ASHS 2015 Annual Conference

Acrylamide, a suspected human carcinogen, has been found in a series of processed food. Acrylamide is formed mostly between a reducing sugar glucose and a free amino acid asparagine during cooking at high temperature (>120 ºC). Potato products such as French fries and chips are one of the main dietary sources of acrylamide. In the past two years, both the FDA and its European counterpart have published information for industry and consumers to raise awareness about acrylamide in foods and to suggest strategies for reducing public exposure and improving food safety. The U.S. potato industry recognizes that the development of new varieties with low acrylamide-forming potential is one of the most critical approaches to mitigate the acrylamide issue. Consequently, a National Fry Processing Trial (NFPT), was started at Idaho, North Dakota, and Washington state in 2011, and expanded to Maine and Wisconsin in the following two years. During the three years of trial, more than 140 advanced breeding lines primarily from the major potato breeding programs in the country were assessed for their agronomic and biochemical properties during short-, intermediate-, and long-term storage. Dozens of breeding lines were identified with a more than two folds reduction in acrylamide compared to the standard check 'Russet Burbank' and 'Ranger Russet', both of which are commonly planted and processed commercial varieties. Of these, several stood out for also having high marketable yield, the industry desired size distribution and specific gravity for good processing quality. Similar to previously published reports, the glucose content in raw tubers of NFPT lines was highly predictive of acrylamide in finished fries all through the storage time (R² = 0.64 – 0.77), but asparagine was not a significant predictor of acrylamide, potentially due to its presence at an order of magnitude higher concentration than glucose in the raw tubers. Analysis of covariance has indicated that in addition to glucose, genotype was highly significant (P ≤ 0.001) for predicting acrylamide at early and late stage of storage, suggesting there are some unidentified genetic loci to target for future breeding. The NFPT has demonstrated that reducing acrylamide is an easy breeding objective to achieve, and the bigger challenge is to find new potato varieties with low-acrylamide-forming potential but also meets the complex processing quality standards set by the food industry. Phenotyping methods are being developed to efficiently assess effects of some raw tuber traits related to quality after processing.