Classification of oolong tea varieties based on computer vision and convolutional neural networks

Abstract

BackgroundIn the contemporary food industry, accurate and rapid differentiation of oolong tea varieties holds paramount importance for traceability and quality control. However, achieving this remains a formidable challenge. This study addresses this lacuna by employing machine learning algorithms—namely Support Vector Machines (SVM) and Convolutional Neural Networks (CNNs)—alongside computer vision techniques for the automated classification of oolong tea leaves based on visual attributes.ResultsAn array of 13 distinct characteristics, encompassing color and texture, were identified from five unique oolong tea varieties. To fortify the robustness of the predictive models, data augmentation and image cropping methods were employed. A comparative analysis of SVM and CNN‐based models revealed that the ResNet50 model achieved a high Top1 accuracy rate exceeding 93%. This robust performance substantiates the efficacy of the implemented methodology for rapid and precise oolong tea classification.ConclusionThe study elucidates that the integration of computer vision with machine learning algorithms constitutes a promising, non‐invasive approach for the quick and accurate categorization of oolong tea varieties. The findings have significant ramifications for process monitoring, quality assurance, authenticity validation, and adulteration detection within the tea industry.This article is protected by copyright. All rights reserved.

A β-Primeverosidase-like Enzyme in Soybean [Glycine max (L.) Merr] Hypocotyls: Specificity toward 1-Octen-3-yl and 3-Octanyl β-Primeverosides

“…In our previous study, in addition to 1-octen-3-yl β-primeveroside, a new glycoside was purified from the methanol extracts of soybean hypocotyls and confirmed as 3-octanyl β-primeverosides . Various tea-aroma constituents, such as geraniol, benzyl alcohol, 2-phenylethanol, and ( Z )-3-hexenol, have been shown to be present mainly as diglycoside precursors, such as β-primeverosides in tea plant leaves used to produce oolong tea. , They are known to be cleaved in an endomanner into primeverose and aglycones by β-primeverosidase. For instance, β-primeverosidase, an enzyme that hydrolyzes β-primeverosidically bound volatiles to free volatiles, has been isolated, identified, and functionally characterized in tea leaves and flowers. , The β-primeverosidase in tea leaves exhibited strict substrate specificity for β-primeveroside but not for monoglucosides.…”

“…18 Various tea-aroma constituents, such as geraniol, benzyl alcohol, 2-phenylethanol, and (Z)-3-hexenol, have been shown to be present mainly as diglycoside precursors, such as β-primeverosides in tea plant leaves used to produce oolong tea. 6,40 They are known to be cleaved in an endomanner into primeverose and aglycones by β-primeverosidase. For instance, β-primeverosidase, an enzyme that hydrolyzes β-primeverosidically bound volatiles to free volatiles, has been isolated, identified, and functionally characterized in tea leaves and flowers.…”

“…Tea plants (Camellia sinensis) store volatile organic compounds in their leaves, primarily in the form of water-soluble diglycosides, known as β-primeverosides (6-O-β-D-xylopyranosyl-β-D-glucopyranosides). 1,6 Flavor is considered the essence of food, 7,8 and the perception of flavor 9 is a complicated process. 10 Soybean is a plant material rich in protein, and it is commonly used in the production of plant-based products.…”

“…Glycosidically bound volatiles have been identified in various plants and plant-derived foods. − In many cases, alcohols such as benzyl alcohol, 2-phenylethanol, ( Z )-3-hexenol, and linalool can be transformed into glycosidic forms. , β-Glucosides were further modified at the C -6 position of the glucose by a O -glycosidic bond with various monosaccharides (glucose, xylose, and arabinose), resulting in the synthesis of disaccharide glycosides such as β-primeverosides, β-gentiobiosides (6- O -β- d -glucopyranosyl-β- d -glucopyranosides), and β-vicianoside (6- O -α-L-arabinopyranosyl-β- d -glucopyranoside). Tea plants (Camellia sinensis) store volatile organic compounds in their leaves, primarily in the form of water-soluble diglycosides, known as β-primeverosides (6- O -β- d -xylopyranosyl-β- d -glucopyranosides). , Flavor is considered the essence of food, , and the perception of flavor is a complicated process . Soybean is a plant material rich in protein, and it is commonly used in the production of plant-based products.…”

Differences of Typical Wuyi Rock Tea in Taste and Nonvolatiles Profile Revealed by Multisensory Analysis and LC–MS-Based Metabolomics

“…Oolong tea (Camellia sinensis), one of the six major tea types manufactured via a semifermentation process, possesses a color between green tea and black tea . In recent years, oolong tea has gained widespread consumer recognition for its distinctively sweet and grassy flavor, accompanied by a unique fruity and floral aroma. , Oolong tea also has health-promoting benefits, such as antioxidant, anticancer, antiobesity, antiatherosclerosis, antidiabetes, and antiallergic activity. , Southern Fujian, northern Fujian, Guangdong, and Taiwan are the regions with the longest history of oolong tea production, known for high-quality oolong tea cultivars, such as Wuyi Rock tea, Tieguanyin tea, Shuixian tea, High Mountain tea, Dongding tea, Oriental Beauty tea, Phoenix Dancong tea, and Phoenix Shuixian tea. There are great differences in the quality characteristics of oolong teas from different regions.…”