50 °C revealed optimum retention of ascorbic acid, sugar/acid ratio and red hue, whereas, drying at higher temperature (65 and 70 °C) resulted in a considerable decrease in nutrients and colour quality of the slices.

An experiment was conducted on pear fruit (cv. 'Lagoon') to extend the shelf life by using different packaging materials. Fruits were packed in low density polyethylene (LDPE, 0.025 mm), polypropylene (PP, 0.025 mm), linear low density polyethylene (LLDPE, 0.0125 mm) and high density polyethylene (HDPE, 0.025 mm) with or without perforation and stored at ambient condition (25 ± 2 °C and 65.0 ± 5% RH). Periodical observations were recorded on CO2 & O2 concentration (%), physiological loss in weight (PLW, %), decay loss (%), firmness (kgf), colour value (colour difference and colour index), total soluble solid (TSS, °Brix), acidity (mg of malic acid/g), and ascorbic acid loss (%) at 3 days interval. Reduced rate of PLW and decay losses was recorded in pear fruits packed in PP non-perforated (8.04%) and PP perforated (12.5%), respectively as compared to other treatments. The maximum firmness (5.18 kgf) and minimum ascorbic acid loss (49.97%) were also recorded in PP non-perforated up to 12 and 15 days of storage, respectively. It could be inferred that the, PP non-perforated (0.025 mm) was the most suitable packaging materials for extending the shelf life of pear fruits up to 15 days at ambient condition.

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SummaryIntegration of vermicompost and organic mulch as elements of vegetable production system sustain soil fertility and crop productivity. A field experiment was conducted with the objective to investigate the effects of vermicompost, NPK fertilizer and organic mulch on crop growth, nodulation and pod yield of French bean (Phaseolus vulgaris L.) with an ultimate aim of optimizing water and nutrient requirement in mild-tropical climate during dry season. The shoot growth traits, namely shoot length, number of primary branches, shoot fresh weight and shoot dry weight were increased by 28-63% through application of N P 2 O 5 K 2 O 8:13:10 kg·ha -1 + vermicompost 3.75 t·ha -1 and by 5-50% in organic mulching treatments. Application of vermicompost reduced nodule fresh weight and nodule dry weight by 44.9 and 44.5%, respectively. Likewise, corresponding nodule number, nodule fresh weight and nodule dry weight were reduced by 8.6, 11.1 and 14.1% with organic mulching. Poor nodulations might be due to reduced oxygenation of the soils under vermicompost and organic mulch which is ultimately impeding the nitrogenase activity and biological nitrogen fixation. Mulching of French bean with dried grasses and crop residues are also led to higher single pod weight, pod length, pod weight/plant and pod yield by 10.9, 12.8, 20.1 and 20.2%, respectively. Present study shows that application of N P 2 O 5 K 2 O fertilizer 8-15:13-25:10-20 kg·ha -1 , vermicompost 2.50-3.75 t·ha -1 , 4 cm thick mulch of dried crop residues and 50% irrigation is the most suitable and sustainable strategy to improve plant growth, pod formation and pod yield of French bean, and soil health of mild-tropical climate during dry season.