Development of bio-based PLA/cellulose antibacterial packaging and its application for the storage of shiitake mushroom.

This study presents the extraction of cellulose from water bamboo byproducts to prepare polylactic acid (PLA)/cellulose antibacterial packaging material. The cellulose was modified using a silane coupling agent, which improved the interfacial compatibility between cellulose and PLA. Upon coating the PLA onto the modified cellulose sheet, the water contact angle of the composite material increased from 11.42° to 132.12° and the water absorption rate decreased from 182.52% to 55.71%, which improved the water resistance performance of the material. The addition of cinnamaldehyde in the PLA layer imparted antibacterial activity to the PLA/cellulose packaging material. This packaging material effectively inhibited the mycelial growth and spore germination of Aspergillus niger and Trichoderma harzianum isolated from shiitake mushroom. Additionally, the study investigated the effects of the composite on the postharvest quality of shiitake mushroom. Overall, the packaging material contributed to shiitake mushroom storage and can be applied to other perishable food products.

Preparation of modified polyvinyl formal vibration-damping material and its application in strawberry.

Mechanical damage and microbial infestation were critical issues during strawberry transportation. This study prepared a modified polyvinyl formal (PVFM) vibration-damping material and investigated its application in strawberry transportation. This modified PVFM was primarily composed of polyvinyl alcohol, starch, formaldehyde, and allyl isothiocyanate. Our results showed that the modified PVFM had good vibration-damping and antifungal properties with 0.137 g/m3 of density, a water absorption ratio value of 6.24, 278 Pa of tensile strength, 3.86 Pa of elastic modulus, a buffer coefficient of 0.318, and antifungal rates of 68.8% and 80.6% against Bacillus anthracis and Botrytis cinerea, respectively. Moreover, this modified PVFM could enhance the storage life of strawberry by improving PAL activity from 376 to 3,125 U/g, inhibiting POD activity with a maximum value of 3.1 U/g, and decreasing CAT activity from 324 to 35 U/g. The modified PVFM presented a good vibration-damping capacity and the potential to extend strawberry shelf life. PRACTICAL APPLICATIONS: Berry fruits were vulnerable to mechanical damage caused by vibration during transportation, resulting in quality deterioration, rot, and aging. In this study, modified polyvinyl formal (PVFM) was prepared and was of low density and displayed good mechanical, vibration-damping, and antifungal properties. The modified PVFM could improve the storage life of strawberry. Thus, the modified PVFM could have potential application in berry fruits transportation.

Effects of packaging materials on storage quality of peanut kernels.

In order to obtain optimum packaging materials for peanut kernels, the effects of four types of packaging materials on peanut storage quality (coat color, acid value, germination rate, relative damage, and prevention of aflatoxin contamination) were examined. The results showed that packaging materials had a major influence on peanut storage quality indexes. The color of the peanut seed coat packaged in the polyester/aluminum/polyamide/polyethylene (PET/AL/PA/PE) composite film bag did not change significantly during the storage period. Color deterioration was slower with polyamide/polyethylene (PA/PE) packaging materials than with polyethylene (PE) film bags and was slower in PE bags than in the woven bags. The use of PET/AL/PA/PE and PA/PE bags maintained peanut quality and freshness for more than one year and both package types resulted in better germination rates. There were significant differences between the four types of packaging materials in terms of controlling insect pests. The peanuts packaged in the highly permeable woven bags suffered serious invasion from insect pests, while both PET/AL/PA/PE and PA/PE bags effectively prevented insect infection. Peanuts stored in PET/AL/PA/PE and PA/PE bags were also better at preventing and controlling aflatoxin contamination.