An Alum-Free Jellyfish Treatment for Food Applications

Abstract

Jellyfish, marketed and consumed as food in The Far East, are traditionally processed using salt and alum mixtures. In recent years, the interest of Western consumers in jellyfish (JF) as a food source is increasing. In Europe [European Union (EU)], JF-derived food products are regulated by a novel food law, but methods for JF treatment and processing have not been developed yet. In this study, a protocol for the stabilization and processing of JF into semi-finished food products without the use of alum is proposed for the first time. Safety and quality parameters, together with a series of technological and nutritional traits, were used to monitor the proposed process and for the characterization of the JF-derived products. Calcium lactate (E327), calcium citrate (E333), and calcium acetate (E263), which are food thickening/stabilizing agents allowed by EU regulations, were used in order to control the presence of possible microbial pathogens and spoilage species. The use of calcium lactate and citrate led to an increase in texture values (~1.7–1.8-fold higher than in starting raw materials) and in several nutritional traits such as antioxidant activity, and protein and fatty acid content. In particular, the combination of JF treatments with calcium salts and phenolic compounds resulted in an antioxidant activity increase of up to 8-fold, protein concentration increase of up to 2.6-fold, fatty acid composition maintenance, and a ω6/ω3 ratio lower than 1. For the first time, the application of phenolic compounds to improve JF technological and nutritional features was verified. This study proposes a new procedure for JF treatment and stabilization useful for future potential food applications in Western countries.

Jellyfish as Food: A Narrative Review

“…Alum metal ions modify the mechanical–chemical properties of jellyfish tissue and have rubber-like hardening effects that is likely due to cross-linked collagen jellyfish fiber and the partial disinfection of jellyfish material [ 14 ]. According to the applied treatment and the given jellyfish species, the whole procedure can take 4–40 days [ 54 ]. Gaining a better understanding of the gelatin gel properties caused by peptide or protein contents is useful for enhancing gelatin functionality in both non-food and food applications.…”

“…Noteworthily, the obtained products were satisfactory in nutritional, technological and microbiological terms. The procedure is an apparently efficacious processing operation to produce semifinished jellyfish food products that confirm the quality and safety requirements of the EU regulations currently in force [ 54 ]. However, one study reports that Ca ions were unable to substitute alum in collagen cross-linking when producing the rubber-like jellyfish structure.…”

“…However, one study reports that Ca ions were unable to substitute alum in collagen cross-linking when producing the rubber-like jellyfish structure. This was attributed to not only Ca ions being unable to efficiently bring down pH as alum can, but also the metal ions’ different valence [ 54 , 66 ]. The investigators observed that the pH values obtained at the end of treatment fell within the 4.89–7.15 range and would, thus, prevent jellyfish tissue dissolution.…”

“…The investigators observed that the pH values obtained at the end of treatment fell within the 4.89–7.15 range and would, thus, prevent jellyfish tissue dissolution. These findings suggest that this parameter would not be fundamental to maintain jellyfish [ 54 ]. Despite Pedersen et al [ 66 ] proving Ca ions unsuitable for tanning, treating jellyfish samples with Ca-salt-based brine presented increased texture after a 5-day period under each testing condition and, albeit not crunchy, consistency was somewhat gelatinous-stiff.…”

Biochemical Characterization of Cassiopea andromeda (Forsskål, 1775), Another Red Sea Jellyfish in the Western Mediterranean Sea

“…The market value of this kind of commodity is indeed considerable but, in Europe, there is yet no tradition of the food use of jellyfish, no food market related to JF as food, or any other use. Only recently, the Mediterranean species Rhizostoma pulmo was suggested as raw material for human foods [18][19][20]; however, jellyfish living in EU seas are currently labelled as "novel food" in European Regulation and its consume is still not allowed (EU Regulation 2015/2283 of 25/11/2015 http://eur-lex.europa.eu/eli/reg/2015/2283/oj accessed on 22 April 2021).…”