Obtention and evaluation of physico-chemical and techno-functional properties of macauba (Acrocomia aculeata) kernel protein isolate

The consumption of plant proteins is increasing worldwide. These proteins have an important role in human nutrition as well as in the technological properties of foods. Thus, there is a great interest in exploring new sources of plant proteins, such as macauba (Acrocomia aculeata), which is a promising tropical palm tree, native to Brazil, whose fruits are rich in oil, proteins and dietary fiber. Hence, the objective of this work was to obtain and evaluate the physico-chemical and techno-functional properties of the macauba kernel protein isolate (MKPI). Defatted macauba kernel flour was obtained and used to produce the MKPI by isoelectric precipitation. Then, the proximate composition, amino acid profile, and physico-chemical and techno-functional properties of the MKPI were determined. The MKPI stood out for its high protein content (94.9%) and high levels of arginine (16.21%) and glutamate (20.84%). The MKPI average isoelectric point was at pH 4.9 and its proteins showed low solubility in the pH range from 4.0 to 6.0. Moreover, the hydrophobicity of MKPI proteins was higher at pH 3.5 than at pH 7.0, and they had higher oil holding capacity (153.77%) than water holding capacity (97.29%). Regarding the MKPI emulsifying and gelling properties, emulsions with 0.5% and 1.0% of MKPI remained stable during storage and the minimum gelling concentration was 14%. Thus, the MKPI has a great potential to be produced and used by the food industry due to its nutritional and techno-functional properties.