Immersive Reality in the Sensory Laboratory: From Vision to Reality
isi has started to use Immersive Context in sensory research. The development gives customers ever...
A quiet revolution is taking place in our supermarkets: sugar content in products is declining. Customers have hardly noticed the change because the taste has mostly remained the same. The change towards more healthy sugar content has been largely accepted by consumers not least because of the part played by a sector that normally remains in the background: sensory market research.
When Robert Möslein stands in front of the shelves lined with yogurt offerings at the supermarket, he always looks carefully at the fine print. He likes to choose the variety with the least amount of sugar for his six-year-old son. “For a long time, a lot of consumer products contained ever increasing amounts of sugar, musli and yogurt being two good examples. This trend has changed direction in the past couple of years. Manufactures have responded to consumer demand and are taking health research more into consideration”, explained Möslein from isi (the Institute for Sensory Market Research and Innovation Consulting) in Göttingen.
The British National Health Service (NHS) has directed producers, resellers and restaurants to reduce sugar content by twenty percent before 2020 (Gibson 2017). This is the equivalent to 20,000 tons of sugar per year. From Singapore to Spain similar initiatives have been started. Leading producers have not been caught off-guard. Most have already developed strategies for incrementally reducing sugar levels. According to a study by Consumer Goods Forum, as of 2016 over 100 producers have already altered 180,000 products with the intention of making them healthier. In the coming years, large enterprises - amongst them Rewe, Lidl, Edeka and Aldi- intend to further reduce the sugar content in their products.
“Sugar out, wherever possible!” An example of this is Rewe, which has taken an aggressive advertising stance in promoting its own branded products, among them chocolate ice cream, chocolate crisps and cream kefir. In the beginning of 2018, Rewe began a marketing campaign to introduce this to customers, who could decide between four different varieties of chocolate pudding. The majority of customers chose the variety with 30 percent less sugar than the original variety. As of May 2018, Rewe stocks the new product. “Having the customers vote is a good idea for awakening awareness regarding sugar reduced products. For a more meaningful result, however, a more scientifically based methodology is necessary,” added Robert Möslein.
Just a five thousandth part of a teaspoon of sugar dissolved in a glass of water lends a discernible sweetness for some people. If customer notice that the product has lost some of its sweetness, they might not just react with a shrug of the shoulder. People experience greater pain from a loss than they experience the positive aspects of a comparably significant benefit (Tversky 1981). For this reason, any reduction of sugar in a well known product should be undertaken with care.
We are born with a biological predisposition to prefer sweet over bitter foods (Forestell 2015). Humans just like other primates love sugar because it is an indicator of inherent nutritional value as found, for example, in ripened fruit. Notwithstanding our round-the-clock access to food, the reward centre in the brain has retained a craving for sweet things albeit at a risk to our health. The consequence of this high consumption level of sugar is an increase in obesity, diabetes, cardiovascular diseases and cavities. For example, two glasses of soft drinks per day results in an eleven-fold increase in the risk of developing Type-2 Diabetes. For this reason, an increasing number of people are trying to decrease their consumption of sugar.
A large part of the extra sugar that we consume every day is hidden in processed foods such as yogurt, ketchup, sausages, cakes, ices, fruit nectars, soft drinks, frozen pizzas, salad dressings, breakfast cereals and chocolate bars. Around a quarter of food products have added sugar (Popkin 2016). According to the World Health Organization (WHO) and the United States American Heart Association, free sugars should only make up about 5 percent of our daily energy intake. That would be about 25 grams, or six teaspoons of sugar – about the amount in just one large fruit yogurt.
Reports from people’s experience in magazines and blogs demonstrate how difficult it is to reduce sugar consumption. “Sometimes I just wanted to give up,” wrote a Focus reporter about her own experience, “40 Days without Sugar”. Low sugar products could provide consumers a way to reduce sugar consumption. Studies have shown that it is possible to reduce extra sugar by up to 50 percent depending on the product without consumers perceiving a noticeable loss in taste. According to recent estimates in Great Britain, over the next two decades up to 300,000 people could avoid becoming severely overweight or developing Type-2 Diabetes if the sugar levels in sweetened beverages were reduced by 40 percent within the next five years.
"We never really questioned the sugar levels in our food. My grandmother would pick strawberries in the garden and then put them on the table with a hefty layer of sugar sprinkled on top. Today, that would be too sweet for my taste. My children like them without or just with a little sugar on top," reports Robert Möslein. "In the last two decades sugar content has spiralled upward. However, this trend is now reversing."
How is it possible for a sensory market research company to find out if sugar reduced products meet consumer’s taste profiles? “We use a multi-layered testing scheme,” explained Robert Möslein. In the first step it is determined whether the consumer is able to distinguish the reduced sugar variety from the original (Morlein 2017). Sensory researchers call this method a Similarity Test. If the consumer is not able to tell the difference, then the producer can choose the less sweetened option and introduce it onto the market immediately. In all probability the sugar level in your favourite yogurt has already been reduced sometime in the last few years without you noticing it.
However, if the consumer notices a discernible difference in taste then the second step becomes necessary. At this point, sensory market research examines if the sugar reduced variety is equally well accepted or even preferred over the standard product. “This happens sometimes. The lower sweetness level is noticeable, the product tastes different, but the consumer prefers the new version over the original,” says Robert Möslein. This is called the Non-Inferiority Test. The producer can be fairly confident of the success of the product in this case.
However, if the sugar reduced product fails the test, then we begin the third step,” reports Möslein. Instead of a blind taste test, the product tester receives information about the product. In this case, the fact that the recipe for the product has been changed, that it is less sweet but healthier and fuller in taste is included either in an information sheet or directly on the packaging. It is quite possible that the consumer is then willing to accept the change in taste. If the product is poorly received in this so-called Branded Test, no further testing is possible. “Then we sit down with the producer and consider a new strategy. This might include recommendations for changes to the recipe,” says Möslein.
Producer can draw on a variety of tools to make sugar reduced products more appealing to customers. Smell, texture, spices – like vanilla – strengthen the perceived sweetness of a dish. In a recently study published by the University of Uruguay, participants of a focus group accepted a 40 percent reduction of sugar in pudding when additional vanilla and starch were added (Alcaire 2018). Why don’t the producers just replace sweetness with alternative sweeteners? “Alternative sweeteners probably increase the caloric absorption rate. For this reason, producers are implementing other strategies,” explains Robert Möslein. Studies have indicated that sweeteners that are disassociated from caloric rich substances, those that only incompletely activate metabolic functions associated with the food-rewards centre, actually induce hunger. In addition to which sweeteners can negatively impact the intestinal microbiome and the intestine-brain axis (Mooradian 2017). All good reasons to look at alternatives.
These are, for example, strategies in which several sensory channels interact with each other. Studies indicate that curved shapes, red colours, high pitched tones, fruity scents, creamy textures, and flat and soft surfaces all appear to reinforce the perception of sweetness (Spence, 2017). Researchers call this mutually reinforcing influence on the senses cross-modal, and it has developed into its own branch of research. Above all, aromas that consumers associate with sweetness such as the scent of caramel, vanilla and strawberry help make changes in a product’s sugar levels imperceptible. Nonetheless, experts caution that the cross modal effect shouldn’t be implemented haphazardly. At least some of the effects are probably based on learned associations and are therefore dependent on prior experiences. (Hamilton-Fletcher 2018). A European consumer might enjoy a blue coloured yogurt which is reinforced by an association with sweet blueberries. The same blue might, however, remind a Vietnamese consumer of the taste of mouthwash (Durrschmid, 2018).
At the end of 2017 the German Food Association, Die Deutsche Lebensmittelgesellschaft (DLG), published a volume dedicated solely to these reduction strategies. The authors of the volume set out the many promising possibilities that natural ingredients offered to make sugar reduction possible. According to a DLG questionnaire given to 247 food experts in 2017, only 17 percent of the respondents were familiar with the methodology and its potential applications. (Cicek 2017).
Improved techniques can also be used to reduce sugar. Nestle developed a hollow sugar crystal that contains less sugar, but is perceived to be just as sweet as conventional sugar. Already this year the first products using this crystal have come to market. The Israeli start-up DouxMatok is promoting its custom designed sugar molecules intended to reinforce the impression of sweetness. The new sugar is expected to reduce sugar content by up to 40 percent.
A mistake in changes to the recipe can be very costly for producers. Sales of Cadbury Chocolate Eggs fell by seven million euro after a change in the recipe. When Coca Cola US decided to use Stevia instead of sugar in its Vitamin Water customers complained on Facebook, Twitter and other social media platforms so loudly that Coca Cola was forced to reverse the change several months later. In February of 2018, the Firm LRS replaced sugar with alternative sweeteners and fillers in its sweetened beverage Ribena. Many fans of the sweetened blackcurrant drink promptly publicly renounced their beloved beverage.
Sensory professionals often advise against announcing sugar reduction in products already introduced to the marketplace (Spence 2017). When consumers are made aware of a change, then they tend to become aware of each and every change in the taste profile. Our memory for aroma makes us particularly attuned to exactly such changes. It is much easier for us to remember a smell than to name a taste (Mojet 2016).
If a product doesn’t meet expectations in a first test series, the recipe is changed, and this in turn is sent back for renewed sensory market research testing. The researcher doesn’t just weigh the product variations against one another, but also asks test subjects to unlock the sensory profile of a product. What are the perceptions of the testers with regard to the characteristic sensory properties of the product? What characteristics are of special importance to the consumer? What could be changed to increase the pleasure in consuming the product? A group of trained product testers known as the sensory panel is right at the centre of this process. They are capable of putting their perceptions into words and make it possible for researchers to delve into the key attributes of the product. The result helps the producer to adapt the recipe. “Descriptive sensory analysis is the highest discipline in sensory research,” explains Robert Möslein. “We rely on panels with many years of experience that are specialized in milk products, beverages, chocolate as well as in other product categories.”
Sometimes, as is the case with cake, the reduction of sugar results in a loss of volume which in turn has to be substituted with fillers. This also results in changes with respect to mouthfeel or texture. Precisely these changes require the input of the sensory panel to identify olfactory changes, changes in texture or shifts in taste.
There is a big difference between the taste tests that one sees in TV shows or in the supermarket (“Try this please and point to the yogurt that tastes better.”) and the research done by sensory market researchers. They work according to scientific methods, follow DIN / ISO standards, use hundreds of product testers and analyze the results with the help of modern statistical methods. In the laboratory, they guarantee that the same amounts of a product are compared, under the same lighting conditions, at the same temperature and in adherence to other standard conditions. Moreover, they examine whether the laboratory results are also consistent with use in everyday situations: the muesli bars during the work break, the ice cream dessert on the kitchen table, the refreshment at the fitness centre. “Sometimes Television crews come to us and ask us if we could test a couple of food products,” explains Hans-Peter Volkmer, Managing Director at isi. “Most of them are astonished when we explain how all-encompassing the testing process has to be in order to deliver meaningful results.”
Various research groups are currently working intensely on the subject of sugar reduction. In a recent study, Denize Oliveira and her colleagues at the University of Uruguay demonstrated that a reduction in sugar levels in fruit nectar from four to eight percent (dependent upon the variety of fruit) was not perceptible to test subjects, and even a reduction of 20 percent had no influence on likeability (Oliveira 2018). As a general principle, the sweeter the standard nectar, the more sugar reduction is possible before customer satisfaction declines. However, the scientists discovered that the test subjects could be separated into two groups. One group especially preferred sugary drinks, the second group less so. As the sugar content of the fruit nectar sank, the subjects in the second group liked it even more. Denize Oliveira finds the results encouraging. “A gradual reduction in sugar in sweetened beverages is a realistic strategy that could result in a decline in sugar consumption resulting in a global improvement in health.”
One only needs to look at reductions in salt use to see how a quiet change in the nutritional behaviour of millions of people is possible. The Foods Standards Agency in Great Britain decided in 2003 that the salt content in processed foods in 86 different categories including bread, cereals and soups should be reduced. Eight years later, salt consumption in the general population had declined by 15 percent. During the same time period, the rate of strokes leading to death fell by 42 percent, which experts associate directly to salt reduced nutritional changes. Similar to the case of sugar reduction, sensory analysts like Gastón Ares from the University of Uruguay recommend that salt levels be reduced incrementally over a longer period of time (Antunez 2016). As soon as consumers become accustomed to a salt reduced diet, the next barely perceptible step can follow.
Is the sugar reduction strategy effective? The answer is still open. It will probably be possible for producers to bring low-sugar products to market. What is still not clear is how far consumers’ metabolic dispositions will go along with the change (Tey 2018, O’Reilly 2017). It is quite possible that the body just tries to get the calories some other way, and that consumers will start foraging in the freezer for some ice cream soon after consuming a sugar reduced yogurt. According to research by the Monell Institute, the worldwide leading research institute in the field of taste and smell, the sugar level of a beverage can be lowered, but the sweetness that the consumer perceives as optimal remains the same even after the sugar reduction.
Current Data from Germany indicates that an increased awareness in the population about high sugar consumption has already lead to a real change in consumer behaviour. According to the Robert Koch Institute, consumption of sweetened beverages among young adolescents increased in the period 2003 to 2006, but from 2012 to 2016 consumption sank from 83 to 78 litres per person. That is still too much, but the trend is going in the right direction. Health researcher Sigrid Gibson and her colleagues hope that this health trend will continue to grow as a result of the efforts of industry and the will of individuals (Gibson 2017).
There is no official strategy in Germany comparable to that of Great Britain. However, producers and supermarket chains in Germany have already begun to herald the change in sugar consumption. “The major players in the food sector that haven’t already intensified their efforts in sugar reduction might be at a disadvantage in the coming years,” says Robert Möslein. The reduction in sugar content in the food sector won’t make everyone in Germany lighter and healthier in an instant, but it is a step in the right direction towards a healthier lifestyle for everyone.”
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(from top to the bottom) - unsplash (candy), Peter Bond - unsplash.com (supermarket), isi Archiv (sensory lab), Cody Davis - unsplash.com (Orange), Toa Heftiba - unsplash.com (juice)
Dr. Fabienne Hübener is a freelance science journalist specializing in the senses and sensory research. She has been writing for us since 2017 and also likes to accompany our team with the video camera in the lab and at conferences.
Apr 2, 2018
isi has started to use Immersive Context in sensory research. The development gives customers ever...