By "minimum" absorbance value, I'm assuming that there is another absorbance peak which has the smallest of the intensities, right? And, does this pertain to UV-Vis spectroscopy?
Quantitative analysis, such as when constructing a beer's law based calibration plot, is done using the maximum absorbance value, in particular, because it works well with the wavelength peak that has a high absorptivity at that wavelength. For the latest uv-vis spectrometers you want the absorbance peak to be between 1.0 and 3.0 absorbance units, and the peak should be pretty broad, assuming that all peaks have an ideal shape, the one with the highest intensity will be more reliable. The position of the peaks can shift at times, with broader peaks, the corresponding change in the intensity value will be less dramatic.