PSI - Issue 68

Krastena Nikolova et al. / Procedia Structural Integrity 68 (2025) 845–853 K. Nikolova et al. / Structural Integrity Procedia 00 (2025) 000–000

850

6

Alginate

Alginate + oil

Chitosan

Chitosan + oil

HPMC

HPMC + oil

Pectin

Pectin + oil

Fig. 5 Film morphology

3.3. Mechanical properties of the investigated film One of the most important properties of edible films are their mechanical parameters, as they determine their applicability as packaging material. The mechanical properties of polysaccharide films in this research were investigated using a tensile test. Stress at break, strain at break and Young modulus were determined from stress-strain dependences – Fig. 6. For the empty films, the highest value for the stress at break is detected for the alginate film - (76 ± 13) MPa, followed by chitosan film – (64 ± 11) MPa, HPMC film – (52 ± 7) MPa, and the lowest one is for pectin – (48 ± 3) MPa. All of them are higher than those reported by other authors, probably because of the lower amount of glycerol, which was used as a plasticizer (Sutharsan et al., 2022; Shivakumara et al., 2017; Van Rooyen et al., 2023).

Fig. 6 Mechanical properties of films