Improving dehydrated yellow peach slices quality using modified kraft paper coated with starch-stearic acid...

Yellow peach slices are popular for their nutritional value and portability, but they tend to absorb moisture and lose nutrients during storage. In this study, a biodegradable, superhydrophobic, and moisture-resistant paper-based packaging material was developed by coating kraft paper (KP) with a composite formulation of pea starch (PS), shellac (SH), zein (ZE), and stearic acid (SA). The selection of this composite system was based on the complementary functional properties of its components: PS provided a biodegradable matrix with good film-forming ability, SH contributed moisture resistance and adhesion, ZE enhanced mechanical strength and hydrophobicity, while SA further lowered surface energy to achieve superhydrophobicity. The coatings were applied through hydrogen bonding and electrostatic interactions, creating a robust barrier on the paper surface. The coated papers were evaluated for oxygen permeability (OP), water vapor transmission rate (WVTR), water contact angle (WCA), and rolling angle (RA). Results demonstrated that the PS/SH/ZE/SA-coated KP exhibited an 83.1 % reduction in WVTR and a 79.8 % decrease in OP compared to unmodified KP. The optimal formulation (KP/PS/SH/ZE/SA-3 %) displayed the lowest moisture content (MC) and achieved a WCA exceeding 150°, confirming superhydrophobicity. Additionally, the coatings significantly improved thermodynamic stability and imparted self-cleaning properties to the paper. These findings suggest that the developed composite coating can effectively modify paper-based packaging for moisture-sensitive applications, such as dehydrated yellow peach slices and other dry foods, offering a sustainable alternative to conventional plastic-based packaging.