Acidification of Strawberry Puree Affects Color and Volatile Characteristics during Storage

Abstract

Color degradation of strawberry-based products negatively affects consumer acceptance of these products. To improve the color stability of strawberry puree during storage, an acidification step (pH 1.5 and 2.5) prior to pasteurization was performed and quality changes of strawberry puree during storage (35 °C, 40 days) were monitored. Acidification prior to pasteurization resulted in an improved color and anthocyanin stability. However, the volatile fraction of strawberry puree was negatively influenced by acidification of the puree. Low acidic conditions (pH 1.5) resulted in the hydrolysis of esters, oxidation of terpene oxides, and acid-catalyzed reactions of terpene alcohols during storage. The volatile fraction of strawberry puree stored at pH 2.5 and 3.5 (the latter being the original strawberry puree) were more similar. Furthermore, after 4 days of storage, the pH of the acidified purees was brought back to the natural pH of the system (3.5) and subsequently thermally treated and stored. During this second storage, color showed a slightly faster degradation rate in those purees that were previously acidified, whereas anthocyanins exhibited similar trends suggesting that the advantage of acidification to preserve color would be beneficial after thermal processing, but more limited during storage of the regenerated product (second storage).

LDPE/M‐TiO2 composite films for modified atmosphere packaging to realize comprehensive preservation of strawberry (Fragaria × ananassa Duch.)

“…However, it is worth noting that the process of change and the magnitude of the value are equally important for titratable acids. The chaotic fluctuation means that the respiration of microorganisms produces new acidic substances, which does not contribute to the taste of strawberries but can harm the human body 40 . M‐TiO 2 can stabilize the changes in strawberries in the package and delay the overall corruption.…”