*3.2. Identification of Flavonols by HPLC*/*MS*

The WBB powder used to prepare the products contained at least 12 flavonols (Table 2), which were identified by comparing their mass-to-charge (*m*/*z*) values and elution orders with previous studies [9,32]. The WBB powder contained one syringetin derivative, three myricetin derivatives, and eight quercetin derivatives. We were unable to identify peak 8, which appeared to be a quercetin derivative based on its aglycone *m*/*z* of 300, but the molecular ion *m*/*z* of 623 was ambiguous.


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**Table 2.** Peak assignments, retention times (RT in min), and mass spectral data of flavonols in extract from WBB powder.

#### *3.3. Stability of Anthocyanins in Blueberry Products during Storage*

#### 3.3.1. Ice Pop

The total anthocyanin content of the ice pop over eight weeks of storage at −20 ◦C is shown in Figure 1. The total amount of anthocyanins significantly decreased with storage time (*p* = 0.0056), but the percent retention remained high with 93% of total anthocyanins retained in the product after eight weeks. Consistent with our results, total anthocyanin content of frozen blueberries was stable over three months of storage at −20 ◦C [35]. Changes in major individual anthocyanins in the ice pop over eight weeks of storage at −20 ◦C are shown in Figure S1. Most of the individual anthocyanins did not significantly decrease over storage. For the anthocyanins that decreased during storage, their percent retention after eight weeks remained over 87%: malvidin-3-glucoside (87.3%), malvidin-3-galactoside (94.5%), cyanidin-3-galactoside (91.2%), malvidin-3-(6 ′′ -acetyl) glucoside (91.1%), petunidin-3-glucoside (91.4%). − − − (6"

**Figure 1.** Stability of total anthocyanins and chlorogenic acid in ice pop stored at − −20 ◦C (*n* = 3/time point). Shaded area around lines represents 95% confidence intervals for predicted values.
