2. It is known that fresh shiitake mushrooms contain $90 \% \sim 99 \%$ water, while dried shiitake mushrooms contain $30 \% \sim 45 \%$ water. Then, under the influence of drying, by what maximum factor can the weight of fresh shiitake mushrooms be reduced?
2. Let the weights of fresh mushrooms, baked mushrooms be $m_{1} \mathrm{~g}, m_{2} \mathrm{~g}$, and the weight of dried mushrooms be $x \mathrm{~g}$ (unknown). Then the range of the proportion of dried mushrooms in fresh mushrooms and baked mushrooms is
$$
\begin{array}{l}
0.01=1-0.99 \\
\leqslant \frac{x}{m_{1}} \leqslant 1-0.90=0.10, \\
0.55=1-0.45 \\
\leqslant \frac{x}{m_{2}} \leqslant 1-0.3=0.70 .
\end{array}
$$

Therefore, the maximum multiple of the weight of fresh mushrooms to the weight of baked mushrooms is
$$
\frac{m_{1}}{m_{2}}=\frac{\frac{x}{m_{2}}}{\frac{x}{m_{1}}}=\frac{0.70}{0.01}=70 .
$$