Abstract
The release of free vitamin B12 (B12) from the ingested foods during gastric digestion is first step for absorption of B12. The free B12 can be bound by salivary haptocorrin under the acidic conditions of somach and followed by the subsequent process. Here, we demonstrate how extent of free B12 can be released from egg and fish meats (rich in B12) with or without culinary methods (dilution, boilling, or beating; mixed with egg white and egg yolk).
Egg, beated egg, beated-diluted egg and mackerel meats were cooked in boiling water. The boiled meats were incubated fo 30 min at 37 0C in the presence of pepsin (167 ug/ml in 0.1M HCl) and then centrifuged at 10,000 x g for 15min. The supernatant was used as the soluble B12 fraction. A portion of the soluble B12 fraction was applied to a gel filtration column (PD-10) to determine the content of free B12. B12 was assayed with Lactobachillus delbrueckii subsp. lactis ATCC7830.
The gel filtration experiments indicated that about 30 % of B12 found in the soluble fraction of the boiled mackerel meats was recovered in the free B12 fraction. About egg, the dilution was accelerate the release of free B12 from the binding protein, but boiling and beating was not accelerated. Moreover the beating egg disturb release of vitamin B12, because that compound from egg yolk was mixed with egg white, bound to binding protein originated from egg white. These results were suggested one of the best dish; Chawanmushi with egg yolk and extract of fish meat, ex. Dashi.
