Supercritical CO2 and subcritical water technologies for the production of bioactive extracts from sardine (Sardina pilchardus) waste

Multi-Step Subcritical Water Extracts of Fucus vesiculosus L. and Codium tomentosum Stackhouse: Composition, Health-Benefits and Safety

“…The total protein content of the SWE extracts is shown in Table 5. Subcritical water extracted and hydrolyzed the protein fraction of the seaweeds, and the temperature was beneficial to obtain extracts richer in protein, confirming the behavior reported by other authors [30,83]. C. tomentosum extracts had higher protein contents than F. vesiculosus extracts, which was expected, given the much higher initial protein content of C. tomentosum (see Table 1).…”

“…50% of C. tomentosum. Two consecutive processes occur during SWE extraction/hydrolysis of seaweeds: the direct extraction of the most soluble proteins, especially at lower temperatures, and the hydrolysis of the proteins into small peptide units and/or free amino acids at the higher operating temperatures [83].…”

Protein Hydrolysis by Subcritical Water: A New Perspective on Obtaining Bioactive Peptides

“…It is understood that the increase in temperature promotes an increase in the hydrolysis rate constants and, with it, a reduction in the reaction time. Attention to the conditions of the process is relevant as the objective is to obtain bioactive peptides, because, although the increase in temperature reduces the process times, accelerating the process can lead to a greater release of amino acids by the medium, promoting the degradation of larger amino acids (more thermosensitive) into smaller amino acids [51], and increasing the products of the Maillard reaction (increasing the browning) [55] or the generation of products derived from the hydrolysis of the latter degradation products such as organic acids [56]. The kinetics of the reactions that can be carried out during an SW process are discussed in the next section.…”

“…The reaction due to the bicatalytic characteristics of water could be carried out in the same way with the union at the onset of the ion OH − and after the proton H + . It is relevant to mention that the increase in ions modifies the pH of the medium correlated with the temperature of the treatment, observing a tendency to decrease at temperatures below 180 • C and increase above 200 • C, mainly associated with the degradation of amino acids and reaction products of Maillard [45,51,62].…”

“…Hao and coworkers [41] used a unifactorial approach to evaluate the effect of temperature from 110 • C to 230 • C in the antioxidant activities and protein hydrolysis of abalone viscera. Similarly, Melgosa and coworkers [51] used a temperature range up to 250 • C to hydrolyze sardine protein to improve its antioxidant and antiproliferative biological activity. It is always important to keep in mind, nonetheless, that when there would be interaction effects among factors, OFAAT experimentation is inefficient in the usage of resources and potentially induces a loss of information when more factors than temperature and pressure are involved in the process or some component within the raw material may have an effect on the performance of the same process [69].…”