Investigation of a water-yam starch-based film reinforced with polyethylene and eggshell nanoparticles for beef preservation under varying processing conditions

Beef is highly susceptible to microbial spoilage due to its rich moisture and nutrient content, along with the limitations of conventional packaging. This study investigates a biodegradable film made from water-yam starch reinforced with polyethylene and eggshell nanoparticles (WSPeN) for preserving beef under various processing conditions. The film was developed using thermal ultrasonication-assisted dispersion and its physicochemical and thermal properties were determined. Beef samples were wrapped in the WSPeN film and stored at different temperatures (4 °C, 8 °C, 10 °C), beef thickness (5 mm, 7 mm, 10 mm), and storage durations (5, 10, 15 days). Quality parameters, such as microbial load, moisture loss, color (L*-lightness, a*-redness, b*-yellowness), and tenderness (N), were assessed throughout storage. Optimization using a Distance-Based Design approach identified 5 mm beef thickness, 4 °C storage, and 13.55 days as the most effective combination. Under these conditions, bacterial and fungal loads significantly decreased from initial counts of 5.62 × 103 CFU/g and 3.27 × 102 CFU/g to 2.91 × 10³ CFU/g and 1.46 × 10² CFU/g, respectively (p < 0.05). In comparison, control samples packaged in low-density polyethylene (LDPE) exhibited higher microbial loads (7.8 × 103 CFU/g for bacteria and 3.4 × 102 CFU/g for fungi). The difference in redness values between packaged (16.0) and control samples (16.2) was not statistically significant (p > 0.05), indicating color stability. In contrast, moisture loss was significantly lower in the packaged beef (2.9%) compared to the control (3.1%) (p < 0.05), and tenderness was significantly improved in the packaged samples (50 N) relative to the control (34 N) (p < 0.05). These results suggest better texture preservation, likely due to the film’s moisture retention and barrier properties. Additionally, the WSPeN film exhibited excellent thermal stability, with decomposition temperatures exceeding 439 °C, indicating its robustness for prolonged cold storage. Overall, these findings highlight the film’s potential as a sustainable, high-performance packaging material for extending beef shelf life and reducing spoilage.