Active wrapping paper against mango anthracnose fungi and its releasing profiles

Abstract

Active wrapping papers varied in bio‐based coating materials (chitosan and carboxymethyl cellulose) and vanillin concentrations (0.5%, 1.0%, 2.0%, and 4.0% (w/v)) were prepared to study their antifungal effects and release properties. Chitosan‐coated paper with 1% (w/v) vanillin gave the best inhibition against mycelial growth of mango anthracnose fungi and could inhibit its conidiospores germination. The release of vanillin from a chitosan‐coated paper under different conditions of temperatures (13°C, 25°C, and 37°C), relative humidity (RH) (75%, 86%, and 96% RH), and pH values (pH 3.8, 5.2, and 6.2) was studied. Moreover, the vanillin release from the paper to mango fruit under an actual commercial storage condition (13°C, 90% RH) was also investigated. The predominant mechanism of vanillin release under low temperatures (13‐25°C) and all RH studied was a Fickian diffusion, whereas the high temperature (37°C) and in all buffers varying pH showed a non‐Fickian behaviour. Increasing temperature and RH enhanced in diffusion coefficient (D value) from 78.24 × 10−10 to 162.10 × 10−10 cm2/s and 42.87 × 10−10 to 59.98 × 10−10 cm2/s, respectively. Meanwhile, the increasing pH value reduced the D value from 233.87 × 10−10 to 122.74 × 10−10 cm2/s. The kinetic of vanillin release under an actual wrapping application exhibited a non‐Fickian behaviour, and the D value was considerably low (approximately 65.36 × 10−12 cm2/s). The developed active wrapping paper can be great interest for food industry and is practically reasonable for postharvest mango fruits.

Efficacy of chitosan‐coated paper incorporated with vanillin and ethylene adsorbents on the control of anthracnose and the quality of Nam Dok Mai mango fruit

“…The release of vanillin from active‐coated papers could greatly contribute to the activity against anthracnose, which is similar to the research of other active‐coated papers that has previously been studied . In previous research, we demonstrated that the released vanillin was quite effective for inhibiting the fungal growth in association with reactive functional groups of vanillin that can directly damage the fungal cell membrane . Thus, mango fruits wrapped with vanillin and zeolite papers were free from anthracnose symptom throughout 10 days of storage.…”

“…Then, 1.0% ( w / v ) vanillin (Sigma‐Aldrich, St. Louis. MO, USA) was added to the chitosan solution and heated at 83°C until the solution became homogeneous . Two types of ethylene adsorbents, including activated carbon (NORIT E SUPRA, Alpharetta, GA, USA) and natural zeolite (Sigma‐Aldrich, St. Louis, MO, USA), with various concentrations (0%, 0.1%, 0.2%, and 0.4%, w / v ) were incorporated into the vanillin‐chitosan coating solution and stirred until homogeneous.…”

“…However, the internal atmosphere created by a direct coating changes fruit respiration and gas permeability of the coating film, leading to an alcohol flavor . Additionally, the direct addition of preservatives into food should be avoided, in to gain consumer acceptance …”

“…The coating solution with combinations of chitosan and antimicrobial agents is responsible for both mechanical and antimicrobial properties of the wrapping paper . In order to inhibit the microbial spoilages of fruits, several kinds of antimicrobial agents such as nisin, organic acids, vanillin, cinnamon, and oregano essential oil have studied as incorporated agents . Among several antimicrobial agents, vanillin is generally regarded as a safe (GRAS) flavoring compound and widely used in many industries .…”

“…In previous work, vanillin‐chitosan was used to develop antimicrobial films and active coated paperboard against food spoiling bacteria for a bakery product package . Likewise, our recent study has developed the vanillin‐chitosan coated paper (vanillin paper) against Colletotrichum gloeosporioides and found that the coated paper could inhibit mycelial growth of C. gloeosporioides with a 63.33% percentage of inhibition of radial growth (PIRG) and its spore germination …”