Glycoalkaloids in potato

One of the most consumed vegetable crops in the world is the potato (Solanum tuberosum L.). Due to the potato’s high nutritional value, its quality is very important. Potato consumers are potentially endangered by toxic compounds contained in the tubers called glycoalkaloids (commonly known as total glycoalkaloids or TGA for short). The presence of glycoalkaloids in potato, stems and leaves is thought to help protect the plant from insect attacks and bacterial and fungal diseases.

These compounds are accumulated in the potato during growth, harvest and storage. Glycoalkaloids are distributed throughout the potato plant, but the highest concentrations are found in the leaves, stems, sprouts, flowers and under the skin of potato tubers.

The acceptable concentration level of glycoalkaloids in fresh potato tubers should not be greater than 200 mg / kg fresh weight. Consumption of potatoes with excessive content of glycoalkaloids can be dangerous to human health. TGA poisoning can have a toxic effect on the nervous system and cause digestive problems, diarrhea, vomiting. Therefore, in potato cultivation, special attention is now paid to the selection of suitable varieties with a genetically determined low content of glycoalkaloids in tubers, preferably below 50 mg / kg of fresh tuber weight.

glycoalkaloids in potato

Currently, few research results and scientific publications are available on the effect of plant protection products and biostimulants on the accumulation of glycoalkaloids in potato tubers and leaves. Therefore, the aim of my research was to determine the content of glycoalkaloids in potato tubers and leaves grown with herbicides and biostimulants.

Let us briefly explain what plant biostimulators are. Well, modern agriculture, in addition to pesticides, also uses a number of substances that stimulate life processes and increase the resistance of plants to stress conditions. These biostimulants are friendly to the environment and consumer health.

In the experiment conducted in 2012-21014, the three edible potato cultivars studied differed in the content of glycoalkaloids in leaves and tubers. The level of TGA did not exceed 200 mg / kg fresh weight of tubers, so the three tested potato varieties are safe for human consumption. The glycoalkaloid content in potato tubers ranged from 90.38 to 93.76 mg / kg fresh potato tubers, and the glycoalkaloid concentration in leaves ranged from 276.80 to 279.60 mg / kg. Thus, the content of glycoalkaloids in potato leaves was three times higher compared to potato tubers.

The level of glycoalkaloids in potato leaves and tubers was significantly affected by the applied cultivar, herbicides and biostimulants. The content of this component was also affected by weather conditions during the growing season and by the applied cultivation methods. Herbicides themselves contributed to an increase in the content of glycoalkaloids both in potato tubers and leaves. And when herbicides were applied in combination with biostimulants, TGA content decreased slightly. The glycoalkaloid content in potato leaves was slightly lower in units where herbicide and biostimulant combinations were applied compared to units treated with herbicides alone.

To avoid toxic levels of glycoalkaloids, it is very important to select an appropriate potato variety. Improper post-harvest handling conditions are a major cause of excessively high levels of these toxic chemicals in potatoes. To keep the glycoalkaloid content low, store potatoes at lower temperatures, keep potatoes away from light, sell them in opaque films and paper bags.

These findings are described in the article entitled The effect of biostimulants and herbicides on glycoalkaloid accumulation in potato, published in the journal Plant, Soil and Environment and an unpublished doctoral dissertation [link to abstract]: Dołęga H., 2015: The influence of plant growth regulators and herbicides on quality of potato tubers. University of Natural Sciences and Humanities, Siedlce
Translation was done with the assistance of DeepL translator.