Identifikasi Komponen Pembentuk Gel (KPG) dan Potensi Antioksidan Daun Kacapiring (Gardenia jasminoides Ellis)

Abstract

Leaf of Kacapiring (Gardenia jasminoides Ellis) is a part of plant which has hydrocolloid component and can form gel. The aims of this research were (1) to evaluate physical and chemical properties of leaves and gel, (2) to extract, isolate, fractionate and identify gel forming component (GFC), and (3) to analyse the potency of antioxidant capacity of its gel. The research was devided into three steps as follows (1) Physical characterization were done for the dimension of leaves, and gel properties by sensory analysis. Chemical components of leaf and gel were quantified by proximat analysis and mineral component was analyzed by atomic absorption spectrophotometer (AAS) such as Cu, Fe, Mg and Ca. Dietary fibre component was analyzed by enzymatic method and estimation of pectic substances was done by spectrophotometer (2) Isolation of GFC was done by extraction using 0.028 M ethylendiamintetraacetate (EDTA). GFC was fractionated by ultrafiltration membrane. Monomers of GFC was identified by paper chromatography, and (3) Bioactive components such as, chlorophyll total was analyzed by spectrophotometer and its derivations of acetone extract (99.9%) by thin layer chromatography (TLC), meanwhile phenolic total and antioxidant capacity were analyzed by spectrophotometer. The results showed that kacapiring leaves contained water, ash, protein, fat, and carbohydrate. The mineral content in leaf and gel consisted of Ca of 19974.70+49.31 and 5429.71+68.98 mgKg-1db, Mg of 4263.15+38.66 and 2800.63+110.96 mgKg-1 db respectively, while Fe and Cu were not detected. The best gel can be obtained by AQ (1:15) treatment. Dietary fibre of leaf and gel contained of 24.98+0.72 and 90.61+1.02 %db respectively. Pectic substances of GFC isolate contained 56.53+0.61 %db galacturonic acid as pectin monomers. Isolate of 0.25% GFC was fractionated by ultrafiltration membrane and 96.78 % of retentate was separated in 5 μm membrane filter. Analysis by paper chromatography showed that GFC isolate contained galacturonic acid and glucose. Bioactive component of kacapiring leaves and gel contained chlorophyll total of 4926.25+190.31 and 1166.86+8.73 mgKg-1db. Both of them had 5 fractions by acetone extract, i.e. chlorophyll a, chlorophyll b, lutein (chlorophyll derivations), feofitine and carotene. Phenolic total in leaves and gel contained 5215.91+2.97 and 2648.16+56.22 GAE/g db, and antioxidant capacity had 1.5 x 10-1+0.00 and 3.1x10-3 +0.00 mM TEAC/mg dw respectively.