Assessment of the Physicochemical, Textural, Sensory, and Antioxidant Properties of Sorbet Enriched with Alfalfa Protein Concentrate

This study investigated alfalfa protein concentrate (APC) as a functional ingredient for developing protein-enriched apple sorbet. APC obtained by ultrasound-assisted aqueous extraction was characterized for its physicochemical, nutritional, phytochemical, antioxidant, textural, and functional properties and incorporated into sorbet at 2.5–10%. APC contained 86.45% protein (DW), 2297.4 mg GAE/100 g DW total polyphenols, and 983.6 mg QE/100 g DW total flavonoids. APC incorporation increased sorbet protein content from 0.11% in the control sample to 8.05% at 10% APC, while total polyphenols increased from 243.22 to 579.58 mg GAE/100 g DW and ABTS antioxidant activity from 487.41 to 904.49 mg TE/100 g DW. Following simulated gastrointestinal digestion, ABTS activity reached 1110.71 mg TE/100 g DW at 10% APC. Increasing APC concentrations reduced protein digestibility from 74.90% to 55.83%, overrun, hardness, and apparent viscosity and progressively modified sorbet color. Sensory evaluation showed the highest acceptance for formulations containing 2.5–7.5% APC, whereas 10% APC reduced sensory quality. Overall, moderate APC incorporation provided an effective balance between nutritional and functional enhancement and sensory acceptability.