Optimizing the Extraction of Bioactive Compounds (Polyphenols, Lipids, and Alpha-Tocopherol) from Almond Okara to Unlock Its Potential as Functional Food
Mariam Taha,
Krasimir Dimitrov,
Jennifer Samaillie,
Benjamin Caux,
Sevser Sahpaz,
Nicolas Blanchemain,
Caroline West,
Céline Rivière
Affiliations
Mariam Taha
BioEcoAgro, Joint Research Unit 1158, University of Lille, INRAE, University of Liège, UPJV, JUNIA, University of Artois, University Littoral Côte d’Opale, ICV—Institut Charles Viollette, 59650 Villeneuve-d’Ascq, France
Krasimir Dimitrov
BioEcoAgro, Joint Research Unit 1158, University of Lille, INRAE, University of Liège, UPJV, JUNIA, University of Artois, University Littoral Côte d’Opale, ICV—Institut Charles Viollette, 59650 Villeneuve-d’Ascq, France
Jennifer Samaillie
BioEcoAgro, Joint Research Unit 1158, University of Lille, INRAE, University of Liège, UPJV, JUNIA, University of Artois, University Littoral Côte d’Opale, ICV—Institut Charles Viollette, 59650 Villeneuve-d’Ascq, France
Benjamin Caux
ICOA, CNRS UMR 7311, Pôle de Chimie, University of Orleans, Rue de Chartres BP 6759, CEDEX 2, 45067 Orleans, France
Sevser Sahpaz
BioEcoAgro, Joint Research Unit 1158, University of Lille, INRAE, University of Liège, UPJV, JUNIA, University of Artois, University Littoral Côte d’Opale, ICV—Institut Charles Viollette, 59650 Villeneuve-d’Ascq, France
Nicolas Blanchemain
INSERM, CHU Lille, U1008—Advanced Drug Delivery Systems, 59000 Lille, France
Caroline West
ICOA, CNRS UMR 7311, Pôle de Chimie, University of Orleans, Rue de Chartres BP 6759, CEDEX 2, 45067 Orleans, France
Céline Rivière
BioEcoAgro, Joint Research Unit 1158, University of Lille, INRAE, University of Liège, UPJV, JUNIA, University of Artois, University Littoral Côte d’Opale, ICV—Institut Charles Viollette, 59650 Villeneuve-d’Ascq, France
Almond okara, a by-product of almond milk production, is rich in bioactive components, such as polyphenols, lipids, and alpha-tocopherol, making it a valuable functional food ingredient. This work aimed to investigate its composition while exploring two main aspects: (i) the impact of extraction time, solid-to-solvent ratio, ethanol concentration, and temperature on polyphenol recovery, and (ii) the quantification of okara’s triglycerides (TG) and alpha-tocopherol contents. The polyphenols’ optimal extraction conditions were 90 min, a 1:30 solid-to-solvent ratio (w/v), 50% ethanol, and 60 °C. These conditions achieved a total polyphenol yield of 523 mg GAE, tannin yield of 340 mg GAE, total flavonoid yield of 548 mg CE, and a total antioxidant capacity of 779 mg AAE per 100 g dry okara. The Peleg model effectively described the extraction kinetics. Additionally, TG levels, quantified by UHE/LPSFC-APCI-MS, in okara were comparable to those in almonds, and alpha-tocopherol levels, quantified by LC-UV, were 14,400 µg/100 g in almonds and 15,600 µg/100 g in okara. These findings highlight the potential of okara as a valuable resource, with a straightforward, scalable, and cost-effective solid-liquid extraction (SLE) method for polyphenols and a supercritical fluid extraction method for TG, for use in the functional food, nutraceutical, and cosmetic industries.
