Structural, Thermal, Physicochemical, and Techno-Functional Properties of Proteins from Pequi (Caryocar brasiliense) Almonds

Abstract

Pequi (Caryocar brasiliense) is a native fruit of the Brazilian Cerrado, known for its nutritional value, which contains approximately 30% protein and 50% lipids. This study aimed to obtain defatted pequi almond flour through hydraulic pressing and Soxhlet extraction, produce a protein isolate via isoelectric precipitation, and evaluate its properties for food applications. The protein extraction yield from defatted pequi flour was 69.01%, resulting in a protein isolate with a content of 91.16%. The thermal stability analysis revealed a denaturation temperature of 83.87 °C and an enthalpy of denaturation of 1.61 J·g–1. The protein isolate exhibited secondary structures of 10.76% α-helices and 55.14% β-sheets, reduced solubility at pH 4.43, and notable oil (155.30%) and water (80.42%) holding capacities. Compared with conventional proteins, emulsions containing 0.25% isolate demonstrated greater stability over 28 days, highlighting the potential of the isolate for use in food systems.