Color / Sweet / R&D

The Role of Sensory Properties in Food Development

All of the senses influence what people choose to eat, so how do you stimulate them in new products?

By Lauren R. Hartman, Product Development Editor

Our 10,000 or so taste buds play the most vital role in food selection. Beyond taste, sensory properties such as smell, sound, appearance and texture influence what we select to eat. Food must taste delicious, certainly, but mouthfeel, texture, looks and smell are also important to the overall eating experience.

"The aroma component of flavor is key," says Jean-Xavier Guinard at the University of California-Davis Extension, which is now accepting applications for its applied sensory and consumer science certificate program. Foods must smell fresh or ripe, and have what we recognize as the proper color, size, shape, consistency and opacity. Thumping a melon, for example, tells us a lot about its texture and ripeness, as does checking other foods for flakiness, moistness, dryness, oiliness and so on.

Sound is important, as consumers know foods must maintain a certain level of crunch, bubble, sizzle, pop, snap and crackle, without negatively affecting shelf life or nutritional profile. Food that's supposed to be crispy and crunchy should have the same crunch and crispness every time it's eaten.

Evoking a multi-sensory experience through food, condiment manufacturer Mizkan America Inc. (www.mizkan.com), Mt. Prospect, Ill., says a fusion of sensory responses is what creates a pleasurable experience. "When quality ingredients are at the core of the food we eat, all of the senses are positively stimulated," notes Sara Delach, brand manager at Mizkan.

The 'wow' meter

At Tasty Bite, a Stamford Conn., maker of Indian and Asian microwavable entrees, a trained, discriminating sensory panel considers five food attributes when developing something new: color/appearance, texture, taste, aroma and flavor. (Tasty Bite was a winner of our 2016 R&D Teams of the Year. Read more about the company)

"We work with a lot of ingredients across different cuisines, which helps us create specific attributes across variety of products, [so] defining the sensory parameters becomes absolutely critical," explains Shashish Hodlur, head of R&D. "We focus on delivering robust and bold flavors while ensuring the desirable appearance, texture and consistency."

Products must register high on the panel's "wow meter" in order to pass the test. Flavors should be robust and clean, and in synch with consumer expectations, Hodlur says. "We have an index that measures ... 'wow levels,' and assess the factors that contribute to a wow."

Every product must look appealing the moment it comes out of the package, he continues. "Basmati rice has to look white, with long grains, and be free flowing. We expect a sauce to have a smooth consistency, and the vegetables should have a firm texture. The lentils in our lentil-based products must be firm but perfectly cooked. A cheese-based sauce should have a silky, smooth consistency without lumps."

Food scientists at TIC Gums Inc. (www.ticgums.com), White Marsh, Md., use a combination of triangle tests and descriptive analyses. Triangle tests decide if there's a significant, perceptible difference between products when a change is made to one of them, explains Lauren Schleicher, food technologist. "After a difference is identified, the next step involves a descriptive analysis to determine how the products compare across different sensory characteristics." The food scientist then analyzes individual texture attributes, such as mouth coating, viscosity and astringency to hone in on which attribute causes it to be different than the others. TIC Gums has compiled a comprehensive set of sensory terms to standardize how product texture is described during the development process, she says.

Tate & Lyle Hoffman Estates, Ill. (www.tateandlyle.com), uses a mix of discriminatory product tests for customers, including one to see if there's a detectable difference among two or more products; consumer affective testing, which uses a large group of untrained participants to help determine how much a product is liked; and a descriptive analysis that evaluates appearance, aroma, flavor, oral texture, geometrical parameters, fat/moisture parameters and skin-feel characteristics.

Consumers want bolder textures, says Judy Whaley, senior vice president of sweeteners and texturants for new product development at Tate & Lyle. "They want cleaner labels and exceptional sensory experiences. But ultimately, consumers aren’t willing to give up on great taste."

External preference mapping and principle components regression are other techniques the company uses. Mapping combines results from consumer affective testing with a descriptive analysis to reveal which attributes are the most important to consumers and what levels are desired, Whaley says. Principal components regression analyzes sets of statistics that estimate the relationships among variables. These help correlate those attributes with ingredient formulation.

Textural qualities

"Texture is as important as flavor, as it directly impacts whether a consumer likes something," says Layo Jegede, senior manager-global sensory in the Bridgewater, N.J., R&D center of Ingredion (www.ingredion.com). "When developing new products, it's important that texture is optimized first and then flavor, because texture will directly impact the flavor release and how it will be perceived by the consumer."

He also pays heed to the other senses. "Consumers can 'see' flakiness in a baked product prior to consumption. If a product doesn't have an appealing aroma, consumers won't taste it."

From 2011 to 2015, products launched with a texture claim on the front of pack increased by 74 percent in North America, Whaley says. Achieving certain food textures also requires a thorough understanding of ingredient structure/function relationships, ingredient interactions and processing conditions, and how these influence sensory properties. "Understanding the properties of starch and its concentration in use enables food manufacturers to control and optimize textural properties," she says.

Once the right texture is determined, quantitative textural specifications can be set and measured. "Simple changes in texture can turn a single product into a platform that appeals to a wide range of consumers," adds TIC Gums' Schleicher. "Manufacturers can create a hard, soft and liquid version of the same candy by altering the ingredients in their formulations. Stabilizers such as gum acacia change the desired texture of the application, allowing formulators to develop and expand their existing product line."

The choice of evaluation methods depends on the objectives for a new food product, timing and the amount of the sample available, says Jegede. "We use a range, from descriptive analysis to temporal perception, oral processing, discrimination, consumer tools and techniques. The focus is on the essential sensory quality attributes that drive consumer acceptance and purchase. Flavor and texture profiling and consumer studies are conducted the way the consumer will use the product or the way the foodservice operator prepares the product."

Customers enhance products to distinguish them from the competition or maintain the essential sensory characteristics of an existing product while developing such claims as low fat, low sugar and gluten-free, says Marcelo Nichi Sr., Ingredion's marketing manager for texture. "They're also interested in developing new and innovative textures. We have seen a growing interest in clean-label starches in the past few years, and many customers are looking for cost-effective solutions usually met by food modified starches. Understanding these properties is critical because it can determine the success or failure of a product in the marketplace."

Scott Rangus, president and CEO of Ingredients Solutions (www.isi.us.com), Waldo, Maine, says hydrocolloids and carrageenan provide a variety of textural and sensory properties that can be measured in terms of gel strength and elasticity. "To [determine] this, a texture analyzer quantitatively measures gel break force and elasticity in gelled products," he points out. "These measurements assure consistent properties in the finished consumer products, such as pudding, gummi candies and dessert gels. Viscosity can be measured in things like dairy beverages."

Beyond quantitative measurements, Rangus recommends taste panels if the numbers alone don't distinguish one formulation from another. "Flavor and mouthfeel properties could be different between two products, so sometimes humans are needed to render the final judgment," he points out. "Gel color in carrageenan can affect the color of deli sliced turkey lunchmeat, for example. A darker gel could darken the finished meat. The same applies to flavor and odor."

Food producers also want to build texture and improve the "richness," or the perception of high fat content in reduced-fat foods, he says. In beverages, gums can restore the thickness and mouthfeel lost when fat or sugars are reduced.

Once a base formula is established, areas of deficiency can then be identified and ingredients can be found to improve those deficiencies, Rangus says. "The process continues until the ideal texture and sensory properties are achieved. From there, we collaborate with the customer to fine-tune the finished product."

Color blinds

Color tells a lot, too. It can increase acceptability or rejection -- indicating if a food has been heated or not, is burnt, stale, past its prime or not yet ready to eat.

However, "When it comes to colors, consumers want ingredients they can easily identify and feel comfortable with," says Tom Schufreider, COO at Sethness Products Co. (www.sethness.com), Skokie, Ill. "Colors and hues present in the finished product should mimic the colors found in nature or through familiar processes such as grilling, roasting and toasting," he says. "Some consumers prefer and value subtle, less intensely hued products that previously have been colored with more vibrant FD&C dyes. It's important for color manufacturers to offer a palette of colors the consumer considers more authentic in color and hue."

Mars Inc. is setting goals to reduce artificial colors, salt and sugar, although it's finding it difficult to move some products to natural colors. Skittles candies feature bold, bright reds, greens, yellows and purples central to its appearance and "Taste the Rainbow" ad campaign.

Finding the right natural colors that function well with Skittles' formulation could be tough, especially given the candy's hard exterior. Partnering with suppliers to identify new ingredients and formulas will help, and the company already works with several naturally sourced colors in its global product portfolio. Depending on consumer preferences, ingredient availability and local regulations, slightly different formulations and products may exist in different markets. But all are safe, the company says.

"Product developers must be careful to evaluate the colors they want to use to make sure their performance and long-term integrity won't be compromised by interactions with other ingredients," cautions Schufreider. "The perceived color, performance and stability of caramel colors [for example] can be affected by factors in a finished product including pH, alcohol content, salt content, proteins and ionic charge. Knowing what the expected interactions will be can either help prevent color instability or anticipate desired changes, especially in hue."