The below titles are part of useful supporting publications from various well-known journal to ensure the beneficialness of yeast products

Yeast extract

-Utilization of brewer's yeast cells for the production of food-grade yeast extract. Part 1: effects of different enzymatic treatments on solid and protein recovery and flavor. (For more detail please visit http://www.sciencedirect.com/science/journal/09608524)

-The Use and Utility of Glutamates as Flavoring Agents in Food: Umami and Food Palatability. (For more detail please visit http://www.nutrition.org/)

Utilization of brewer's yeast cells for the production of food-grade yeast extract. Part 1: effects of different enzymatic treatments on solid and protein recovery and flavor characteristics

Hee Jeong Chae a , Hyun Joo b , Man-Jin In c

a Department of Food Technology, Hoseo University, Asan 336-795, South Korea b Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA c Department of Human Nutrition and Food Science, Chungwoon University, Chungnam 350-800, South Korea

ABSTRACT

Yeast extract was produced from brewer's yeast of a beer factory by combined enzymatic treatments using endoprotease, exoprotease, 5 ’ -phosphodiesterase, and adenosine monophosphate (AMP)-deaminase. Effects of enzyme combination, enzyme dosages and treatment sequence on the recovery of solid and protein, flavor and compositional characteristics were investigated. Exoprotease dosage strongly affected the recovery of protein and degree of hydrolysis (DH) and sensory characteristics. When the yeast cells were treated using optimal combination of endoprotease and exoprotease (0.6% Protamex TM and 0.6% Flavourzyme TM), high solid recovery (48.3±53.1%) and the best flavor profile were obtained. Among various treatment sequences using multiple enzymes, treatment with protease followed by nuclease resulted in the highest 5 ’ -guanosine monophosphate (5 ’ -GMP) content. The optimal concentrations of both 5 ’ -phosphodiesterase and AMP-deaminase were found to be 0.03%. After treatments using optimal combination of enzyme, enzyme dosages and treatment sequence for four enzymes, a high solid yield of 55.1% and 5 ’ -nucleotides content of 3.67% were obtained.

Keywords: Brewer's yeast; Yeast extract; Enzymatic hydrolysis; Solid and protein recovery

Credited by:
ã 2000 Published by Elsevier Science Ltd.                                                                          Bioresource Technology 76 (2001), 253-258

The Use and Utility of Glutamates as Flavoring Agents in Food: Umami and Food Palatability

Shizuko Yamaguchi2 and Kumiko Ninomiya *

Faculty of Applied Bioscience, Department of Nutritional Science, Tokyo University of Agriculture and *Technical Committee, Umami Manufacturers Association of Japan, Tokyo, Japan

ABSTRACT

Umami is the term that identifies the taste of substances such as L-glutamate salts, which were discovered by Ikeda in 1908. Umami is an important taste element in natural foods; it is the main taste in the Japanese stock “dashi,” and in bouillon and other stocks in the West. The umami taste has characteristic qualities that differentiate it from other tastes, including a taste-enhancing synergism between two umami compounds, L-glutamate and 5’-ribonulceotides, and a prolonged aftertaste. The key qualitative and quantitative features of umami are reviewed in this paper. The continued study of the umami taste will help to further our general understanding of the taste process and improve our knowledge of how the taste properties of foods contribute to appropriate food selection and good nutrition.

Keyword: umami; glutamic acid; nucleotides; taste; food; food palatability

Credited by:
ã 2000 American Society for Nutritional Sciences.                                                              Journal of Nutrition 130 (2000), 921S–926S