Characterization of Anthocyanins and Anthocyanidins in Purple-Fleshed Sweetpotatoes by HPLC-DAD/ESI-MS/MS

Abstract

Purple-fleshed sweetpotatoes (PFSP) can be a healthy food choice for consumers and a potential source for natural food colorants. This study aimed to identify anthocyanins and anthocyanidins in PFSP, and to evaluate the effect of thermal processing on these polyphenolic compounds. Freeze-dried powder of raw and steamed samples of three PFSP varieties were extracted with acidified methanol using a Dionex ASE 200 accelerated solvent extractor. Seventeen anthocyanins were identified by HPLC-DAD/ESI-MS/MS for Stokes Purple and NC 415 varieties with five major compounds: cyanidin 3-caffeoylsophoroside-5-glucoside, peonidin 3-caffeoylsophoroside-5-glucoside, cyanidin 3-caffeoyl-p-hydroxybenzoylsophoroside-5-glucoside, peonidin 3-caffeoyl-p-hydroxybenzoyl-sophoroside-5-glucoside, and peonidin-caffeoyl-feruloylsophoroside-5-glucoside. Okinawa variety showed 12 pigments with 3 major peaks identified as cyanidin 3-caffeoylsophoroside-5-glucoside, cyanidin 3-(6'',6'''-dicaffeoylsophoroside)-5-glucoside and cyanidin 3-(6''-caffeoyl-6'''-feruloylsophoroside)-5-glucoside. Steam cooking had no significant effect on total anthocyanin content or the anthocyanin pigments. Cyanidin and peonidin, which were the major anthocyanidins in the acid hydrolyzed extracts, were well separated and quantified by HPLC with external standards. Cyanidin and peonidin, which contribute to the blue and red hues of PFSP, can be simply quantified by HPLC after acid hydrolysis of the anthocyanins.

Effect of drying conditions on properties, pigments and antioxidant activity retentions of pretreated orange and purple-fleshed sweet potato flours

“…The major anthocyanins from purple-fleshed sweet potatoes are found to be mono-or di-acylated derivatives of 3-(2-glucosyl) glucosyl-5-glucosyl peonidin and cyaniding (Yang and Gadi 2008;Oki et al 2002;Suda et al 2002). Truong et al (2010) also identified anthocyanins and anthocyanidins in various purple-fleshed sweet potato cultivars and found that cyanidin and peonidin were the major anthocyanidins in the acid hydrolyzed extracts. The anthocyanin content of flour samples was enhanced by drying processes.…”

“…It is intersting to note that total phenolic contents and antioxidant activity of purple sweet potato flours (Phichit 65-3) obtained from both drying processes were significantly (P < 0.05) higher than that of orange sweet potato flours (T101). It was reported that most anthocyanidins acted as strong antioxidants (Tokusoglu and Yildirim 2012) and the purple-fleshed sweet potatoes contained much higher total phenols than the orange-fleshed sweet potatoes (Truong et al 2010). For hot air drying, phenolic content and antioxidant activity of T101 and Phichit 65-3 were highest after drying at 70 C. For drum drying, flour produced at 95 C and 3 rpm drum speed had the highest phenolic content and antioxidant activity for both cultivars.…”

“…Drying processes increased the L * value of all purple-fleshed sweet potato flours. Truong et al (2010) reported that cyanidin and peonidin contribute to the blue and red hues of purple-fleshed sweet potatoes. Yang and Gadi (2008) also indicated that the change in color values of purple-fleshed sweet potato flour pretreatment with steaming before drying was due to the formation of polymeric anthocyanins and some non-enzymatic browning pigments.…”

Physiological, Morphological Changes and Storage Root Yield of Sweetpotato [Ipomoea batatas (L.) Lam.] under PEG-Induced Water Stress

“…Apart from carbohydrates, the storage roots are rich in proteins, β-carotene, anthocyanins, ascorbic acid, potassium and calcium (Truong et al, 2010;Mukhopadhyay et al, 2011;Mohanraj and Sivasankar, 2014;Motsa et al, 2015). The green leaves are rich in anthocyanins, polyphenolic acid and essential oils (Islam et al, 2002;Islam, 2006;Wang et al, 2010).…”

Characteristic of Analog Rice Using Hot Extruder Twin Screw

“…Hal ini disebabkan oleh adanya perbedaan bahan baku. Warna ungu pada ubi jalar sebagai bahan baku disebabkan oleh adanya zat warna alami yang disebut antosianin 25 dengan komponen antosianin ubi jalar ungu adalah turunan mono atau diasetil 3-(2-glikosil)-5-glukosil peonidin dan sianidin 26 . Sedangkan pada jagung, warna kuning atau oranye disebabkan karena kandungan lutein dan zeasantin yang merupakan pigmen karotenoid 27 .…”