Eco-friendly methods for recycling of crayfish “Procambarus clarkii” by-product for astaxanthin extraction and quantification

     Astaxanthin has been extracted in the current study using eco-friendly methods. Compared to the chemical method, a natural method using flaxseed oil at different time intervals, a biological method using standard fungal and bacterial probiotics (the fungal probiotics are Saccharomyces cerevisiae and Candida utilis, while the bacterial probiotics are Lactobacillus lactis and Bifidobacterium lactis), and a mixed-novel method using both flaxseed oil and the fungal and bacterial probiotics were approached. The natural extraction by flaxseed oil (used alone) resulted in a gradual increase in the astaxanthin concentration with the increase of the time interval. The highest concentration was observed in the accumulated method after 48 hours. For the biological method using probiotics, the concentration of the extracted astaxanthin by the fungal probiotics using S. cerevisiae was higher than that recorded by using C. utilis. On the other hand, a higher concentration was detected when using bacterial probiotics L. lactis compared to B. lactis. While in the mixed-novel method (using both flaxseed oil and probiotics), the highest concentration of astaxanthin was recorded in L. lactis, followed by B. lactis, S. cerevisiae and C. utilis, respectively, using the accumulated method after 48 hours. Remarkably, the concentration of astaxanthin in the chemical method was lower than in the biological and mixed-novel methods.