Effects of Peppermint Extract and Chitosan-Based Edible Coating on Storage Quality of Common Carp (Cyprinus carpio) Fillets

Abstract

Edible coatings have recently been developed and applied to different food matrices, due to their numerous benefits, such as increasing the shelf life of foods, improving their appearance, being vehicles of different compounds, such as extracts or oils of various spices that have antioxidant and antimicrobial activity, as well as being friendly to the environment. The objective of this research was to develop a new edible coating based on chitosan enriched with peppermint extract and to evaluate its effectiveness to inhibit microbial development in vitro and improve both the quality and shelf life of common carp (Cyprinus carpio) during refrigerated storage (4 ± 1 °C). Three treatments were used: edible coating (C + EC), edible coating +, 5% chitosan (C + ECCh) and edible coating + 1.5% chitosan + 10% peppermint (C + ECChP). Prior the coating carp fillets; the antibacterial activity and antioxidant capacity were evaluated in the peppermint extract and coating solutions. After coating and during storage, the following were determined on the fillet samples: microbiological properties, observed for ECP, an inhibition halo of 14.3 mm for Staphylococcus aureus, not being the case for Gram-negative species, for ECCh, inhibition halos of 17.6 mm, 17.1 mm and 16.5 mm for S. aureus, Salmonella typhimurium and Escherichia coli, respectively; for the ECChP, inhibition halos for S. aureus, S. typhimurium and E. coli of 20 mm, 17 mm and 16.8 mm, respectively. For the physicochemical characteristics: an increase in solubility was observed for all treatments during storage, reaching 46.7 mg SN protein/mg total protein for the control, and values below 29.1 mg SN protein/mg total protein (p < 0.05), for fillets with EC (C + EC > C + ECCh > C + ECChP, respectively at the end of storage. For the pH, maximum values were obtained for the control of 6.4, while for the fillets with EC a maximum of 5.8. For TVB-N, the fillets with different CE treatments obtained values (p < 0.05) of 33.3; 27.2; 25.3 and 23.3 mg N/100 g (control > C + E C > C + ECCh > C + ECChP respectively). Total phenolic compounds in the aqueous peppermint extract were 505.55 mg GAE/100 g dried leaves, with 98.78% antioxidant capacity in the aqueous extract and 81.88% in the EC. Biomolecule oxidation (hydroperoxide content) had a significant increase (p < 0.05) in all treatments during storage, 1.7 mM CHP/mg protein in the control, to 1.4 in C + EC, 1.27 in C + ECCh and 1.16 in C + ECChP; TBARS assay values increased in the different treatments during refrigerated storage, with final values of 33.44, 31.88, 29.40 and 29.21 mM MDA/mg protein in the control; C + EC; C + ECCh and C + ECChP respectively. In SDS -PAGE a protective effect was observed in the myofibrillar proteins of fillets with ECChP). The results indicate that the C + ECCh and C + ECChP treatments extend the shelf life of 3–5 days with respect to microbiological properties and 4–5 days with respect to physicochemical characteristics. A reduction in lipid and protein oxidation products was also observed during refrigerated storage. With these findings, this is considered a promising method to increase the shelf life of fish fillets combined with refrigeration and we are able to recommend this technology for the fish processing industry.

Effect of Locust Bean Gum-Sodium Alginate Coatings Combined with High CO2 Modified Atmosphere Packaging on the Quality of Turbot (Scophthalmus maximus) during Refrigerated Storage

“…The TVB-N value was measured with reference to Valdez's method [27]: a 25 mL filtrated sample was added to the distillation tube, and steam distillation was performed with a Kjeldahl apparatus (Kjeltec8400, Foss, Hilleroed, Denmark). The results are expressed as mg N/100 g.…”

Optimization of the Physical, Optical and Mechanical Properties of Composite Edible Films of Gelatin, Whey Protein and Chitosan

“…These types of raw materials include various by-products of earlier technological processes related to agriculture and food processing [ 8 ]. Among the materials obtained from agroindustrial by-products, which are employed in the elaboration of edible packaging, extruded corn, post-extraction rapeseed meal, dried fruit pomace (chokeberry, currant, apple and raspberry pomace) and microcrystalline cellulose (MCC), whey protein, gelatin, chitosan, soy protein and zein can be found, among others [ 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Gelatin is a protein of animal origin, which is mainly obtained from porcine or bovine by-product.…”

“…It is composed of different fractions of protein: β-lactoglobulin (β-Lg), α-lactoalbumin (α-La), serum albumin (BSA) and immunoglobulin (Ig) [ 19 , 20 ]. Due to its characteristic functions, it has been employed in the food industry as an emulsifier [ 13 , 14 , 21 , 22 ], dietary supplement and has been studied as a raw material for the preparation of CEFs [ 23 , 24 ]. Protein films are characterized by presenting good mechanical properties, as well as being excellent as barriers to gases [ 25 ]; however, they present little resistance to water, tend to present a higher water vapor permeability than other biopolymers and lack antimicrobial properties [ 26 ].…”

“…It is a co-polymer of N-acetyl-D-glucosamine and D-glucosamine, with the latter being superior to 60% [ 29 , 30 ]. The biodegradability, biocompatibility, excellent film formation capacity [ 13 , 14 ] and its antimicrobial properties [ 31 , 32 ] could explain its use in a wide range of applications that may include areas such as pharmaceuticals, biotechnology, biomaterials, biomedicine, agriculture and food processing [ 33 ], so using it as a material for the development of a biodegradable bioplastic is a cost benefit with a great impact on the environment compared to polyethylene-based plastics that take up to 700 years to degrade [ 4 ]. The biodegradable plastics market is projected to grow from over 2.0 billion USD in 2015 to 3.4 billion USD by 2020, with a growth rate of 10.8% per year [ 34 , 35 ].…”

“…Coatings with two independent components have been studied [ 36 , 37 ], but, until now, the interaction of multicomponents in a film has not been studied. Studies have been carried out between pairs of ingredients, such as gelatin–whey protein [ 11 , 36 ], gelatin–chitosan [ 7 , 12 , 13 , 37 , 38 , 39 ] and whey protein–chitosan [ 40 , 41 , 42 ], demonstrating that the combination of different proportions of polysaccharides and proteins offers the possibility of fabricating composite films with improved properties in order to satisfy the expectations of the consumer [ 36 ]. Nonetheless, until this moment, there are no records on composite films consisting of gelatin, whey protein and chitosan, and, thus, there is a need to study the relationship between these components since the composition of the film affects its structure and properties [ 27 ].…”