Potato Tuber Chemical Properties in Storage as Affected by Cultivar and Nitrogen Rate: Implications for Acrylamide Formation

• Published in: Foods
• Main Authors: Na Sun, Yi Wang, Sanjay K. Gupta, Carl J. Rosen
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Subjects: reducing sugars; glucose; asparagine; acrylamide; potato; cultivar; storage time
• Online Access: https://www.mdpi.com/2304-8158/9/3/352

Recently released potato cultivars Dakota Russet and Easton were bred for low reducing sugars, and low acrylamide-forming potential in French fries. The objectives of this study were to determine: (1) the effects of nitrogen rate and storage time on tuber glucose concentrations in different cultivars; (2) the relationships between acrylamide, glucose, and asparagine for the new cultivars and Russet Burbank. The study was conducted at Becker, Minnesota over a period of two years on a loamy sand soil under irrigated conditions. All cultivars were subjected to five N rates from 135 to 404 kg ha^&#8722;1 in a randomized complete block design. Following harvest, tubers were stored at 7.8 &#176;C and sampled at 0, 16, and 32 weeks. Dakota Russet and Easton had significantly lower concentrations of stem- and bud-end glucose, asparagine, and acrylamide than those of Russet Burbank in both years. The effect of storage time on glucose concentration was significant but differed with cultivar and year. N rate effects on stem- and bud-end glucose concentrations were cultivar and storage time dependent. After 16 weeks of storage, both asparagine and acrylamide concentrations linearly increased with increasing N rate. Glucose concentration was positively correlated with acrylamide concentration (<i>r</i>² = 0.61). Asparagine concentration was also positively correlated with acrylamide concentration (<i>r</i>² = 0.45) when the asparagine:glucose ratio was &lt;1.306. The correlation between fry color and stem-end glucose concentration was significant over three cultivars in both years, but stronger in a growing season with minimal environmental stress. Taken together, these results suggest that while acrylamide formation during potato processing is a complex process affected by agronomic practices, environmental conditions during the growing season, and storage conditions, cultivar selection may be the most reliable method to minimize acrylamide in fried products.