Fig. 2.

Remaining III/II% index from beads subjected to four cycles of freezing and thawing (− 196/25 °C) (left) and continuous freezing with 1 month at − 18 °C (right). The index III/II% is obtained from the percentage ratio of absorbance values of peak III (503 nm) and peak II (472 nm), being standardized by the indices of the respective initial time (zero time) of each bead. Standard deviations values are included. The letters above the columns indicate significant differences between values of different beads for the same treatment with p value < 0.05