## 1 Introduction  
Food systems strive to adapt to the increasing pressure on sustainability issues and the need for a circular economy perspective in food production [1]. To this end, the valorization of agro-food by-products has been receiving increasing attention worldwide as a means to overcome the current production and consumption prevailing model of conventional agriculture, based on the intensive exploitation of land and resources (e.g., water), towards a swift transition to a more sustainable and ecological approach in primary food production, following less-intensive agricultural practices [2].  
More recently and in the last four decades, with the concept of functional foods having emerged in Japan [3], consumers have continuously demanded healthier food choices and products with functional properties [4]. Thus, natural sources that are rich in antioxidants or other bioactive compounds have gained attention as functional food ingredients [5]. From this point of view, the addition of olive oil, edible plants, and seeds could be a good strategy to increase the antioxidant and phytochemical content of such products [6; 7; 8]. However, owing to the complex mechanisms involved in the digestion process of antioxidants and the various factors that may affect the degree of their biological activity, the study of the predicted bioavailability of these compounds is of vital importance. Therefore, various in vitro digestion models can be used to predict relative bioavailability in a low-cost and less time-consuming manner [9].  
Purslane is one of those edible plants rich in nutrients that could offer several desirable properties in the food to which it is added. Egyptian literature from the Pharaoh era describes purslane (_Portulaca oleraca_); a ubiquitous nutrient-dense vegetable suitable for both animal (fodter) and human consumption [10; 11]. It was listed globally as the eighth most common weed and is thought to be a highly invasive plant as it can grow in almost any warm and moist area during the summer and spring seasons, including gardens, crop fields, and waste places [12; 13]. Purslane can be eaten raw as a salad or can be consumed cooked and/or as a sauce in soups. According to relevant studies, purslane is a promising natural product with a great nutritional and medicinal potential along with its increased antioxidant capacity [7; 14; 15]. It is among the most abundant green plant sources of linoleic acid and omega-3 fatty acids [7; 16], conferring to the lower incidence of cancer and cardiovascular diseases in the areas where it is consumed [17]. The nutritional and therapeutic qualities of purslane have established it as a \"new crop\" and as a \"power food of the future\" [18].  
The aim of the present study was to develop a new spreadable plant-based product of high added value with functional properties, exploiting purslane's nutritional and phytochemical components and having it as the main raw material in the product. To the best of our knowledge, no such widely distributed product with purslane as the main ingredient is on the market so far. Its industrial production is expected to be a sustainable solution to the ever-demanding trend of minimizing the environmental footprint by using less-intensive agricultural practices and crops [19].