SPDS Set 1 ERP Book

ANTH-001

Question

Response

General

AOAC Method Number:

ANTH-001

Determination of Anthocyanins in Brazilian and Floridian Açaí (Euterpe oleraceae Mart) Using LC-MS/MS

Method Title:

Method Author(s):

Tran et al.

Reviewer Name:

Jungmin Lee

Summary of Method

Describes quantitative Acai anthocyanin analysis.

Method Scope / Applicability:

Could be relevant to Acai anthocyanin analysis.

General Comments About the Method:

Authors did not demonstrate that their method is capable of separating Vaccinium fruit anthocyanins. Protocol is too ambiguous. Authors used term ‘anthocyanidins’ incorrectly. Mass to charge ratios for the 2 anthocyanins are incorrect in Figures 2 and 3 (Mother ions > daughter ions of cyanidin-glucoside- 449 > 287 and cyanidin- rutinoside, 595 > 449 > 287). There are inaccuracies with their peak identifications. Cyanidin-glucoside typically elutes before cyanidin-rutinoside under similar HPLC conditions, in addition to the mix up in anthocyanin m/z (mass to charge) results and labeling in both Figs 2 and 3. Euterpe oleracea contains cyanidin-sambubioside (581 > 287), cyanidin- glucoside (449 > 287), cyanidin-rutinoside (595 > 449 > 287), and peonidin-rutinoside (609>301) (in the order of HPLC elution; Schauss et al. 2006 JAFC 54:8598-8603; slightly different in minor peaks according to Heinrich et al. 2011. Phytochem 4:10-21). Cyanidin-rutinoside will elute after cyanidin-glucoside (in opposite order to what authors report here). Again, authors did not identify acai anthocyanins correctly. Could have ability to qualitatively and quantitatively analyze 2 anthocyanins, but incorrect cyanidin-glucoside and cyanidin-rutinoside identification is highly suspect. Method must prove that the peaks of a complex anthocyanin mixture can be sufficiently separated.

Method Clarity

Pros/Strengths

Cons/Weaknesses