## 1 Introduction  
Macroalgae is a significant component of global aquaculture, comprising 27% of total production. Its ecological advantages and diverse applications have made it extremely popular [1]. Southeast Asia is a significant producer in this industry, underscoring the region's critical role in cultivating and harvesting macroalgae. In addition to being an essential food source, microalgae are also important for environmental management and sustainable development, highlighting their significance for the food and aquaculture sector and larger ecological systems [2]. The genus Gracilaria is a major species of macroalgae in the phylum Rhodophyta. It is as important as red algae and has many uses in biotechnology, aquaculture, and traditional medicine. Agar production from Gracilaria species is widely used in many industries, accounting for 80% of the world's total production [3]. Furthermore, with more than 190 species, the genus Gracilaria is widely distributed throughout tropical and temperate regions, contains high concentrations of bioactive compounds, and may have health benefits. One of the most common species in the genus is the red seaweed _Gracilaria fisher_ (GF), which has been garnered for its phenotypic plasticity and chemical diversity. These attributes support its extensive applications, rendering it highly valuable across multiple sectors, including biotechnology, aquaculture, and traditional medicine [4]. GF has long been considered a wholesome food source in Southeast Asia, Japan, and the Caribbean [5]. It is frequently used in various recipes, including salads, soups, and desserts, highlighting its cultural significance and culinary adaptability. In Thailand, it is sold either fresh or dried and mainly used to make savory salad. Apart from food, GF have long been used in traditional medicine to treat various illnesses, such as thyroid-related conditions, intestinal problems, and respiratory problems [6]. Furthermore, GF polysaccharides--particularly agar--are essential raw materials for producing a hydrocolloid widely used in the food, pharmaceutical, and biotechnology industries. The sulfated galactans, also known as agarans, from GF have remarkable gelling, stabilizing, and thickening qualities [7]. These characteristics make it possible for them to be used in various consumer products, such as desserts, soups, beverages, and jelly candies, highlighting the exceptional adaptability and worth of GF for both culinary and industrial uses. Other bioactivities that these polysaccharides display include antiviral, antibacterial, anti-inflammatory, and antioxidant qualities. The potential therapeutic effects of these bioactivities support their incorporation in nutraceuticals and functional food [8]. The fast-paced lifestyle has increased the demand for nutritious, time-efficient food options. A major challenge is developing a ready-to-eat product that satisfies consumers and satiates hunger [9]. Drinking jelly, characterized by its viscous consistency, has emerged as a novel food product with potential health benefits. Its versatility and adaptability to diverse formulations make it a convenient option for consumption at any time. Typically, the drinking jelly combines a gelatinous base with various flavorings and nutritional additives. The production and consumption of drinking jelly are influenced by its health benefits, manufacturing techniques, and sensory properties. Drinking jelly can have significant health benefits, particularly when enriched with specific ingredients. For instance, a jelly drink containing polyphenol-rich roselle calves extract and passion fruit juice demonstrated antioxidant, anti-inflammatory, and lipid-lowering effects [10]. Producing drinking jelly involves creating a viscous base, often using ingredients such as amaranth flour or seaweed-derived gelling agents. Seaweed gelling agents are increasingly being used inthe formulation of drinking jellies due to their health benefits and functional properties. Agar-agar is a natural, plant-based gelling agent.