Red-fleshed dragon fruit (Hylocereus polyrhizus) contains abundant vitamins, carbohydrates, dietary fiber, betacyanin, and polyphenols that provide numerous health benefits and help reduce oxidative stress. In Vietnam, red-fleshed dragon fruit is extensively cultivated in the provinces of Long An, Tiền Giang, and Tây Ninh, with large production volumes primarily consumed in fresh form (Trần Xuân Hiển, 2017). Therefore, developing preservation and processing methods for red-fleshed dragon fruit is essential to enhance its economic value.

To date, several studies have explored the processing of red-fleshed dragon fruit into various products, including the production of natural pigment powder from dragon fruit peel for coloring fermented yogurt (Vũ Thị Thanh Đào, 2017), red dragon fruit juice combined with aloe vera (Trần Xuân Hiển, 2017), fermented beverages produced from red dragon fruit and rose myrtle fruit (Phan Thị Ngọc Hạnh et al., 2020), dragon fruit gummy candy with strawberry filling (Trần Thị Thùy et al., 2022), the use of dragon fruit peel as a partial substitute for wheat flour in high-fiber biscuits (Anh et al., 2022), and fermented beverages made from red-fleshed dragon fruit (Hoàng Quang Bình et al., 2020; Hà Thanh Toàn et al., 2023).

To diversify gummy candy products in general and red-fleshed dragon fruit products in particular, a study on the processing of betacyanin-rich gummy candy from red-fleshed dragon fruit was conducted. The objective was to create a new product with high nutritional value that meets food safety and hygiene standards while ensuring consumer health.

The ingredients used for producing red dragon fruit gummy candy include red-fleshed dragon fruit, lemon, sucrose, and gelatin (Figure 1).

The gummy candy production process consists of the following steps:

Red-fleshed dragon fruit → Blending → Filtering → Extract collection → Mixing (dragon fruit extract, gelatin, sugar, lemon juice, and water) → Heating (90°C for 10 minutes) → Molding → Stabilization (rapid cooling at 20–30°C) → Candy removal
(Nhan Minh Trí & Diệp Kim Quyên, 2014; Trần Thị Thùy et al., 2022)

After harvesting, the dragon fruits are peeled, cut into small pieces, and filtered through a sieve to obtain the juice extract containing fine pulp particles and some seeds. The extract is then mixed thoroughly with sugar, gelatin (previously soaked in water for 20–30 minutes), lemon juice, and water. The mixture is heated at 90°C for approximately 10 minutes. After cooking, the mixture is poured into molds, rapidly cooled to 20–30°C (typically in a refrigerator), and subsequently evaluated for sensory quality.

Research results showed that red-fleshed dragon fruit contains high moisture content, a mildly sweet taste, and considerable amounts of vitamin C and betacyanin, a powerful natural antioxidant (Table 1). These characteristics make it an excellent raw material for gummy candy production, enhancing both nutritional value and product diversity.

Table 1. Selected Nutritional Components of Red-Fleshed Dragon Fruit

The study found that the addition of 20% red dragon fruit extract and 10–12% gelatin contributed to a moderately chewy texture, attractive color, and characteristic flavor of the gummy candy, resulting in a product with favorable sensory evaluation scores.

The incorporation of red dragon fruit extract and gelatin significantly influenced the texture, color, and flavor of the gummy candy. A formulation containing 20% dragon fruit extract provided the candy with the characteristic color and flavor of red-fleshed dragon fruit. Meanwhile, a gelatin concentration of 10–12% produced a desirable chewy texture and achieved the highest sensory acceptance.

Betacyanin can be utilized as a natural color additive in various industries, including food, pharmaceuticals, and material applications. Developing a processing technology for betacyanin-rich gummy candy from red-fleshed dragon fruit has significant practical value, helping to address post-harvest losses during peak harvest seasons and product shortages during off-seasons.

With its low cost, abundant availability, long shelf-life potential, and simple, cost-effective processing methods, red-fleshed dragon fruit represents an innovative and highly suitable raw material for producing betacyanin-enriched products. This research is expected to contribute to the development of new food products that are safe for consumers, environmentally friendly, and capable of adding significant value to Vietnam’s agricultural resources.