Writing in LWT - Food Science and Technology, a team of scientists from the UK have demonstrated that is possible to repuropse fish industry by-products for the generation of fish flavour formulations using a method that involves protease biocatalysis.
Led by Irene Peinado Pardo from Northumbria University, the team used amino acid-rich extracts derived from fish by-products, along with added glucose and/or fish oil, to generate seafood flavours and flavour precursors that have added-value.
Peinado and her UK-based colleagues said the development of novel means of processing to convert various sources of food wastes and by-products into forms that are safe, marketable and acceptable to the consumer has become an area of growing interest in recent years.
“[The] conversion of low value fish derived materials such as fish powder, into more valuable products such as flavour precursors and subsequently flavour compounds might be a commercially viable proposition for the fish industry,” concluded the team.
The team tested how a fish powder hydrolysates (FPH) generated from waste sources could be used as a source of amino acids for the generation of value-added flavours. With the addition of a source of sugar and fish oil, Peinado and her team successfully produced volatiles at a laboratory scale.
“The use of various enzymes produced different amounts of amino acids in the FPHs with important amounts of lysine, leucine, glutamic acid and alanine being released,” they wrote - adding that enzyme “B” (exopeptidase) on its own or in combination with endopeptidases is suggested as the starting point to liberate amino acids from fish protein, while the dual activity enzyme “A” produced a lower amount of free amino acids.
Indeed, a combination of endo and exo peptidases resulted in the most marked increased in free amino acids, particularly for leucine, lysine and glutamic acid, they said.
“Fish oil had a great impact on the volatile compounds associated with fish aroma; its addition enhanced the concentration of some lipid oxidation products such as hexanal, heptanal, 4-heptanal, 2,4,-hetadienal, 1-penten-3-ol or 1-octen-3-ol, characteristic impact compounds in seafood, that have been previously identified in the volatile profile of cooked fish or meals containing seafood,” wrote Peinado and her colleagues.
They added that ‘grilled’ and ‘fried’ aromas, which were generated when FPHs heated with fish oil, were preferred by sensory panellists, “while fish oil on its own produced unpleasant aromas.”
“Future work involving different types and concentrations of fish oil together with sensory evaluation is suggested to investigate the acceptability of seafood-derived fish-like flavouring formulations based on such approaches,” they said.
Source: LWT - Food Science and Technology
Published online ahead of print, doi: 10.1016/j.lwt.2015.09.025
“Production of seafood flavour formulations from enzymatic hydrolysates of fish by-products”
Authors: I. Peinadoa, G. Koutsidisa, J. Amesb