Baker's yeast mitochondria, gassing power and freeze–thaw tolerance in dough

Abstract

When tested in dough, six commercial baker's yeast samples showed some variation of freeze–thaw tolerance and mitochondrial protein content (P ≤0.05), an indication of their cell mitochondrial development. However, variation of freeze–thaw tolerance was not related to mitochondria protein content (P ≤0.05). On the whole, yeast gas production before or after freezing as well as after storage periods of 1 or 5 weeks at 4°C was not related to its mitochondrial protein content. Some of the yeast samples were more tolerant to rapid freezing rates (9.2°C min −1; no storage in freezer) and others survived better slow freezing rates (1°C min −1, with storage for 12 weeks at −30°C).