The addition of natural umami-containing ingredients during the cooking of meat can provide enhanced umami and salty taste characteristics. This can lead to increased liking by some consumers, particularly those with raised taste detection thresholds.

Diminished sensory ability, and specifically smell and taste deterioration caused by ageing or due to medication and illness, is one common factor which contributes to malnutrition within older adults (1) . However, it has been shown from previous studies that flavour enhancement of food using monosodium glutamate and/or added flavours resulted in increased food intake among sick and healthy elderly individuals (2) .The aim of this study was to increase the liking of food for older adults by enhancing the savoury (umami) characteristics. The novelty of this project lies in the optimisation of naturally occurring tastants at levels preferred by an elderly cohort. Initially, a variety of natural ingredients, such as fermented soy products (soy sauce and miso paste), yeast extract, shiitake mushroom extract and mycoscent (a natural flavouring which is a byproduct of mycoprotein) were used in order to increase the umami taste of minced meat samples. These samples were then offered to a group of older volunteers (n 32, age 62-83, mean 73) and they were asked to score their liking. There was no significant difference in consumer mean liking between the products, nor any correlation between liking and umami intensity.To further intensify the umami taste of the minced meat samples, combinations of the soy sauce (Kikkoman) with mycoscent or shiitake extract or a commercial concentrated tomato extract (Santé, Lycored Ltd.) were prepared. The minced meat samples were evaluated by a trained analytical sensory panel (n 10) using quantitative descriptive profiling and, after appropriate ethics approval, by older volunteers (n 36, age 62-87, mean 71), who scored liking using a nine-point hedonic scale. Mean values with the same superscript letters were not significantly different (Nemenyi's procedure for non-parametric data; P < 0.05).From the sensory evaluation of the samples it was found that there were significant differences (P < 0.05) in thirty-seven attributes among which the most important, as seen in Fig. 1, are umami taste, sweetness and bitterness, and flavour attributes such as beef stock, yeast extract and shiitake mushroom flavour. From the liking results the soy sauce plus tomato extract sample had the highest mean liking score, but there was no significant difference in mean liking. Considering the positive and negative comments made by the volunteers about the samples, the sensory profile and the liking scores, the soy sauce plus tomato extract sample will be taken forward to the next part of the study which includes the taste enhancement of a real food (cottage pie) served in the hospital.Study was sponsored by Research into Ageing.

2016-12-23T18:49:38

No abstract

Umami has been recognised for over a century and is now known as the fifth taste, alongside, salty, sweet, sour and bitter (1) . Monosodium glutamate (MSG), a glutamate salt, is the most common source of umami and is known to increase palatability of foods through flavour enhancement (2,3) , increase food intake (4) , improve immunity and physical strength in both sick and healthy older people (5) . However, as direct addition of MSG to food has raised some concerns, this research seeks to identify alternate natural sources of umami that may be used to enhance the flavour of foods for older adults, especially those at risk of malnutrition.In this research, a meat formulation developed from a typical UK recipe of cottage pie was selected to be representative of a complex food in real meat system. It consisted of minced meat, onion, olive oil, stock, tomato puree, plain flour and salt. Different natural sources rich in umami (yeast extract 1, yeast extract 2, soy bean paste and tomato paste) were used and the amounts added were determined by the Equivalent Umami Concentration equation (6) equivalent to MSG at 0.5 % (w/w). These ingredients were individually added into the meat formulations, to investigate whether they enhanced umami intensity. The four modified meat products alongside the meat control and meat with added 0.5% MSG were evaluated by thirteen panellists, using a quantitative descriptive profile. Six groups of sensory attributes (appearance, smell, taste, flavour, mouthfeel and after effect) were developed from a consensus vocabulary session; the panel were asked to score each attribute on an unstructured line scale, 0-100 mm. Thirty-two of fifty-seven attributes showed significant (P < 0.05) differences between the meat products, including umami intensity (P = 0.0088). Overall, results of this study showed the potential to use the natural ingredients rather than MSG to enhance umami intensity, as all, but one of the modified products, had a mean umami score higher than the control and similar to the formulation where MSG was added directly. However, where tomato paste was added to meat, the umami score was significantly (P < 0.05) lower than other enhanced formulations. This unexpected effect may be caused by sweetness and/or sourness suppression; hence, sweet and sour tastes were found substantially (P < 0.0001) higher where tomato paste was added. Future work, therefore, is to investigate whether sugar and acid compounds suppress umami perception in real food systems.