Development of instant jelly powder from elephant foot yam
\n(Amorphophallus oncophyllus) and roselle (Hibiscus sabdariffa L.) as a
\nfunctional food for diabetes mellitus patients

Elephant foot yam (Amorphophallus oncophyllus) is one of Indonesia's most widely
\ngrown agricultural commodities. It has a myriad of benefits, especially as a functional
\nfood for people with diabetes mellitus. Roselle (Hibiscus sabdariffa L.) is a flowering
\nherb rich in polyphenols and anthocyanins with antioxidant and antidiabetic potentials.
\nTherefore, the aim of this study was to create a functional food that is suitable for diabetes
\nmellitus patients. In this study, a functional food product in the form of instant jelly
\npowder was developed from the yam and roselle. Glucomannan extract, obtained from the
\nyam flour by leaching, was tested using a Fourier-transformed infrared (FTIR)
\nspectrophotometer (qualitative) and determined the content. Three formulas with different
\namounts of glucomannan and iota carrageenan were developed to determine the most
\noptimized formulation. The most optimized formulation was determined based on
\norganoleptic characteristics and the results of the gel strength and hardness, total phenolic
\ncontent (TPC), and antioxidant activity tests using the ABTS (2,2'-azino-bis(3-
\nethylbenzothiazoline-6-sulfonic acid) assay. Glucomannan extraction produced a 92.40%
\nyield, with 46.32% glucomannan content. The spectrophotometric analysis indicated the
\npresence of glucomannan in the extract, and further tests showed it increased with the
\ndecrease in gel strength and hardness. It was found that formula I produced the best jelly
\ntexture with a total phenolic content of 0.30% GAE (formula II 0.13% GAE; formula III
\n0.27% GAE) and an ABTS radical scavenging activity of 90.51% (II: 73.49%; III:
\n88.16%). In conclusion, formula I containing 6.35 g of carrageenan, 2.12 g glucomannan,
\n1.5 g roselle, 0.03 g citric acid, and 0.003 g sucralose has the best composition to create
\nthe most elastic and firm jelly texture with the highest phenolic content and radical
\nscavenging activity.