“The objective of the study was to determine the ascorbic acid, thiamin, riboflavin, and vitamin B6 content in a wide range of edible tissues of ‘Beauregard’ and ‘LA 07-146’ sweet potatoes, two important commercial cultivars in Louisiana,” Wilmer Barrera and David Picha from Louisiana State University Agricultural Center said.
The scientists analyzed a variety of sweet potato tissue types (mature leaves, young leaves, young petioles, buds, vine sections, and root tissue) and conducted another experiment to study water-soluble vitamin content among different sweet potato root tissues.
The research findings showed differences in total ascorbic acid (AA) and Riboflavin content among different sweet potato tissue types. Young leaves contained the highest AA content, followed by mature leaves and buds. Buds also contained significantly higher AA content than sweet potato roots, vines, and petiole tissues. Leaf tissue contained higher total vitamin B6 content compared with other tissues. Mature leaves contained 3.4 times higher vitamin B6 than roots, whereas mature petioles contained 2.3 times more than roots. Bud tissue and young leaves also contained higher B6 levels than roots, whereas the vine and young petiole tissue contents were lower than roots.
Barrera and Picha ultimately determined that ascorbic acid, riboflavin, and vitamin B6 contents were higher in leaf tissue than in other tissue types. The vitamin B6 content in the sweet potato leaves compared to fruits and vegetables such as broccoli, avocados, carrots, bananas, and cauliflower.
Wilmer A. Barrera, David H. Picha. Ascorbic Acid, Thiamin, Riboflavin, and Vitamin B6 Contents Vary between Sweetpotato Tissue Types. HortScience, November 2014