Feasibility Study of Nanochitosan Solution as a Potential Coating for Shelf Life Extension of Apples

In the present study, a low-cost and facile nanochitosan solution was developed by the ionotropic gelation method to preserve the quality attributes of the apples during 15 day storage period. Low molecular weight chitosan (LMC), glacial acetic acid, and sodium tripolyphosphate (STTP) were used to prepare 0.5%, 1% and 1.5% (w/v) nanochitosan solutions respectively. The size of the nano chitosan solutions ranged from 209.6 ± 14.10 to 431.1 ± 17.46 nm, whereas the zeta potential ranged from 40.06 ± 5.33 to 62.45 ± 4.75 mV. Apples were coated with 0.5%, 1% and 1.5% w/v solutions (S1, S2, and S3) and kept under two different storage conditions at (25 ± 5) °C and (35 ± 10)% RH and 10 °C and 75% RH. The quality attributes, such as weight loss, moisture content, color, total soluble solids, titratable acidity, pH, vitamin C, antioxidants and firmness were studied and compared with the control apples. Among all the combinations of nanochitosan coated apples, SI3 exhibited a minimum weight loss of 1.53% and firmness ranged from 7.3 to 5.409 N. The antioxidant activity ranged from 94.53 ± 0.61 to 77.73 ± 0.66, whereas ΔE values ranged from 3.12 ± 0.01 to 7.92 ± 0.02 and were considered most effective in maintaining the quality indicators of the apples. The key findings substantiate the potential benefits of using a nanochitosan as a low-cost coating solution to preserve the quality attributes of fresh produce.