THE STUDY OF COFFEE HUSK FIBER AND POLYVINYL ALCOHOL ADDITION ON CASSAVA STARCH-BASED BIOFOAM FORMULATION AND ITS EXPERIMENTAL DESIGN OPTIMIZATION

Polystyrene plastic or styrofoam is very popular to be used as a food packaging container even though Styrofoam
has a bad impact on health and the environment. One alternative to styrofoam is biodegradable foam made from
starch and fiber. It is safe for health and can be broken down naturally. Cassava peel is rich in starch
(carbohydrates) but has low fiber content. Meanwhile, coffee husk is rich in fiber and minimal in carbohydrates.
Both types of waste have the potential to become biodegradable foam raw materials. The addition of synthetic
PVA polymer is expected to improve the characteristic of biodegradable foam. This study aims to obtain the best
formulation for the manufacture of biodegradable foam from cassava starch with the addition of various coffee
husk fiber's concentration (5%, 10%, 15%, 20%) and various PVA concentration (10%, 15%, 20%). The
optimization of experimental design using RSM resulted in optimum variable to produce biodegradable foam. The
optimum formulation for best tensile strength is 20% coffee husk fiber and 15% PVA with tensile value 2,73
N/mm2. The optimum formulation for the lowest water absorption is 10% coffee husk fiber and 12% PVA with
water absoption value 22,19%. While optimum formulation for the most biodegradable foam is of 8,51% coffee
husk fiber and 10% PVA with biodegrabability value 99,9% in 30 days.