Optimization and Characterization of Protein Extraction from Asparagus Leafy By-Products

Area of Science:

• Food Science
• Biotechnology
• Sustainable Agriculture

Background:

• Asparagus production generates substantial leafy by-products.
• By-products are rich in nutrients and phytochemicals.
• There's a growing demand for novel plant-based protein sources for human consumption.

Purpose of the Study:

• To optimize the aqueous extraction of proteins from asparagus leafy by-products.
• To develop new protein ingredients from agricultural waste.
• To evaluate the properties of the extracted protein isolate.

Main Methods:

• Response Surface Methodology (RSM) was employed for process optimization.
• Extraction conditions optimized for pH, time, temperature, and concentration.
• Protein content, yield, amino acid profile, antioxidant activity, and technological properties were analyzed.

Main Results:

• Optimal extraction achieved at pH 9, 50°C for 40 minutes at 5 g·L^-1.
• Resulting protein isolate contained 90.48% protein with a 43.47% yield.
• Identified amino acids include alanine, proline, valine, leucine/isoleucine, asparagine, and phenylalanine.
• Demonstrated significant antioxidant activity (145.76 μmol TE·100g^-1 for ABTS, 65.21 μmol TE·100g^-1 for DPPH).
• Favorable technological properties: water absorption capacity (4.49 g·g^-1) and oil absorption capacity (3.47 g·g^-1).
• Product color was dark green (L* 31.91, a* -1.01, b* -2.11).

Conclusions:

• Optimized aqueous extraction effectively produces a high-purity protein isolate from asparagus by-products.
• The protein isolate possesses desirable nutritional and functional properties.
• This demonstrates the potential of asparagus by-products as a sustainable source for novel protein ingredients.