Liquid Chromatographic Determination of α-Solasonine in Frozen Green Peas as an Indicator of the Presence of Nightshade Berries

Abstract

Nightshade berries containing glycoalkaloids can be a contaminant in green peas. Methodology was developed to detect this contamination. The glycoalkaloid α-solasonine was extracted from frozen green peas with 1% (v/v) acetic acid, cleaned up on a C18 cartridge, and determined by liquid chromatography with UV detection at 200 nm. Method performance characteristics for the determination of α-solasonine include linearity from 140 to 1500 ng injected (r = 0.9996–0.9999); recovery ranging from 68 to 79%; limit of quantitation (LOQ) = 4.5 ppm (280 ng standard), and limit of detection = 0.64 ppm (40 ng standard). At the LOQ, the expanded uncertainty at 95% confidence was 0.38 × the reported value. The method was applied to the detection of α-solasonine in frozen green peas in a 2-year study of 60 samples of frozen green peas from Ontario, Canada. None of the samples contained α-solasonine. No unripe berries of Solanum nigrum were detected visually in the samples.

Risk assessment of glycoalkaloids in feed and food, in particular in potatoes and potato‐derived products

“…The potential of S. nigrum and the related species S. ptycanthum Dun (eastern black nightshade) to contaminate food crops, such as beans, peas and soybeans, is a problem noted by several authors (Eldridge and Hockridge, 1983;Ogg et al, 1981;Ogg and Rogers, 1989). Cavlovic et al (2003) reported unripe berries of S. nigrum to contain 1,100 mg/kg fw a-solasonine and 900 mg/kg fw a-solamargine. In a follow-up of the RASFF notification 2013.0804, six samples of S. nigrum green berries were analysed by LC-MS/MS (P. Mulder, 2019, personal communication).…”