Investigating particle-size-induced changes in composition, physical, rheological, and bioactive properties of black tea powder.

BACKGROUND: People brew tea to drink an infusion that only contains 25% water-soluble constituents, leading to most of the insoluble materials being wasted. Tea powder could be drunk directly by mixing with water without producing any waste. Tea powder can also be used as a natural additive to improve the flavour and taste in beverages and foods. Much detailed information on the particle properties of tea powder is required with its increasing consumption. The aim of this study was to investigate the effects of particle size ranging from median diameter D50  = 4.32 to 26.59 µm on the composition, physical, rheological, and bioactive properties of black tea powder. RESULTS: The results indicate that large powder sizes had high bulk density and flowability, whereas small powder sizes possessed good swelling ability and wettability. The contents of water extract, total polyphenols, crude fibre, catechins, and thearubigins reduced with a decrease in particle size. To change the particle size and concentration could adjust the elastic modulus and the viscous modulus of the black tea powder suspension. Moreover, black tea powder with small particle size could regulate blood lipids in a hyperlipidaemic rat model by lowering triacylglycerols and elevating high-density lipoprotein cholesterol, whereas large particles presented an advantage in reducing body weight. CONCLUSION: Our investigation extended the knowledge of commercial black tea powder in composition, physical, rheological, and bioactive properties. These results lay the foundation for future exploration of the use of tea powder in the food industry. © 2022 Society of Chemical Industry.

Structural characterization and antibacterial properties of konjac glucomannan/soluble green tea powder blend films for food packaging.

Antimicrobial activity is a promising property for food packaging which could prolong the shelf life of food products. In this paper, the physicochemical and antimicrobial properties of konjac glucomannan (KGM)/soluble green tea powder (SGTP) edible films were firstly prepared and analyzed through light barrier properties, Fourier transform infrared spectroscopy (FT-IR), tensile strength (TS), X-ray diffraction (XRD), thermogravimetric analysis and scanning electron microscope (SEM). The results showed that appropriate addition of SGTP could improve the TS of composite films. With the increase of SGTP content, the transmittance of the films in the ultraviolet region decreased obviously, and the thermal stability was improved in a SGTP dependent manner. KGM/SGTP films present a fairly smooth and flat surface without any fracture when 0.5% SGTP was provided. The bacteriostatic test showed that the bacteriostatic performance of the composite films against Staphylococcus aureus and Escherichia coli was also significantly enhanced. When 1% SGTP was provided, the zones of inhibition for Escherichia coli and Staphyloccocus aureus reached to 13.45 ± 0.94 mm and 13.76 ± 0.92 mm, respectively. Overall, the KGM/SGTP films showed great potential as bioactive packaging materials to extend food shelf life.

Effect of green tea and mulberry leaf powders on the gut microbiota of chicken.

BACKGROUND: The gut microbiota is closely correlated with host health and is strongly influenced by food composition. Chinese herbs are usually used as natural feed additives in livestock production. Therefore, the present study assessed the influence of diet supplementation with green tea and mulberry leaf powders on the chicken gut microbiota. The gut microbiota compositions were determined using 16S rDNA sequencing. RESULTS: Enhanced relative abundances of Bacteroides, Prevotella, and Megamonas were found in the chicken gut when mulberry leaf powder was added to diet. Conversely, a higher abundance of potentially pathogenic Gallibacterium was found in the chicken gut when the diet was supplemented with green tea powder. These results indicated that green tea powder and mulberry leaf powder can greatly affect the gut microbiota of chickens by changing their compositions. CONCLUSIONS: It is imperative to examine and evaluate the effects of Chinese herbs on animal health before they are introduced as feed additives in animal production.

Effect of particle size on the bioaccessibility of polyphenols and polysaccharides in green tea powder and its antioxidant activity after simulated human digestion.

The bioaccessibilities of polyphenols and polysaccharides in green tea powders (GTPs) with different particle sizes of 564.24 µm, 74.85 µm, 34.62 µm and 15.10 µm and their antioxidant activities were investigated using an in vitro simulated gastrointestinal digestion model. The results showed that particle size significantly affected the bioaccessibilities of polyphenols and polysaccharides before and after digestion, except for the bioaccessibility of polysaccharides after gastric plus intestinal (GI) digestion, thus significantly affecting the antioxidant activity of GTPs. Compared with the undigested initial amount, the bioaccessibilities of polyphenols in all GTPs were approximately 59.98-71.00% after gastric digestion and 9.69-15.57% after GI digestion, and the bioaccessibilities of polysaccharides were approximately 71.10-79.51% after gastric digestion and 113.78-190.38% after GI digestion. With the decrease in particle size, the FRAP value of GTP before digestion was significantly increased and that of 15.10 µm was the largest (4.96 mmol Fe2+/g). Both the FRAP and DPPH values after digestion showed a trend of first increasing and subsequently decreasing; 74.85 µm GTP had the largest FRAP (4.11 mmol Fe2+/g) and DPPH (156.61 mg VCE/g) values after gastric digestion, and 34.62 µm GTP had the largest FRAP (0.16 mmol Fe2+/g) and DPPH (1.43 mg VCE/g) values after GI digestion. This study suggested that the bioaccessibilities of polyphenols and polysaccharides in GTPs and their antioxidant activity can be improved by properly reducing the particle size such that TGPs can exert more beneficial health effects.

A gradient based facile HPLC method for simultaneous estimation of antioxidants extracted from tea powder.

A new simple, rapid and precise RP-HPLC method was developed for the extraction and quantitative estimation of caffeine (C), (-)-epigallocatechin gallate (EGCG), (+)-catechin(Ct), (-)-epicatechin(EC), and (-)-epicatechin gallate (ECG) (collectively named as Tea Powder Bioactives TPBAs) extracted from tea powder using different ratios of ethanol: water. The simultaneous determination of TPBAs was performed using the UV spectrophotometric method which employs the absorbance at 205 nm (λmax of caffeine and polyphenols). This method is a gradient based HPLC method with a flow rate of 0.8 mL/min using Inertsil ODS 100 × 4.6 mm, 3 µm column with methanol and ammonium dihydrogen phosphate (pH-2.8) as mobile phase. The method was validated in terms of specificity, precision, linearity, accuracy, limit of quantification (LOQ), and limit of detection (LOD). The linearity of the proposed method was investigated for concentration ranging between 0.5-60 µg/mL with regression co-efficient, R(2) = 0.999-1.0. This method estimates all the TPBAs simultaneously with enhanced precision and linearity as per the ICH guidelines. Also, to confirm the individual TPBA, the antioxidant property of the each TPBA was analyzed which was commensurate with that of the previous reports.

Quality characteristics and cooking-induced changes on phenolic compounds of dried green tea noodles.

Incorporating green tea powder (GTP) into wheat flour-based noodles can significantly improve nutritional value. So, this study investigated the effects of GTP (0%, 0.5%, 1%, 1.5%, and 2.0%) on the quality properties of dried green tea noodles (DGTN) and cooking-induced changes to phenolic compounds. Mixolab analysis of wheat flour with GTP showed more water absorption of dough, and the developed dough had a firmer structure. GTP markedly increased the toughness of the noodle sheet. DGTN fortified with GTP showed more stable textural properties during cooking and storage, representing higher hardness and tensile strength. The viscosity and thermal properties of DGTN showed that GTP affected the gelatinization and retrogradation behavior of starch, which were closely related to the textural properties. Overall, DGTN prepared with 1.5% GTP showed better quality properties. However, ultra-performance liquid chromatography-time (UPLC/Q-TOF-mass spectrometry [MS]/MS) analysis showed that cooking by boiling significantly decreased phenolic content in 1.5% DGTN; further analysis revealed that the thermal degradation is a key factor in the loss of polyphenols. Therefore, further studies are necessary to focus on the mechanism of cooking-induced polyphenol loss, which is of great significance for improving the nutritional value of cooked DGTN.

Effect of Black Tea Powder on Antioxidant Activity and Gel Characteristics of Silver Carp Fish Balls.

The effect of black tea powder on the antioxidant activity and gel characteristics of fish balls from silver carp were investigated after freezing storage for 7 days. The results show that black tea powder with different concentrations of 0.1%, 0.2% and 0.3% (w/w) could significantly increase the antioxidant activity of fish balls (p < 0.05). In particular, at the concentration of 0.3%, the antioxidant activity was the strongest among these samples, where the reducing power, DPPH, ABTS and OH free radical scavenging rate were up to 0.33, 57.93%, 89.24% and 50.64%, respectively. In addition, black tea powder at the level of 0.3% significantly increased the gel strength, hardness and chewiness while greatly reducing the whiteness of the fish balls (p < 0.05). ESEM observation found that the addition of black tea powder could promote the crosslinking of proteins and reduced the pore size of the gel network structure of the fish balls. The results suggest that black tea powder could be used as a natural antioxidant and gel texture enhancer in fish balls, which we found to be much related to the phenolic compounds of black tea powder.

The Comparison with Commercial Antioxidants, Effects on Colour, and Sensory Properties of Green Tea Powder in Butter.

Oxidation is one of the most important factors limiting shelf life and is a major deterioration process affecting both the sensory and nutritional quality of food. The high oxidation stability of lipids, which can be improved by the addition of antioxidants, is important for health protection, food quality, and economic reasons. In recent years, research on plant-derived antioxidants for use in human health and food has steadily increased. The aim of this study was to compare the antioxidant effects of green tea powder (GTP) in butter with those of commercial antioxidants (BHA, BHT, α-tocopherol, and Trolox). In addition, the effects on colour, sensory, gross physicochemical properties, and ß-carotene content were investigated in butter. After the separation of butter into five pieces, the first part was chosen as the control sample without GTP; the second part has 100 mg/kg of BHT added to it; and the third, fourth, and fifth parts had 1, 2, and 3% of GTP added in the samples. They were stored at 4 ± 1 °C. Analysis was performed at intervals of 15 days. According to the iron reduction, CUPRAC and FRAP methods were performed, and parallel results were observed. Using the radical elimination methods (ABTS, DPPH•, and DMPD•+), IC50 values were calculated for the samples. According to the IC50 values, the GTP-containing samples were good antioxidants. The total phenolic andf ß-carotene contents increased as the GTP addition increased. The addition of GTP had an antioxidant capacity equal to or higher than that of the BHT-added sample. For the production of a sensory-pleasing, greenish-coloured, new functional butter, the 1% GTP addition showed the most positive results.

Effects of green tea powder on production performance, egg quality, and blood biochemical parameters in laying hens.

The paper aimed to evaluate the effects of dietary inclusion of green tea powder (GTP) on laying performance, egg quality, and blood biochemical parameters of laying hens. A total of 240 Jingfen No. 6 laying hens (age, 24 wk) were randomly allocated into 4 groups: control group (CON, basal diet), GTP0.5, GTP0.75, and GTP1.0 (basal diet included 0.5, 0.75, and 1.0% GTP, respectively). Each group has 5 replicates with 12 birds each. The feeding trial lasted 8 wk. The results showed that the hen-day egg production rate in GTP0.5 and GTP 0.75 group was higher than that of GTP1.0 group (P < 0.05), hen-day egg production rate in the GTP1.0 group was lower compared to the CON group (P > 0.05), the feed conversion ratio (FCR) in the GTP0.75 group was lower than that in CON and GTP 1.0 group (P < 0.05) during the entire experimental period. Albumen height and Haugh unit were higher in the GTP0.75 and GTP1.0 group compared to the CON group at d 56 (P < 0.05). At the end of experiment, plasma TG content in the GTP0.75 and GTP1.0 group was lower than that in the CON group (P < 0.05), the T-CH concentration in the GTP0.5 and GTP0.75 group was lower compared to the CON group (P < 0.05), plasma LDL-C and CORT concentrations were decreased by dietary GTP supplementation (P < 0.05), the HDL-C and BUN concentrations in the GTP0.75 and GTP1.0 group were higher than that in the CON group (P < 0.05). The antibody titers of H5N1 in the GTP0.75 and GTP1.0 group, and H7N9 in the GTP1.0 group were lower than that in the CON group (P < 0.05). In conclusion, dietary GTP inclusion could affect laying performance, regulate lipid metabolism, and have no favorable influence on antibody titers of H5N1 and H7N9, herein, dietary 0.5% GTP inclusion is suggested for Jingfen No. 6 laying hens during the peak laying period.

Application of visible-near infrared spectroscopy in tandem with multivariate analysis for the rapid evaluation of matcha physicochemical indicators.

Consumer preference for matcha is heavily influenced by its physicochemical properties. The visible-near infrared (Vis-NIR) spectroscopy technology coupled with multivariate analysis was investigated for rapid and non-invasive evaluation of particle size and the ratio of tea polyphenols to free amino acids (P/F ratio) of matcha. The multivariate selection algorithms such as synergy interval (Si), variable combination population analysis (VCPA), competitive adaptive reweighted sampling (CARS), and interval combination population analysis (ICPA) were compared, and eventually, the variable selection strategy of ICPA and CARS hybridization was firstly proposed for selecting the characteristic wavelengths from Vis-NIR spectra to build partial least squares (PLS) models. Results indicated that the ICPA-CARS-PLS models achieved satisfactory performance for the evaluation of matcha particle size (Rp = 0.9376) and P/F ratio (Rp = 0.9283). Hence the rapid, effectual, and nondestructive online monitoring, Vis-NIR reflectance spectroscopy in tandem with chemometric models is significant for the industrial production of matcha.

Effects of Tea Powder on the Cooking Properties, Antioxidative Potential and Volatile Profiles of Dried Noodles.

Numerous studies indicate that tea has versatile health benefits, and attempts are being made to use it as a food additive. In this study, three types of tea powder (TP) [matcha tea powder (MTP), green tea powder (GTP), and black tea powder (BTP)] were used in noodle processing, and the cooking properties, antioxidant potential, and volatile profiles of dried tea noodles (DTN) were investigated. Between 0.5% and 2% TP addition decreased the cooking time, cooking loss, and water absorption of DTN, regardless of concentrations. TP decreased the brightness (L*) of the DTN while increasing the greenness (|-a*|) and yellowness (b*) values of matcha tea noodles (MTN) and green tea noodles (GTN), as well as the redness (a*) and yellowness (b*) values of black tea noodles (BTN). The results of the 1,1-Diphenyl-2-Picrylhydrazyl (DPPH) scavenging activity (10.84-95%), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free scavenging activity (2.03-92.23%), and total phenolic content (TPC) (97.32-540.97 mg/g) of the noodles increased as the TP addition increased. Besides, TP also enriched the flavor of the DTN, with alcohol, aldehydes, and ethers being the main components. In conclusion, the addition of TP positively improved the quality of the DTN and increased its antioxidative potential.

Green tea powder inclusion promoted hatchability through increased yolk antioxidant activity.

Dietary supplementation of green tea powder (GTP) changes egg quality of hens, however, whether these changes affect incubation is still unknown. This study was to compare the proteomic difference of incubated eggs from hens with GTP supplemented or not. Huainan partridge chickens (1,080) at 35 wk of age were allocated into 2 groups, one group fed basal diet (CG) and one group fed basal diet plus 1% GTP (EG). After 4 wk feeding, artificially fertilized eggs were collected for yolk cholesterol determination and incubation. During incubation, 6 embryos from each group were randomly selected in each day for yolk protein extraction and quantification. Yolk cholesterol content was significantly lower, while the hatchability was significantly higher in EG than that of the CG group (P < 0.05). Yolk protein concentration at embryonic days (ED) of 0, 2, 6, and 13 showed significant changes and were selected for proteomic analysis by 2-dimensional gel electrophoresis combined with liquid chromatography-tandem mass spectrometry. Fifty-one differentially expressed (DE) protein spots were identified among different incubation stages between CG and EG group which were mainly classified into vitellogenin, immunoglobulin, and ovoinhibitor, and occupied 45.1, 23.5, and 15.7%, respectively, to the total DE proteins. Ovotransferrin, participated in extracellular sequestering of iron ion process, was significantly lower in EG group than that of the CG group (P < 0.05). Ig light chain precursor (Immunoglobulin) exhibited higher expression at ED6 in EG group as compared with that of the CG group, and was participated in immune response related processes. Ovoinhibitor, mainly involved in protease binding activity, showed lower abundance at ED13 in EG group as compared with that of the CG group. Vitellogenin-3, showed lower expression in EG group as compared with that of the CG group, was mainly participated in lipid transportation and localization according to GO enrichment. Chickens fed diet with GTP provided eggs more antioxidant ability that increased hatchability, indicated that GTP could be considered as additive in breeding layer.

The Effect of Microwave Radiation on the Green Color Loss of Green Tea Powder.

Microwave radiation is one of the main heating methods for food processing, especially affecting the color quality of colorful foods. This work presents the effect of microwave radiation on the green color loss of green tea powder (GTP) by the color description (L*, a*, b*, and Ha of green tea powder, L*:whiteness/darkness, a*: redness/greenness, and b*: yellowness/blueness; Ha derived from Hunter a and b could visually describe the color space) of the Hunter color system. First, the L*, a*, and b* were determined from the GTP samples treated with various microwave powers with the change of time to investigate the kinetic of color loss. Then, the L*, a*, and b*and temperature of GTP samples with serious thickness treated with constant microwave power (700 W) for a different time were determined to study the effect of sample thickness on the color loss. Finally, the chemicals that contributed to color change in the GTP samples treated with mild, moderate, and severe radiation were analyzed. The results showed that L*, |a*| (|a*|was the absolute value of a*), b*, and Ha decreased with the power increase in microwave radiation, and their changes conformed to the first-order kinetics. The activation energies (Ea) of different thickness GTP for change of L*, a*, b*, and Ha values could be predicted with the fitting models, and Ea for 20 mm-thick GTP were approximately 1/5, 1/8, 1/8, and 1/13 of those for 4 mm-thick GTP. The color loss was mainly caused by the Mg2+ loss of chlorophylls and the formation of derivates under mild radiation, the degradation of chlorophylls and the formation of theaflavin from catechins under moderate radiation, and the degradation of chlorophylls and their derivates accompanied by Maillard reaction between reducing sugar and amino acids under severe radiation. The results indicate that sample thickness and radiation time are two key parameters to keeping the color of GTP in food processing and microwave pasteurization.

Synthesis of sustainable chemicals from waste tea powder and Polystyrene via Microwave-Assisted in-situ catalytic Co-Pyrolysis: Analysis of pyrolysis using experimental and modeling approaches.

In the current study, catalytic co-pyrolysis was performed on waste tea powder (WTP) and polystyrene (PS) wastes to convert them into value-added products using KOH catalyst. The feed mixture influenced the heating rates (17-75 °C/min) and product formation. PS promoted the formation of oil and WTP enhanced the char formation. The maximum oil yield (80 wt%) was obtained at 15 g:5 g, and the maximum char yield (44 wt%) was achieved at 5 g:25 g (PS:WTP). The pyrolysis index (PI) increased with the increase in feedstock quantity. High PI was noticed at 25 g:5 g, and low PI was at 5 g:5 g (PS:WTP). Low energy consumption and low pyrolysis time enhanced the PI value. Significant interactions were noticed during co-pyrolysis. The obtained bio-oil was analyzed using GC-MS and a plausible reaction mechanism is presented. Catalyst and co-pyrolysis synergy promoted the formation of aliphatic and aromatic hydrocarbons by reducing the oxygenated products.

The role of solvent soaking and pretreatment temperature in microwave-assisted pyrolysis of waste tea powder: Analysis of products, synergy, pyrolysis index, and reaction mechanism.

This study focuses on microwave-assisted pyrolysis (MAP) of fresh waste tea powder and torrefied waste tea powder as feedstocks. Solvents including benzene, acetone, and ethanol were used for soaking feedstocks. The feedstock torrefaction temperature (at 150 °C) and solvents soaking enhanced the yields of char (44.2-59.8 wt%) and the oil (39.8-45.3 wt%) in MAP. Co-pyrolysis synergy induced an increase in the yield of gaseous products (4.7-20.1 wt%). The average heating rate varied in the range of 5-25 °C/min. The energy consumption in MAP of torrefied feedstock (1386 KJ) significantly decreased compared to fresh (3114 KJ). The pyrolysis index dramatically varied with the solvent soaking in the following order: ethanol (26.7) > benzene (25.6) > no solvent (10) > acetone (6). It shows that solvent soaking plays an important role in the pyrolysis process. The obtained bio-oil was composed of mono-aromatics, poly-aromatics, and oxygenated compounds.

Effects of ß-Carotin and Green Tea Powder Diets on Alleviating the Symptoms of Gouty Arthritis and Improving Gut Microbiota in C57BL/6 Mice.

As a chronic metabolic disease caused by disorders of purine metabolism, gout has shown increasing incidence rate worldwide. Considering that gout is not easily treated and cured, further studies are explored to prevent gout development through diet modification. Both ß-carotin and green tea powder are rich in dietary fiber, which helps maintain the balance of gut microbiota in humans. The aim of this study was to investigate the effects of ß-carotin and green tea powder diet on the prevention of gouty arthritis in relation to the bacterial structure of gut microbiota in mice. We successfully induced gouty arthritis in C57BL/6 mice by injecting monosodium urate (MSU) crystals and feeding high-fat diet (HFD), and further investigated the effects of additional ß-carotin and green tea powder in the diets of mice on the prevention of gouty arthritis in mice. Our results showed that diet of ß-carotin and green tea powder reduced the joint swelling and pain in mice with gout, reduced the levels of serum uric acid (UA) and three types of pro-inflammatory cytokines, i.e., interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), improved the gut microbiota profile, and reduced the metabolic levels of purines and pyrimidines. In conclusion, our study provided evidence to support the application of ß-carotin and green tea powder diet as a dietary adjustment method to prevent and treat gouty arthritis.

Physicochemical indicators coupled with multivariate analysis for comprehensive evaluation of matcha sensory quality.

The sensory quality of matcha is a pivotal factor in determining consumer acceptance. However, the human sensory panel test is difficult to popularize by virtue of professional requirements and inability to evaluate large samples. The analysis showed that physicochemical indicators of matcha were significantly related to sensory quality. Hence, principal component analysis (PCA) based on selected key physicochemical indicators was proposed to evaluate the sensory quality of matcha in this research. The eight key indicators were selected from twenty-four physicochemical indicators based on least absolute shrinkage and selection operator (LASSO) for the establishment of the PCA comprehensive evaluation model. The results demonstrated that the PCA comprehensive evaluation model achieved superior performance, with -0.895 rc (correlation coefficient in calibration set) and -0.883 rp (correlation coefficient in prediction set) for overall sensory quality. This work demonstrated that LASSO-PCA comprehensive evaluation as an objective protocol has great potential in predicting matcha sensory quality.

Differential regulation and preventive mechanisms of green tea powder with different quality attributes on high-fat diet-induced obesity in mice.

Tea powder has been reported to have some physiological functions. However, there is no report on whether there are differences in the active ingredients of tea powder with different qualities and whether there are different prebiotic mechanisms. This study was aimed to investigate the effects of different qualities of tea powder on preventing obesity from different aspects, namely antioxidation, inflammation, lipid-lowering, and intestinal flora, using an obesity mouse model. The results showed that all three types of tea powder with different qualities could reduce body weight and decrease serum TC, TG, and LDL-C. However, tea powder with different quality attributes exhibited diverse modulatory effects and mechanisms. Tender tea powder contained more tea polyphenols, and it had a better effect on improving oxidative stress. Tender tea powder significantly decreased the abundances of Blautia, Bilophila, and Oscillibacter, and increased the abundances of Alloprevotella, Lachnoclostridium, Romboutsia, and Ruminococcaceae_UCG-004. Coarse tea powder contained more dietary fiber, and had a better effect on reducing the food intake and improving lipid metabolism, which could reduce lipid synthesis and increase lipid ß-oxidation. Coarse tea powder significantly decreased the abundance of Dubosiella and increased the abundances of the Lachnospiraceae_NK4A136 group and Coriobacteriaceae_UCG-002. Our findings provide a theoretical reference for the comprehensive utilization of tea powder.

Effects of Dietary Tea Powder on the Growth Performance, Carcass Traits, and Meat Quality of Tibetan Pig × Bama Miniature Pigs.

This study was conducted to evaluate the effects of tea powder in diets on the growth performance, meat quality, muscular amino acid, fatty acid profile, and serum biochemical indices of pigs. A total of 120 local Chinese pigs (Tibetan × Bama miniature pigs) were randomly assigned to five treatment groups, each with six pens and four pigs per pen. During a 60-day experiment, these groups of pigs were fed the normal diet and the diet supplemented with 1%, 2%, 4%, and 6% tea powder, respectively. The results showed that the supplementation of tea powder did not affect the growth performance of pigs. However, the dietary tea powder inclusion decreased (p < 0.05) the average fat thickness, total fat, and abdominal fat, and increased (p < 0.05) the total muscle as well. In addition, the dietary 2% tea powder decreased (p < 0.05) the muscle lightness (L*) and yellowness (b*). Compared with the control group, the dietary supplementation with 1%, 2%, and 4% tea powder raised (p < 0.05) the total amino acids (TAA) and essential amino acids (EAA), and dietary 4% and 6% tea powder increased (p < 0.05) the C20:5n3 in the muscle tissue. Furthermore, the serum lipid metabolism-related biochemical indices and mRNA expression levels were improved with the addition of tea powder. These results indicated that dietary tea powder might improve the carcass traits and meat quality of the Chinese native finishing pigs, but it does not affect their growth performance. Tea powder could be fully developed and reasonably applied as a dietary supplement.

Simultaneous quantification of chemical constituents in matcha with visible-near infrared hyperspectral imaging technology.

This study aimed to assess the feasibility of identifying multiple chemical constituents in matcha using visible-near infrared hyperspectral imaging (VNIR-HSI) technology. Regions of interest (ROIs) were first defined in order to calculate the representative mean spectrum of each sample. Subsequently, the standard normal variate (SNV) method was applied to correct the characteristic spectra. Competitive adaptive reweighted sampling (CARS) and bootstrapping soft shrinkage (BOSS) were used to optimize the models. They were built based on partial least squares (PLS), creating two models referred to as CARS-PLS and BOSS-PLS. The BOSS-PLS models achieved best predictive accuracy, with coefficients of determination predicted to be 0.8077 for caffeine, 0.7098 for tea polyphenols (TPs), 0.7942 for free amino acids (FAAs), 0.8314 for the ratio of TPs to FAAs, and 0.8473 for chlorophyll. These findings highlight the potential of VNIR-HSI technology as a rapid and nondestructive alternative for simultaneous quantification of chemical constituents in matcha.