Applications of Electronic Nose Coupled with Statistical and Intelligent Pattern Recognition Techniques for Monitoring Tea Quality: A Review

Abstract

Tea is the most widely consumed non-alcoholic beverage worldwide. In the tea sector, the high demand for tea has led to an increase in the adulteration of superior tea grades. The procedure of evaluating tea quality is difficult to assure the highest degree of tea safety in the context of consumer preferences. In recent years, the advancement in sensor technology has replaced the human olfaction system with an artificial olfaction system, i.e., electronic noses (E-noses) for quality control of teas to differentiate the distinct aromas. Therefore, in this review, the potential applications of E-nose as a monitoring device for different teas have been investigated. The instrumentation, working principles, and different gas sensor types employed for E-nose applications have been introduced. The widely used statistical and intelligent pattern recognition methods, namely, PCA, LDA, PLS-DA, KNN, ANN, CNN, SVM, etc., have been discussed in detail. The challenges and the future trends for E-nose devices have also been highlighted. Overall, this review provides the insight that E-nose combined with an appropriate pattern recognition method is a powerful non-destructive tool for monitoring tea quality. In future, E-noses will undoubtedly reduce their shortcomings with improved detection accuracy and consistency by employing food quality testing.

E-Nose Technology for Mycotoxin Detection in Feed: Ready for a Real Context in Field Application or Still an Emerging Technology?

“…There are a variety of PARC methods that can be used depending on the type of data and the required results ( Figure 2 ). For a comprehensive description and discussion regarding analysis of e-nose data, readers are referred to the literature [ 69 , 77 , 78 , 79 ].…”

“…E-nose showed a very good discrimination capability for grain quality discrimination and detection of fungal contamination of cereal grain by discriminating contaminated and non-contaminated grains by Penicillium and Fusarium spp. and changes during the crucial stages of fungal growth [ 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 ,…”

Efficient Monitoring of Microbial Communities and Chemical Characteristics in Incineration Leachate with Electronic Nose and Data Mining Techniques

“…Sensor data are then processed and analyzed using machine learning to identify specific compounds and determine their concentration [11]. With the advantage of providing rapid and non-invasive analyses, e-noses are suitable for use in a wide range of industries and applications [12,13]. However, studies on leachate detection based on e-nose technology are rare, according to our best knowledge.…”

A Novel Resource-Saving and Traceable Tea Production and Supply Chain Based on Blockchain and IoT

“…To relieve the high-quality tea product of the requirement of experience manpower and avoid the risk of human oversight, resourcesaving automatic control must be achieved. With the rapid development of Internet of Things (IoT) technology, some research develops IoT-based agricultural information systems to enhance productivity and save human resources [2], [3]. Currently, most tea PSCs adopt IoT technology in the production process, while they often lack traceability throughout the entire process.…”

“…Therefore, current tea PSCs are suffering from the effect of counterfeit tea products and inadequate supervision, which harms the tea market and receives considerable critical attention [4], [5], [6], [7]. Malicious enterprises that produce counterfeit and lowquality tea products are hidden in the tea market, and these counterfeit tea products could cause economic losses and health damage for tea consumers [3], [8]. It is worth noting that various enterprises are involved in the tea PSC but their information systems are isolated.…”