282: Valorization of Crab Shell Waste to Obtain Quality Proteins and Sweet Amino Acids: A Promising Alternative for Low-Calorie Sweeteners

Introduction

Seafood consumption has steadily increased in recent years, as seafood has been increasingly recognized as a valuable source of nutrients for human health. Among them crab shells have made a significant contribution to global waste. Worldwide, 6–8 million tons of crab shells are dumped as biowaste annually. However, most crab shell valorization methods have focused on extraction of chitin for biomedical purposes, or its utilization as a mineral ingredient for animal feed. The protein from these processes is usually discarded as a secondary waste product. This protein is hypothesized to have sweet taste properties. With the rise in demand for sugar substitutes, the development of sweet proteins is significant for food industries. Sweet proteins and amino acids have better sensorial value and health benefits.

Methods

In this research, cooked and uncooked snow crab shell waste, one of the main crab species fished in Quebec, was used. A protein fraction was extracted by using different solid-liquid extraction techniques (alkaline and Natural Deep Eutectic Solvents (NADES) assisted extraction) and ultrasonication extraction techniques. Optimization for highest yield of proteins from different extraction methods was done. Bio activity studies will be done by using bioactivity assays. High-performance liquid chromatography will be used to determine amino acid profile and chirality of amino acids. Taste characteristics of sweet amino acid will be studied by using an electronic tongue.

Results

The chemical composition of the cooked versus uncooked (fresh) crab shells determined on a dry weight basis (% dw) ranged from protein (15.41- 17.08 %), fat (0.04-0.14%), ash (50.2-51.5%). The highest protein yield from both cooked and uncooked crab shells was extracted by using NADES-assisted extraction which was 15.01±1.52% and 14.52 ± 0.56% respectively. The proteins extracted using ultrasonication combined with NaOH exhibited the highest functional properties, including solubility, foaming capacity, and emulsifying activity index.

Significance

This research focuses on transforming waste materials into commercially valuable products, reducing environmental waste, and producing high-quality proteins for biobased processing. The availability and affordability of sweet amino acids will provide consumers with functional products of low-calorie, and multiple bioactivities. This research contributes to food security, environmental sustainability, and a circular bioeconomy.

Authors: Tharuka Wijesekara, Idaresit Ekaette