Dried fish stock may be salt enhancer for food

Promising results published in the Journal of Food Science​ indicate that the salt content of certain food products could be reduced by 15 percent without affecting palatability.

“The results of these sensory evaluations indicated that the characteristic flavor of dried bonito stock induced saltiness enhancement,”​ wrote M. Manabe from Doshisha Women’s College of Liberal Arts in Kyoto.

“In everyday Japanese food, the flavor of dried bonito stock could enhance saltiness and prevent the loss of palatability that would otherwise result from reducing the salt content. ​

“This finding is expected to be useful for improvement of the palatability of salt-reduced food,”​ added Manabe.

A body of evidence has linked excess salt (sodium chloride) in the diet to an increased risk of high blood pressure and stroke. Campaigns are underway around the world to encourage consumers to reduce their daily intake. The UK's Food Standards Agency (FSA), for example, advises that adults should consume no more than six grams of salt a day.

While an important part of reformulating foods to contain less salt lies with enhancing the taste of the salt that is there, ingredients companies are collaborating with their customers to do their part in reducing sodium in the individual components that go in to a finished product.

Study details​

The Japanese researcher performed two sensory evaluations. In the first, which used a model system, the saltiness of a salt solution containing 0.8 percent sodium chloride was achieved with only 0.68 percent sodium chloride when used in combination with the dried bonito stock (six percent).

On the other hand, no enhancement of saltiness was observed when 0.12 percent monosodium glutamate (MSG) was used.

In the second evaluation, the dried stock was tested in two Japanese foods – a traditional soup and a steamed egg custard.

While no salt-enhancement was observed in the soup, wrote Manabe, a reduction of the salt content by 15 per cent did not affect the perceived palatability.

When formulated into the custard, however, saltiness and palatability were enhanced by the fish stock.

“These results suggested that the dried bonito egg custard was considered palatable even if the NaCl concentration was decreased to 0.75 percent,”​ wrote Manabe.

Chemistry behind bonito​

According to Manabe: “The characteristic flavor of dried bonito stock is very popular with the Japanese. Inosine 5'-monophosphate (IMP), another typical umami substance, is known to be a major contributor to the flavor that has ensured the popularity of dried bonito as a stock. ​

“In addition to IMP, the stock contains various taste active components, including glutamic acid, histidine, lactic acid, and others. Moreover, the aroma of dried bonito stock is also an important factor in its desirability.”​

Source: Journal of Food Science​August 2008, Volume 73, Issue 6, Pages S321-S325, doi: 10.1111/j.1750-3841.2008.00844.x“​Saltiness Enhancement by the Characteristic Flavor of Dried Bonito Stock”​Author: M. Manabe