たまご醤油の調製に関する研究 第2報 : ピザ台への麹菌培養と卵白液の醤油化

Abstract

This research was aimed to produce a fermented egg white sauce that taste strong umami by use of pizzacrusts as a solid medium for koji cultivation. Pizza crusts were made from dough of bread flour and glutenpowder with yeast, and cut into small pieces about 5mm square sections. After adjusting moisture content at45%, Aspergillus oryzae was cultured on the pizza crusts. A. oryzae favorably grew into the crusts, because ofporous structure of the crusts. Enzyme activities of protease, acidic carboxypeptidase and amylase extractedfrom the crust koji were 2-3 times higher than those of usual Koji cultivated on delipidated soybean and wheat.The crusts koji were mixed with liquid egg white and salt to prepare egg white moromi (16% NaCl) for fermentation. Formol nitrogen and total amino acid content of the crusts moromi were gradually increased from0.12% and 0.37% at start to 0.93% and 8.8% at 6 months, respectively, resulting in much amino acid producedby degradation of proteins by enzymes in koji. The moromi at 6 months was filtered and sterilized to obtain afermented egg white sauce. The glutamic acid content of the egg white sauce was about 1.6%. This value wasabout 2 times higher comparing to that of soy sauce commercially available.It was revealed by sensory evaluation that pizza crusts koji with 16% salted liquid egg white produced fermented egg white sauce with unique egg flavor, much umami taste, and lighter color comparing to that ofusual soy sauce. Moreover, egg proteins were completely decomposed to peptides or amino acid, which couldnot be detected by an egg allergy detection ELISA kit in the fermented egg white sauce at 6 months. It might bethe first to utilize pizza crust to ferment A. oryzae. It also might be the first to use the crust koji with liquid eggwhite and salt during fermentation of egg white sauce. The egg white sauce will be a new fermented seasoningin our dietary life as well as in food industry.