Use of shellfish and crustacean by-products and improvement of the method of enzymatic extraction of Pacific White Shrimp (Litopenaeus vannamei) with ultrasound
Author: José Stênio Aragão Rebouças Júnior (Currículo Lattes)
Advisor: Dr Marcelo Borges Tesser
Co-advisor: Drª Juliana Machado Latorres
Abstract
There is a growing worldwide demand for food, and aquaculture is an excellent tool to meet the demand for food. As a result, world aquaculture production has grown massively in recent years. However, a large part of this production becomes waste for which it does not have an adequate destination. Knowing that this biomass is an excellent source of several compounds of human interest, two studies were carried out, which are written in two chapters. The first chapter is a bibliographical review on the compounds of interest present in the discards from the production of molluscs and crustaceans from fishing and aquaculture, such as: proteins, carotenoids, chitin and its derivatives, fatty acids and minerals. Subsequently, studies are reported that seek to obtain and apply these compounds, thus adding commercial value to these biomasses that can be used in the manufacture of drugs to fight cancer, neurodegenerative and cardiovascular diseases, manufacture of structures for civil construction and biofilms used as dressings and packaging, foods such as feed and concentrated protein hydrolysates. The second chapter deals with obtaining protein hydrolyzate using as raw material the exoskeleton and cephalothorax of the Pacific white shrimp (Litopenaeus vannamei) using ultrasound. For protein extraction, a hydrolysis was performed using the enzyme Alcalase 2.4L using 2% (Enzyme/Substrate) of protein, 1:1 (weight:volume), pH 8.0, temperature of 55 oC, for one hour and assisted previously with ultrasound treatment to obtain protein hydrolyzate. The experiment had four treatments where increasing treatments of ultrasound (1 W/mL) were applied at different time intervals (5, 10, 15 minutes and a control). The analyzes performed on the obtained hydrolyzate were the reducing power, DPPH and ABTS. The hydrolyzate obtained presented 69.09 ± 4.2% of protein, 12.7 ± 2.25% of lipids, 11.91 ± 4.2% of carbohydrates and 39.32 ± 3.00 μg/g of content total carotenoids. The ultrasonic treatment was able to accelerate the kinetic curve of protein hydrolysis, as well as change the degree of hydrolysis from 9.55 ± 0.7 to 12.18 ± 0.7%. It was possible to concentrate from three (160.17 ± 6.27 μg/g) to five times (393.29 ± 3.00 μg/g) the total carotenoid content compared to the amount present in the residue (64.38 ± 2 .41 µg/g). The study positively proves the effect of ultrasonic treatment before protein hydrolysis of shrimp residues.