Oil-in-water emulsion loaded with optimized antioxidant blend improved the shelf-life of trout (Oncorhynchus mykiss) fillets: a study with simplex-centroid design

Abstract

This study aimed to obtain optimized mixture with three essential oils (EOs) for maximum antioxidant activity through the augmented simplex-centroid mixture design and evaluate the effect of this optimized blend on total aerobic psychrotrophic count (TAPC), lipid and protein oxidation, instrumental color parameters and texture profile in rainbow trout fillets at refrigerated storage for nine days. Considering the DPPH and FRAP assays, the ideal EO blend was 66% lemongrass and 34% oregano. During refrigerated storage, this blend at 2000 ppm was equally effective as BHT (100 ppm) (p > 0.05), mitigating the discoloration (a* and b*), lipid, and protein oxidation in 38.83%, 12.95%, 76.13%, and 35.13%, respectively, besides shows greater effectiveness for preserving texture changes (p < 0.05) and extending the shelf life in 13 h. The lemongrass + oregano EO blend reveals a promising natural alternative to enhance the quality of rainbow trout fillets under refrigerated storage. Furthermore, the multiresponse optimization showed to be a strong ally in enabling the use of these EOs by food industries.

Ultrasound-Assisted Nanoemulsion Loaded with Optimized Antibacterial Essential Oil Blend: A New Approach against Escherichia coli, Staphylococcus aureus, and Salmonella Enteritidis in Trout (Oncorhynchus mykiss) Fillets

“…These authors inoculated E. coli (5 log 10 CFU/g) in beef samples and reported a reduction of 0.23 and 0.37 log CFU/g by washing with thyme and carvacrol nanoemulsions (0.8%) after 7 days at 4 • C, respectively. Torres Neto et al [6] presented the first report on controlling psychotropic bacteria from the blend of ORE and LG in trout fillets, increasing the shelf life by 13 h.…”

“…For these purposes, obtaining EOB through MD may increase the mixture quality at a low cost, which can be a powerful incentive to enable the use of the synergistic or additive potential of EOs by food industries [2][3][4][5]. However, studies with this approach are limited to in vitro assays, and there is only one report evaluating the blend's effectiveness in any food matrix in the literature [6]. Our research group is at the forefront of investigating and implementing the in situ application of EOB with MD [4,6].…”

“…However, studies with this approach are limited to in vitro assays, and there is only one report evaluating the blend's effectiveness in any food matrix in the literature [6]. Our research group is at the forefront of investigating and implementing the in situ application of EOB with MD [4,6]. Despite that, further research is warranted to address this significant gap in the literature by comprehensively exploring the potential of optimized EOB for oxidative and antimicrobial control in food products.…”

“…In this sense, different strategies to try to improve the safety, quality, and shelf life have been evaluated with individual EOs in fish, such as the use of thyme or garlic essential oil (EO) together with vacuum packaging in hot smoked rainbow trout [15], oregano EO with chitosan in the storage of red porgy (Pagrus pagrus) [16], turbot (Scophthalmus maximus) fillets treated with clove, cumin, or spearmint EO fumigation [17], the use of bio-nanocomposite active packaging films with carboxymethyl cellulose, myrrh gum, TiO 2 nanoparticles, and dill essential oil for preserving fresh fish (Cyprinus carpio) [18], a whey protein coating containing nanoliposome dill (Anethum graveolens L.) essential oil [19], pomelo peel essential oil applied in varieties of freshwater fish (Rohu, Bahu, Silver carp) [20], and grape and cinnamon EO NEs applied to chilled flathead mullet fillets [21]. Additionally, an oil-in-water emulsion with a mixture of these three EOs (ORE, THY, and LG) controlled oxidation and extended the shelf life of trout fillets [6]. However, despite several advantages that the development of EOBs present [4,6], currently, the evaluation of optimized antimicrobial EOBs in fish storage is still unexplored, yet the assessment of these blends in the control of pathogens in trout rainbow fillets could represent an essential response to the demands of FAO and the United Nations [22,23].…”

“…Additionally, an oil-in-water emulsion with a mixture of these three EOs (ORE, THY, and LG) controlled oxidation and extended the shelf life of trout fillets [6]. However, despite several advantages that the development of EOBs present [4,6], currently, the evaluation of optimized antimicrobial EOBs in fish storage is still unexplored, yet the assessment of these blends in the control of pathogens in trout rainbow fillets could represent an essential response to the demands of FAO and the United Nations [22,23].…”