# Emerging Trends in Sustainable Biological Resources and Bioeconomy for Food Production
## 5 Common Resources in Green and Blue Bioeconomy
### Natural Polypphenols and Antioxidants  
Bioactive compounds are naturally occurring chemical constituents found in small quantities in plants and other natural sources. These compounds have the capacity to interact with biological systems, thereby producing health-promoting effects [77]. These compounds can be classified into different categories according to their chemical structure and functions, including phenolic compounds, terpenoids, alkaloids, carotenoids, and organosulfur compounds [78]. Their physiological activities encompass antioxidant, antiinflammatory, and antimicrobial functions, among others, rendering them valuable for applications in functional foods, nutraceuticalals, and pharmaceuticals [79; 80; 81]. Of these, phenolic compounds represent the most substantial and varied group of plant secondary metabolites, comprising over 10,000 known structures. Structurally, these compounds are characterized by one or more aromatic rings with one or more hydroxyl groups, ranging from simple phenols to complex polymers such as tannins and lignans [82]. Phenolic compounds are distributed widely in a variety of foodstuffs, including fruits, vegetables, grains, herbs, and beverages such as tea and wine. In plants, these compounds fulfill a number of physiological functions and play a significant role in defense against environmental and biological stressors. Moreover, their presence in foods has been demonstrated to contribute to organoleptic characteristics, including color, bitterness, and aroma [83; 84]. In recent decades, phenolic compounds have attracted considerable attention due to their ability to exhibit a wide spectrum of biological effects, including antioxidant, anti-inflammatory, anticancer, antiviral, and immunomodulatory actions [77]. The central role of their antioxidant capacity in their health-promoting potential is evidenced by their ability to neutralize reactive oxygen species (ROS), thereby mitigating oxidative stress, a factor implicated in the onset of conditions such as cardiovascular diseases, cancer, diabetes, and neurodegenerative disorders. Beyond ROS scavenging, phenolic compounds have been demonstrated to modulate signaling pathways, induce apoptosis, arrest cellular proliferation, and potentially reverse epigenetic alterations associated with disease progression. Evidence has been posited to suggest a dual antioxidant and pro-oxidant behavior, which would be contingent on the cellular environment. This behavior could be a contributing factor to their chemopre effects. In addition, phenolic compounds have been demonstrated to support immune function by downregulating chronic inflammation and inhibiting angiogenesis in tumor development [82; 85]. Polyphenols are present in a wide variety of plant-derived foods, though their concentrations and significance vary substantially among sources. On a global scale, the most significant contributors to polyphenol intake are commodities that are both rich in polyphenols and widely consumed, such as green and black tea, red wine, coffee, and cocoa [86]. Fruits and vegetables are commonly cited as sources of phenolic compounds; however, their overall contribution is often secondary, due to lower concentrations and variability in content. Nonetheless, specific fruits like berries, grapes, and pomergnates; and vegetables like onions, garlic, or spinach contain notable levels of flavonoids and phenolic acids [87]. Other important sources of structurally unique phenolic compounds with high antioxidant potential are different herbs and spices, nuts, oilseeds, extra virgin olive oil, and certain algae [88]. Additionally, polyphenols can be delivered through plant extracts used in dietary supplements, pharmaceuticals, and nutticosmetics, extending their relevance beyond conventional food matrices. In recent years, the search for novel sources of phenolic compounds has intensified, driven by the growing demand for bioactive ingredients in the functional food and nutraceuticalal industries.