Dynamic Changes in Chemical Constituents during Processing of Miang (Thai Fermented Tea Leaf) in Various Degree of Tea leaf Maturity

Immature and tender tea leaves always produce high-quality tea than mature tea leaves. Depending on the maturity and age of the leaf, the colour and texture of the tea leaf are different. The photosynthesis capacity of the tea leaf also changes with the change of leaf maturity. Though the tea farmer plucks, classifies, and recognizes the best tea leaves (immature and tender) by viewing the visual symptoms and position of the leaves, the method is not authentic all time and leads to the overall degradation of the tea quality. The present study presents a smartphone assist tea leaf recognition system by analyzing the colour and texture properties of the tea leaf. The six different colour features and 4 Haralick texture features were extracted in the colour and grey domain of the leaf images. Three types of tea leaves, i.e., mature, immature, and tender, were classified using Deep Neural Network (DNN) with ADAM (Adaptive Moment Estimation) optimizer. With an accuracy of 97%, the DNN outperformed the Support Vector Machine (SVM) and K Nearest Neighbor (KNN). The SVM and KNN reported a total of 94.42% and 95.53% accuracy, respectively. The investigated system using DNN with an average precision and recall value of 98.67 and 98.34, respectively, may detect and classify the tea leaf maturity status. The system also can be used in AI-based tea plucking robotic systems or machines.

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Study of the dynamic changes in the chemical constituents of Soapberry (Sapindus mukorossi Gaertn.) pericarp during fruit development by a non-targeted metabolomics approach

10.21203/rs.3.rs-148385/v1 ◽

2021 ◽

Author(s):

Yuanyuan Xu ◽

Yuan Gao ◽

Zhong Chen ◽

Guochun Zhao ◽

Jiming Liu ◽

...

Keyword(s):

Fruit Development ◽

High Performance ◽

Chemical Constituents ◽

Biomass Energy ◽

Alpha Tocopherol ◽

Targeted Metabolomics ◽

Dynamic Changes ◽

Kegg Pathways ◽

Orbitrap Mass Spectrometer ◽

Q Exactive

Abstract Soapberry (Sapindus mukorossi Gaertn.) is a multi-functional tree, which is widely used in daily chemicals, biomedicine, biomass energy and landscaping. The pericarp of soapberry can be used as medicine or detergent. However, there is no systematic study on chemical constituents of soapberry pericarp in fruit development, and the dynamic changes of these constituents are far from clear. In this study, we applied a non-targeted metabolomics approach using an ultra-high performance liquid chromatography-Q Exactive HF hybrid quadrupole-Orbitrap mass spectrometer (UHPLC-QE-HF-MS) to comprehensively profile the variations of metabolites in soapberry pericarp at eight fruit development stages. The metabolome coverage of UHPLC-QE-HF-MS on a HILIC column was higher than that of a C18 column. A total of 111 metabolites were putatively identified, and these metabolites showed three accumulation patterns (pre-accumulation, mid-accumulation and post-accumulation) with fruit development. Twenty-five of these 111 metabolites (including amino acids and their derivatives, flavonoids, organic acids, fatty acids, nucleotides and their derivatives, alkaloids, carbohydrates, terpenoids, vitamins, phosphorylated intermediates) were present at significantly different levels between the two adjacent stages, which were involved in 13 KEGG pathways, among them 5 pathways (flavonoid biosynthesis; histidine metabolism; aminoacyl-tRNA biosynthesis; flavone and flavonol biosynthesis; and phenylalanine, tyrosine and tryptophan biosynthesis) were most relevant. S8 stage (fruit ripening stage) is the most suitable stage for fruit harvesting to utilize the pericarp, during which the accumulation of many bioactive and valuable metabolites (e.g., furamizole, alpha-tocopherol quinone, sucrose) in the pericarp was highest. To the best of our knowledge, this was the first time that the metabolomics in soapberry pericarp during the whole fruit development was profiled. This study will be beneficial to guide the harvesting, processing and application, and pave the way for further studies on the biosynthesis mechanism of the main metabolites of the soapberry pericarp.

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