• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.411-416
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• 1993

This study was conducted to determine optimum levels of ingredients including yeast autolyzate, first for the beef flavored soup base and then for the soy paste stew mix as a final product. Response surface methodology was used for the optimization. Beef flavored soup base with optimum sensory characteristics could be prepared with 8g/l yeast autolyzate, 0.8g/l nucleotide seasoning, and 0.09g/l succinic acid. And soy paste stew mix could be produced with 8g/l beef flavored soup base, 28g/l soy paste powder, and 16g/l corn starch. Soy paste stew prepared with optimum levels of ingredients were comparable in acceptability to that with commercial product containing beef extracts. It was suggested that sufficient beef flavor could be obtained with yeast autolyzate in such products as soy paste stew mix.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.78-82
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• 1993

This study was carried out to develop a new processing method for the production of yeast autolyzate (YA) by which the yield and the quality could be improved, compared to the conventional method. The result indicated that 85.3% of yeast cell walls treated with glucanase and protease was ruptured by homogenizing at 10,000 psi. Alkali treatment, however, was not effective in disintegrating yeast cell walls. Optimum conditions for autolysis of ruptured yeast cells, obtained with help of response surface methodology (RSM), were pH 7.0, $30^{\circ}C$, ethanol 4% and salt 3%. YA produced by the developed method had significantly higher yield and better sensory quality than that produced by the conventional method.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.201-205
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• 2003

The optimum autolysis conditions were investigated to prepare yeast autolyzate (extract) using yeast slurry collected from brewery plants. Brewers yeast slurry was washed with caustic soda to eliminate bitter hof substances attached to yeast cell walks. The pH of brewers yeast slurry was adjusted to 9.8 with caustic soda, and centrifuged at 3,000 rpm for 5 min. The supernatant was discarded, and the bottom cake was rehydrated and collected. Bitterness unit (BU) of washed yeast slurry was 24.1 BU, below the threshold value of 25.0. Yeast extract could be obtained from washed brewers yeast slurry at maximum yield up to 38% by autolyzing at pH 6.8 and $53^{\circ}C$ for 20 h.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.475-481
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• 1999

Yeast extracts were prepared using either autolysis or enzymatic digestion methods for industrial application of the Saccharomyces cerevisiae B24 strain developed previously to have high RNA content. Extraction ratio of yeast extract from yeast cell reached 65% when autolysis of yeast slurry having 10% solid content was induced at $50^{\circ}C$ and pH 5.0 by agitating with 100 rpm. However, neither 5'-IMP nor 5'-GMP was detected from the autolyzate. In another attempt to prepare a yeast extract S. cerevisiae B24 culture was treated at $90^{\circ}C$ and then treated by various enzymes including ${\beta}-1,3-glucanase$, phosphodiesterase (nuclease P1), adenylic deaminase, and a protease. The yeast extract prepared by the enzymatic digestion method contained 3.2g of 5'-IMP and 5'-GMP/100g dry yeast extract.