Breakfast cereals are widely consumed as convenient and nutritionally balanced breakfast foods. Numerous studies have reported that cereals, particularly those derived from whole grains, provide important nutritional benefits due to their high content of carbohydrates, protein, iron, and calcium [1]. Regular consumption of breakfast cereals has also been associated with improved dietary quality and increased intake of essential nutrients and recommended food groups [2]. In recent years, the development of fruit-based cereals has attracted increasing attention as the incorporation of fruits can enhance the nutritional value of cereal products by providing additional dietary fiber, vitamins, minerals, and bioactive compounds such as carotenoids and polyphenols [3, 4]. Despite this growing interest, many commercially available breakfast cereals still contain high levels of refined sugars and artificial additives. This has created increasing demand for healthier cereal products formulated with natural ingredients and functional components.

Tarap (Artocarpus odoratissimus) is a tropical fruit widely cultivated in Sabah, Sarawak, and parts of the Philippines and Indonesia. The fruit is characterized by its soft, sweet, and aromatic pulp and is known to contain substantial amounts of carbohydrates, dietary fiber, and essential minerals such as potassium, iron, and zinc, as well as various vitamins and bioactive compounds [5]. Previous studies have reported that tarap exhibits several functional properties including antibacterial, anticancer, and antidiabetic activities [6]. Furthermore, different parts of the fruit including the peel, seeds, and pulp contain antioxidant compounds such as polyphenols and flavonoids that contribute to free radical scavenging activity [7]. Despite its promising nutritional and functional properties, the commercial utilization of tarap remains limited. The fruit is highly perishable due to its high moisture content and short postharvest shelf life, which restricts its storage, transportation, and market distribution. According to the Department of Agriculture Malaysia, although Sabah remains the main production region with an annual production of approximately 1,920.39 metric tons, tarap production has declined by more than 67% between 2019 and 2023. This decline highlights the underutilization of the fruit and the need for value-added processing approaches that can extend its shelf life while enhancing its economic value.

In addition to the underutilization of tarap, agro-industrial by-products such as brewer’s rice also remain largely undervalued. Brewer’s rice is a by-product of rice milling consisting mainly of small broken rice fragments, often accompanied by portions of bran and germ [8]. Although brewer’s rice possesses a nutritional profile comparable to white rice, with additional dietary fiber and micronutrients contributed by bran and germ fractions, it is frequently utilized in low-value applications such as animal feed due to its susceptibility to lipid oxidation and limited shelf stability [9]. The valorization of brewer’s rice into human food products aligns with the principles of sustainable food systems and circular economy, where agricultural by-products are converted into value-added food ingredients with improved nutritional and economic value.
To effectively incorporate both tarap pulp and brewer’s rice into cereal formulations, an appropriate processing technique is required. Drum drying is widely used in the food industry for producing cereal flakes and instant cereal products due to its ability to process viscous or slurry-based materials such as fruit pulps and cereal pastes [10]. The technique involves spreading the slurry as a thin film on a heated rotating drum, allowing rapid moisture removal and formation of dried flakes. Compared with other drying methods such as spray drying or freeze drying, drum drying is particularly suitable for thick and fibrous materials and can produce shelf-stable products with relatively low processing costs while maintaining acceptable nutritional quality [11, 12]. Therefore, the application of drum drying provides a promising approach for transforming highly perishable fruit pulp into stable cereal products.

This study was carried out to develop a tarap-based breakfast cereal using brewer’s rice as the main base and drum drying as the processing method. The developed formulations were then assessed in terms of proximate composition, physicochemical properties, sensory acceptability, and storage stability under ambient conditions.