Ice cream enriched with fish proteins may be acceptable after production, but storage is a problem, according to new research.
The study, published in Journal of the Science of Food and Agriculture, investigated the effects of enriching the frozen confectionery product with fish protein to enhance its nutritional value.
The authors, from the University of Iceland and the Iran Fisheries Research Organization (IFRO), found that that enriching ice cream with fish protein powder did not influence the sensory or chemical characteristics of the products after production, however unwanted attributes including fish flavour and off-odour were increased after more than 2 months of storage.
“The objective of this work was to study the influence of fortifying ice cream with fish protein on chemical characteristics and sensory quality of the product in order to provide some useful information to food industry on how to develop such products and with the specific aim of increasing fish protein consumption,” said the authors, led by Dr Gholam Shaviklo.
“From the results it can be concluded that ice cream with fish protein can have good sensory quality for up to 2 months after production,” they added.
Dr Shaviklo and his colleagues explained that a variety of food products can be fortified without distinguishing them from non-fortified foods. They said that several ingredients are used for enhancing the functional value of food products, including fish protein, soy protein, whey protein, olive oil, fish oil, certain fruits, nuts and minerals and vitamins.
‘Fishy’ flavours could be a problem when using fish protein ingredients, although, the researchers noted that most of the “fishy flavour components are removed” during fish protein production. The protein product (surimi) can then be dried and used for fortifying food products.
“There are a growing number of food products enriched with fish ingredients on the market,” said Shaviklo and colleagues.
“Fish ice cream is produced in Japan by using different types of aquatic products,” they added.
Fish ice cream with crab (Kani Aisu), eel (Unagi Aisu), octopus (Taco Aisu), and with shrimp (sakura Ebi Aisu) are all available and accepted on Japanese markets, said the authors.
However, they said that many studies report negative effects both on flavour and odour if fish proteins they are used to enrich foods at inappropriate levels.
“These effects depend mainly on the amounts of ingredients and type of product,” they said.
They said that the fortification of ice cream with different types of proteins, including soy and whey proteins, have been reported to have little effects on sensory properties and consumer liking.
The new study investigated the effect of fortification with different levels of fish protein powder (FP) on chemical properties and sensory quality of Persian ice cream.
The ice cream was prepared from cow milk according to a traditional recipe for Persian ice cream. Three prototype fortified ice creams were prepared by replacing 10, 20 and 30 grams per kg of milk with fish protein powder, for an initial sensory analysis.
In the initial sensory analysis test, the authors reported no differences for colour, odour, flavour, texture and overall acceptability between ice cream with 10, 20 or 30 grams per kg fish protein powder and a non-FP control ice cream.
“Two products with 30 and 50 grams per kg FP, along with a control product, were [then] selected to study the influence of fish protein fortification on sensory properties of ice cream during storage,” said the authors.
Shaviklo and colleagues found there were no differences between fortified samples and the control after production – except for colour.
After two months of storage at − 18 °C, significant differences were detected between products. In the fortified products, fishy, rancid and ‘off’ odours and flavours, in addition to bitterness and sandiness increased, whilst cohesiveness decreased and colour faded.
The authors said that further studies “on how to stabilise the sensory properties of fortified ice cream to improve eating quality are needed,” whilst studies on consumer acceptance and attitudes “are also recommended if companies are planning such products.”
Source: Journal of the Science of Food and Agriculture
Published online ahead of print, doi: 10.1002/jsfa.4299
“Chemical properties and sensory quality of ice cream fortified with fish protein”
Authors: G.R. Shaviklo, G. Thorkelsson, K. Sveinsdottir, F. Rafipour