| Summary: | Hibiscus rosa-sinensis (China rose) leaves have been known for its high
biopolymer of polysaccharide content in a form of mucilage. Biopolymer of
polysaccharide is one of the basic components in edible films making. However,
the research about edible film made from the biopolymer from its leaves is never
to be done. The aims of this study were to characterize biopolymer of Hibiscus
rosa-sinensis leaves for chemical properties (methoxyl group, water, ash, protein,
fat, and carbohydrate content) and to characterize edible films made from the
biopolymer added with glycerol as plasticizer for physical (tensile strength,
elongation, and solubility) and barrier properties (water vapor transmission rate).
The biopolymer of the leaves were extracted by water, then precipitated by
ethanol, dried, and crushed. Three concentrations of biopolymer (1%, 1.25%, dan
1.5% b/v) were used in edible films making, while the concentration of glycerol
was the same in each formula (30% b/b biopolymer). Result showed that the yield
of biopolymer extraction was 4.17% (b/b), or gave about 41.7 grams of yield per
kg of fresh leaves. The biopolymer isolate contained methoxyl groups about
5.11%, 11.70% of ash, 9.13% of water, 11.89% of protein, 0.96% of fat, and
58.68% of carbohydrates (by difference). The reducing sugar was not detected in
the biopolymer hydrolyzed by acid. It also showed that as the concentration of
biopolymer isolate film increased
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