Tasty waste: Seaweed by-product may offer industry flavour potential
Writing in Food Chemistry, scientists from Thailand revealed that it is possible to isolate seafood-like flavours for industrial use from the waste streams of seaweed agar production via the production of seaweed protein hydrolysates.
Led by Natta Laohakunjit from King Mongkut’s University of Technology, the team noted that thermally processed flavourings have become widely used as savoury flavouring agents in various products, such as soups, sauces, snacks, and ready meals.
"Seaweed by-products after agar extraction are good sources of plant protein and contain taste-active amino acids, such as aspartic acid, glutamic acid, arginine, and lysine, in addition to a low fat content," explained the team.
The new research demonstrates the potential to produce a paste-like enzymatic bromelain seaweed protein hydrolysate (eb-SWPH) which has the potential to be used in the identification and isolation of seafood flavours from a non-animal waste stream source.
Currently, protein hydrolysates from marine animal sources - including fish, shrimp, clam, crab, and seafood by-products - are generally used to produce seafood flavourings.
"The paste-like eb-SWPH demonstrates great potential as a precursor to thermally processed seafood-like flavour that can be used as a flavour supplement and as a savoury flavour source for various seafood products," said Laohakunjit and colleagues.
"The meaty or beefy flavour is generated by heating a combination of protein hydrolysate, amino acids, and reducing sugars under controlled conditions through the Maillard reaction," the team explained - adding that the thermal processing of a variety of plant protein sources including soy, wheat, and Brassica have been shown to produce meaty or beefy flavours to replace flavouring agents from animal protein sources.
The team produced and characterised an enzymatic bromelain seaweed protein hydrolysate (eb-SWPH) using enzyme activity = 119,325 U/g) at 0–20% (w/w) for between 0.5–24 hours.
"The proposed model took into account the interaction effect of the enzyme concentration and hydrolysis time on the physicochemical properties and volatile components of eb-SWPH," said the team, who revealed that the optimal hydrolysis conditions for the production of eb-SWPH were 10% bromelain for three hours - which resulted in a 38.15% yield and a 62.91% degree of hydrolysis value.
"Three free amino acids, arginine, lysine, and leucine, were abundant in the best hydrolysate," they said - adding that ten volatile flavours of the best eb-SWPH were identified using gas chromatography/mass spectrometry.
"The predominant odourants were hexanal, hexanoic acid, nonanoic acid, and dihydroactinidiolide. The thermally processed seafood flavour produced from eb-SWPH exhibited a roasted seafood-like flavouring."
Source: Food Chemistry
Volume 158, 1 September 2014, Pages 162–170, doi: 10.1016/j.foodchem.2014.02.101
"Seafood-like flavour obtained from the enzymatic hydrolysis of the protein by-products of seaweed (Gracilaria sp.)"
Authors: Natta Laohakunjit, Orrapun Selamassakul, Orapin Kerdchoechuen