Hydrogels, Oleogels and Bigels as Edible Coatings of Sardine Fillets and Delivery Systems of Rosemary Extract

Abstract

Edible coatings provide an alternative way to reduce packaging requirements and extend the shelf life of foods by delaying oxidation and microbial spoilage. Hydrogels, oleogels and bigels were applied as coatings on fresh sardine fillets. The effectiveness of these coatings as delivery systems of rosemary extract (RE) was also evaluated. Three groups of sardine fillet treatments were prepared: (i) the control (C), which comprised sardine fillets without coating, (ii) sardine fillets with plain hydrogel (H), oleogel (O) or bigel (BG) coatings, and (iii) sardine fillets with RE incorporated into the H, O and BG coatings. The different treatments were evaluated for lipid oxidation (TBA test), total volatile basic nitrogen (TVB-N) and microbiological growth during cold storage at 4 °C. Results showed that hydrogel, oleogel and bigel coatings delayed oxidation. The incorporation of RE into coatings significantly retarded lipid oxidation but did not affect the proliferation of microorganisms during storage. When RE was incorporated in the oleogel phase of the bigel coating, it produced significantly lower TVB-N values compared to the control and BG treatments. The incorporation of RE into the oleogel phase of the bigel coating may be a promising method of maintaining the storage quality of the sardine fillets stored at refrigerated temperatures.

Safety and quality attributes of fresh sardines (Sardina pilchardus) in storage scenarios imitating harvest‐to‐refrigerator conditions

“…The initial TVB‐N content of sardine samples ranged between 15 and 20 mg TVB‐N/100 g of fish flesh (Fig. 1), indicating a good quality of fresh fish (El Marrakchi et al ., 1990; Chen et al ., 2020; Kanelaki et al ., 2022). According to EU regulation No.…”

Food-Grade Oleogels: Trends in Analysis, Characterization, and Applicability

“…For extending shelf life and reducing packaging requirements, some edible coatings in the form of hydrogels (H), oleogels (O), and bigels (BG) were evaluated by Aikaterini Kanelaki et al [39] as regards oxidation delay and microbial spoilage in fresh sardine fillets. In addition, one group of gel (H, O, and BG) coatings was enhanced with rosemary extract (RE) as an antioxidant agent.…”

“…However, the addition of RE into the gel coatings did not show any changes in the growth of microorganisms during storage. The embedding of RE in the oleogel as part of the bigel proved to be the most suitable coating option for sardine fillets in terms of quality maintenance under refrigeration storage conditions and good potential in bioactive compound delivery [39].…”

“…For example, they can be used in food products as a replacement or for the reduction of solid fats, such as trans fats or hydrogenated fats, to create healthier options without compromising their texture, mouthfeel, and stability [1,[29][30][31][32][33][34][35][36]. Oleogels can also be used to encapsulate and deliver bioactive compounds, such as antioxidants or flavors, in food products, providing enhanced stability and controlled-release properties [2,[37][38][39][40][41][42][43][44]. Additionally, oleogels can offer new possibilities for product innovation by creating unique textures, structures, and sensory experiences in food products [45].…”

Bigels as Fat Replacers in Fermented Sausages: Physicochemical, Microbiological, Sensory, and Nutritional Characteristics

“…Bigels can act as delivery systems for both hydrophobic and hydrophilic molecules and bioactive compounds modulating their release profile, such as β-carotene, lycopene, or rosemary extract [ 22 , 23 , 24 , 25 ]. Until now, bigels have been developed and analyzed mostly for cosmetic and pharmaceutical purposes and there are only a few studies related to the development of edible bigels [ 26 , 27 , 28 ].…”