Identification of Functional Groups and Types of Anthocyanin Pigments of Purple Sweet Potato cv. Antin 2 and cv. Antin 3

¹ Department of Agricultural Industrial Technology, Malang of Agricultural Institute, Jl. Soekarno-Hatta, Malang 65141, East Java, Indonesia
² Department of Food Science and Technology, University of Muhammadiyah Malang, Jl. Raya Tlogomas No 246, Malang 65144, East Java, Indonesia
³ Department of Animal Science, University of Muhammadiyah Malang, Jl. Raya Tlogomas No 246, Malang 65144, East Java, Indonesia
⁴ Faculty of Agriculture and Forestry, University of Tay Nguyen, 567 Le Duan Street, Buon Ma Thuot City, Daklak Province, Vietnam

^* Corresponding author: farida.siti0705@gmail.com

Abstract

Purple sweet potatoes (Ipomoea batatas L. Lam.) contain anthocyanin pigments which act as natural antioxidants which are very beneficial for health. The research aimed to identify the functional groups and types of anthocyanin pigments in purple sweet potato cv. Antin 2 and cv. Antin 3, using FTIR and identification of anthocyanin pigment types using LCMS/MS. The results of FTIR analysis show that the purple sweet potato cultivar Antin 2 has 12 spectrum peaks ranging from wavelengths of 570.48 cm^-1 to 3 394.40 cm^-1. Functional groups detected include benzene nuclei, hydrocarbons (dominating), carbonyls, carboxyl esters, aromatics, aldehydes, and alcohols. Meanwhile, the purple sweet potato cultivar Antin 3 has 15 spectrum peaks ranging from wavelengths of 417.88 cm^-1 to 3 365.86 cm^-1. The functional groups detected include core-benzene hydrocarbons, carboxyl esters, methyl, aromatics, carbonyls, carbonyl esters, aldehydes, aldehyde carbons, and hydroxyl carbons. The LCMS/MS identification results of purple sweet potato anthocyanin pigments of the Antin 2 cultivar detected 11 types, including Cyanidin 3-(6“-caffeoyl sophoroside)-5-glucoside and Cyanidin 3-(6“-feruloyl sophoroside)-5-glucoside. In the purple sweet potato cultivar Antin 3, 14 types of anthocyanins were found, including, Malvidin 3-5 diglicoside, Cyanidin 3-(6“-caffeoyl sophoroside)-5-glucoside, Cyanidin, and Cyanidin 3-(6“feruloyl sophoroside)-5-glucoside.