Enzyme-assisted extraction enhancing the umami taste amino acids recovery from several cultivated mushrooms

Effects of different pretreatments and proteases on recovery, umami taste compound contents and antioxidant potentials of Labeo rohita head protein hydrolysates

Effects of the pretreatments namely heating, microwave (MW), and ultrasound (US), followed by the enzymatic hydrolysis using different proteases (flavourzyme, neutrase, and protamex) on the protein recovery, umami taste compound content, and antioxidant activities of the Labeo rohita head (LRH) protein hydrolysate was investigated. US and MW pretreatments increased the protein recovery, MSG-like amino acid and flavour 5'-nucleotide contents, equivalent umami concentration (EUC) and antioxidant activities of LRH protein hydrolysates significantly (p < 0.05). The type of enzyme influenced the protein recovery and EUC significantly but did not influence the flavour 5'-nucleotide content of LRH protein hydrolysate (p > 0.05). The highest recovery yield of LRH protein hydrolysate (69.75%) was obtained with the MW pretreatment followed by the protamex hydrolysis, while the highest EUC (41.82 g monosodium glutamate (MSG)/kg) was yielded with the combination of the US pretreatment and the flavourzyme hydrolysis. These results indicate that US and MW pretreatments can help to enhance the recovery yield, umami taste compound content and antioxidant activities of the LRH protein hydrolysate.

Production of Different Mushroom Protein Hydrolysates as Potential Flavourings in Chicken Soup Using Stem Bromelain Hydrolysis

The pleasant taste of edible mushrooms, which is attributed to their high protein content, makes them an attractive source for the production of protein hydrolysates with good taste properties. In the present work, different mushroom protein hydrolysates were produced from shiitake, oyster, bunashimeji and enoki mushrooms using stem bromelain hydrolysis at 0.5% (m/m) enzyme/substrate ratio at pH=6.5 and 40 °C for 20 h. The produced liquid mushroom protein hydrolysate yielded 0.77–0.92% crude protein (p>0.05). Bunashimeji mushroom protein hydrolysate was the lightest in colour, while shiitake mushroom protein hydrolysate was the darkest (p<0.05). Enoki mushroom protein hydrolysate had the highest dry matter content. There was no significant difference in the degree of hydrolysis among different mushroom protein hydrolysates (53.52–67.13%, p>0.05), with the highest yield of bunashimeji and the lowest of shiitake mushroom protein hydrolysate (p<0.05). Preference test of chicken soup with added different mushroom protein hydrolysates was performed using 58 untrained panellists to evaluate their taste-enhancing effect, compared to monosodium glutamate (MSG). Soup with MSG had the highest score for the tested attributes, while soups with bunashimeji and oyster mushroom protein hydrolysates showed higher aroma, taste, mouthfeel and overall preference scores than negative control, which contained neither MSG nor any of the hydrolysates (p<0.05). This finding suggests that bunashimeji and oyster mushroom protein hydrolysate have the potential to be used as taste enhancers in food applications.