Chitosan as an Edible Invisible Film for Quality Preservation of Herring and Atlantic Cod

Abstract

The effect of chitosan with different molecular weights as coatings for shelf-life extension of fresh fillets of Atlantic cod (Gadus morhua) and herring (Clupea harengus) was evaluated over a 12-day storage at refrigerated temperature (4 +/- 1 degrees C). Three chitosan preparations from snow crab (Chinoecetes opilio) processing wastes, differing in viscosities and molecular weights, were prepared; their apparent viscosities (360, 57, and 14 cP) depended on the deacetylation time (4, 10, and 20 h, respectively) of the chitin precursor. Upon coating with chitosans, a significant (p < or = 0.05) reduction in relative moisture losses of 37, 29, 29, 40, and 32% was observed for cod samples coated with 360 cP chitosan after 4, 6, 8, 10, and 12 days of storage, respectively. Chitosan coating significantly (p < or = 0.05) reduced lipid oxidation as displayed in peroxide value, conjugated dienes, 2-thiobarbituric acid reactive substances and headspace volatiles, chemical spoilage as reflected in total volatile basic nitrogen, trimethylamine, and hypoxanthine, and growth of microorganisms as reflected in total plate count in both fish model systems compared to uncoated samples. The preservative efficacy and the viscosity of chitosan were inter-related; the efficacy of chitosans with viscosities of 57 and 360 cP was superior to that of chitosan with a 14 cP viscosity. Thus, chitosan as edible coating would enhance the quality of seafoods during storage.

Physicochemical characterization of chitosan extracted from Metapenaeus stebbingi shells

“…The viscosities of both produced and commercial chitosans decreased with increasing temperature, and there were significant differences between the two groups at all degrees of temperature (p < 0.05). In a similar study, Jeon, Kamil, and Shahidi (2002) obtained chitosans with 86.40-91.30% of deacetylation degree and values of 14, 57 and 369 cP for apparent viscosities through the deacetylation of chitin extracted from snow crab (Chinoecetes opilio) processing waste. The researchers reported that the chitosan viscosity was closely related to the deacetylation time and that the chitosan reached its highest viscosity with a short deacetylation time.…”

Coating with chitosan film of sea bream (Sparus aurata) fillets: determining shelf life in refrigerator conditions

“…Günlü & Koyun (2013) stated that the increase of TMA-N value in the chitosan film coated and vacuumed D. labrax samples were smaller scale when compared to the uncoated samples. Other researchers also reported that chitosan coating process of fish restricts the increase in TMA (Jeon et al, 2002;Nicholas, 2003;Alak et al, 2011;Mohan et al, 2012).…”

“…In this study the limit value was exceeded in C and VP group samples on storage day 5 th while in CF+VP group samples it was surpassed on the 15 th day. Jeon et al (2002) indicated that, following the storage in the refrigerator for 12 days, microorganism development in chitosan coated cod and herring fillets was less significant than those not coated. Souza et al (2010) showed that, total aerobic plate count of chitosan film coated salmon fillets did not reach limits (15 th day), but the salmon fillets without any coating reached to 7.05 log cfu/g on the 12 nd day and exceeded the limit level (7 log cfu/g).…”

“…Chitosan's applicability in foods is due to their biocompatibility and nontoxicity (Jeon et al, 2002).…”

Effects of Fibers on the Quality of Fish Patties Stored at (0-4ºc)

“…AP count is generally used as an acceptability index for fish and fish products because of the bacterial effects in spoilage (Jeon et al, 2002;Çoban and Özpolat, 2013). The inital AP count of fish patties was 5.22-5.94 log CFU/g.…”