Yeast Extracts: Nutritional and Flavoring Food Ingredients

Abstract

Yeast extracts are the concentrates of the soluble fraction of yeast and more particularly Saccharomyces cerevisiae. As food ingredients, yeast extracts are described for their nutritional composition and flavoring properties. They are produced principally from autolysis, but in some cases, acid or exogenous enzyme preparations are added. The main nutritional components of yeast extracts include partly hydrolyzed protein with 35−40% of free amino acid, and they also contain B vitamins and some trace elements. As flavoring ingredients in foods, they provide diverse flavors depending on the methods used for their production. These flavors include meaty, kokumi, umami, and salty taste along with taste masking properties. Yeast extracts are a source of amino acids, including glutamic acid, with a content of about 5% and 10% w/w free and total glutamate, respectively. Yeast extracts have the capacity to induce the umami taste, the flavoring effect of monosodium glutamate (MSG), when providing glutamate at an amount below 1% in foods, i.e., below the amount required for pure MSG. The latest studies indicate that they can also be used as sources of bioactive substances in functional foodstuffs and dietary supplements.

Extracellular electron transfer increases fermentation in lactic acid bacteria via a hybrid metabolism

“…However, reduction was highest when L. plantarum was incubated in mannitol-containing MRS (mMRS) with both DHNA and ferric ammonium citrate present ( Figure 1—figure supplement 1D ). The addition of riboflavin to the growth medium did not further increase iron reduction by L. plantarum ( Figure 1—figure supplement 1E ), potentially because riboflavin is already present in high quantities in MRS, a medium containing yeast extract ( Tomé, 2021 ). Thus, L. plantarum was grown in mMRS supplemented with DHNA and iron before ferrihydrite reduction assays in all subsequent experiments.…”

Exploiting Catabolite Repression and Stringent Response to Control Delay and Multimodality of Bioluminescence Signal by Metal Whole-Cell Biosensors: Interplay between Metal Bioavailability and Nutritional Medium Conditions

“…The relative magnitudes of ∂Lum max,1 /∂c * Cd in 0.1% LB and 0.1% tryptone are quite comparable, especially at high values of x. Here, the loss in bioluminescence expected from the lower bioavailability of Cd ions in 0.1% LB due to a larger complexation (higher K s in Equation ( 8)) than in 0.1% tryptone is counterbalanced by the higher quality of the provided food in the LB medium compared to that in tryptone (i.e., higher c max p,1 ) due to the presence of a yeast extract that contains various amino acids, vitamins and minerals [46]. In turn, in qualitative agreement with Equation ( 8), both food quality and metal bioavailability features have to be advanced to understand the rather similar performance of the biosensors in 0.1% LB and 0.1% tryptone.…”

Yeast Genomics and Its Applications in Biotechnological Processes: What Is Our Present and Near Future?

“…Nutritional yeast is whole dried, deactivated yeast cells, most commonly S. cerevisiae . Its nutty and umami flavor makes it a vegan substitute for cheese powder and is typically found in the form of yellow flakes or powder [ 60 ]. Another common application is as a topping for popcorn.…”

“…It is available as flakes or as a yellow powder with a texture similar to cornmeal. It is sometimes referred to as “savoury yeast flakes” in Australia [ 60 ].…”

“…Both of the yeast foods mentioned above are added with B-complex vitamins [ 60 ], making them an appealing vegan nutritional supplement. Nutritional yeast, in particular, is naturally low in fat and sodium, as well as a source of protein, vitamins, and other minerals and cofactors needed for growth.…”