Enhanced shelf-stability of cottage cheese using synergistic starch-based nanocomposite films reinforced with montmorillonite, starch nanocrystals, and antimicrobial lemongrass oil

The present study evaluated the effects of starch nanocrystals (SNCs, 1% w/v) and montmorillonite (MMT, 1.5% w/v) reinforced corn starch bionanocomposites, loaded with 2% v/v lemongrass oil nanoemulsion (LNE), on the shelf life of cottage cheese stored for 16 days at 4 °C. Results demonstrated that SNCs and MMT enhanced the mechanical properties and reduced the water vapor transmission rate (WVTR) of the films, while LNE conferred antimicrobial and antioxidant properties, rendering the bionanocomposites active. Fourier-transform infrared (FTIR) spectroscopy confirmed increased hydrogen bonding with the addition of nano-reinforcements. Biodegradability tests revealed that non-reinforced films decomposed more readily in nature. Among the films tested, MMT/LNE bionanocomposites exhibited the least changes in physicochemical and microbiological properties of cottage cheese, maintaining texture, tyrosine value (25.34 mg/100 g), and free fatty acid value (0.6 μm/g) for up to 12 days of storage, attributed to their lowest WVTR (0.1836 × 10⁻⁴ g/h.cm²). Both MMT/LNE and SNCs/LNE bionanocomposites extended the shelf life of cottage cheese to 12 days, compared to 4 days for the control (non-packaged) and 8 days for cottage cheese packaged in simple corn starch film. These findings illustrate the potential of SNCs and MMT reinforced bionanocomposite films loaded with LNE to serve as active packaging materials, enhancing the shelf stability of cottage cheese.