Formulation and Quality Assessment of Diabetic Jelly Marmalade 'Karkade' Fortified with Succinic Acid

Complex diet therapy for type II diabetes involves confectionery products based on fructose, sugar substitutes, and/or intensive sweeteners. The formulation of diabetic jelly marmalade ‘Karkade’ does not contain sugar or molasses. Sweetness was provided by the combination of sorbitol (E420) and glycosyl stevioside ‘Crystal’. Their sweetness to sucrose ratio was 0.6 and 150, respectively. Polydextrose was used as a filler. Polydextrose is a low-calorie prebiotic (1 kcal/g) and a water-soluble dietary fiber with a neutral taste. Water infusion of dry bracts of hibiscus (Hibiscus Sabdariffa L.), or Karkade, gave the marmalade its color and physiologically active substances. Fortification was provided by succinic acid, which was chosen as an acidity regulator since it increases cell insulin resistance and reduces the risk of diabetic complications. For maximum extraction of anthocyanins, the raw material was infused for 30 minutes at a ratio of 1:10 at 80°C. Citric acid (1.2 g/100 g) was added into the infusion to stabilize the anthocyanins. The research involved standard methods. The method of pH-differential spectrophotometry was used to determine the level of anthocyanins, while the method of gas-liquid chromatography was employed to determine organic acids in the marmalade. The optimal ratio of agar, stevioside, and hibiscus infusion (%) was defined as 16.0:0.4:15.0. No preservative was used. The marmalade contained 380 g/kg of sorbitol and 2 g/kg of succinic acid. The sensory properties of the marmalade corresponded with the State Standard. The marmalade had a slightly astringent sweet and sour taste, a burgundy color, and a jelly-like consistency with no syneresis. The average value of physical and chemical parameters at the time of manufacture was as follows: moisture – 18.7%, total acidity – 12.4 degrees, plastic strength – 22.0 kPa. The average content of micronutrients (mg/100 g) was as follows: anthocyanins – 38.8, potassium – 33.1, calcium – 11.3, magnesium – 5.1, manganese – 0.48, iron – 0.35, zinc – 0.0015, and succinic acid – 214.0. No loss of succinic acid was registered during processing and 3 months of storage. The content of succinic acid in 50 g marmalade was amounted to about 100g, or 50% of the acceptable daily intake. Thus, marmalade 'Karkade' with succinic acid can be considered a functional fortified product for diabetic diet.