Preparation, composition, and functional properties of a protein isolate from a defatted mamey sapote (Pouteria sapota) seed meal

The proximate composition, functional properties, and proportion of protein fractions in a mamey sapote defatted meal (MSDM) were investigated. Additionally, a mamey sapote protein isolate (MSPI) was obtained by isoelectric precipitation from MSDM and partially characterized. MSDM had a protein content of 240.6 g/kg with the following protein distribution: glutelins (57.25%), prolamins (18.65%), albumins (17.85%) and globulins (6.25%). The maximum solubility and precipitation of MSDM proteins were found at pH 9.8 and 3.5, respectively. MSPI had a protein content of 950.9 g/kg and an in vitro digestibility of 73.6%. MSPI exhibited a lower water absorption capacity than MSDM but higher oil absorption and emulsifying capacities. The highest foam capacity (76.79%), foam (29.73%) and emulsifying (70.0%) stabilities of MSPI were obtained at pH 10. These results demonstrate that MSDM is a suitable material for the production of a high-purity protein isolate that could be used as an ingredient in meat or bakery products.