Levels of glycoalkaloids in potato crisps and French fries sold in Nairobi, Kenya

Glycoalkaloids are natural secondary metabolites occurring in potatoes (Solanum tuberosum L.) and are stable, remaining unaffected during processing ending up in the final products. Despite the increasing consumption of potato and potato products, safety concerns as a result of glycoalkaloids toxicity have not been determined in Kenya. This study aimed at determining the α-solanine and α-chaconine contents in crisps and French fries sold within Nairobi County in Kenya in order to quantify their total glycoalkaloids (GAs). Crisps were bought from supermarkets and local vendors while French fries were obtained from low, middle and high end outlets. Glycoalkaloids were extracted and quantification done by high pressure liquid chromatography. The GAs ranged from 19.62 to 128.12 mg kg-1 dry weight (d.w) and averaged 56.29 mg kg-1 d.w for crisps. The GAs levels for branded and unbranded crisps were not significantly different (p>0.05). GAs levels in the French fries from street, middle and high end outlets were not significantly different (p>0.05) with means for samples being 19.16, 21.40, 19.48 mg kg-1 d.w, respectively. The α-chaconine and α-solanine levels had positive correlations - Pearson’s coefficient (r) of 0.946 (p<0.0001) for crisps and 0.944 (p<0.001) for fries. None of the samples exceeded the recommended limit of 1000 mg/kg d.w and therefore consumption of fries and crisps was safe. However, there is need for processors and consumer awareness of post-harvest handling practices for potatoes since these contribute to accumulation of high levels of GAs that contaminate the end products.