In the era of rising concerns over obesity, weight management remains a top priority for consumers when choosing food and drinks. Recently, the focus has shifted to the calorie content of beverages, recognized as a major contributor to excessive sugar intake globally, leading to unwanted weight gain. Hence, low-calorie or mid-calorie beverages hold significant potential in helping individuals reduce their sugar and calorie intake, providing better weight control. In this context, “low-calorie” doesn’t adhere to any specific regulatory definition but rather refers to beverages designed to assist consumers in cutting calorie intake compared to full-calorie drinks. Despite numerous launches in the market, the success rate of these beverages hasn’t always been optimal.
Challenges in Crafting Low-Calorie Beverages
The challenge of balancing taste and nutrition in beverages is a primary reason for the varying success rates. Removing calories from drinks often results in using calorie-free water as a substitute for calorie-rich ingredients like sugar, juice, or fat sources, sometimes resulting in a diluted taste. However, the challenge lies in the fact that these components not only contribute calories but also offer flavor, color, aroma, body, and mouthfeel.
Addressing Taste Challenges in Low-Calorie Beverages
One of the most challenging aspects of addressing taste issues in low-calorie beverages is that consumers find it difficult to precisely articulate why a beverage is less popular, making solutions hard to pinpoint.
Taste is a broad term, and mouthfeel is often inseparable from flavor and aromatic components. Consumers might struggle to express something they don’t easily discern, such as mouthfeel. Lack of proper sensory vocabulary leaves consumers unable to convey what’s missing in low-calorie beverages, explaining the consumer struggle with this product type. Reduced mouthfeel in low-sugar products can disrupt the overall profile, potentially lowering consumer preference due to diminished flavor, complexity, fullness, and balance.
When people engage in sensory testing and describe what they taste or notice in a product, it often introduces what sensory scientists call the “halo effect.” The halo effect refers to the subconscious influence of liking scores on attribute scores. For instance, testers overall prefer Sample 1 and, merely by being liked more frequently, it receives higher taste ratings, even if the taste isn’t actually more popular. This can lead to evaluating unknown features together, making it challenging to differentiate easily.
Distinguishing Taste and Mouthfeel
Training technicians using food and beverage dictionaries can help fill gaps to better understand what consumers mean when they say things like “it’s fake, not genuine, lacks depth, and I feel something is missing.” They know what sweetness is, but adding sweeteners to low-sugar products differs from the experience of full-sugar products. For example, when comparing full-sugar soda to sugar-free soda, consumers notice the sugar coating is gone, and the mouthfeel is lost, but it’s challenging to articulate this difference.
The mouthfeel experienced in the oral cavity during eating or drinking includes various tactile attributes such as acidity, dryness, granularity, hardness, mouth coating, wetness, juiciness, etc. These complex sensory attributes may be challenging to describe and comprehend, getting further lost in translation during communication among consumers, product developers, food scientists, and sensory scientists.
Role of Analytical Science
Connecting these sensory attributes with analytical characterizations like rheology (study of substance flow) and tribology (study of friction, lubrication, and wear) allows us to fully understand factors influencing the taste and mouthfeel of food and beverages, such as viscosity in the oral cavity, and develop suitable solutions. These processes may be iterative, time-consuming, and dependent on the type of application.
Linking analytical parameters with sensory attributes presents some challenges. For example, some group members may perceive large particles as gritty, while others might think of them as “chalky” and/or powdery. Thus, disparities in descriptions among group members are found. Additionally, some sensory parameters, like grittiness, chewiness, thickness, powdery, and stickiness, can be mapped to large particle size, high viscosity, solid particles, and higher solid-like behavior, respectively.
Quantifying information about mouthfeel using techniques like rheology and tribology is extensive, but instrumental prediction of mouthfeel should further develop since it requires capturing dynamic aspects of food breakdown in the mouth, such as mixing, biting, saliva interaction, and structure breakdown. For instance, low-viscosity liquids may provide good taste perception, but defining friction coefficients using tribology is challenging, even though it affects viscosity and lubrication. Therefore, different methods/experimental sets need development based on the application or the problem to be addressed.
Overcoming Taste Challenges in Low-Calorie Beverages
Currently, there’s a growing focus on using vegan fat systems in plant-based dairy alternatives, driving a surge in taste innovation. In the context of sugar reduction, it’s crucial to focus on taste solutions that restore or enhance specific lost sensory attributes. For example, it’s necessary to reconstruct a syrupy sensation in beverages. Similarly, in low-fat products, solutions need to be developed to restore creamy, mouth-coating, reduce chalkiness, and increase smoothness attributes. Presently, research and development are centered on adding modifiers and other tools to restore sweetness in low-sugar products, bringing back some sensory features such as syrup and mouthfeel that consumers refer to as “body” or “fullness.”
To enhance taste, a multidisciplinary approach is required. A significant challenge for commercially available taste enhancers/components is finding solutions that allow for clean labels, including natural, halal, kosher, non-GMO, and organic. To develop these types of components, understanding rheology and tribology is essential, along with knowledge of the time-dependency aspects of food digestion (mixing, saliva interaction, and structure breakdown) to capture changes in lubrication texture and viscosity occurring during consumption. Different taste enhancers may be used based on the type of food and its different textures. Thickeners, fillers, and particulate ingredients have been studied for fat replacements.
Sensory science is a crucial tool in balancing nutrition with taste to ensure healthier beverages are widely accepted and become a part of consumers’ daily lives.