Potato glycoalkaloids: formation and strategies for mitigation

Abstract

With the increasing production and consumption of potato and its products, glycoalkaloid (GA) formation and toxicity are likely to become an important focus for food safety researchers and public health agencies. Not only the presence of GA, particularly in the form of α-solanine and α-chaconine, but also the changes occurring as a result of various post-harvest handling practices and storage, are critical issues influencing the quality of stored potatoes. Studies on various factors (pre-harvest, during harvest and post-harvest) affecting GA have been carried out from time to time, but it is difficult to compare the results of one study with another due to wide variation in the parameters chosen. This review aims to develop a clear understanding of these issues. Published information on the types of GA, their effects on health, their typical concentrations in potatoes, their formation mechanisms, and how their levels can be controlled by following appropriate post harvest practices and storage regimes are critically analysed. The levels of GA in potato can be controlled effectively by adopting appropriate post-harvest practices. Further studies are necessary, however, to investigate best practices, which either check completely or retard substantially their formation.

The influence of French fries processing on the glycoalkaloid content in coloured-fleshed potatoes

“…to 24.45 mg 100 g −1 f.w. nema et al [23] reported that Tga content in frozen peels of different edible varieties ranged from 6.5 to 12.1 mg 100 g −1 f.w. Many authors, Friedman and Dao [6], Wünsch and Munzert [39], Friedman [5], and Friedman and levin [7], reported that most Tga in the tuber are accumulated in the peel, especially in the area of eyes, whereas the distribution of Tga in a tuber differs among varieties.…”

“…The ratio of α-solanine to α-chaconine varies between varieties, although α-chaconine usually occurs in distinctly higher concentration than α-solanine [6,8,16,23,30,37]. The scientific literature most frequently has provided data on the ratio of α-solanine to α-chaconine in lightfleshed varieties.…”

“…The lethal dose of these components is 3-5 mg kg −1 body weight, with an effect similar to strychnine or arsenic [9,12]. The toxicity of Tga is associated with the synergistic interaction between two main components of Tga: α-solanine and α-chaconine [8,16,19,23].…”

“…glycoalkaloids occur both in potato tubers of traditional, light-flesh [5,8,19,23] and in coloured-fleshed potatoes [7,10,38]. Both α-solanine and α-chaconine are triglycosylated derivatives of the same aglycone and solanidine but differ in the carbohydrate moiety [8,35].…”

“…In potatoes, α-solanine constitutes about 40 % of Tga and α-chaconine 60 %, which is more toxic than α-solanine, and hence, the ratio of these compounds is important [8,9,20]. The ratio of α-solanine to α-chaconine and total Tga content depend on the anatomical part of the potato plant and its variety [5,8,20,23,26].…”