Behind the freshness of cincau, the threat of formalin still lurks

Cincau is a traditional beverage that has long been known and consumed by the Indonesian people. Its utilisation continues to develop, not only as a ready-to-drink beverage served with ice, sugar, coconut milk, or syrup but also as an additional ingredient in various modern beverage products. Cincau can be found easily, from traditional markets, traditional beverage vendors, to modern outlets and packaged processed food products. Besides ready-to-drink versions, soft drink products containing cincau in packaged processed food form are also widely circulated. BPOM data (2026) recorded at least 181 registered beverage products containing cincau. Registered products are certainly easier to evaluate for safety, both through pre-market and post-market surveillance. The plant raw materials used to produce ready-to-drink cincau beverages are diverse. However, among the public, two types of cincau are the most popular and widely known. Firstly, green cincau, derived from the plants Cyclea barbata or Premna oblongifolia, obtained through a process of kneading the leaves with water (Gangga et al., 2017). This type of cincau is commonly found in traditional beverages served with a mix of ice, sugar, coconut milk, or syrup. Secondly, black cincau, which comes from the black cincau plant Mesona palustris Bl (Wahyono et al., 2015). This black cincau is also widely found as a mixture in other ready-to-drink beverages, such as mixed fruit ice, mixed shaved ice, cappuccino cincau, and others. Unlike green cincau, which is generally produced and sold directly by traditional beverage vendors to consumers, black cincau is now produced more widely by manufacturers who market it in large quantities or bulk form to traditional markets. From traditional markets, the black cincau is then resold to ready-to-drink beverage vendors or households to be processed and served as a consumption beverage. Research by Nurulkhusna et al. (2024) explains that black cincau has a hydrophilic gel structure with a matrix dominated by water bound in a hydrocolloid network. This high water content causes black cincau to be very susceptible to physical changes, syneresis, spontaneous fermentation, and microbiological damage during the storage process. Sanitation studies on black cincau also confirm that the high water content can become a medium supporting the growth of microorganisms (Nurulkhusna et al., 2024). These findings align with the Hurdle Effect theory (Leistner, 1978), which explains that factors such as heating, storage temperature, water activity, and acidity level play an important role in the food preservation process. Indeed, not all black cincau products contain formalin. However, various tests conducted by the Technical Implementation Unit (UPT) of BPOM in a number of regions show that some black cincau products are still found to contain harmful substances.