Sheep taste good at all ages

In a research project with the goal of developing tasty products based on lamb and mutton, researchers at Nofima have carried out tests both with a trained sensory panel and with consumers. One of the conclusions is that mutton has a large potential.

“We believe that lamb has better eating quality than mutton, but our tests showed that most people do not taste any difference between lamb and mutton from a 4-year-old sheep,” says project leader Kristine S. Myhrer of Nofima.

The overall aim in the project was to test the market potential of mutton to improve the use of the raw materials and to increase added value.

Descriptive words

Which sensory attributes do we find in lamb and mutton? Can the meat be described as sour, metallic, like wet wool, of liver, rancid, cloying, or malodour? Is the meat tough, tender, juicy, fatty or grainy?

In particular, the scientists wanted to obtain knowledge about the vocabulary that consumers use for descriptions of meat from lambs and sheep. Which words have positive associations, and which ones negative?

The test was carried out in March 2015 with 90 consumers who tasted samples from three legsof lamb (from an animals aged four months) and samples from three legs of mutton (from an animals aged four years).

“The consumers were asked to indicate their liking of the sample on a scale from 1-9, and subsequently to select the words they would use to describe the sample,” explains Kristine Myhrer.

The consumers were given a list of 36 descriptors to choose from. The words they chose can be seen in the word cloud that illustrates this article:

“Lean”, “mild” and “tender” were the most prominent words in the description of the lamb.

“Mild”, “juicy”, and “tender” were most commonly used for descriptions of the mutton.

Finally, the consumers were asked to complete a questionnaire about their consumption of lamb and mutton, and their attitudes to the two types of meat.

“When consumers are asked to choose which type of meat they would serve for an Easter meal or for the traditional Norwegian autumn meal based on lamb and cabbage, most consumers stated that they preferred lamb to mutton. However, our experiments demonstrate that consumers do not perceive large differences between lamb and mutton when they do not know what they are eating. Some consumers in the study also confused lamb with pork, and mutton with beef,” says Kristine S. Myhrer.

Sensory

Sensory analysis describes properties that the human senses can experience when eating and drinking: the smell, taste, appearance and the texture of a product. Only by studying human senses can we understand how food is experienced by the consumer.

The professional assessors at Nofima have been selected on the basis of their abilities to smell and taste, which satisfy the ISO requirements for sensory analysis. The sensory panel undergo regular training, testing and monitoring. The sensory assessors do never discuss whether they like or do not like what they eat: instead they take an analytical approach to how the food can be described.

The results of the analyses carried out by the sensory panel on lamb and mutton show that lamb has a mild taste and is experienced as more sour, while roast mutton has a more powerful total intensity of both smell and taste. The lamb is also experienced as somewhat more tender than mutton. However, the differences in attributes were all relatively small.

It is also important to emphesize that none of the samples of roast mutton was experienced as tasting of wool, which is a commonly held belief about the taste of mutton.

The Nofima scientists point out that a sheep’s leg is, of course, heavier than a lamb’s leg and thus gives more meat, so if a meat with a stronger, gamey taste is desired, it’s a good idea to try preparing a roast from older animals.

Meatballs

The work to analyse the taste of mutton and lamb started as early as the autumn of 2013, and was followed up with further experiments in 2014. The sensory panel was initially used to study differences in the sensory properties of meatballs with different fat percentages from lamb and sheep of different ages. The meatballs were produced by Nortura, and the results showed that meatballs from older animals had a stronger intensity of taste than those from younger animals.

When corresponding tests with meatballs were carried out with untrained persons, however, a different picture emerged: They were not able to distinguish between mutton and lamb in a blind test. In contrast, when the consumers were told whether they were eating mutton or lamb, more consumers were able to tell the difference, but the result was not significant.

“In summary, we can say that the sensory panel can distinguish between lamb and mutton, while consumers cannot do so in blind tests. We can also say that information about and expectations to products increases the sensitivity of the consumers. This means that it is important to continue to study the effect of information,” says Kristine S. Myhrer.

Based on all of the investigations that the scientists carried out, they also conclude that consumers often have low expectations to products based on mutton, and that this may have a negative effect on the taste experience.

And the main conclusion:

“There is a potential to improve consumers perceptions of mutton both by positive communication and new products in the market.”

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