Formulation Challenge: Savory Flavors Heat Up Stews

A stew generally refers to a dish with meat, vegetables and a thick soup-like broth. Stewing helps tenderize tough pieces of meat and allows the different ingredient flavors to marry or blend deliciously.

Stews conjure up images of home-cooked meals simmering for hours on a Sunday afternoon. However, time-pressed consumers can now come home from work any day of the week to thaw frozen meals in the microwave. In a short time, they can have satisfying stews—almost like Mom used to make.

Formulators can create tasty prepared stews by adding flavors and flavor enhancers. The challenge is selecting the right blend of these ingredients for savory applications that look and taste like homemade foods.

Flavorful Options

Stews derive their flavor from long, slow cooking. Ingredients generally include meat, fish, or chicken, vegetables, and stock. Stock can be canned or prepared by simmering bones, meat, fish, or chicken parts, vegetables, spices, and salt for several hours. Through this “kitchen chemistry” process, basic flavor building blocks are extracted. The entire stew-making process can take anywhere from two to six hours. Few consumers have time for this.

Flavor suppliers provide an almost endless variety of meat and savory flavors that enhance overall flavor and provide a home-cooked taste to a frozen meal. Reaction flavor technology allows flavor houses to create savory flavors with many nuances by combining amino acids, reducing sugars, nucleotides, yeast extracts and other ingredients, and reacting them together.

For example, a beef flavor can contain notes such as roasted, smoked, fried, sautéed, bloody, fatty, or au jus. Poultry flavors are available in light or dark meat, and may contain various levels of skin notes, in addition to some of the previously mentioned flavor attributes. Savory broth flavors and fatty flavors and ingredients also are available. Many flavors are obtainable in dry, liquid or paste forms.

In addition to true meat flavors, flavor potentiators such as salt, yeast-based ingredients, monosodium glutamate (MSG), hydrolyzed vegetable protein (HVP), and 5' nucleotides (e.g. disodium inosinate and disodium guanylate), can enhance meaty and vegetable-type notes. The synergy between nucleotides and MSG, or glutamate-containing ingredients, is well known.

Time-constrained consumers are searching for products that have a home made flavor. Presenting convenient foods with flavors that convey many hours spent in the kitchen is difficult.

“Today's consumers want more intense flavors—yeast and yeast-extracts intensify and round out flavors, and provide truer meaty notes in the appropriate application—such as stews,” says Franny Hildabrand, manager, technical services, Provesta Flavor Ingredients, Bartlesville, Okla. “Frozen products today have come a long way from the old packaged items of the 1960s that contained mainly HVP as a flavor.” HVP consists of sodium chloride, glutamic and various amino acids.

Foods cooked in steam kettles may not achieve the full meaty and roasted flavors that a manufacturer wants, Hildabrand points out. Flavors and flavor enhancers provide the missing link to homemade savory taste.

Yeast-based flavor enhancers give a boost to the overall flavor of a system including salt perception, green herb and brown spice notes, and spice heat. They also contribute umami, the fifth basic taste that is often described as brothy or savory. They work in synergy with nucleotides and MSG. With their high flavor strength, low levels can be used for enhancement.

Yeast-Based Ingredients

Yeast-derived flavors and flavor enhancers manufactured from mostly Saccharomyces species and (Torula), have become key tools in savory flavor systems. There are three basic forms of inactive yeast—inactive dried yeast, autolyzed yeast, and yeast extract.

Inactive dried yeasts are generally manufactured from Torula and are labeled as “Torula yeast.” Inactive dried yeasts find application as flavor enhancers, clean label MSG replacers and nutritional ingredients.

Autolysis involves self-digestion of the yeast cells where the yeasts' own enzymes break down the cells under carefully controlled conditions. “Autolysates” comprise the entire contents that result from this process. Yeast extract is the soluble portion of the autolysate after centrifugation and removal of the insoluble cell wall. The ingredients are concentrated into a paste and, subsequently, can be dried. These ingredients are labeled as “autolyzed yeast extract” (USDA) or “yeast extract” (FDA). If the cell wall is not removed the product is “autolyzed yeast”.

Through the processing of autolyzed yeast and yeast extract, water-soluble flavor-enhancing compounds such as peptides, amino acids (including glutamic acid), monosaccharides, nucleotides and salts, are released. Some specialty yeast extracts contain higher levels of nucleotides. Through drying processes, yeast extracts can take on enhanced flavor characters of their own such as meaty and roasted notes.

The addition of 0.03% of a yeast-based "beef" flavor in a lowfat, reduced-sodium beef gravy increases flavor intensity and salt perception.

“With autolyzed yeast, you've broken the cell wall, but all the components are still there, nothing is removed, including the cell wall,” says Hildabrand. “This makes for a turbid product that is useful where clarity is not important, as in stews and certain soups. With the cell wall removed, yeast extracts are clear so they can be used in applications such as clear bouillon.”

More concentrated yeast extracts usually are used at 0.1 to 0.25% on a finished product basis. Autolyzed yeasts and yeast-based flavors typically are used at 0.5 to 1.0%

The key to deciding which flavors and flavor enhancers to use lies in first defining the flavor performance objective, then determining what flavors are present or absent in the system. Labeling decisions play a role in selecting enhancers. Some yeast-based ingredients contribute naturally-occurring free glutamic acid and 5'-nucleotides that do not require additional labeling.

A word of advice from Hildabrand: “Sometimes people will set up yeast-based ingredients from various suppliers in water as an initial screening process,” she says. “Torula yeast in water alone tastes like the water from boiled potatoes. You'd be much better off tasting yeast-based ingredients in the appropriate broth, such as beef, chicken, or vegetable, to assess performance.”

Stocking Up on Flavor

Soup, broth or stew contains chicken or beef broth for body and flavor. Some companies use stocks in their reaction vessels in the production of finished flavors. “Beef or chicken stock is a key element in stews, for flavor enhancement and for labeling purposes—consumers want to see this on the label,” says Kim Peterson, senior food applications scientist, Proliant Inc., Ames, Iowa. Stocks can be used from 0.5 to 2.0%.

Fat is another key ingredient for tasty stews. Fat from a flavoring component and from meat itself helps contribute homemade taste—in addition to rounding out the flavor profile and providing mouthfeel.

“We recommend using around 0.5% beef, chicken, or turkey fat in a stew,” says Peterson. Usually sold frozen, chicken fat, turkey fat or beef tallow can be liquefied by the customer before use.

Such ingredients give a “mother's touch” to stews and other savory foods at a time when mothers are stretched for time.