Screening of protein hydrolysates from malt rootlets and their relationship with technological properties

The malting industry produces a large quantity of by-products, and these have barely been explored in the research into their valorisation. Malt rootlets are rich in protein, and that content can be extracted to generate ingredients with a range of functionalities. Our study confirms that the extraction conditions for the type of enzyme and concentration, as well as the temperature, can affect the production yield and properties from malt rootlets protein hydrolysates. The pH effect was also studied, and it has only shown an effect on technological properties. Alcalase & REG; can generate protein hydrolysates with higher protein content, reaching 33.2%, which in turn implies a higher emulsifying activity (up to 33.9% greater). On the other hand, Protamex & REG; ensures a higher weight yield (up to 49.8%) and higher emulsifying stability, reaching 53.6%. In any case, protein hydrolysates do not improve foaming capacity on malt rootlets mainly due to relative low values of total protein content needed for these properties. All protein hydrolysates showed a high angiotensin-converting enzyme (ACE) inhibitory activity attributed to the similar amount of low molecular fraction (500-200 Da) present in all samples.