An Integrated Autolysis Process Utilizing Endogenous Enzymes for Enhanced Astaxanthin Extraction and...

Area of Science:

• Biotechnology
• Food Science
• Marine Biology

Background:

• Natural astaxanthin, a high-value carotenoid from Antarctic krill, has significant nutraceutical and functional food potential.
• Extraction challenges include krill's structural matrix hindering solvent penetration and astaxanthin's esterified forms limiting bioavailability.
• Conventional methods often rely on harsh chemicals or exogenous enzymes, posing environmental and cost concerns.

Purpose of the Study:

• To develop an efficient, cost-effective, and environmentally benign method for natural astaxanthin extraction and bioactivity enhancement from Antarctic krill.
• To address challenges of matrix disruption and low bioavailability of esterified astaxanthin.
• To explore the comprehensive, high-value utilization of Antarctic krill biomass.

Main Methods:

• An integrated autolysis process utilizing krill's endogenous enzymes (proteases, lipases, chitinases) for simultaneous matrix disruption and astaxanthin de-esterification.
• Optimization of autolysis conditions through experimental design (pH 7.5, 60°C, 2 hours).
• Analysis of astaxanthin yield, protein hydrolysate composition (essential amino acids), free astaxanthin proportion, and antioxidant activity.

Main Results:

• Optimized autolysis achieved an astaxanthin yield of 91.18 µg/g, significantly higher than conventional methods.
• Simultaneous production of protein hydrolysate with elevated essential amino acids (from 12.276 ± 0.013 to 34.368 ± 0.042 mg/100 g).
• Increased free astaxanthin proportion from 18.11% to 30.50%, leading to enhanced antioxidant activity.

Conclusions:

• The developed green and cost-effective autolysis process enables efficient natural astaxanthin extraction and de-esterification from Antarctic krill.
• This method enhances astaxanthin bioavailability and antioxidant activity while simultaneously upgrading the nutritional value of the protein hydrolysate.
• The strategy offers a promising approach for the high-value utilization of Antarctic krill biomass in nutraceutical and functional food industries.