## 1 Introduction
### Tradition, Innovation, and Consumer Acceptance in Functional Dairy Foods  
Traditional food products play a vital role in European culture, identity, and heritage [28; 29]. This is particularly evident in the case of artisanal cheese production, which embodies both historical practices and regional distinctiveness. However, according to [PERSON] [30], \"innovation is the key to the future growth of the cheese market\". Balancing tradition with innovation remains a challenge, as consumers often resist modifications that alter the defining sensory characteristics of traditional foods [31], which are closely linked to their cultural significance and perceived quality [28].  
Sustainability in traditional and Protected Designation of Origin (PDO) food products is a multidimensional concept encompassing environmental, socio-cultural, and economic dimensions. In Europe, many PDO cheeses are rooted in centuries-old artisanal practices that contribute to local food heritage, reinforce rural economies, and promote biodiversity through the maintenance of traditional grazing systems and animal breeds [32; 33]. These production systems often rely on low-input methods, short supply chains, and seasonal cycles that reduce environmental footprints while preserving cultural identity [34]. Moreover, traditional cheese production plays a critical role in sustaining livelihoods in marginal areas, fostering social cohesion and safeguarding culinary traditions [35]. The integration of sustainable practices into cheese production--from animal feed management and milk sourcing to energy use and packaging--is increasingly viewed as essential to ensure long-term viability in the face of climate change, market volatility, and consumer demand for responsible food systems [36].  
In general, consumers tend to be more critical of unfamiliar food products or significant modifications to familiar ones, which can potentially lead to rejection. This presents a major challenge when introducing new food products to the market. However, familiarity with food is a key determinant of consumer acceptance [29]. Traditional foods, in particular, offer a sense of trustworthiness that aligns with consumer preferences, allowing tradition to serve as a source of inspiration for the development of innovative products [37].  
Food neophobia has been identified as a significant barrier to consumer acceptance of seaweeds [38; 39]. Therefore, incorporating seaweeds into traditional products--such as goat's cheese--in small concentrations, without significantly altering its traditional characteristics, can help familiarize consumers with seaweed consumption and enhance its acceptance. This strategy was employed in the present study.  
To the best of our knowledge, the supplementation of hard or semi-hard cheeses with seaweeds has not been widely studied. The only available reference is a study by [PERSON] et al. [6] on Iberian cheese made from a blend of cow, ewe, and goat milk supplemented with five seaweed species (_Himanthalia elongata_, _Laminaria ochroleuca_, _Porphyra umbilicalis_, _Ulva lactuca_, _Undaria pinnutifida_).  
Given the increasing need for sustainable and health-oriented food systems that also preserve cultural and artisanal values, this study explores the integration of two seaweed species--_Palmaria palmata_ and _Ulva_ sp.--into traditional semi-hard goat cheeses (SHGCs) produced in Portugal. Through the characterization of their physicochemical parameters, food safety, and sensory attributes, the research aims not only to advance scientific understanding but also to develop a novel functional food product that combines the nutritional richness and distinctive organoleptic features of seaweeds with the authenticity and heritage of artisanal dairy production. This approach seeks to foster innovation grounded in tradition, addressing contemporary consumer expectations while reinforcing regional identity and promoting responsible food innovation.