Effect of protein extraction and fractionation of chia seeds grown in different locations: Nutritional, antinutritional and protein quality assessment

Chia (Salvia hispanica) has become increasingly popular in recent years due to its high protein content, among other nutritional benefits. This study aims to evaluate the nutritional and antinutritional composition, protein profile and protein quality of two chia seeds grown in Mexico and the UK, as well as to assess the impact that occurs during protein extraction and fractionation. Protein content of chia samples showed an increase after degumming, defatting, and extraction, obtaining protein concentrates from Mexican (MPC) and British (BPC) chia seeds with 88.32 and 89.20 g/100 g dw, respectively. Main protein fractions found in both chia seeds were globulins (Glo) and albumins (Alb). Essential amino acid index (EAAI) of chia samples ranged between 189.40 and 496.73% showing a 2-fold increase in comparison to the reference protein. In vitro protein digestibility (IVPD) increased after protein extraction (91% for MPC and BPC) but decreased after fractionation (similar to 68%). Trypsin inhibitors increased 78-82% after protein extraction, while total phenolics content (TPC) increased 7.77and 5.76-fold for Mexican albumins (MAlb) and British albumins (BAlb), respectively. Phytic acid content showed a reduction of > 90% after extraction/fractionation. These findings showed that depending on the extraction and/or fractionation methods used the protein quality, digestibility and antinutrients will be highly influenced.