Preparation of protein powder from the liver of Yellowfin tuna (Thunnus albacores): a comparison of acid- and alkali-aided pH-shifting

For the high-value utilization of tuna liver, effects acid-aided (Acid-pH) and alkali-aided pH-shifting (Alkali-pH) on physicochemical functional properties protein powder prepared by freeze-drying were studied. As expected, with high purity could be obtained through Acid-pH or Alkali-pH followed freeze drying, while led to a higher yield, ratio, lower lipid ratio heavy metal content than Acid-pH. The amino acid profile (Alkali-PP) was similar that (Acid-PP). In addition, compared Acid-PP, Alkali-PP possessed greater capacities in emulsion activity, foaming capacity fat absorption capacity. Furthermore, capacity, foam stability better soy powder. Therefore, would alternative prepare high-quality from liver food industry.