## 1 Introduction  
Sesame seeds (_Sesamum indicum_ L.) contain a multitude of phenolic compounds, which exhibit beneficial effects on human health. Phenolic components, known for their antioxidant, anti-inflammatory and hypolipidemic activities, and, specifically, sesame lignans like sesamin and sesamolin have attracted large interest regarding their nutritional benefits for humans in conditions such as atherosclerosis, hypertension, hyperlipidemia, obesity, diabetes, osteoporosis, arthritis and Alzheimer's disease [1, 2, 3, 4, 5, 6, 7, 8]. A number of studies with sesame oil have reported a reduction in oxidative stress and an increase in vitamin E levels [9, 10]. However, there is limited data concerning the effect of tahini consumption on human health. A recent study shows that the ingestion of tahini enhances the biomarkers related to metabolic and antioxidant status throughout the postprandial period in healthy men [11], and a second study presents novel findings indicating that the consumption of tahini may have a beneficial impact on blood pressure, pulse rate and endothelial function in healthy men, implying that including tahini into one's diet as a healthier alternative to snacks with unfavorable lipid profiles could be advantageous [12].  
An alternative utilization of food by-products rich in bioactive compounds is their incorporation into other foods, thus making them functional [13; 14; 15].  
Red grape pomace is a low-cost source of valuable phenolic compounds [16; 17; 18]. It has been studied extensively over the past two decades, with clear evidence indicating its effectiveness in reducing the risk of various diseases. Given the plethora of potential health benefits associated with grape phenolic compounds, there has been a growing demand for functional foods fortified with grape extract polyphenols [19; 20].  
On the other hand, chickpea boiling water called aquafaba produced at home or from canned chickpeas is usually discarded. However, it is valuable not only for its high content of health-promoting compounds, such as polyphenols, but also for its high protein content [21; 22].  
Red grape pomace and aquafaba are considered by-products of the wine and chickpea industries, respectively. In a circular economy framework, utilizing these by-products as fortifiers for tahini can help minimize waste and create value from materials that would otherwise be discarded. This aligns with the principles of sustainability and resource efficiency. At the same time, fortifying tahini with red grape pomace can enhance its nutritional profile, potential health benefits and appeal to health-conscious consumers.  
The purpose of this study was to evaluate in vitro the fortification of tahini with an extract of red grape pomace of the Limnio variety and aquafaba from Lemian chickpeas of the Panagia variety and their effect on its bioactivity. Oxidation, inflammation and thrombosis mechanisms are directly involved in the development of chronic diseases and the study of food substances with possible antioxidant, anti-inflammatory and anti-thrombotic activity can reveal bioactivities that indicate a preventive effect against their development [23; 24; 25].