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ARS Home » Southeast Area » Raleigh, North Carolina » Food Science Research » Research » Publications at this Location » Publication #368219

Research Project: Improved Processes for the Preservation and Utilization of Vegetables, Including Cucumber, Sweetpotato, Cabbage, and Peppers to Produce Safe, High Quality Products with Reduced Energy Use and Waste

Location: Food Science Research

Title: Determination of free amino acids in five commercial sweetpotato cultivars by hydrophilic interaction liquid chromatography-mass spectrometry

Author
item QIU, XIAO - North Carolina State University
item Reynolds, Rong
item Johanningsmeier, Suzanne
item TRUONG, VAN-DEN - Retired ARS Employee

Submitted to: Journal of Food Composition and Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/7/2020
Publication Date: 9/1/2020
Citation: Qiu, X., Reynolds, R., Johanningsmeier, S.D., Truong, V. 2020. Determination of free amino acids in five commercial sweetpotato cultivars by hydrophilic interaction liquid chromatography-mass spectrometry. Journal of Food Composition and Analysis. 92:103522. https://doi.org/10.1016/j.jfca.2020.103522.
DOI: https://doi.org/10.1016/j.jfca.2020.103522

Interpretive Summary: A new method for the determination of free amino acid profiles in sweetpotatoes was developed and validated. This method was used to determine the free amino acid composition of five commercial sweetpotato cultivars. Asparagine was the most abundant free amino acid and content varied significantly among the cultivars. Fifteen other amino acids also varied among cultivars and contributed to the differentiation of the varieties based on their complete amino acid profiles. The method described herein is efficient, reliable, sensitive, and could be used for profiling free amino acid content to develop high-value sweetpotato varieties.

Technical Abstract: A sensitive and rapid method was developed for the determination of free amino acid profiles in sweetpotatoes. The method utilized an ultra-high-performance liquid chromatography system with hydrophilic interaction liquid chromatography (HILIC) separation coupled with tandem mass-spectrometry (MS/MS) detection without the need for chemical derivatization. Separation of 36 amino acid standards was achieved on a silica HILIC column in a single MS/MS run of 19 min. This validated method was applied for the analysis of the free amino acid composition of five commercial sweetpotato cultivars (Covington, Beauregard, Hatteras, Murasaki-29 and O’ Henry) from two planting lots grown in experimental fields. Analysis of variance with Tukey’s test was used to determine the differences in individual free amino acid content among the analyzed samples, and principle component analysis (PCA) was implemented to evaluate the variation in amino acid profiles of different sweetpotato cultivars. Asparagine was the most abundant free amino acid and its content varied significantly among the cultivars (p < 0.05). Fifteen additional amino acids also varied among cultivars and contributed to the differentiation of the genotypes by PCA based on their complete amino acid profiles. The efficient, reliable, sensitive method described herein could be used in quantifying amino acids in food matrices similar to sweetpotatoes.