Combined effect of oxygen-scavenger packaging and UV-C radiation on shelf life of refrigerated tilapia (Oreochromis niloticus) fillets

Abstract

This study investigated the physicochemical, instrumental and bacterial parameters of tilapia fillets subjected to oxygen-scavenger packaging, alone or in combination with UV-C radiation at two doses (0.102 and 0.301 J/cm2), stored at 4 ± 1 °C for 23 days. The oxygen scavenger, both UV-C doses, and the oxygen scavenger combined with UV-C, independently of the dose, extended the shelf life in 5, 6 and 7 days, respectively, by decreasing the bacterial growth rate and the formation of degradation compounds (e.g., TVB-N and ammonia). Oxygen-scavenger packaging, alone or in combination with UV-C at 0.102 J/cm2 and 0.301 J/cm2 showed lower amounts of free amino acids (FAA; 34.39, 34.49 and 34.50 mg L-lysine/kg fish tissue, 3.63, 3.57 and 3.61 mg L- ornithine/kg fish tissue, 27.52, 27.63 and 27.67 mg L-arginine/kg fish tissue), biogenic amines (BA; 3.81, 3.87 and 3.89 mg cadaverine/kg fish tissue, 12.88, 12.91 and 12.86 mg putrescine/kg fish tissue, 2.41, 2.44 and 2.47 mg spermidine/kg fish tissue), redness (2.53, 2.55 and 2.59), yellowness (6.65, 6.69 and 6.72), lipid oxidation (1.52, 1.53 and 1.58 mg malondialdehyde/kg fish tissue) and protein oxidation (5.06, 5.11 and 5.18 nmol carbonyls/mg protein), with higher hardness (3273.41, 2652.98 and 2687.57 g) than control (air packaging; 41.97 mg L-lysine/kg fish tissue, 4.83 mg L- ornithine/kg fish tissue, 37.33 mg L-arginine/kg fish tissue, 4.82 mg cadaverine/kg fish tissue, 16.56 mg putrescine/kg fish tissue, 3.21 mg spermidine/kg fish tissue, 4.26 of redness, 8.17 of yellowness, 2.88 mg malondialdehyde/kg fish tissue, 9.44 nmol carbonyls/mg protein and 2092.58 g of hardness), respectively, on day 13 of storage when the control fillets were unfit for consumption (7 log CFU/g) (p < 0.05). However, in the same day of storage, both UV-C doses had similar values for BA (p > 0.05), higher amounts of FAA (44.28 and 44.13 mg L-lysine/kg fish tissue, 5.16 and 5.12 mg L- ornithine/kg fish tissue, 40.20 and 40.28 mg L-arginine/kg fish tissue), redness (4.86 and 5.33), yellowness (9.32 and 10.01), lipid oxidation (3.09 and 3.52 mg malondialdehyde/kg fish tissue) and protein oxidation (10.27 and 11.93 nmol carbonyls/mg protein), as well as lower hardness (1877.54 and 1767.39 g), respectively, than control fillets (p < 0.05). The combined preservation methods were the most effective in extending the shelf life and prolonging the physicochemical quality of the refrigerated tilapia fillets and the O2 scavenger proved to be a potential alternative to prevent the negative changes induced by both UV-C doses.

Application of Active Packaging in Refrigerated Rainbow Trout (Oncorhynchus mykiss) Fillets Treated with UV-C Radiation

“…To overcome this challenge, the United Nations Food and Agriculture Organization [1] suggests studies concerning viable preservation technologies aiming to achieve a maximum shelf life without compromise the original quality parameters of fish, which is one of the most challenges for the scientific community and food industry by the use of a single method. In this way, studies about combined preservation treatments have increased [7][8][9][10].…”

“…UV-C radiation is a promising non-thermal technology for the fish production chain. Beyond the proven efficacy to decrease the bacterial growth rate during refrigerated storage of fish species, UV-C has low cost, does not generate toxic residues and can be easily implemented in the fishery industry without changing the production flow [9,11,12]. The effects of UV-C depend mainly on the dose used, food composition, type and load of microorganisms into the food matrix [11][12][13][14].…”

“…The effects of UV-C depend mainly on the dose used, food composition, type and load of microorganisms into the food matrix [11][12][13][14]. Nevertheless, in general, UV-C doses (0.10-0.30 J/cm 2 ) needed to reach a shelf life extension of 2-6 days in refrigerated fish species, including rainbow trout, lead to one or more oxidative damages by producing reactive oxygen species (ROS) compromising overall fish quality, which is the main limiting factor for the use of UV-C at industrial scale [9,12,13,15,16]. O 2 scavenger or O 2 absorber has been used preferentially to vacuum packaging (VP) and modified-atmosphere packaging (MAP) due to its ability to reduce and maintain the O 2 concentration inside the package at levels less than 0.01% being effective against oxidative degradation from ROS and growth of obligate aerobic microorganisms during the entire storage period [10,17,18].…”

“…Furthermore, O 2 scavengers are mainly sold in sachet form at low cost and do not require the use of equipment. At the present moment, it is known that O 2 scavenger extends the shelf life in 5-7 days while prevents the oxidation during refrigerated storage of fish species, including rainbow trout [7,9,19]. Therefore, O 2 scavenger could be a simple and effective alternative to mitigate the adverse effects of UV-C radiation.…”

“…Despite these facts, there is only one recent study evaluating the combined effect of O 2 scavenger and UV-C radiation in tilapia fillets stored under refrigeration [9], however rainbow trout is more prone to oxidative degradation than tilapia [2,3,13]. In this context, this study aimed to investigate the effect of oxygen-scavenger packaging and two UV-C doses (0.102 and 0.301 J/cm 2 ), alone or in combination, on oxidative stability, instrumental color and texture parameters of rainbow trout (Oncorhynchus mykiss) fillets stored at 4 ± 1 • C for 9 days.…”