The Potential of Insects as Alternative Sources of Chitin: An Overview on the Chemical Method of Extraction from Various Sources

Abstract

Chitin, being the second most abundant biopolymer after cellulose, has been gaining popularity since its initial discovery by Braconot in 1811. However, fundamental knowledge and literature on chitin and its derivatives from insects are difficult to obtain. The most common and sought-after sources of chitin are shellfish (especially crustaceans) and other aquatic invertebrates. The amount of shellfish available is obviously restricted by the amount of food waste that is allowed; hence, it is a limited resource. Therefore, insects are the best choices since, out of 1.3 million species in the world, 900,000 are insects, making them the most abundant species in the world. In this review, a total of 82 samples from shellfish—crustaceans and mollusks (n = 46), insects (n = 23), and others (n = 13)—have been collected and studied for their chemical extraction of chitin and its derivatives. The aim of this paper is to review the extraction method of chitin and chitosan for a comparison of the optimal demineralization and deproteinization processes, with a consideration of insects as alternative sources of chitin. The methods employed in this review are based on comprehensive bibliographic research. Based on previous data, the chitin and chitosan contents of insects in past studies favorably compare and compete with those of commercial chitin and chitosan—for example, 45% in Bombyx eri, 36.6% in Periostracum cicadae (cicada sloughs), and 26.2% in Chyrysomya megacephala. Therefore, according to the data reported by previous researchers, demonstrating comparable yield values to those of crustacean chitin and the great interest in insects as alternative sources, efforts towards comprehensive knowledge in this field are relevant.

In Vitro Study of Cricket Chitosan’s Potential as a Prebiotic and a Promoter of Probiotic Microorganisms to Control Pathogenic Bacteria in the Human Gut

“…Sea creatures have been the main sources of chitin and its derivative chitosan; insects are a new potential source [22]. Chitin yield, molecular weight and the degree of deacetylation determine its properties, [6,7,23,24] and insects have been shown to have a higher deacetylation percentage. The most likely antibacterial activity of chitosan is by binding to the negatively charged bacterial cell wall, disrupting the cell and, thus, altering the membrane permeability, followed by attachment to DNA causing inhibition of DNA replication and subsequently cell death.…”

Evaluating Invasive Marbled Crayfish as a Potential Livestock for Sustainable Aquaculture

“…Our results show that marbled crayfish exoskeletons contain 3 times more chitin per animal compared to whiteleg shrimp (L. vannamei) exoskeletons, the main source of commercially produced chitin (Younes and Rinaudo, 2015). Chitin yields strongly depend on extraction parameters but are generally consistent among crustacean species (Zainol Abidin et al, 2020), suggesting that the comparably high exoskeleton weight of marbled crayfish represents a major competitive advantage. It will be important to further determine the quality and suitability of marbled crayfish chitin for established processes.…”

Development of Chitosan Films from Edible Crickets and Their Performance as a Bio-Based Food Packaging Material

“…Like crustaceans, insects are arthropods and have similar chitin rich exoskeletons. As a result, a focus of recent chitosan research sourced from insects was recently reviewed [14,15]. The reviews highlight extraction and purification of insect chitin, and characterize the physicochemical properties of chitin and its modification to chitosan.…”