For control digested samples, both

For control digested samples, both casein andb-lactoglobulin were degraded after 1, 3, and 6 h. The bands of these proteins on SDS–PAGE sheet were diminished and their size was
reduced (Fig. 4). In the control sample, band sizes decreased
in a stepwise manner during the digestion time course.
Digestibility of proteins from animal and plant products appeared to depend strongly on the fermentation process. To
verify this, samples from the original digested samples were
centrifuged, and the molecular weights of active peptides in
supernatants were determined by SDS–PAGE. These samples
showed a slight decrease in size. However, we observed some
differences in band density. Samples digested for 6 h had almost no density compared to samples digested for 1 h. The
biological protein activities of both centrifuged and non-centrifuged samples did not differ, and degradation had occurred
to the same extent. Regardless of calcium, the results suggested that the increase in both essential and free amino
acids partly occurred from digestion of milk proteins. These
results suggested that skimmed milk proteins were degraded
to smaller molecular species and some newly generated peptides might be present in the product; these peptides might
have potential health benefits.
To further determine the molecular weight range of proteins in the skimmed milk powder digested withkojiextract
for 6 h, we centrifuged 6-h digestion samples for HPLC analysis. Low molecular-weight fractions were observed (data not
shown). These data support our hypothesis that new peptides are generated during fermentation. Thus, we explored
the hypothesis that biological modification of soybeans by
fermentation results in hydrolysis of milk proteins, which
leads to the generation of peptides and essential amino
acids.
3.4. Calcium content of milky miso (mg/100 g)
Understanding interactions between soy proteins and milk
calcium could provide insights into ways of improving the
nutritional properties of products such as miso shiru.Fig. 5
shows how calcium content increased in MM during fermentation over 3 months. The data indicated that the calcium
content in MM was five-fold higher than in control samples.
This is a considerable increase in an element that is considered to be crucial for human function. In general, daily consumption of a certain amount of calcium-containing foods
such as vegetables, cereals, and non-fat milk products is recommended. The greater the consumption of such foods, the
healthier the diet, allowing the body to obtain sufficient
amounts of calcium. Therefore, we propose that MM is
healthy for elderly women, especially for women whose diet