OPTIMAZION AND CHARACTERIZATION OF STARCH GLUCOMANNAN AS EDIBLE COATING ON STRAWBERRY (Fragaria x annasa)

• Main Author: Nurliasari Suparno, Desy
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/34368
• Institution: Institut Teknologi Bandung

Glucomannan is one type of polysaccharide which found in the plant specially iles- iles (Amorpophallus oncophyllus). Glucomannan composed by units of D-Mannose in the ratio 1.6 : 1 and has ?-1,4-glycoside lingkage. Glucomannan can be applied as edible coating which is one of the primary packaging in the thin layers form to coat the fruit, can be eaten and degested. The role of edible coating is to extend the shelflife of perishable fresh produch, such as strawberry. Strawberry are one of the fruits that have high value economic but easily damaged and short shelflife because it has a high water content (90% of total weight) and a thin layer of skin can get mechanical injuries easily. In this research, there are two kinds of flour glucomannan which learned as a material coating, glucomannan of iles-iles flour and glucomannan of isolated iles-iles flour. The purpose of this study is to optimize and characterize the physic and chemist properties of edible coating from iles-iles flour before and after isolated to applied as strawberry coating. The research was conducted in three steps, there are isolation of glucomannan from iles-iles flour, optimazion and characterization of edible coating on the sheet’s form (edible film) from glucomannan iles-iles flour, and application of edible coating on strawberry. Optimazion of edible coating properties of glucomannan to formed films with glucomannan flour content of 0.4%, 0.6%, 0.8%, and 1% (w/v) were mixed with 0.3% CMC (w/v) and 1% glycerol (v/v) in water solvent then measured the water content, water vapor transmission rate (WVTR), and tensile strength value to get optimum levels og glucomannan flour. Furthermore, the application edible coating of glucomannan on strawberry characterized weight loss, the optimum color intensity and brightness, also hardness for seven days. These results indicate that the edible coating can be made from glucomannan iles-iles flour both before and after isolated. Evaluation of these results based on the lowest water content and water vapor transmission rate (WVTR) and the largest tensile strength values in edible films, the optimum levels indicated by the 0.8% (w/v) glucomannan iles-iles flour before isolated and 1% (w/v) glucomannan iles-iles flour after isolated. Edible films from glucomannan flour before and after isolated sequentially provides 5.516% and 2.39% water content, 36.6242 g/m2. 24 hr and 55.639 g/m2. 24hr water vapor transmission rate, 5.84 MPa and 4.85 MPa tensile strength value. Tensile strength values of edible film glucomannan from iles-iles flour before isolated with 1% (w/v) levels lower than edible films glucomannan from iles-iles flour after isolated with 0.8% (w/v) levels, it caused in addition the glucomannan flour with 1% (w/v) levels give the high viscosity solution so that the matrix of the film became cracking, the using water as solvent is slight and the hydrogen bonds is too small. Aplication of edible coatings glucomannan from iles-iles flour before and after isolated than strawberry standard in 3.13% weight loss values obtained 2 days to save time without coatings strawberry, strawberry coated glucomannan for 3 days before isolated, and 5 days for strawberry coated glucomannan after isolated. At the brightness value 31.4 and 26.89 of color intensity value obtained for the retention time of 1 day strawberry without coated, 3 days for strawberry coated glucomannan before isolated, and 4 days for strawberry coated glucomannan after isolated. At 0.76 Pascal hardness value be obtained at the retention time of 1 day without strawbeery coated and 3 days on strawberry coated glucomannan both before and after isolated by iles-iles flour.