Evaluation of the Properties of NaC/PVA/CA Composite Films for Grape Packaging


Yılmaz S., Demirel M., Daler S., Kasım R., Kasım M. U., Aytaç A.

COATINGS, cilt.16, sa.6, 2026 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 16 Sayı: 6
  • Basım Tarihi: 2026
  • Doi Numarası: 10.3390/coatings16060642
  • Dergi Adı: COATINGS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Applied Science & Technology Source, Compendex, Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
  • Kocaeli Üniversitesi Adresli: Evet

Özet

In this study glycerol-plasticized sodium caseinate/polyvinyl alcohol NaC/PVA composite films were prepared by solution casting, and the effects of incorporating caffeic acid powder at different concentrations 0% 2.5% 5% and 15% w/w on structural mechanical barrier and postharvest performance were investigated. Caffeic acid (CA) (3,4-dihydroxycinnamic acid) is a naturally occurring phenolic compound commonly found in plant tissues and food sources such as apples, blueberries, and coffee. FTIR analysis revealed that shifts and broadening in OH bands indicated hydrogen bonding interactions between caffeic acid and the polymer matrix influencing structural organization. The pure NaC/PVA film exhibited high WVTR due to glycerol while maintaining low OTR. Adding 2.5% caffeic acid reduced WVTR but increased OTR through structural disruption. At 5% a continuous hydrogen-bonded network formed, restricting chain mobility and reducing free volume, thus lowering WVTR and OTR while preserving mechanical integrity. SEM micrographs revealed that high CA concentrations, particularly at 15%, led to aggregation-induced partial phase separation and consequent performance loss. Packaging treatments mainly affected physical and color attributes rather than primary metabolites. The NaC/PVA/5CA reduced weight loss and delayed sugar accumulation compared with NaC/PVA. Sugars peaked earlier in NaC/PVA but increased continuously in NaC/PVA/5CA, reaching maximum at the final storage stage. These findings indicate concentration-dependent mechanisms and highlight the potential of caffeic acid-based active packaging to regulate metabolism and extend postharvest quality. Overall results support its application in sustainable packaging systems for improved shelf life management.