Analisis Pengendalian Mutu Kadar Air Teh Hitam pada Industri Pengolahan Teh

Quality control is intended to maintain and improve quality and maintain the safety of the products produced. This study uses Statistical Process Control by using several tools such as check sheets, control charts and fishbone diagrams to determine the cause of the decline in quality in tea with the aim that the next process can minimize the level of product quality decline. This study aims to determine the dominant cause of the decline in tea quality when viewed from the water content in tea. Based on the results of the study, it can be seen that the dominant cause of the decline in tea quality is the highwater content of dry tea. This type of deterioration can be caused by human error and other factors such as machine condition, raw materials and process monitoring.

A Quadratic Regression Model to Quantify Plantation Soil Factors That Affect Tea Quality

Tea components (tea polyphenols, catechins, free amino acids, and caffeine) are the key factors affecting the quality of green tea. This study aimed to relate key biochemical substances in tea to soil nutrient composition and the effectiveness of fertilization. Seventy tea samples and their corresponding plantation soil were randomly collected from Xinyang City, China. The catechins, free amino acids, and caffeine in tea were examined, as well as the soil pH, nitrate (NO3--N), ammonium (NH4+-N), available phosphorus (AP), available potassium (AK), and soil organic matter (SOM). The ordinary kriging was employed to visualize the spatial variation characteristic by ArcGIS. A quadratic regression model was used to analyze the effects of the soil environment on the tea. The results showed that the soil pH of the study area was suitable for cultivating tea plants. The relationship between soil pH and tea polyphenols and catechins presented the U-shape curve, whereas the soil pH and NH4+-N and the free amino acids, the soil pH, and caffeine presented the inverted U-shape curve. Soil management measures could be implemented to control the soil environment for improving the tea quality. The combination of the macro metrological model with individual experimentation could help to analyze the detailed influence mechanisms of environmental factors on plant physiological processes.

Effect of Different Types of Pruning Operations on Yield and Quality of Tea

Aims: Pruning is the cutting of branches of a tea bush at predetermined height and at a specified interval in order to reinvigorate and bring tea bushes within reach of the pluckers, which directly related to the productivity and quality of tea. In Bangladesh, Three and four year pruning cycles were the conventional recommendations for the tea plantation. In this experiment, along with BTRI recommended four types of pruning operations (LP, DSK, MSK and LSK), two more types of pruning operations such as: UP (Unprune) and LoS (Level of Skiff) were considered as treatments. This experiment was conducted with two main objectives: to evaluate the yield and yield related parameters of tea due to different types of pruning operations as well as to find out the effect of pruning operations on organoleptic quality of black tea. Study Design, Place and Duration of Study: This experiment was conducted ‘D2 Thall’ area at the main research farm of Bangladesh Tea Research Institute (BTRI) from December 2017 to November 2019. The experimental design was Randomized Completely Block Design (RCBD) with six treatments and three replications. Methodology: The treatments are denoted as T1 (UP: Unpruned) control, T2 (LP: Light Pruning), T3 (DSK: Deep Skiffing), T4 (MSK: Medium Skiffing), T5 (LSK: Light Skiffing) and T6 (LoS: Level of Skiffing) respectively. Data were collected under the following parameters: Number of plucking point or pluckable shoot/bush in each plucking Fresh weight (g) of 100 shoots (three leaves and a bud) Oven Dry weight (g) of 100 shoots (three leaves and a bud) to calculate Dry Matter Content Green leaf weight (kg) to calculate Yield of each treatment Number of plucking round to calculate Yield gap of each treatment Black Tea Quality of each treatment by Organoleptic Tasting Method. Results: It was found that, number of plucking points/pluckable shoot and yield were found significantly high in T6 (Level of Skiffing), T5 (Light Skiffing) and T1 (Unpruned) than the other treatments. But in terms of tea quality, lowest quality tea was found in T1 (Unpruned), T6 (Level of Skiffing) and T5 (Light Skiffing) treatment. So, it can be concluded that, ‘Skiff Pruning’ or ‘Unprune’ technique had positive effect on yield but the quality of these technique were poor in comparison with other treatments. T2 (Light Pruning) treatment gave more tender and fresh shoot than the other treatment. For this reason, dry matter was low in T2 (Light Pruning) treatment but tea quality was much better than the other pruning technique. Conclusion: Pruning has positive or negative effect on yield and quality of tea. ‘Skiff Pruning’ or ‘Unprune’ has positive effect on yield but the quality of is poor than the other treatments. Best Quality tea can be produced from Light Pruning tea section because of having more tender and fresh shoot than other treatments.

Different Withering Times Affect Sensory Qualities, Chemical Components, and Nutritional Characteristics of Black Tea

The present study emphasizes the effect of withering time set at 4 ± 0.5 h (WT4), 6 ± 0.5 h (WT6), 8 ± 0.5 h (WT8), 10 ± 0.5 h (WT10), and 12 ± 0.5 h (WT12) on the sensory qualities, chemical components, and nutritional characteristics of black tea. The sensory evaluation revealed high total quality scores at WT8 and WT10. Polysaccharides, amino acids, and soluble sugars significantly increased with an increase in withering time, and an apparent peak value was obtained at WT10. However, polyphenols, flavonoids, glycosides, organic acids, catechins, alkanoids, and theaflavins decreased with an increase in withering time. With an increase in withering time, the content of aromatic substances showed a trend of increasing first and then decreasing. The peaks of alcohols, aldehydes, and acids appeared at 10 ± 0.5 h, 10 ± 0.5 h, and 8 ± 0.5 h, respectively. The content of esters, ketones, and hydrocarbons showed a downward trend with an increase in withering time. Aroma analysis revealed that withering time could not exceed 10 ± 0.5 h. Black tea withered up to WT10 showed enhanced inhibition of α-glucosidase and α-amylase activity with good sensorial attributes. Glucose uptake inhibition capacity increased up 6 ± 0.5 h and then decreased, while antioxidant capacity decreased with an increase in withering time. The overall results show that the 8 ± 0.5 h to 10 ± 0.5 h withering time could improve black tea quality and nutritional characteristics.

The effects of tea plants-soybean intercropping on the secondary metabolites of tea plants by metabolomics analysis

Background Intercropping, especially with legumes, as a productive and sustainable system, can promote plants growth and improves the soil quality than the sole crop, is an essential cultivation pattern in modern agricultural systems. However, the metabolic changes of secondary metabolites and the growth in tea plants during the processing of intercropping with soybean have not been fully analyzed. Results The secondary metabolomic of the tea plants were significant influence with intercropping soybean during the different growth stages. Especially in the profuse flowering stage of intercropping soybean, the biosynthesis of amino acids was significantly impacted, and the flavonoid biosynthesis, the flavone and flavonol biosynthesis also were changed. And the expression of metabolites associated with amino acids metabolism, particularly glutamate, glutamine, lysine and arginine were up-regulated, while the expression of the sucrose and D-Glucose-6P were down-regulated. Furthermore, the chlorophyll photosynthetic parameters and the photosynthetic activity of tea plants were higher in the tea plants-soybean intercropping system. Conclusions These results strengthen our understanding of the metabolic mechanisms in tea plant’s secondary metabolites under the tea plants-soybean intercropping system and demonstrate that the intercropping system of leguminous crops is greatly potential to improve tea quality. These may provide the basis for reducing the application of nitrogen fertilizer and improve the ecosystem in tea plantations.

Theanine Improves Salt Stress Tolerance via Modulating Redox Homeostasis in Tea Plants (Camellia sinensis L.)

Theanine, a unique non-proteinogenic amino acid, is one of the most abundant secondary metabolites in tea. Its content largely determines green tea quality and price. However, its physiological roles in tea plants remain largely unknown. Here, we showed that salt stress significantly increased the accumulation of glutamate, glutamine, alanine, proline, and γ-aminobutyric acid, as well as theanine, in the new shoots of tea plants. We further found that salt stress induced the expression of theanine biosynthetic genes, including CsGOGATs, CsAlaDC, and CsTSI, suggested that salt stress induced theanine biosynthesis. Importantly, applying theanine to the new shoots significantly enhanced the salt stress tolerance. Similar effects were also found in a model plant Arabidopsis. Notably, exogenous theanine application increased the antioxidant activity of the shoots under salt stress, suggested by reduced the reactive oxygen species accumulation and lipid peroxidation, as well as by the increased SOD, CAT, and APX activities and expression of the corresponding genes. Finally, genetic evidence supported that catalase-mediated antioxidant scavenging pathway is required for theanine-induced salt stress tolerance. Taken together, this study suggested that salt stress induces theanine biosynthesize in tea plants to enhance the salt stress tolerance through a CAT-dependent redox homeostasis pathway.

Inovasi Pembuatan Teh Herbal dari Jantung Pisang dengan Tambahan Daun Stevia Sebagai Pemanis Alami

(Article History: Received August 27, 2021; Revised Sept 17, 2021; Accepted Sept 26, 2021) ABSTRAKInovasi bahan dasar yang dapat dijadikan teh herbal adalah jantung pisang, karena memiliki metabolit sekunder berupa flavonoid, kumarin dan golongan fenolik. Penelitian ini bertujuan untuk membuat teh herbal jantung pisang dan mengetahui standar mutunya. Pembuatan teh herbal dilakukan dengan variasi suhu pengeringan 50°C; 90°C; 110°C dan waktu pengeringan 110; 130; 150 menit kemudian dilakukan uji standar mutu dan skrining serbuk teh herbal. Hasil uji persyaratan mutu teh herbal: kadar air (7,1%; 6,8%; 2,3%), kadar ekstrak dalam air (5,96%; 8,6%; 5 0,76%), kadar abu total (7,4%; 6,2%; 3,9%), kadar abu larut air (4,62%; 7,88%; 10,09%), kadar abu tidak larut asam (0,93%; 0,7%; 0,47%), kandungan flavonoid total 0,0002543 mg QE/g ekstrak dan cemaran mikroba 3,3×104 koloni/ml. Pembuatan teh jantung pisang dengan tambahan pemanis alami stevia memenuhi standar mutu produk teh herbal.Kata kunci: Teh herbal; jantung pisang; daun stevia; variasi suhu ABSTRACTBasic ingredient innovation that can be used as herbal tea is banana blossom, because of its secondary metabolites such flavonoids, coumarins and phenolic groups. This study aims to make banana blossom herbal tea and determine the quality standard. Formulation of herbal tea by varying drying temperature of 50°C; 90°C; 110°C and drying time 110; 130; 150 minutes, the quality standard test and herbal tea powder screening were carried out. Results of herbal tea quality: water content (7.1%; 6.8%; 2.3%), extract content in water (5.96%; 8.6%; 5 0.76%), ash content total (7.4%; 6.2%; 3.9%) water soluble ash content (4.62%; 7.88%; 10.09%) acid insoluble ash content (0.93%; 0, 7%, 0.47%, total flavonoid content 0.0002543mg QE/g extract, microbial contamination 3.3×104 colonies/ml. Formulation of banana blossom tea with the addition of natural sweetener stevia meets the quality standards of herbal tea products,Keywords: Herbal tea; banana blossom; stevia leaf; temperature variation