Changes in the perception of bitter constituents in thermally treated yeast extract

Abstract

BACKGROUND Many studies have been performed over the past four decades to identify and quantify the odor‐active key volatiles in yeast extract (YE) but knowledge of the nonvolatile taste compounds is still rather fragmentary. In particular, research on bitter peptides with various structures during the thermal treatment of YE is still scarce. RESULTS Compounds imparting a bitter taste to thermally treated YE were investigated using sensory‐guided fractionation. This research found that when the treatment temperature reached 130 °C, bitter peptides were generated. Sensory evaluation of the purified, synthesized peptides revealed that four of these peptides showed a pronounced bitter taste with a taste dilution (TD) factor from 5 to 9. Guidance is provided for the production of bitter peptides in the flavor industry. CONCLUSION Based on results from previous work on umami peptides, and this study, keeping the thermal reaction temperature under 120 °C could maximize the umami flavor and control bitterness so that it remains in an acceptable range. © 2019 Society of Chemical Industry

Yeast Extracts: Nutritional and Flavoring Food Ingredients

“…The thermal reaction temperature influences the umami flavor, the production of flavor-active components, and controls bitterness of the extracts. 42,43 The control of the Maillard reaction can allow production of different flavors such as beef, chicken, or other meat flavors. The sensory properties of the extracts are strongly affected by processes like evaporation and drying, during which Maillard compounds are formed which are responsible for giving cooked meat flavors.…”

“…These extracts provide savory flavors and umami taste sensations, in relation to the presence of different components including amino acids, peptides, nucleotides, and other flavoring molecules produced during the process of yeast extract preparation. ,− In these yeast extracts, the significant amounts of glutamic acid, nucleotides together with various amino acids, and peptides act synergistically for intensifying the flavor of foodstuff products. Due to the yeast fermentation process, yeast extracts naturally contain glutamic acid, accounting for 5% on average within the free amino acid fraction, contributing to the specific taste and more particularly providing a umami taste.…”

“…Appropriate control over autolysis, via regulating temperature, pH, and reaction duration, changes the sensory profile of the produced extracts, thus enabling flavors such as roast meat, bouillon (broth), meat, and even cereal to be achieved. ,,,,, When processed in complex food systems, yeast extract undergoes a series of thermally induced reactions at elevated temperatures, thus generating a wide variety of thermally derived volatile compounds responsible for the roast-like, meaty, and caramel-like odors. , Flavoring components like those found in cooked meat are produced by the reaction of 5′-nucleotides, glutamic acid, and cysteine with sugars. The thermal reaction temperature influences the umami flavor, the production of flavor-active components, and controls bitterness of the extracts. , The control of the Maillard reaction can allow production of different flavors such as beef, chicken, or other meat flavors. The sensory properties of the extracts are strongly affected by processes like evaporation and drying, during which Maillard compounds are formed which are responsible for giving cooked meat flavors.…”

Characteristics of the enzyme-induced release of bitter peptides from wheat gluten hydrolysates

“…In recent years, researches ( 12 , 13 ) on eliminating the bitterness of enzymatic hydrolysates to develop more functional foods with high nutritional value have been reported successively ( 14 ). Enzymatic debittering is to cut off the hydrophobic amino acid at the end of the peptide by exo-peptidase (carboxypeptidase or aminopeptidase) to generate a free amino acid with low bitterness, and it is widely used for debittering of hydrolysates due to mild conditions and no loss of physiologically active components ( 15 ).…”

Investigating characteristics and possible origins of off‐odor substances in various yeast extract products

“…YE has the characteristics of seasoning and nutrition. Due to the action of amino acids and peptides in the ingredients, the flavoring significantly increases the mellow flavor, freshness, and saltiness of the product (Alim, Song, Yang, et al, 2019). 2‐Furylmethyl mercaptan and 4‐hydroxy‐2,5‐dimethyl‐3(2H)‐furanone in YE provide a baked aroma, whereas 2‐methyl‐3‐furanmethanol and 2‐methyl‐3‐methyldithiofuran provide a rich meaty aroma (Festring & Hofmann, 2010; Hofmann & Shieberle, 1998; Lin et al, 2013).…”