Development of Nutmeg Shell (Myristica Fragrans) Powder- Reinforced Starch Bioplastic Films

Abstract

The increasing accumulation of agricultural residues has encouraged their valorization as biofillers in biodegradable polymer systems. This study developed starch-based bioplastic films incorporating Myristica fragrans (nutmeg) shell powder and quantified the effect of filler concentration on tensile strength, water absorption, thickness, and soil-burial weight loss. Films were prepared by solution casting using corn starch and agar as matrix materials, glycerol as a plasticizer, and nutmeg shell powder at 0, 3.23,

6.25, 9.09, and 11.76% (w/w). For corn starch- based films, mean tensile strength decreased from

15.58 N at 0% to 8.82 N at 3.23% filler and subsequently increased to 13.89 N at 11.76%. Water absorption (Mean) increased progressively from 24.98% to 66.65%, while film thickness increased from 1.26 mm to 1.98 mm at 9.09% filler and remained at 1.94 mm at 11.76%. Seven-day soil-burial weight loss increased from 6.57% in the unfilled film to 33.17% at 11.76% filler. In contrast, agar-based films exhibited a progressive reduction in tensile strength (mean) from 31.23 N at 0% to 7.93 N at 11.76% filler, while water absorption ranged from 60.83% to 72.20%. At 6.25% nutmeg shell powder, the corn starch film exhibited a tensile strength of 9.70 N, water absorption of 35.55%, thickness of 1.96 mm, and seven-day soil-burial weight loss of 20.40%, with coefficients of variation of 0.03, 0.11, 0.12, and 0.10, respectively. These results establish the concentration-dependent effects of M. fragrans shell powder on starch-based bioplastic film properties and demonstrate its feasibility as a lignocellulosic biofiller for biodegradable film development.