Diverging fates of cadmium and glyphosate during pasta cooking

Abstract

Durum wheat cultivars with varying abilities to accumulate cadmium were grown and treated in the field with a glyphosate-containing herbicide at different stages of maturity to produce grain with higher and lower concentrations of cadmium (0.066–0.214 mg/kg) and glyphosate (0.474–0.874 mg/kg). The grain was milled, and fractions were analysed for cadmium and glyphosate. The highest concentrations for both cadmium and glyphosate were associated with bran and shorts, although the percentage of total cadmium mass in bran (23–25%) was less than glyphosate (38%). The preparation of dried pasta from semolina and flour milling fractions reduced concentrations by a factor of 1.8 for glyphosate and 1.4 for cadmium. Dried pasta was cooked and analysed along with the cooking water for cadmium and glyphosate at seven-time points from 0 to 15 min. Concentrations of glyphosate in cooked pasta decreased significantly with cooking time; no decrease was observed for cadmium concentrations. Analysis of cooking water demonstrated that glyphosate migrated from pasta to the cooking water. After 15 min of cooking, approximately 73% of the total glyphosate mass had transferred from pasta to cooking water. Over the same time period, only 5% of the total cadmium mass had transferred from pasta to cooking water.

Keywords:

• Spaghetti
• cooking
• pesticide residues
• heavy metal
• contaminant
• processing

Acknowledgment

Dave Turnock performed the milling, and Michael Bestvater assisted with the preparation of samples for analysis.

Credit authorship contribution statement

Sheryl A. Tittlemier: conceptualization, project administration, methodology, supervision (chemical analyses), formal analysis, writing – original draft. Lianna Bestvater: investigation, writing – review & editing. Jason Chan: investigation. Valentina Timofeiev: investigation. Anja Richter: supervision, validation, writing – review & editing. Kun Wang: investigation, methodology, writing – review & editing. Marta Izydorczyk: supervision (milling). Yuefeng Ruan – resources (durum production), supervision (durum production), methodology (field trialling with herbicide application), writing – review & editing. Bin Xiao Fu: conceptualization, project administration, supervision (pasta production, cooking), methodology, writing – review & editing.