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Influence of Nanoparticles on the Shelf Life of Food in Packaging Materials
Published in Sanjay Mavinkere Rangappa, Parameswaranpillai Jyotishkumar, Senthil Muthu Kumar Thiagamani, Senthilkumar Krishnasamy, Suchart Siengchin, Food Packaging, 2020
Malinee Sriariyanun, Atthasit Tawai, Yu-Shen Cheng
The physical parameters, especially temperature, are prime determinators of food shelf life. During transportation and distribution of food products from food producer to retailers and consumers, the temperature conditions may fluctuate and this scenario could accelerate the microbial activities and food deterioration. Unfortunately, these temperature fluctuations are unknown to customers. Although perfect food packages with un-expired date may be in consumer hands, no one is able to guarantee that the quality of the food product is still acceptable. The irreversible temperature sensor is consequently useful in monitoring the thermal history during food storage, handling, and distribution and to provide information to consumers and retailers to help them make decisions during purchasing and stock management. A time-temperature indicator (TTI) is a sensor device, such as a temperature data logger, used in the monitoring of time-temperature history of the product during the transportation and distribution process. This smart logger is important to control the quality of food, especially frozen food or cold chain products. The application of this sensor device is not limited to only food industries, but also pharmaceutical, medical, and chemical industries as well. Zhang et al. (2013) developed a TTI device from Ag nanocubes with 30 to 70 nm-size from a mixture of CH3COOAg, sodium hydrosulfide, and hydrochloric acid. The detection of time-temperature profile is reported as a colorimetric change and could be visualized by the naked eye. Youn et al. (2018) reported the production of silver nanoparticle-based sensor for blood samples in the form of silver nanowires and colorless polyimide film integrated with a wireless data transmission circuit. The change of time and temperature activated the resistance of transmission circuit and the signal was transmitted in real time to the receivers. In addition to the silver nanoparticle-based sensor, other types of sensors were developed. For example, a glucose biosensor based on glucose oxidase was applied as a TTI sensor for smart food packaging (Rahman et al., 2018). The glucose sensor was integrated with a three-electrode potentiostat to report the time and temperature profile as an electrical signal and color development at the same time. The reaction kinetics of this sensor monitoring by the colorimetric change was studied based on Arrhenius assumption under isothermal condition. Anbukarasu et al. (2017) invented a TTI based on the function of depolymerase enzyme that reported the signal as the color change. This smart sensor was made from a dye-loaded polyhydroxybutyrate (PHB) film mixed with a depolymerase enzyme. Therefore, during the progress of time and temperature, the hydrolysis reaction proceeded to cause the release of dye. The dye release kinetics were studied at different temperatures ranging from 4 to 37°C, and the sensor can function to report the color change up to 168 h.
Enzyme immobilization as a sustainable approach toward ecological remediation of organic-contaminated soils: Advances, issues, and future perspectives
Published in Critical Reviews in Environmental Science and Technology, 2023
Litao Wang, Xuran Du, Ying Li, Yuhong Bai, Teng Tang, Jing Wu, Hong Liang, Dawen Gao
The microencapsulated embedding method uses small vesicles made of various polymers to encapsulate enzymes. Polymeric semi-permeable membranes commonly encapsulate enzymes, including polyamide membranes (Saeki et al., 2013). Microencapsulated immobilized laccases can be prepared in several ways, including sol-gel, layer-by-layer, and electrospinning emulsions (Wenting et al., 2020). Laccase was immobilized on electrospun chitosan/polyvinyl alcohol fibers with a specific surface area of 17.05 m 2/g to enhance the stability of the enzyme time-temperature indicator (Jhao-Rong et al., 2020). Although this method is harmless and simple, its main drawbacks are pore size limitations and low enzyme concentrations (Stanislava et al., 2018). Embedding is the most preferred method for enzyme immobilization in the industry because it is easier to operate, does not alter the enzyme structure, and minimizes enzyme loss in solution (Datta et al., 2021). When the enzyme is immobilized, it is essential to ensure that the spatial barrier between the enzyme molecule and the substrate is as tiny as possible, so that the enzyme does not prevent the substrate from diffusing to the catalytic activity center of the enzyme molecule (Aziz & Şenay, 2001).