Tea By-products Research Articles

Effects of supplementation with green tea by-products on growth performance, meat quality, blood metabolites and immune cell proliferation in goats.

Forty-eight castrated male goats were used to determine the effects of feeding green tea by-products (GTB) on growth performance, meat quality, blood metabolites and immune cell proliferation. Experimental treatments consisted of basal diets supplemented with four levels of GTB (0%, 0.5%, 1.0% or 2.0%). Four replicate pens were assigned to each treatment with three goats per replicate. Increasing dietary GTB tended to linearly increase the overall average weight gain and feed intake (p = 0.09). Water holding capacity, pH and sensory attributes of meat were not affected by GTB supplementation, while cooking loss was reduced both linearly and quadratically (p < 0.01). The redness (linear; p = 0.02, quadratic; p < 0.01) and yellowness (quadratic; p < 0.01) values of goat meat were improved by GTB supplementation. Increasing dietary GTB quadratically increased protein and decreased crude fat (p < 0.05), while linearly decreased cholesterol (p = 0.03) content of goat meat. The proportions of monounsaturated fatty acid, polyunsaturated fatty acid (PUFA) and n-6 PUFA increased linearly (p < 0.01) and n-3 PUFA increased quadratically (p < 0.05) as GTB increased in diets. Increasing dietary GTB linearly increased the PUFA/SFA (saturated fatty acid) and tended to linearly and quadratically increase (p ≤ 0.10) the n-6/n-3 ratio. The thiobarbituric acid-reactive substances values of meat were lower in the 2.0% GTB-supplemented group in all storage periods (p < 0.05). Dietary GTB linearly decreased plasma glucose and cholesterol (p < 0.01) and quadratically decreased urea nitrogen concentrations (p = 0.001). The growth of spleen cells incubated in concanavalin A and lipopolysaccharides medium increased significantly (p < 0.05) in response to GTB supplementation. Our results suggest that GTB may positively affect the growth performance, meat quality, blood metabolites and immune cell proliferation when supplemented as a feed additive in goat diet.

Assessment of Anti-nutritive Activity of Tannins in Tea By-products Based on In vitro Rumen Fermentation.

Nutritive values of green and black tea by-products and anti-nutritive activity of their tannins were evaluated in an in vitro rumen fermentation using various molecular weights of polyethylene glycols (PEG), polyvinyl pyrrolidone (PVP) and polyvinyl polypyrrolidone as tannin-binding agents. Significant improvement in gas production by addition of PEG4000, 6000 and 20000 and PVP was observed only from black tea by-product, but not from green tea by-product. All tannin binding agents increased NH3-N concentration from both green and black tea by-products in the fermentation medium, and the PEG6000 and 20000 showed relatively higher improvement in the NH3-N concentration. The PEG6000 and 20000 also improved in vitro organic matter digestibility and metabolizable energy contents of both tea by-products. It was concluded that high molecular PEG would be suitable to assess the suppressive activity of tannins in tea by-products by in vitro fermentation. Higher responses to gas production and NH3-N concentration from black tea by-product than green tea by-product due to PEG indicate that tannins in black tea by-product could suppress rumen fermentation more strongly than that in green tea by-product.

Biotransformation of tea catechins using Aspergillus niger tannase prepared by solid state fermentation on tea byproduct

A tannase that was prepared from Aspergillus niger by a solid-state fermentation on tea byproducts was investigated to transform the catechins in tea infusion. The tannase could effectively hydrolyze epigallocatechin gallate (EGCG), gallocatechin gallate (GCG) and epicatechin gallate (ECG) of tea infusion, which showed pH values ranged from 4.8 to 5.3 during the tannase treatment. The enzyme was active and stable within pH 3.0–7.0 and 4–60 °C. The enzyme had Kms of 14.89 mmol/L, 16.13 mmol/L and 3.57 mmol/L for EGCG, GCG and ECG, respectively in pure solutions. However, the hydrolysis of individual EGCG, GCG and ECG in the tea infusion showed different kinetic parameters from those in pure solutions. The transformation of EGCG was the dominant reaction in tea infusion. After the tannase treatment, tea infusion was detected to have significant increases in the clarity and activities for scavenging 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical, 2, 2-diphenyl-1-picryl-hydrazyl (DPPH) radical and hydroxyl radical. The results indicated the tannase was effective to transform the catechins, which could be possibly used for commercial extraction of catechins. In addition, the results suggested it is more desirable to follow the dynamic model to control the tannase treatment of tea infusion for a better processing.

Fermentation Characteristics, Tannin Contents and In vitro Ruminal Degradation of Green Tea and Black Tea By-products Ensiled at Different Temperatures.

Green and black tea by-products, obtained from ready-made tea industry, were ensiled at 10°C, 20°C, and 30°C. Green tea by-product silage (GTS) and black tea by-product silage (BTS) were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG) as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at 10°C. The GTS stored at 20°C and 30°C showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on NH3-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and NH3-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and NH3-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin’s activity in the rumen.

Determination of lutein from green tea and green tea by-products using accelerated solvent extraction and UPLC.

We aimed to identify the optimum conditions for the extraction of lutein from green tea using accelerated solvent extraction, and achieve improved analytical resolution and sensitivity between lutein and zeaxanthin using an ultra performance liquid chromatography (UPLC) system. The optimized method employed 80% ethanol as the extraction solvent, 160 °C as the temperature, 2 static cycles, and 5 min of static time. In the validation of the UPLC method, recovery was found to be in the range approximately 93.73 to 108.79%, with a correlation coefficient of 0.9974 and a relative standard deviation of <9.29% in inter- and intraday precision analyses. Finally, the lutein contents of green tea and green tea by-products were measured as 32.67 ± 0.70 and 18.18 ± 0.68 mg/100g dw, respectively. Furthermore, we verified that green tea by-products, which are discarded after producing green tea beverages, might be used as a great resource for massive lutein production. We have demonstrated that the common problem of inadequate resolution between lutein and zeaxanthin during carotenoid analyses can be overcome by optimizing the combined techniques of accelerated solvent extraction and ultra performance liquid chromatography (UPLC). UPLC was highly effective for saving time, solvent, and labor, as well as providing better resolution. The results in this study demonstrated that green tea by-products could be used as new sources for industrial lutein production owing to their massive production during the extraction of green tea beverages.

Dietary supplementation of green tea by-products on growth performance, meat quality, blood parameters and immunity in finishing pigs

Green tea has a long-standing reputation for its health-promoting properties. It has a useful content of amino acids, proteins, vitamins, tannins and polyphenols, such as epicatechin, epigallocatechin, epigallocatechin gallate and gallocatechin. This study evaluated the potential use of green tea by-products in finishing pig diet. A total of 100 finishing pigs were assigned to 5 dietary treatments with 4 replications for 6 weeks in a completely randomized design. The treatments were as follows: control (basal diet), antibiotic (basal diet with 0.003% chlortetracycline), and basal diet with 0.5, 1 or 2% green tea by-products (GTB). In this experiment, a poor weight gain and feed conversion ratio was observed for the GTB-2% group when compared with the antibiotic group. Both crude protein and crude fat contents of the meat were inversely proportional to each other in the GTB groups and 0.5 to 1% level differed with the antibiotic group. The slaughter weight and shear value were higher in GTB-1 and 0.5%, group respectively, while a lower heating loss and higher tenderness were observed in the GTB-2% group. Supplementation of the pig diet with GTB reduced the thiobarbituric acid reactive substances values of the meat, and increased white blood cells (WBC) and red blood cells (RBC) content compare to others. Although, spleen weight was decreased in the GTB-1 and 2% groups, spleen cells growth and, IL-6 and TNF-α production were improved by the addition of GTB to the feed. These combined results indicated that 0.5 to 1% GTB hold great promise to use as feed additive for finishing pigs. Key words: Green tea by-products, growth, meat, blood, immunity, pigs.

Recent trends in soft beverages edited by L Jagan Mohan Rao and K Ramalakshmi, Woodhead Publishing India Pvt. Ltd.,New Delhi

Though there are many voluminous books on coffee, tea and soft beverages, this book is unique in providing updated information on tea, coffee and soft fruit drinks in one volume. It is a reader’s delight and has three main parts. Part I deals with coffee, which is the most fascinating beverage throughout the world. This part is in four chapters comprising introduction, health benefits, recent trends in value addition and value added by-products. Coffee is one of the internationally well accepted beverages and is the second largest traded in the world next to crude oil. First section describes a brief historical perspective of beverage, botany, processing of green to roasted coffee, chemical composition and tasting of coffee. Effect of roasting on chemical composition, physical and chemical changes during roasting and their significance in nutritional quality and physiological impact on quality is also discussed in detail. Second section describes the health benefits of coffee and coffee beverage. The positive and negative biological activities of coffee are correlated with central nervous system, reproductive system, bone system and cardiovascular system. Third section deals with recent value-added coffee products. This section details about the variety of speciality coffee beverages, canned coffee, ready mix coffee, coffee jelly, fortified coffees, honeyed coffee, coffee tablets, variety of flavoured coffee, coffee wine, coffee candy, germinated coffee, coffee cookies, pizza with coffee colorant, carbonated coffee, decaffeinated coffee, instant coffee, monsoon coffee and coffee paste. The fourth section describes the utilization of by-products of coffee. Part II describes tea, which is the second most widely consumed beverage in the world next to water. This part is in chapters 5–9, viz., introduction to tea, types of tea and processing, chemical composition, pharmacological and medical properties of tea, high impact value added products of tea and tea by-products. Considerable interest has developed in the past decade in unravelling the beneficial health effects of tea, in particular, polyphenolic components and its antioxidant activity. The origin and history, various types of tea are discussed in the fifth and sixth section respectively. Chemical composition and medicinal and pharmacological properties of tea are explained in the seventh section. Eighth section entitled “High impact value-added products” describes relevant fine points about tea bags, instant tea, iced tea, herbal tea, tea concentrate, carbonated tea, various flavoured teas, decaffeinated tea, different fortified teas, tonic tea, tea cider and vinegar, tea kombucha, toyama kurocha, canned tea and instant tea granules. Detailed description about “Soft drinks” is described Part III, which is presented in chapters 10–17. Introduction to drinks and the beverage consumption pattern is depicted in chapters 10 and 11, respectively. The term ‘soft drinks’ includes all types of non-alcoholic liquid and powder beverages, although it is generally used to signify carbonated beverages. Soft drinks includes ready to drink, concentrated soft drinks and other categories are well explained in 12th chapter. The 13th chapter entitled, “Ingredients of soft drinks” deals the essential components of the soft drinks namely water, sweeteners, acidulants, colors, flavors and clouding agents. Advances in technology have improved all aspects of the soft drink industry. Chapter 14 includes the major processing technologies of soft drinks such as handling raw material, pulping and extraction, clarification, concentration, syrup preparation, blending, pasteurization and carbonation. Clean-in-place system, which is one of the major issues during manufacturing of soft drinks, is also included. Quality control and packaging aspect are well explained in chapters 15 and 16. Future trends presented in chapter 17 includes healthy carbonated drinks, functional drinks, mixed fruit juice beverages and carbonated beverages from waste of fruits. This is a well documented book in a precise manner without missing any of the aspects relevant to the subject. As a very useful ready reckoner, the book gives the latest information on coffee, tea and soft carbonated fruit drinks. The editors have taken utmost care in providing main aspects of chemistry, technology and quality control with respect to raw material as well as finished product. The information on value addition and marketing aspects are dwelt very well. One doesn’t find many books by Indian authors on coffee, tea and soft drinks and the effort by the editors is praiseworthy and the editors need to be complimented for the excellent work. The information provided is highly useful for researchers, teachers, students and industry personnel who are interested in the beverages such as coffee, tea and carbonated beverages.

Evaluation of green tea by-product and green tea plus probiotics on the growth performance, meat quality and immunity of growing–finishing pigs

The present study was conducted to evaluate the effects of green tea by-product (GTB) and green tea plus probiotics (GT+P) on the growth performance, carcass characteristics, meat quality, blood parameters and immunity of growing–finishing pigs. In total, 80 crossbreed growing pigs were assigned to receive four dietary treatments for a period of 8 weeks. The dietary treatments were a basal diet (control), basal diet supplemented with 0.003% chlortetracycline (antibiotic), basal diet with 0.5% GTB (GTB) and basal diet containing 0.5% GT+P (GT+P). The results of our study indicated that bodyweight gain increased (P &lt; 0.05) in response to the addition of GT+P to the basal diet. Crude protein and crude ash content, and shear values of loin meat were significantly (P &lt; 0.05) increased in the GT+P group, although moisture and juiciness were decreased (P &lt; 0.05). The GTB group had higher (P &lt; 0.05) serum glucose concentrations, whereas the GT+P exhibited lower (P &lt; 0.05) insulin concentrations. The values of thiobarbituric acid-reactive substances of fresh loin meat and meat that had been preserved for 1 week were lower (P &lt; 0.05) in the GT+P group than those of the control and GTB groups. The growth of spleen cells incubated in concanavalin A (Con A) and lipopolysaccharide (LPS) medium was statistically higher (P &lt; 0.05) for the GT+P group than for the GTB or antibiotic group. IL-6 and TNF-α production by spleen cells induced by Con A and LPS was increased in the GTB and GT+P group (P &lt; 0.05) compared with the antibiotic group. Taken together, the results of the present study indicated that GT+P exerts positive effects on weight gain, meat composition, blood parameters and immunity in pigs, and could be used as an alternative to antibiotics for growing–finishing pig feeds.

Anti-influenza virus activity of green tea by-products in vitro and efficacy against influenza virus infection in chickens

Polyphenolic compounds present in green tea, particularly catechins, are known to have strong anti-influenza activity. The goal of this study was to determine whether green tea by-products could function as an alternative to common antivirals in animals compared to original green tea. Inhibition of viral cytopathic effects ascertained by neutral red dye uptake was examined with 50% effective (virus-inhibitory) concentrations (EC₅₀)determined. Against the H1N1 virus A/NWS/33, we found the anti-influenza activity of green tea by-products (EC₅₀ = 6.36 µg/mL) to be equivalent to that of original green tea (EC₅₀= 6.72 µg/mL). The anti-influenza activity of green tea by-products was further examined in mouse and chicken influenza infection models. In mice, oral administration of green tea by-products reduced viral titers in the lungs in the early phase of infection, but they could not protect these animals from disease and death. In contrast, therapeutic administration of green tea by-products via feed or water supplement resulted in a dose-dependent significant antiviral effect in chickens, with a dose of 10 g/kg of feed being the most effective (P < 0.001). We also demonstrated that unidentified hexane-soluble fractions of green tea by-products possessed strong anti-influenza activity, in addition to ethyl acetate-soluble fractions, including catechins. This study revealed green tea by-product extracts to be a promising novel antiviral resource for animals.

EFFECT OF IRRADIATION ON TOTAL PHENOL AND CATECHINS CONTENTS AND RADICAL SCAVENGING ACTIVITY OF GREEN TEA LEAF AND STEM EXTRACT

ABSTRACT Green tea (Camellia sinensis) leaf and stem extracts, major by-products of the green tea industry, were compared in terms of biochemical quality and catechin composition after 20 kGy of irradiation. Irradiation decreased total phenolic contents of green tea leaf extracts (GLE) from 98.6 to 79.91 mg/g. However, phenolic contents of green tea stem extracts (GSE) increased from 67.83 to 71.94 mg/g after irradiation. The 50% inhibition concentration (IC50, µg/mL) of GLE and GSE against superoxide and hydroxyl radical also demonstrated that GSE showed higher activity when irradiation was applied. However, catechin and caffeine contents of both GLE and GSE decreased after irradiation at 20 kGy. Results suggest that green tea stems, major by-products of the green tea industry, can be a compatible functional material to green tea leaves for industrial use when cost-effectiveness is considered. In addition, irradiation of GSE may increase its functional activity. PRACTICAL APPLICATIONS Every year, as much as 50 tons of green tea by-products are produced in one green tea production area in Korea alone, but the value of green tea by-products is much lower (approximately 1/100) than that of green tea leaves. It must be the situation not only in Korea but also in other countries. Therefore, the development of a process utilizing green tea by-products is very valuable for the green tea industry and related fields. This report may give useful information about the use of the green tea by-products as a functional ingredient for food and cosmetic products. In addition, use of irradiation to improve the color of green tea extracts from dark to brighter and more transparent was also suggested for the manufacture of more industry-friendly natural materials with biological functions.

Comparison of the Effect of Green Tea By-product and Green Tea Probiotics on the Growth Performance, Meat Quality, and Immune Response of Finishing Pigs

The objective of this experiment was to compare the effects of green tea by-product and green tea probiotics on the growth performance, meat quality and immune response of finishing pigs. A total of 72 crossbred Landrace×Yorkshire finishing pigs with an average of 76 kg body weight were assigned to 4 dietary treatments in a completely randomized design. Each treatment had 3 replications with 6 pigs per replication. The four dietary treatments were control, antibiotics (control diet with 0.003% chlortetracycline added), and diets containing 0.5% green tea by-product or 0.5% green tea probiotic supplementation. Weight gain was increased in 0.5% green tea probiotics treatment compared to others, but there was no significant difference (p>0.05). The incorporation of 0.5% green tea probiotics to diets reduced the feed conversion ratio in finishing pigs (p>0.05). The incorporation of 0.5% green tea by-product into the pig diet reduced the crude protein and fat contents of the meat (p>0.05). Pigs fed diets containing 0.5% green tea probiotic supplementation had lowered meat TBA values compared to those fed 0.5% green tea by-product (p<0.05). The proliferation of spleen cells stimulated with Con A (concanavalin: 0.1, 0.3, and 1.0 μg/ml) significantly increased with 0.5% green tea by-product treatment compared to antibiotic treatment (p<0.05), but was significantly decreased in 0.5% green tea probiotics treatment compared to the antibiotic treatment (p<0.05). When stimulated with 1.0 μg/ml Con A, splenocyte production of IL-6 from pigs treated with 0.5% green tea by-product or green tea probiotics was significantly increased compared to the antibiotic treatment group (p<0.05). Splenocyte production of TNF-α after treatment with 1.0 μg/ml Con A was significantly higher following 0.5% green tea probiotics treatment (p<0.05), while TNF-α production after 10.0 μg/ml LPS (lipopolysaccharide) was significantly higher in the 0.5% antibiotic treatment group (p<0.05). (Key Words : Green Tea By-product, Green Tea Probiotics, Growth Performance, Meat Quality, Immune Response, Pig)

Ensiled or Oven-dried Green Tea By-product as Protein Feedstuffs: Effects of Tannin on Nutritive Value in Goats

Ensiled or oven-dried green tea by-products (GTB) were evaluated in goats for their nutritive potential as protein feedstuffs based on in vitro and in vivo digestibility. To elucidate the effects of tea tannin on in vitro digestibility, polyethylene glycol (PEG) was used as a tannin binding agent. Both ensiled and dried GTB contained 31.9 to 32.6% of crude protein (CP) on a dry matter (DM) basis. Phenolics and tannins in soybean meal and alfalfa hay were low or not detected, but they were high in both ensiled and dried GTB (7.3-10.1% DM as total extractable tannins). In vitro protein digestibility in the rumen ranked: soybean meal>alfalfa hay cube>ensiled GTB = dried GTB. The protein digestibility post-ruminally of these feedstuffs showed a similar trend to that in the rumen, but the digestibility of ensiled GTB was significantly higher than that of dried GTB. Addition of PEG improved the in vitro protein digestibility of both kinds of GTB in the rumen and post-ruminally, indicating that tannins suppressed the potential protein digestibility of GTB. The increased protein digestibility by PEG addition was not significantly different between ensiled and dried GTB in the rumen, but the percentage increment of ensiled GTB was higher than dried GTB post-ruminally. In the in vivo digestibility trial, ensiled and dried GTB were offered to goats as partial substitutes for soybean meal and alfalfa hay cubes. Offering both GTB to goats as 5-10% on a DM basis did not affect nutrient digestibility, ruminal pH, volatile fatty acids, and ammonia concentration. However, the eating time of the GTB-incorporated diet was longer than that of the basal diet. It took 1.4 and 1.6 times longer than the control diet, to eat the diet completely when GTB silage was offered at 5 and 10% levels, respectively, of the total diet. These results show that ensiled and dried GTB are useful as partial substitutes for soybean meal and alfalfa hay cubes for goats with respect to nutritive value. Because of lessened palatability, it is recommended that GTB be incorporated into the diet at 5% on a DM basis.

Variations in Chemical Composition of Tea By-products among Companies and Production Lots

Variations in Chemical Composition of Tea By-products among Companies and Production Lots

Effects of Gamma Irradiation on the Biological Activity of Green Tea Byproduct Extracts and a Comparison with Green Tea Leaf Extracts

ABSTRACT: Green tea byproduct extract powder, a major byproduct of the green tea industry, was prepared and investigated for its biological activities after a gamma‐irradiation treatment for the purpose of a brightened color. The color, total phenolic contents, antioxidative activity, tyrosinase inhibition activity, cancer cell proliferation inhibition effect, and antimutagenicity were measured and compared with those of a green tea leaf extract powder. Hunter L* values of the irradiated green leaf and byproduct extracts were increased in a comparison with the nonirradiated extracts. The contents of total phenolic compounds of the green tea leaf and byproduct extracts were 424.2 ± 11.45 and 335.5 ± 18.65 mg/g of sample, respectively. The 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging activity of the 20 ppm green tea leaf and byproduct extracts were 68.2% and 57.6%, respectively. Ferric‐reducing ability of the samples showed similar results to the DPPH radical scavenging capacity. The samples showed an inhibition of tyrosinase and also a cancer cell proliferation inhibition effect. Especially, the antimutagenicities of the byproduct extracts showed a strong inhibition effect (96.20% and 57.77%) on 3‐amino‐1,4‐dimethyl‐5H‐pyrido[4,3‐b]indole (Trp) and 2‐nitrofluorene (NF), respectively. Results indicated that, although the biological activity of green tea byproduct extracts is less than that of green tea leaf extract, it may be a potential source of a functional ingredient. In addition, irradiation can be applied to improve the color and biological activity of the material.

Effect of Green Tea By-product on Performance and Body Composition in Broiler Chicks

This experiment was conducted to determine the optimum level of green tea by-product (GTB) in diets without antibiotics and to evaluate its effect on broiler performances. A total of 140 Ross broilers were kept in battery cages for a period of 6 weeks. Dietary treatments used in this experiment were antibiotic free group (basal diet as a control), antibiotic added group (basal+0.05% chlortetracycline), GTB 0.5% (basal+GTB 0.5%), GTB 1% (basal+GTB 1%) and GTB 2% (basal+GTB 2%). Antibiotic added group showed significantly higher body weight gain than other treatments (p 0.05). The addition of green tea by-product to diets tended to decrease blood LDL cholesterol content compared to control group although there were no significant differences among treatments (p>0.05). Addition of green tea by-product increased docosahexaenoic acid (DHA) in blood plasma and tended to decrease cholesterol content in chicken meat, but a significant difference was not observed (p>0.05). The values of TBA in chicken meat decreased in groups fed diets with green tea-by product and antibiotics compared to control group (p<0.05). The crude protein content in chicken meat was decreased slightly in treatments with green tea by-product and antibiotics supplementation. The abdominal fat was increased in chickens fed with diets with green tea by-product compared to the control (p<0.05). (Asian-Aust. J. Anim. Sci. 2003. Vol 16, No. 6 : 867-872)