Physical quality and carotene content of solar-dried green leafy and yellow succulent vegetables

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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antioxidants / analysis*
  • Brassica / chemistry
  • Carotenoids / analysis*
  • Color
  • Daucus carota / chemistry
  • Food Analysis
  • Food Handling / methods*
  • Ipomoea batatas / chemistry
  • Vegetables / chemistry*
  • Vitamin A / analysis*
  • Water / metabolism
  • beta Carotene / analysis


  • Antioxidants
  • beta Carotene
  • Water
  • Vitamin A
  • Carotenoids