Krill Protein Hydrolysate Provides High Absorption Rate for All Essential Amino Acids—A Randomized Control Cross-Over Trial

Background: adequate protein intake is essential to humans and, since the global demand for protein-containing foods is increasing, identifying new high-quality protein sources is needed. In this study, we investigated the acute postprandial bioavailability of amino acids (AAs) from a krill protein hydrolysate compared to a soy and a whey protein isolate. Methods: the study was a randomized, placebo-controlled crossover trial including ten healthy young males. On four non-consecutive days, volunteers consumed water or one of three protein-matched supplements: whey protein isolate, soy protein isolate or krill protein hydrolysate. Blood samples were collected prior to and until 180 min after consumption. Serum postprandial AA concentrations were determined using (1)H NMR spectroscopy. Hunger and satiety were assessed using visual analogue scales (VAS). Results: whey and krill resulted in significantly higher AA concentrations compared to soy between 20–60 min and 20–40 min after consumption, respectively. Area under the curve (AUC) analyses revealed that whey resulted in the highest postprandial serum concentrations of essential AAs (EAAs) and branched chain AAs (BCAAs), followed by krill and soy, respectively. Conclusions: krill protein hydrolysate increases postprandial serum EAA and BCAA concentrations in a superior manner to soy protein isolate and thus might represent a promising future protein source in human nutrition.