Degree
Doctor of Philosophy (PhD)
Department
School of Nutrition and Food Science
Document Type
Dissertation
Abstract
This study explored the processing of extrudates enriched with crawfish meat powder (CP) and microencapsulated crawfish astaxanthin. The extrudates were produced using CP, chickpea flour (CPF), corn flour (CF), and/or tapioca starch. Proximate analysis revealed that CP contained 12.3% protein and 8.3% fat, while CPF and CF contributed higher fiber and carbohydrate contents, respectively. Extrudates with different CPF: CP ratios significantly affected product properties, including water absorption, expansion, hardness, and color. Extrusion temperature and CP content significantly influenced water retention, expansion, and color, bulk density, and thermal stability. Fourier Transform Infrared (FTIR) spectroscopy and Thermogravimetric Analysis (TGA) confirmed that both ingredient composition and processing temperature influenced starch gelatinization, protein denaturation, lipid oxidation, and product stability. Extraction of astaxanthin from crawfish shells using medium-chain triglyceride (MCT) oil yielded the highest astaxanthin recovery and antioxidant activity, along with lower peroxide and Thiobarbituric Acid Reactive Substances (TBARS) values compared to flaxseed and canola oils. Cold plasma pretreatment did not improve extraction efficiency. Microencapsulation of astaxanthin in MCT oil (MA) through spray drying produced a powder with low water activity (0.46), high radical scavenging activity (65.9%), and a stable fatty acid profile dominated by medium-chain saturated fatty acids. TGA and Differential Scanning Calorimetry (DSC) analyses showed that the encapsulated powder remained stable up to 141 °C, indicating its suitability for high-temperature extrusion.
The effects of extruder screw speed, starch source, and MA inclusion were evaluated. Increasing screw speed from 60 to 120 rpm improved expansion and reduced bulk density, especially in tapioca-based extrudates, which exhibited the most significant expansion and lowest density. MA inclusion of up to 10% enhanced the red-orange coloration and increased antioxidant capacity, especially in tapioca and corn formulations. Protein retention and omega-3 content were highest in tapioca extrudates at 120 rpm, while FTIR confirmed effective incorporation of astaxanthin and MCT oil, as indicated by increased C–H and C=O stretching peaks. The best combination of tapioca starch, 120 rpm, and MA addition resulted in extrudates with superior texture, color, nutrition, and functional properties. Overall, this research demonstrated that adding moderate amounts of CP and MA, combined with optimized extrusion parameters, significantly enhanced the physical and chemical qualities of the extrudates.
Date
11-3-2025
Recommended Citation
Benigno, Mariel, "EXTRUSION PROCESSING AND FUNCTIONAL CHARACTERIZATION OF HIGH-VALUE EXTRUDATES FROM CRAWFISH MEAT POWDER AND ENCAPSULATED ASTAXANTHIN" (2025). LSU Doctoral Dissertations. 6949.
https://repository.lsu.edu/gradschool_dissertations/6949
Committee Chair
SUBRAMANIAM SATHIVEL