Green fractionation and hydrolysis of fish meal to improve their techno-functional properties.

A green strategy employing water as solvent has been adopted to obtain protein hydrolysates from fish meal (FM), its water-soluble fraction (WSP), and its non-water-soluble fraction (NSP). The techno-functional properties of the hydrolysates have been investigated and compared to hydrolysates obtained with Alcalase®. In general, SWH hydrolysates presented higher content of free amino acids and higher degree of hydrolysis, which reflected on the molecular size distribution.

Degradation kinetics of sugars (glucose and xylose), amino acids (proline and aspartic acid) and their binary mixtures in subcritical water: Effect of Maillard reaction.

A systematic kinetic study was conducted in subcritical water medium in the temperature range from 150 to 200 °C for pure glucose, xylose, proline and aspartic acid as well as binary mixtures of sugars + amino acids to understand the reaction kinetics and interactions among biomass components and to discern the influence of Maillard reaction (MR) on the overall reaction kinetics. The main degradation products identified for glucose and xylose were the respective dehydration products, hydroxymethyl furfural and furfural, yielding an increasing solid residue with temperature (15.9 wt% at 200 °C) with an augmented heating value.

Production of small peptides and low molecular weight amino acids by subcritical water from fish meal: Effect of pressurization agent.

The hydrolysis of the water-soluble protein (WSP) fraction from tuna fish meal was evaluated by subcritical water (subW) by using N and CO as different pressurization agents in the temperature range from 140 to 180 °C. For both gases, the amino group release increased by increasing working temperature while the Lowry response decreased due to production of smaller-size peptides and free amino acids. The free amino acid content was higher with CO than with N.

Subcritical water as hydrolytic medium to recover and fractionate the protein fraction and phenolic compounds from craft brewer's spent grain.

The valorization of the brewer's spent grain (BSG) generated in a craft beer industry was studied by subcritical water hydrolysis in a semi-continuous fixed-bed reactor. Temperature was varied from 125 to 185 °C at a constant flow rate of 4 mL/min. Biomass hydrolysis yielded a maximum of 78% of solubilized protein at 185 °C.