Mdziniso Phumzile, Hinds Margaret J, Bellmer Danielle D, Brown Barbara, Payton Mark E
Ministry of Agriculture and Co-operatives, Mbabane, Swaziland.
Plant Foods Hum Nutr. 2006 Mar;61(1):13-21. doi: 10.1007/s11130-006-0003-y.
The effects of vegetable type, vegetable dimensions, and solar drier load on dehydration rate; and texture, color, water activity, and carotene content of solar-dried carrots, sweet potatoes, and collard greens were studied. Mean dehydration rates (moisture loss,%/hr) for solar dried loads of 430 g/m2 and 715 g/m2 were 3.3 +/- 0.30% and 3.8 +/- 0.20% for carrots and sweet potatoes, respectively. Loads of 360 g/m2 and 465 g/m2 of collard greens had dehydration rates of 6.3 +/- 0.10% moisture loss per hr. The results showed that vegetable type accounted for significant differences (p < 0.01) in dehydration rate, and beta-carotene content. Vegetable dimensions affected (p < 0.05) water activity. Solar drier load affected water activity (p < 0.01), and hue angle (p < 0.05). Beta-carotene contents (dry basis) of dehydrated carrot, sweet potato, and collard treatments were 10.9-17.4%, 7.6-9.8%, and 11.9-21.5%, respectively. Among the carrot treatments, the 5-mm thick slices packed at a load of 715 g/m2 contained the highest beta-carotene (17.4%, dry basis) and vitamin A activity (362 IU/g, dry basis), and good physical properties. For collard greens, the 2-cm and 3-cm wide strips packed at 360 g/m2 loads had the best combinations of high beta-carotene (21.5% and 17.2%, dry basis, respectively), vitamin A activity (357.2 and 293.1 IU/g, dry basis, respectively), and optimal color, texture, and water activity. Beta-carotene losses due to solar dehydration were 48.9-67.5%, 4.0-5.8%, and 1.9-19.8% (dry basis) in carrots, sweet potato and collard greens, respectively.
研究了蔬菜类型、蔬菜尺寸和太阳能干燥机负载对脱水速率的影响；以及太阳能干燥胡萝卜、红薯和羽衣甘蓝的质地、颜色、水分活度和胡萝卜素含量。对于430 g/m²和715 g/m²的太阳能干燥负载，胡萝卜和红薯的平均脱水速率（水分损失，%/小时）分别为3.3±0.30%和3.8±0.20%。360 g/m²和465 g/m²的羽衣甘蓝负载每小时的脱水速率为6.3±0.10%的水分损失。结果表明，蔬菜类型在脱水速率和β-胡萝卜素含量上存在显著差异（p<0.01）。蔬菜尺寸影响（p<0.05）水分活度。太阳能干燥机负载影响水分活度（p<0.01）和色相角（p<0.05）。脱水胡萝卜、红薯和羽衣甘蓝处理的β-胡萝卜素含量（干基）分别为10.9 - 17.4%、7.6 - 9.8%和11.9 - 21.5%。在胡萝卜处理中，以715 g/m²负载包装的5毫米厚切片含有最高的β-胡萝卜素（17.4%，干基）和维生素A活性（362 IU/g，干基），并且具有良好的物理性质。对于羽衣甘蓝，以360 g/m²负载包装的2厘米和3厘米宽条带具有高β-胡萝卜素（分别为21.5%和17.2%，干基）、维生素A活性（分别为357.2和293.1 IU/g，干基）以及最佳颜色、质地和水分活度的最佳组合。胡萝卜、红薯和羽衣甘蓝因太阳能脱水导致的β-胡萝卜素损失分别为48.9 - 67.5%、4.0 - 5.8%和1.9 - 19.8%（干基）。
