Study of Laurie tea processor black tea mixing fermentation using the simplex centroid design method.

Background: Broken black tea (BBT) is the most consumed black tea in the world. Laurie tea processor black tea (LTP-BT) is one of the most important categories of BBT. In this study, the fresh leaves of three tea plant cultivars including Golden Peony tea, Yunnandaye, and Fuding Dabai were blended to process LTP-BT using the simplex centroid design.

Evaluation of Chongqing Tuo Tea at Different Grades: An Integrated Approach by Artificial and Intelligent Sensory, Non-Volatile, and Volatile Compounds Analysis.

This study aims to investigate the relationship between the grades of Tuo tea and the quality of compounds. A combination of artificial sensory evaluation, intelligent sensory technologies (electronic nose and electronic tongue), gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), chemical-physical analysis, and multivariate statistical analysis were employed to examine the differences among three grades of Tuo tea (SG, 1G, and 2G). The results of artificial sensory evaluation, electronic tongue, and electronic nose revealed that the aroma and taste of different grades of Tuo tea varied greatly.

Sensory-directed isolation and identification of an intense salicin-like bitter compound in infected teas with bird's eye spot disease.

Teas infected with bird's eye spot disease generally exhibited a lingering and long-lasting, salicin-like bitter taste, which was unpalatable to consumers. Sensory-directed isolation processes have been performed in this study to investigate the salicin-like bitter compounds in infected teas. Results showed that infected teas were extracted using a 70% methanol aqueous solution to produce methanol extract, which was then further separated by sequential solvent extraction (SSE) to obtain dichloromethane extract, which contained the salicin-like bitter compounds.

Characterization of triterpenoids as possible bitter-tasting compounds in teas infected with bird's eye spot disease.

Tea infected with bird's eye spot disease generally imparts a long-lasting bitter taste, which is unacceptable to most consumers. This study has comprehensively evaluated the taste profiles of infected and healthy teas and investigated their known bitter compounds previously reported in tea. Quantification analyses and calculation of dose-over-threshold (DoT) factors revealed that no obvious difference was visualized in catechins, caffeine, bitter amino acids, and flavonols and their glycosides between infected and healthy tea samples, which was also verified by principal component analysis (PCA) and hierarchical cluster analysis (HCA).

Effects of Hot Air Drying on Drying Kinetics and Anthocyanin Degradation of Blood-Flesh Peach.

The purpose of this study was to explore the drying kinetics, effective moisture diffusivity, activation energy, color variation, and the thermal degradation properties of anthocyanins of blood-flesh peach under hot air drying for the first time. The results showed that the hot air-drying process of blood-flesh peach belongs to reduced-speed drying. The Page model could accurately predict the change of moisture ratio of blood-flesh peach.

Effects of air-impingement jet drying on drying kinetics and quality retention of tomato slices.

The purpose was to explore the drying kinetics, the moisture effective diffusivities, color, total polyphenols, lycopene and antioxidant activities of dried tomato slices by air-impingement jet drying (AIJD). The results showed that high temperature increased the drying rate, and Modified Page model accurately predicted the AIJD characteristics of tomato slices. AIJD is better than hot air drying in shortening drying time, enhancing drying rate and decreasing the loss of total polyphenols, lycopene and antioxidant capacity of tomato slices.

Lycopene, polyphenols and antioxidant activities of three characteristic tomato cultivars subjected to two drying methods.

The aim of this study was to evaluate the effects of freeze drying and oven drying on appearance, chemical components and antioxidant activities of three cultivars of tomatoes. This study showed cultivar 18,131 would provide the highest phenolic contents and ABTS radical scavenging activity, and cultivar 1862 provide the highest lycopene content after oven drying. On the basis of appearance and contents of polyphenols, freeze drying showed better results.