Characteristics of Red Hard Candy with Addition of Roselle (Hibiscus sabdariffa L.) Flower Extracts

Abstract

There is a growing interest in replacing synthetic dyes with natural colouring agents, primarily driven by increasing health concerns among consumers worldwide. This work aimed to reformulate hard candy products through incorporating different levels of roselle flower extracts (6-15 g) as an alternative colouring agent. The samples were also enriched with Javanese long pepper extract as a source of functional components and xylitol as an alternative sweetener. In this work, the properties of hard candy, including pH, solubility time, colour variation (expressed as Red, Green, and Blue – RGB), DPPH radical scavenging (% inhibition), and sensory acceptability, were evaluated. As a result, while pH, colour, and free radical inhibition were significantly altered, the treatments given did not affect solubility time. The pH level decreased consistently as the amount of roselle flower extract increased. Conversely, the RGB values and percentage inhibition increased with greater incorporation of roselle flower extracts into the formulation. In the case of colour, a higher proportion of the extract led to higher RGB values in hard candy, corresponding to a greater level of brightness achieved by F4. Meanwhile, F2 demonstrated the highest red intensity. Furthermore, the treatments resulted in significant effects on all sensory attributes, except aroma. F1 reached the highest sensory score for taste, texture, and overall attributes, while F2 reached the highest for colour. The work results confirm the further use of roselle flower in the formulation of red hard candy.