Elevated levels of reactive oxygen species (ROS) damage the internal cell components. Padina boryana, a brown alga from the Maldives, was subjected to polysaccharide extraction. The Celluclast enzyme assisted extract (PBE) and ethanol precipitation (PBP) of P. boryana were assessed against hydrogen peroxide (H₂O₂) induced cell damage and zebra fish models. PBP which contains the majority of sulfated polysaccharides based on fucoidan, showed outstanding extracellular ROS scavenging potential against H₂O₂. PBP significantly declined the intracellular ROS levels, and exhibited protection against apoptosis. The study revealed PBPs’ ability to activate the Nrf2/Keap1 signaling pathway, consequently initiating downstream elements such that catalase (CAT) and superoxide dismutase (SOD). Further, ROS levels, lipid peroxidation values in zebrafish studies were declined with the pre-treatment of PBP. Collectively, the results obtained in the study suggest the polysaccharides from P. boryana might be a potent source of water soluble natural antioxidants that could be sustainably utilized in the industrial applications.

Olive flounder (OF) is a widely aqua-cultivated and recognized socioeconomic resource in Korea. However, more than 50% of by-products are generated when processing one OF, and there is no proper way to utilize them. With rising awareness and interest in eco-friendly bio-materialization recycling, this research investigates the potential of enzymatic hydrolysis of OF by-products (OFB) to produce functional ingredients. Various enzymatic hydrolysates of OFB (OFBEs) were generated using 11 commercial enzymes. Among them, Prozyme 2000P-assisted OFBE (OFBP) exhibited the highest protein content and yield, as well as low molecularization. The muscle regenerative potential of OFBEs was evaluated using C2C12 myoblasts, revealing that OFBP positively regulated myoblast differentiation. In an in vitro Dex-induced myotube atrophy model, OFBP protected against muscle atrophy and restored myotube differentiation and Dex-induced reactive oxygen species (ROS) production. Furthermore, zebrafish treated with OFBEs showed improved locomotor activity and body weight, with OFBP exhibiting outstanding restoration in the Dex-induced muscle atrophy zebrafish in vivo model. In conclusion, OFBEs, particularly OFBP, produce hydrolysates with enhanced physiological usability and muscle regenerative potential. Further research on its industrial application and mechanistic insights is needed to realize its potential as a high-quality protein food ingredient derived from OF processing by-products.

Fish head byproducts derived from surimi processing contribute about 15% of the total body weight, which are beneficial to health because they contain essential nutrients. In this study, olive flounder (OF) was the target species in order to maximize the byproduct utilization. In RAW 264.7 macrophages, the seven hydrolysates from OF head byproducts were examined for their inhibitory potential against inflammation and the oxidative stress induced by lipopolysaccharides (LPS). The pepsin hydrolysate (OFH–PH) demonstrated strong anti-inflammatory activity via the down-regulation of NO production, with an IC50 value of 299.82 ± 4.18 µg/mL. We evaluated the inhibitory potential of pro-inflammatory cytokines and PGE2 to confirm these findings. Additionally, iNOS and COX-2 protein expressions were confirmed using western blotting. Furthermore, the results from the in vivo zebrafish model demonstrated that OFH–PH decreased the LPS-elevated heart rate, NO production, cell death, and intracellular ROS level, while increasing the survival percentage. Hence, the obtained results of this study serve as a platform for future research and provide insight into the mediation of inflammatory disorders. These results suggest that OFH–PH has the potential to be utilized as a nutraceutical and functional food ingredient.

Muscle atrophy is a detrimental and injurious condition that leads to reduced skeletal muscle mass and disruption of protein metabolism. Oyster (Crassostrea nippona) is a famous and commonly consumed shellfish in East Asia and has become a popular dietary choice worldwide. The current investigation evaluated the efficacy of C. nippona against muscle atrophy, which has become a severe health issue. Mammalian skeletal muscles are primarily responsible for efficient metabolism, energy consumption, and body movements. The proteins that regulate muscle hypertrophy and atrophy are involved in muscle growth. C. nippona extracts were enzymatically hydrolyzed using alcalase (AOH), flavourzyme (FOH), and protamex (POH) to evaluate their efficacy in mitigating dexamethasone-induced muscle damage in C2C12 cells in vitro. AOH exhibited notable cell proliferative abilities, promoting dose-dependent myotube formation. These results were further solidified by protein expression analysis. Western blot and gene expression analysis via RT-qPCR demonstrated that AOH downregulated MuRF-1, Atrogin, Smad 2/3, and Foxo-3a, while upregulating myogenin, MyoD, myosin heavy chain expression, and mTOR, key components of the ubiquitin–proteasome and mTOR signaling pathways. Finally, this study suggests that AOH holds promise for alleviating dexamethasone-induced muscle atrophy in C2C12 cells in vitro, offering insights for developing functional foods targeting conditions akin to sarcopenia.

Considering the need for developing new senior-friendly processed seafood, this study aimed to develop octopus pulpo with high preference and excellent quality characteristics for elderly individuals by optimizing the vinegar immersion and sous vide softening treatment conditions for octopus (Octopus vulgaris) arms. The optimal sous vide heating temperature (70.0–100.0 °C), time (69.5–170.5 min), and vinegar concentration (0.2–0.8%) were established using response surface methodology (RSM). The pulpo prototype was produced using an octopus arm softened under optimal conditions and seasoned with a potato and olive oil sauce. The physicochemical and nutritional properties of the prototype were evaluated, followed by sensory evaluation and safety assessments. The hardness of softened octopuses obtained by 0.48% vinegar immersion and sous vide treatment (84.3 °C, 139.8 min), determined using RSM, was 394.5 × 1000 N/m², showing a reduction of 83.0%; this was confirmed by electron microscopic observation. The texture of the pulpo prototype with softened octopus arms showed the highest preference (8.4 points) and high physicochemical and nutritional properties. Overall, the octopus pulpo a La Gallega prototype produced using texture-modified octopus arms was suitable for consumption by elderly people with chewing disorders and could help improve their quality of life.

Surimi-based products typically demand cold storage and a cold chain distribution system, which not only affects their physical properties and flavor but also escalates production costs. In this study, we introduced a novel high-temperature and high-pressure retort processing method to enable room temperature storage and distribution of a surimi-based product, a fish paste cake. Our optimization efforts focused on refining the processing conditions for the fish paste cake. This included incorporating transglutaminase, sugar additives, natural herbal or seaweed extracts, and optimizing retort processing conditions to enhance textural properties, minimize browning and off flavor, and extend the shelf-life of the product. Our results demonstrated that the addition of 0.3% ACTIVA TG-K, 1.0% trehalose, and 0.5% sea tangle extract during the production process significantly enhanced the gel strength, minimized browning, and improved the overall flavor of the fish paste cake prototype. Importantly, the developed prototype exhibited favorable biochemical, textual, nutritional, and sensory properties, extending the shelf-life up to 160 days without compromising physical, chemical, or sensory attributes. In addition, the developed prototype exhibited improved elasticity, compared to control groups. The innovative process not only facilitates room temperature storage and distribution of surimi-based products but also holds potential for generating additional profits.