Studies on dehydration of purslane traditional leafy vegetable
VS Gholane, PP Salunke, PM Kotecha, UD Chavan
The objective of this research work was to develop a technology for dehydration of purslane traditional leafy vegetable and to study the changes in chemical composition and sensory properties of dehydrated vegetable during storage packed in low density polyethylene and aluminium foil bag. Preliminary studies were carried out with pretreatment as blanching with chemicals and plain water to standardize the time and temperature for dehydtration. Amaranth vegetable blanched and dehydrated with this treatment T2= KMS (0.02%) + MgO (1.5 g) + citric acid (1%) + NaHCO3 (1.5%) + NaCl(1.5%) for 30 seconds in warm water at 45ºC and cooling immediately in tap water applied prior to dehydration in cabinet drier (45°C).Were found to be better than other combinations in respect to organoleptic properties and nutritional quality. The dehydrated purslane vegetable was packed in low density polyethylene and aluminium foil bag and stored at ambient (30 ± 2 0C) for 180 days. The stored samples were drawn periodically at 30 days interval for organoleptic and chemical analysis. The chemical composition indicated that the fresh purslane vegetable contained on an average moisture 88.07 percent, ash 2.41 percent, protein 12.55 percent, crude fibre 3.95 mg/100g, iron 23.95 mg/100g, calcium 219.02 mg/100g, β-carotene 2.83 mg/100g, ascorbic acid 22.48 mg/100 g and chlorophyll 94.20 mg/100g. The mean score of fresh purslane vegetable for colour and appearance was 8.46, flavour 8.43, taste 8.34 and overall acceptability 8.36 on 9-point hedonic scale. While dehydrated purslane vegetable contains moisture 6.58 percent, ash 2.18 percent, protein 12.18 percent, crude fibre 3.87 mg/100g, iron 22.51 mg/100g, calcium 208.01 mg/100g, β-carotene 2.63 mg/100g, ascorbic acid 21.15 mg/100g chlorophyll 89.80 mg/100g, dehydration ratio 10.21 percent and rehydration ratio 4.28. The cost of dehydrated purslane vegetable for best combination was Rs. 602.69 per kg for various combinations of ingredients. The storage study indicated that the moisture, ash and dehydration ratio increased in storage period, while ascorbic acid, calcium, iron, crude fibre, chlorophyll, rehydration ratio and β-carotene decreased. The rates of increase or decrease were relatively higher in low density polyethylene bag than aluminium foil bag as packaging material.