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Volatile Compounds in Five Starches¹

¹Cooperative Investigations, USDA-ARS, Grain Marketing and Production Research Center, and Department of Grain Science and Industry, Kansas State University. Contribution No. 99-140-J. Kansas Agricultural Experiment Station, Manhattan, KS 66506. Mention of firm names or trade products does not constitute endorsement by the USDA over others not mentioned. ²Graduate student and professors, respectively. Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506. ³Supervisory research chemist, USDA-ARS, Grain Marketing and Production Research Center, Manhattan, KS 66502. Corresponding author. Phone: 785/776-2703. Fax: 785/776-2792. E-mail: okchung@usgmrl.ksu.edu ⁴Research chemist, USDA-ARS, Grain Marketing and Production Research Center, Manhattan, KS 66502.

Volatile compounds in commercial wheat, corn, potato, waxy corn, and tapioca starches and in laboratory-prepared wheat, corn, and potato starches were collected, separated, and identified by a purge and trap concentrator (P&T) interfaced to a gas chromatograph (GC) equipped with a Fourier transform infrared detector (FTIRD) and a mass selective detector (MSD). Hexanal was the most abundant compound in the corn and potato starches and in the laboratory-prepared wheat starch as determined by total ion chromatogram (TIC) peak areas. Hexanal was the third most abundant compound in commercial wheat starch after 2-ethyl-1-hexanol and benzaldehyde. Among the volatile organics, the level of aldehydes was the highest, followed by alcohols, ketones, benzenes, esters, and terpenes. Specific compounds identified, the majority of which appear to be degradation products of lipid peroxidation, include hexanal, heptanal, octanal, nonanal, decanal, benzaldehyde, 2-propanone, 2-propanol, 1-butanol, 2-ethyl-1-hexanol, methylbenzene, and tetradecane. Waxy corn starch, which released a substantially higher level of total volatiles than all other starches, contained large amounts of pentyl, 2-methyl-1-butyl, benzyl, and isobornyl acetates; and citronella and 1,8-cineole. Tapioca starch contained few volatiles but did contain an increased level of 2-propanol. No alcohols occurred in the commercial corn starch. Terpene compounds were detected only in commercial potato, waxy corn, and tapioca starches. Many volatiles detected in wheat and corn starches also were detected in the kernels of their commercial samples.