The influence of the aging on the absorption of the soybean oil and lard was investigated by using rats 1, 4, 10, 14, 18, month rat respectively. Provided that experiment diet contained the soybean oil and lard of 10%. The results obtained were as follows; (1) The absorption of soybean oil and lard gradually decreased with the aging, and the absorption of soybean oil was higher than that of lard. (2) The excretion of neutral sterol was almost constant in the both case of soybean oil and lard, but the excretion of bile acid increased with the aging. (3) When the excretion of bile acid increased, the absorption of fat and oil was apt to decrease. (4) The fatty acid composition of lipids in feces were difference between soybean oil and lard, that is, saturated fatty acids in the feeds were 34-64% (soybean oil) and 60-73% (lard) respectively.
Recently, the production of commercial frozen-stored foods has been increased. However, no investigation has been reported on the lipoper-oxide included in frozen-stored foods in the market. The level of lipoperoxide on 58 kinds of commercial foods was investigated: commercial frozen-stored foods (29 kinds), canned provisions (17 kinds) and dried fishes (12 kinds). The results obtained are shown in Table 1-3. In Table 1, the level of lipoperoxide was found to be increased as their storage time increases. The level of lipoperoxide of dried fishes were higher than those of the other samples.