Antioxidative potential, nutritional value and sensory profiles of confectionery fortified with green and yellow tea leaves (Camellia sinensis)

The Effect of Temperature and Humidity on Yellow Tea Volatile Compounds during Yellowing Process

Yellowing is the key processing technology of yellow tea, and environmental conditions have a significant impact on the yellowing process. In this study, volatile compounds of the yellowing process under different environmental conditions were analyzed by GC-MS. Results showed that a total of 75 volatile compounds were identified. A partial least squares discriminant analysis (PLS-DA) determined that 42 of them were differential compounds, including 12 hydrocarbons, 8 ketones, 8 aldehydes, 6 alcohols, and 8 other compounds, and compared the contents of differential compounds under the conditions of 40 °C with 90% humidity, 50 °C with 50% humidity, and 30 °C with 70% humidity, then analyzed the variation patterns of hydrocarbons under different yellowing environmental conditions. A 40 °C with 90% humidity treatment reduced the content of more hydrocarbons and increased the aldehydes. The content of 3-hexen-1-ol was higher when treated at 50 °C with 50% humidity and was consistent with the results of sensory evaluation. This study could provide a theoretical basis for future research on the aroma of yellow tea.

Exploring antioxidative properties of xanthohumol and isoxanthohumol: An integrated experimental and computational approach with isoxanthohumol pKa determination

This study explores the antioxidative activities of xanthohumol (XN) and isoxanthohumol (IXN), prenylated flavonoids from Humulus lupulus (family Cannabaceae), utilizing the oxygen radical absorption capacity (ORAC) and ferric reducing antioxidant power (FRAP) assays along with computational Density Functional Theory methods. Experimentally, XN demonstrated significantly higher antioxidative capacities than IXN. Moreover, we determined IXN pKa values using the UV/Vis spectrophotometric method for the first time, facilitating its accurate computational modeling under physiological conditions. Through a thermodynamic approach, XN was found to efficiently scavenge HOO• and CH3O• radicals via Hydrogen Atom Transfer (HAT) and Radical Adduct Formation (RAF) mechanisms, while CH3OO• scavenging was feasible only through the HAT pathway. IXN exhibited its best antioxidative activity against CH3O• via both HAT and RAF mechanisms and could also scavenge HOO• through RAF. Both Single Electron Transfer (SET) and Sequential Proton Loss-Electron Transfer (SPLET) mechanisms were thermodynamically unfavorable for all radicals and both compounds.

Cookies Fortified with Clitoria ternatea Butterfly Pea Flower Petals: Antioxidant Capacity, Nutritional Composition, and Sensory Profile

This study aimed to fortify cookies to be functional food by adding Clitoria ternatea flower (CT) at concentrations ranging from 0 to 8%. Sensory profiling identified 6% CT as optimal for organoleptic attributes. The addition of CT did not significantly impact protein, lipid, and ash content but decreased energy value and increased insoluble and soluble fibre levels. The inclusion of 6% CT had a significant effect on the overall total phenolic content (TPC), which increased compared to the control sample. Antioxidative activity analyses showed enhanced antioxidative activity in ABTS, DPPH, ORACFL, and PCL assays. The addition of 6% CT inhibited hydroperoxide production in cookies. However, over a period of 6 weeks, a significant rise in peroxide value was observed during the 4th and 6th weeks of storing fortified cookies. All assessed products met the high microbiological quality standards. The sensory evaluation scores showed that CT can create cookies with health benefits and a good overall acceptance score. The texture of the cookies gradually became softer, but no significant changes in visual appearance were observed. CT can be extensively used in baked cookies as a rich source of polyphenols with strong antioxidant properties and high fibre content, as well as a fortification source for the development of functional foods.

Pruned tea biomass plays a significant role in functional food production: A review on characterization and comprehensive utilization of abandon-plucked fresh tea leaves

Tea is the second largest nonalcoholic beverage in the world due to its characteristic flavor and well-known functional properties in vitro and in vivo. Global tea production reaches 6.397 million tons in 2022 and continues to rise. Fresh tea leaves are mainly harvested in spring, whereas thousands of tons are discarded in summer and autumn. Herein, pruned tea biomass refers to abandon-plucked leaves being pruned in the non-plucking period, especially in summer and autumn. At present, no relevant concluding remarks have been made on this undervalued biomass. This review summarizes the seasonal differences of intrinsic metabolites and pays special attention to the most critical bioactive and flavor compounds, including polyphenols, theanine, and caffeine. Additionally, meaningful and profound methods to transform abandon-plucked fresh tea leaves into high-value products are reviewed. In summer and autumn, tea plants accumulate much more phenols than in spring, especially epigallocatechin gallate (galloyl catechin), anthocyanins (catechin derivatives), and proanthocyanidins (polymerized catechins). Vigorous carbon metabolism induced by high light intensity and temperature in summer and autumn also accumulates carbohydrates, such as soluble sugars and cellulose. The characteristics of abandon-plucked tea leaves make them not ideal raw materials for tea, but suitable for novel tea products like beverages and food ingredients using traditional or hybrid technologies such as enzymatic transformation, microbial fermentation, formula screening, and extraction, with the abundant polyphenols in summer and autumn tea serving as prominent flavor and bioactive contributors.

Effects of adding green tea extract on the oxidative stability and shelf life of sunflower oil during storage

This study aimed to compare different concentrations effect of green tea extract (GTE) (200, 400, and 800 ppm) with TBHQ (75 ppm) in extend the shelf-life of sunflower oil (SO) and to evaluate the protective effect of GTE on the oxidation of refined SO. The sample's peroxide value (PV), acidity value (AV), anisidine value (pAV), Totox value (TV), oxidative stability, and total phenol content (TPC) were analyzed at specific intervals during 12-month at 25 °C and 60-day at 60 °C. The optimum kinetic model corresponding to the first order for PV, TV, and pAV was obtained at 25, 35, and 45 °C. SO containing GTE (800 ppm) had a similar performance to TBHQ at 25 °C and 60 °C and possessed a longer shelf life than samples treated with TBHQ. Due to synthetic antioxidant's health risk and toxicity, GTE can be a good substitute for TBHQ in the edible oil industry.

Flavor Characteristics, Antioxidant Activity and In Vitro Digestion Properties of Bread with Large-Leaf Yellow Tea Powder

Foods containing tea could be widely utilized due to the addition of good tea ingredients, especially large-leaf yellow tea, which is rich with a good flavor. Applying this change to bread containing tea would improve its product quality. In this research, large-leaf yellow tea bread (LYB), possessing a special flavor, was developed using ultrafine large-leaf yellow tea powder and flour as the main raw materials. The amount of ultrafine large-leaf yellow tea powder added to bread was optimized using texture, sensation, and specific volume as comprehensive evaluation indicators. At the optimal dosage, the free amino acids, volatile flavor compounds, antioxidant activity, and in vitro starch digestibility of LYB were measured. Response surface optimization experimental results showed that the comprehensive score of bread was highest when the added amount of ultrafine large-leaf yellow tea powder was 3%. In particular, compared to blank bread (BB), adding ultrafine large-leaf yellow tea powder into bread could effectively increase its amino acid composition, enhance its volatile flavor compounds, improve the antioxidant capacity, and reduce the digestibility of starch.

Impact of ultrasound-assisted extraction of polyphenols and caffeine from green tea leaves using high-performance thin-layer chromatography

Tea is the most popular daily drink consumed globally, with a high concentration of caffeine and polyphenols. In this study, the effects of ultrasonic-assisted extraction and quantification of caffeine and polyphenols from green tea were investigated and optimized using 23 -full factorial design and high-performance thin-layer chromatography. Three parameters were optimized to maximize the concentration of caffeine and polyphenols extracted using ultrasound: crude drug-to-solvent ratio (1:10-1:5), temperature (20-40°C), and ultrasonication time (10-30 min). The optimal conditions achieved from the model for tea extraction were as follows: crude drug-to-solvent ratio, 0.199 g/ml; temperature, 39.9°C; and time, 29.9 min; the extractive value was found to be 16.8%. Images from scanning electron microscopy showed that the matrix underwent a physical alteration and cell wall disintegration, which intensified and accelerated the extraction. This process might be simplified using sonication, which results in a higher extractive yield and a significant concentration of caffeine and polyphenols than the traditional approach, with a smaller quantity of solvent and faster analytical times. The result of high-performance thin-layer chromatography analysis proves a significant positive correlation between extractive value and caffeine and polyphenol concentrations.

Yellow tea: more than turning green leaves to yellow

Yellow tea (YT), a slightly-fermented tea originated from Ming Dynasty with distinctive "Three yellows," mild-sweet smell, and mellow taste attributed to the unique yellowing process. Based on current literature and our previous work, we aim to comprehensively illustrate the key processing procedures, characteristic chemical compounds, health benefits and applications, as well as the interlocking relationships among them. Yellowing is the most vital procedure anchored on the organoleptic quality, characteristic chemical components, and bioactivities of YT, which is influenced by temperature, moisture content, duration, and ventilation conditions. Pheophorbides, carotenoids, thearubigins and theabrownins are the major pigments contributing to the "three yellows" appearance. Alcohols, such as terpinol and nerol, are attributed to the refreshing and sweet aroma of bud and small-leaf YT, while heterocyclics and aromatics forming during roasting result in the crispy rice-like large-leaf YT. Hygrothermal effects and enzymatic reactions during yellowing result in the decline of astringent substances. Meanwhile, multiple bioactive compounds such as catechins, ellagitannins, and vitexin, endow YT with antioxidant, anti-metabolic syndrome, anti-cancer, gut microbiota regulation, and organ injury protection effects. Future studies focusing on the standard yellowing process technology, quality evaluation system, and functional factors and mechanisms, possible orientations, and perspectives are guaranteed.

Accumulation of potentially toxic elements in Chinese tea (Camellia sinensis): Towards source apportionment and health risk assessment

Tea (Camellia sinensis) is a popular beverage that is consumed globally. However, a better understanding of potentially toxic elements (PTEs) content in tea leaves and infusion is necessary to minimize risk on human health. Therefore, 249 tea samples (grown in different areas) covering six types of tea were collected in China to investigate the PTEs contents, identify their potential source and assess the health risk associated with drinking tea. PTE contents in tea leaves across six tea types were ND-0.900 (Cd), 0.005-2.133 (As), ND-5.679 (Pb), ND-13.86 (Cr), 1.601-22.93 (Ni), ND-2.048 (Se), 0.109-622.4 (F), 13.02-269.9 (Rb), 1.845-50.88 (Sr), and 2.796-53.23 (Ba) mg/kg. The result of tea infusion showed that 14.3 %-44.1 % (green tea), 14.5 %-46.7 % (black tea), 10.5 %-25.3 % (dark tea), 13.6 %-34.2 % (oolong tea), 16.9 %-40.7 % (yellow tea), and 19.9 %-35.1 % (white tea) of F were released. All tea types, except green tea, exhibited comparatively low leachability of Cd, As, Pb and Cr in tea infusion. The source apportionment revealed that PTEs in tea leaves mainly originated from soil parental materials, while industrial activities, fertilizer application, and manufacturing processes may contribute to exogenous Se, Cd, As, and Cr accumulation. Health risk assessment indicated that F in tea infusion dominated the health risk. Humans may be exposed to a higher health risk by drinking green tea compared to that of other tea types. Nevertheless, the long-term tea consumption is less likely to contribute to pronounced non-carcinogenic and carcinogenic risks. This study confirmed that tea consumption is an important and direct pathway of PTEs uptake in humans. The health risk associated with drinking tea should be of concern.

Effects of Calcium Lactate-Enriched Pumpkin on Calcium Status in Ovariectomized Rats

This study aimed to evaluate the effects of enriched pumpkin on calcium status in ovariectomized rats. The study was conducted in sixty female Wistar rats, which were divided into six groups: a group fed a standard diet (C) and five ovariectomized groups fed a standard diet (OVX_C) or a diet with calcium lactate (CaL), with calcium lactate-enriched pumpkin (P_CaL), with calcium lactate and alendronate (CaL_B), or with calcium lactate-enriched pumpkin with alendronate (P_CaL_B). After 12 weeks of the intervention, the rats were sacrificed, and their blood and tissues were collected. The calcium concentrations in serum and in tissues were measured using flame atomic absorption spectrometry (AAS). Serum concentrations of procollagen type-1 amino-terminal propeptide (PINP), parathyroid hormone PTH, estrogen (ES), and osteocalcin (OC) were determined with enzyme-linked immunosorbent assay (ELISA). It was found that enriched pumpkin increased the calcium level in the kidneys (194.13 ± 41.01 mg) compared to the C (87.88 ± 12.42 mg) and OVX_C (79.29 ± 7.66 mg) groups. The addition of alendronate increased the calcium level in the femurs (267.63 ± 23.63 mg) and more than six times in the kidneys (541.33 ± 62.91 mg) compared to the OVX_C group (234.53 ± 21.67 mg and 87.88 ± 12.42 mg, respectively). We found that the CaL, P_CaL, and CaL_B groups had significantly lower PINP serum concentrations (4.45 ± 0.82 ng/mL, 4.14 ± 0.69 ng/mL, and 3.77 ± 0.33 ng/mL) and higher PTH serum levels (3.39 ± 0.54 ng/dL, 3.38 ± 0.57 ng/dL, and 3.47 ± 0.28 ng/dL) than the OVX_C group (4.69 ± 0.82 ng/mL and 2.59 ± 0.45 ng/dL, respectively). In conclusion, pumpkin enriched with calcium lactate affects calcium status and normalizes PINP and PTH serum levels in ovariectomized rats. Diet with enriched pumpkin and alendronate increase calcium concentration in the femur. Enriched pumpkin causes calcium to accumulate in the kidneys of ovariectomized rats; alendronate significantly exacerbates this effect.

Improvement of Sourdough and Bread Qualities by Fermented Water of Asian Pears and Assam Tea Leaves with Co-Cultures of Lactiplantibacillus plantarum and Saccharomyces cerevisiae

Qualities of sourdough and sourdough bread using fermented water from Asian pears and Assam tea leaves with Lactiplantibacillus plantarum 299v and Saccharomyces cerevisiae TISTR 5059 as starter cultures were evaluated. Changes in the growth of lactic acid bacteria and yeast, pH, sourdough height, total phenolic contents (TPCs) and antioxidant activities detected by ORAC, FRAP and DPPH radical scavenging assays were monitored during sourdough production. Mature sourdough was achieved within 4 h after 18 h retard fermentation and used for bread production. The bread was then analyzed to determine chemical and physical properties, nutritional compositions, TPCs, antioxidant activities and sensory properties as well as shelf-life stability. Results showed that fermented water significantly promoted the growth of yeast and increased TPCs and antioxidant activities of sourdough. Compared to common sourdough bread, fermented water sourdough bread resulted in 10% lower sugar and 12% higher dietary fiber with improved consumer acceptability; TPCs and antioxidant activities also increased by 2–3 times. The fermented water sourdough bread maintained microbial quality within the standard range, with adequate TPCs after storage at room temperature for 7 days. Fermented water from Asian pears and Assam tea leaves with L. plantarum 299v and S. cerevisiae TISTR 5059 as starter cultures improved dough fermentation and bread quality.

Characterization of Roasting Time on Sensory Quality, Color, Taste, and Nonvolatile Compounds of Yuan An Yellow Tea

Roasting is crucial for producing Yuan An yellow tea (YAYT) as it substantially affects sensory quality. However, the effect of roasting time on YAYT flavor quality is not clear. To investigate the effect of roasting time on the sensory qualities, chemical components, odor profiles, and metabolic profile of YAYTs produced with 13 min roasting, 16 min roasting, 19 min roasting, 22 min roasting, and 25 min roasting were determined. The YAYTs roasted for 22 min got higher sensory scores and better chemical qualities, such as the content of gallocatechin (GC), gallocatechin gallate (GCG), free amino acids, solutable sugar, meanwhile the lightness decreased, the hue of tea brew color (b) increased, which meant the tea brew got darker and yellower. YAYTs roasted for 22 min also increased the contents of key odorants, such as benzaldehyde, nonanal, β-cyclocitral, linalool, nerol, α-cedrol, β-ionone, limonene, 2-methylfuran, indole, and longiborneol. Moreover, non-targeted metabolomics identified up to 14 differentially expressed metabolites through pair-wise comparisons, such as flavonoids, phenolic acids, sucrose, and critical metabolites, which were the main components corresponding to YAYT roasted for 22 min. In summary, the current results provide scientific guidance for the production of high quality YAYT.

Enhancing health benefits of bakery products using phytochemicals

There has been a growing interest in functional bakery products with enhanced health benefits, especially the prevention of some chronic diseases such as type 2 diabetes, cardiovascular diseases and neurodegenerative disorders. Fortification of wheat flour with phytochemicals, plant components with various bio-activities, is one of the promising approaches to improving public health with the ubiquitous consumption of baked goods. This chapter reviews the current knowledge of several representative phytochemicals, mainly plant polyphenols, including catechins, anthocyanins, fucoidan and quercetin extracted from various plant resources, and their application in bakery products, regarding their stability, impact on product quality and potential health benefits.

The Effect of In Vitro Digestion on Matcha Tea (Camellia sinensis) Active Components and Antioxidant Activity

This study investigates the effects of in vitro digestion on the antioxidant activity and release of phenolics, xanthine alkaloids, and L-theanine contents of matcha. It establishes digestibility values between 61.2–65.8%. Considering native matcha, the rutin content (303–479 µg/g) reached higher values than catechin (10.2–23.1 µg/g). Chlorogenic acid (2090–2460 µg/g) was determined as predominant. Rutin, quercetin, ferulic, ellagic, and caffeic acid were the least-released phenolics, and their remaining residues reached 76–84%. Protocatechuic, hydroxybenzoic acid, epigallocatechin, and epigallocatechin-3-gallate were the best-released phenolics, with the remaining residues under 1%. Caffeine, L-theanine, and theobromine contents in native matcha reached 16.1, 9.85, and 0.27 mg/g, respectively. Only caffeine (3.66–5.26 mg/g) and L-theanine (0.09–0.15 mg/g) were monitored in the undigested residue, representing 13 and 0.1% of the remaining part, respectively. A chemiluminescence assay showed that water-soluble antioxidants showed significant antioxidant activity in native matcha, while lipid-soluble compounds showed higher antioxidant activity in the undigested samples. Cinnamic and neochlorogenic acids were determined as the main contributors to the ACW values in the undigested matcha, epicatechin, and quercetin in the ACL fraction. The application of the digestion process reduced the antioxidant activity by more than 94%. SEM has proved specific digestion patterns of in vitro digestibility of matcha.

Impact of Bioactive Compounds of Plant Leaf Powders in White Chocolate Production: Changes in Antioxidant Properties during the Technological Processes

Bioactive compounds present in the powdered leaves of matcha green tea (Camellia sinensis L.) (MGTP) and moringa (Moringa oleifera) (MOLP) seem to be related to health benefits due to their antioxidant properties. The growing accessibility of these powders has led to their being more widely used in food production. The aim of this study was to evaluate the total phenolic content (TPC) and antioxidant capacity (AC) of white chocolate (WCh) supplemented with MGTP and MOLP. AC was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric ion-reducing antioxidant capacity (CUPRAC), and ferric-reducing antioxidant power (FRAP) assays, whereas TPC was determined by the Folin–Ciocalteu (FC) method. Both additives were incorporated at four levels (1, 2, 3 and 4%) in two chocolate processing steps (conching and tempering). Additionally, the amounts of phenolic acids, tocopherols, and carotenoids in WCh samples enriched by MGTP and MOLP were determined to explain their influence on AC. The results showed that the chocolates supplemented with MGTP were characterized by higher antioxidant properties than those with MOLP. In turn, MOLP significantly increased the content of lipophilic antioxidants in chocolates, tocopherols and carotenoids, which also exhibit pro-health effects. Furthermore, the incorporation of these additives during the tempering process was more relevant to the improvement of the antioxidant properties of WCh.

Innovative Application of Chicken Eggshell Calcium to Improve the Functional Value of Gingerbread

Food waste, such as eggshell, can be an environmental problem if it is not properly managed. One of the ways to solve this is by using the eggshell as the cheap calcium source in food products. Polish gingerbread fortified with chicken eggshell powder (ESP) calcium was developed to solve the eggshell waste problem and to reduce the risk of osteoporosis. This study focused on the effect of ESP addition on basic composition, sensory evaluation, and antioxidative activity of gingerbread. Two samples of gingerbread without and with 3% (w/w of wheat flour) ESP, with controlled green tea powder (4% w/w of white chocolate) were analyzed. Results of the research showed that the addition of 3% ESP significantly increased the ash and calcium content (p < 0.05) without changing the appearance, aroma, texture, taste profiles, and the hedonic score of gingerbread. The gingerbread samples were then stored for 2 months and were analyzed every month. The hedonic evaluation of the aroma of both gingerbread samples decreased significantly (p < 0.05) during storage. During 2 months of storage, the antioxidative activity of gingerbread fortified with 3% ESP was not significantly different compared to the control (p > 0.05), particularly in ABTS and ORACFL assay. The ABTS, DPPH, and ORACFL assays showed decreasing antioxidative activity during storage, which was also in accordance with decreasing total phenolic content of both gingerbread samples. In PCL assay, the lipid-soluble antioxidant activity in gingerbread with 3% ESP was significantly higher during 2 months of storage, compared to the control (p < 0.05). The developed product might be a potential alternative to improve the calcium (26% daily value (DV) recommendation per 100 g) and antioxidant intake in order to prevent calcium deficiency. Gingerbread enriched with an organic source of calcium may become an innovative product to reduce the risk of developing osteoporosis in the elderly population, having potential health and economic significance, given the incidence of osteoporosis and the costs of treating this disease.

Temperature Optimization by Electrochemical Method for Improving Antioxidant Compound Extraction Efficiency from Origanum vulgare L. and Its Application in a Bread Production

This study aims to evaluate the effect of extraction temperature on the electrochemical activity of antioxidant compounds in oregano extract and its application in a bread production. Temperature optimisation was performed by determining the electrochemical index (EI), calculated on the parameters of individual peaks observed on the square wave voltammograms (SWV). The highest value of EI (2.5758 µA/V) was observed at 85 °C for the oregano extract. The composition of several types of bread with oregano extract or dried oregano leaves was then proposed. To specify bread samples, both newly prepared and during their storage, their antioxidant properties were determined using FRAP (Ferric Reducing Antioxidant Power) and CUPRAC (Cupric Reducing Antioxidant Capacity) methods. The study revealed that the addition of extract from oregano or oregano leaves increased the antioxidant compounds content in the bread from 30% to more than 138% compared to the control bread samples. The performed sensory evaluation of the bread samples revealed their high acceptability. It was found that the stored bread with oregano leaves changed sensory qualities to a lesser extent compared to the bread with oregano extract.

Antioxidant Activity, Probiotic Survivability, and Sensory Properties of a Phenolic-Rich Pulse Snack Bar Enriched with Lactiplantibacillus plantarum

Pulse-based snack bars incorporated with probiotics were developed to provide an overview for the preparation of simple functional food concerning the antioxidant load and iron status improvement. The study focused on the application of microencapsulated probiotics in dry matrices, such as chickpeas and green lentils, in snack bars. The study aims to analyse the products’ antioxidative activities, chemical and sensory properties, as well as the probiotic survivability in the dry matrices. The basic chemical composition showed that 100 g of product can fulfil up to 4.4% and 3.3% of the daily iron value from chickpeas and green lentils, respectively (assuming the iron bioavailability is 23%). Sensory evaluation and hedonic analysis of the fresh pulse snack bar showed that panelists preferred the chickpea snack bar over the green lentil snack bar. For storage analysis, snack bars were stored at 20 °C and were vacuum packaged in sealed low density polyethylene (LDPE) pouches with no light exposure for two months. Hedonic analysis during storage showed significant differences in the aroma of the snack bars (p < 0.05). Generally, the antioxidant activities decreased during the two months of storage. A strong correlation was observed between total phenolic content (TPC) and antioxidant activity assays: ORAC (Oxygen Radical Absorbance Capacity), DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), PCL (Photochemiluminescence,). Moreover, after two months of storage, a 1-log decrease of probiotic viable cells was observed in both snack bars. To meet the dietary requirement of probiotics, it is suggested that people consume five portions and 9.4 portions of the chickpea and green lentil snack bars, respectively. The resulting products have promising properties with respect to probiotics and antioxidant potential in an unconventional way.

Polyphenol content, color and acceptability of carrot pickles added with yerba mate powder extract

Abstract Yerba mate (Ilex paraguariensis Saint Hilaire) processing generates large amounts of powder that are not added to the final product. This powder has a similar composition to commercial yerba mate and it can be used to extract bioactive compounds. The work aims to prepare carrot pickles added with yerba mate powder extract to improve the Total Phenol Content (TPC) of the final product. The TPC and the color of the pickles were studied in the carrots and the liquid brine for a total of 120 days, by testing two storage temperatures (25 and 45 °C). The TPC was determined by the Folin-Ciocalteu method, and color parameters L*, a*, and b* were measured using a colorimeter. In addition, a sensory acceptability analysis was performed at the end of storage. Pickled carrots without extract addition showed significant losses of polyphenols during storage. The addition of increasing amounts of yerba mate powder extract significantly improved this parameter, thus achieving TPCs even higher than those of fresh carrots. The pasteurization, the addition of extract, and storage caused variations in the color of both fractions of the pickle, especially in the formulations with a higher proportion of yerba mate. However, the color changes were more important in the liquid brine, while in the carrots the variations were minimal. Sensory acceptability tests showed that the addition of extract did not influence the flavor of the pickles but caused changes in color acceptability. However, the product was accepted by consumers. The results showed that yerba mate powder extract can be added in small amounts into other foods for improving their TPC while causing minor modifications in color and sensory acceptability.

Analytical procedures for determination of phenolics active herbal ingredients in fortified functional foods: an overview

Fortification of foods with phenolic compounds is becoming increasingly popular due to their beneficial physiological effects. The biological activities reported include antioxidant, anticancer, antidiabetic, anti-inflammatory, or neuroprotective effects. However, the analysis of polyphenols in functional food matrices is a difficult task because of the complexity of the matrix. The main challenge is that polyphenols can interact with other food components, such as carbohydrates, proteins, or lipids. The chemical reactions that occur during the baking technologies in the bakery and biscuit industry may also affect the results of measurements. The analysis of polyphenols found in fortified foods can be done by several techniques, such as liquid chromatography (HPLC and UPLC), gas chromatography (GC), or spectrophotometry (TPC, DPPH, FRAP assay etc.). This paper aims to review the available information on analytical methods to fortified foodstuffs while as presenting the advantages and limitations of each technique.

Non-Traditional Muesli Mixtures Supplemented by Edible Flowers: Analysis of Nutritional Composition, Phenolic acids, Flavonoids and Anthocyanins

In this study, the effect of using medicinal plants on nutrition composition and biologically active substances in cereal mixtures were investigated. In order to develop new type of non-traditional muesli mixtures supplemented with edible flowers, eight muesli mixtures were prepared applying the mixing ratio of 60‒70% of non-traditional flakes and 30‒40% of lyophilized fruits and edible flowers. This study examines nutritional composition, digestibility, fibres and phenolics of nutraceutical muesli mixtures using enzymatic-gravimetric and chromatographic methods. It shows that the mixture of kamut, einkorn, red and black quinoa or rice flakes together with hibiscus, mallow, rose, fruits has increased the fibre content (11.9‒21.2%) and in vitro digestibility (87.8‒93.8%). The greatest concentrations of individual phenolic contents were determined in free and soluble bound fractions of the mixtures. Cyanidin-3-glucoside (up to 116 mg/kg) and delphinidin-3-glucoside (up to 76.9 mg/kg) were established as major anthocyanins. Considering the individual phenolic fractions, sinapic and protocatechuic acids were the most abundant phenolic acids and quercetin and epigallocatechin represented the most frequent flavonoids. These results indicate that non-traditional muesli with edible flowers containing a high amount of nutrients and bioactive substances have the potential to enhance a nutritionally balanced diet.

Differential Effects of Green Tea Powders on the Protection of Brown Tsaiya and Kaiya Ducklings against Trichothecene T-2 Toxin Toxicity

Simple Summary

The objective of this study is to examine the effects of T-2 toxin (T-2) and green tea powders (GTP) on growth performance, hematology, and pathology parameters in Brown Tsaiya ducklings (BTDs) and Kaiya ducklings (KDs). T-2 toxin shows a strong and differential toxicity in growth suppression, as well as abnormalities in the hematological and pathological parameters of BTDs and KDs. We found that GTP could potentially prevent T-2-induced poor growth performance and improve some hematological parameters. Moreover, BTDs were more sensitive than KDs in terms of responses to T-2 toxicity and GTP detoxification.

Abstract

A 3-week feeding trial in a 3 × 2 × 2 factorial design was conducted with three concentrations (0, 0.5, and 5 mg/kg) of T-2 toxin (T-2) and two levels (0% and 0.5%) of green tea powder (GTP) supplements used in the diets of female brown Tsaiya ducklings (BTDs) and Kaiya ducklings (KDs), respectively. Breed had a significant effect on the growth performances and the relative weights of organs and carcass. In general, the growth performances of KDs were better than BTDs. The relative weights of organs and carcass of BTDs were typically heavier than those of KDs; however, the breast of KDs was heavier than those of BTDs. Both ducklings received 5 mg/kg of T-2 blended in the diet showed lower feed intake and body weight gain (BWG) in the second and the third week. The diet containing 5 mg/kg of T-2 and 0.5% GTP improved the BWG compared to those fed the diet supplemented with 5 mg/kg of T-2 without GTP in BTDs. Ducklings fed the diet containing 5 mg/kg of T-2 induced hypocalcemia and hypomagnesemia, as well as decreased concentrations of creatine phosphokinase and alkaline phosphatase. The concentrations of blood urea nitrogen (BUN) and glutamate oxaloacetate transaminase (GOT) were increased in KDs and BTDs fed the diet containing 5 mg/kg of T-2 without GTP, respectively. However, duckling diets containing 5 mg/kg of T-2 with 0.5% GTP lowered concentrations of BUN and GOT in the blood plasma of KDs and BTDs, respectively. The diet containing 5 mg/kg of T-2 increased the relative kidney weight but decreased the relative breast weight of ducklings. Enlarged gizzards and reduced relative leg weights were observed in BTDs fed the diets containing 5 mg/kg of T-2. In summary, BTDs are more sensitive than KDs in responding to T-2 toxicity and GTP detoxification. Green tea powder has detoxification ability and could potentially mitigate T-2 toxicity on BWG, BUN, and GOT in ducklings.

The Changes in Antioxidant Activity of Selected Flavonoids and Caffeine Depending on the Dosage and Form of Thiamine

Phenolic compounds and thiamine may serve as therapies against oxidative stress-related neurodegenerative diseases. However, it is important to note that these components show high instability under changing conditions. The study’s aim was to determine the impact of the thiamine concentration (hydrochloride—TH and pyrophosphate—TP; in the range 0.02 to 20 mg/100 g on the indices of the chelating properties and reducing power, and free radicals scavenging indices of EGCG, EGC, ECG and caffeine added from 0.04 to 6.0 mg/100 g. Our research confirmed that higher concentrations of TH and TP can exhibit significant activity against the test antioxidant indices of all components. When above 5.0 mg/100 g of thiamine was used, the radical scavenging abilities of the compound decreased in the following order: EGCG > ECG > EGC > caffeine. The highest correlation was found for the concentration of thiamine pyrophosphate to 20.0 mg/100 g and EGCG. Knowledge of the impact of factors associated with the concentration of both EGCG, EGC, ECG or caffeine and thiamine on their activity could carry weight in regulating the quality supplemented foods, especially of nutrition support for people of all ages were oral, enteral tube feeding and parenteral nutrition).

The Effect of Yellow Tea Leaves Camellia sinensis on the Quality of Stored Chocolate Confectionery

Chocolate and tea leaves are considered the most valuable sources of highly bioactive polyphenols due to their potential anti-cancer properties and beneficial effects on the cardiovascular and nervous systems. The objective of the present study was the development of a sensory profiling modality that is correlated with the taste of the chocolate enriched with yellow tea phytochemicals. The additive concentration was optimized in white chocolate and the designed product was evaluated using the sensory profiling method. It was shown that the yellow tea extract in chocolate had a significant effect on the taste and color of the product. Addition of 2.0% yellow tea powdered extract increased the value of color acceptance and caused an intensification of the aromas, particularly the leafy taste, compared to the control samples. The next step of the study was to determine the influence of tea addition in white, milk and dark chocolate subjected to 6 months of storage. The designed chocolates were tested for their activity as antioxidants (DPPH, ABTS and ORAC assay) and cholinesterase inhibitors (AChE, BChE assay). It was confirmed that the yellow tea addition affected the activity of prepared chocolates with respect to radical scavenging activity and was highest for dark chocolate with yellow tea where the values were as follows: 4373 mg Tx/100 g (DPPH), 386 mg Tx/100 g (ABTS) and 4363 µM Tx/100 g (ORAC). An increase in the anti-radical activity of chocolate with yellow tea was found after 3 months of storage, but the subsequent 3 months of storage resulted in its reduction. AChE values ranged from 0.118 to 0.730 [µM eserine/g dw] and from 0.095 to 0.480 [µM eserine/g dw] for BChE assay. Total capacity to inhibit AChE and BChE differed depending on the type of chocolate and was negatively influenced by the half-year storage. Summarizing tested values for individual samples were higher, with increasing content of cocoa liquor and yellow tea extract in the product. The results of the research show that the use of yellow tea in confectionery is promising and may appoint a new direction in functional foods.

Opportunities and challenges for the nanodelivery of green tea catechins in functional foods

Green tea, the least processed tea product, is scientifically known for its rich antioxidant content originating from polyphenols, especially catechins. The most potent green tea catechin is epigallocatechin-3-gallate (EGCG), which is responsible for a wide range of health benefits including anticancer, antidiabetics, and anti-inflammatory properties. However, green tea catechins (GTCs) are very labile under both environmental and gastrointestinal conditions; their chemical stability and bioavailability primarily depend on the processing and formulation conditions. Nanocarriers can protect GTCs against such conditions, and consequently, can be applicable for designing nanodelivery systems suitable for GTCs. In this review, the latest findings about both opportunities and limitations for the nanodelivery of GTCs and their incorporation into various functional food products are discussed. The scientific findings so far confirm that nanodelivery of GTCs can be an efficient approach towards the enhancement of their health-promoting effects with a minimal dose, controlled and targeted release, lessening the dose-related toxicity, and the efficient incorporation into functional foods. However, further investigation is yet needed to fully explain the cellular mechanisms of action of GTCs on human health and to elucidate the effect of encapsulation on their bioefficacy using well-designed, systematic, long-term, and large-scale clinical interventions. There also exists a substantial concern regarding the safety of the manufactured nanoparticles, their absorption, and the associated release mechanisms.

Ultrasound irradiation alters the spatial structure and improves the antioxidant activity of the yellow tea polysaccharide

In this study, the impact of ultrasound irradiation on the structural characteristics and antioxidant properties of yellow tea polysaccharides with different molecular weights (Mw) were investigated. Native yellow tea polysaccharide containing YTPS-3N, YTPS-5N and YTPS-7N were prepared through precipitation with ethanol at various concentrations of 30%, 50%, and 70%, respectively, and irradiated with high intensity ultrasound (20 kHz) for 55 min to yield yellow tea polysaccharide including YTPS-3U, YTPS-5U and YTPS-7U. The molecular weight (Mw) of YTPS-3N (from 37.7 to 15.1 kDa) and YTPS-5N (from 14.6 to 5.2 kDa) sharply decreased upon ultrasound irradiation, coincidentally particle size (Zavg) was also significantly reduced for YTPS-3N (40%), YTPS-5N (48%) and YTPS-7N (54%). The high-performance liquid chromatography and Fourier transform-infrared spectroscopy analysis revealed a partial degradation of native yellow tea polysaccharide treated with ultrasound, though the monosaccharide composition was not altered. Furthermore, changes in morphology and the breakdown of native yellow tea polysaccharide upon irradiation was confirmed with the circular dichroism spectrum, atomic force and scanning electron microscopy. As a consequence, irradiation of yellow tea polysaccharide increased free radical scavenging activity with YTPS-7U exhibiting the highest levels of 2, 2-diphenyl-1-picrylhydrazyl free radical, superoxide and hydroxyl radicals scavenging activity. These results suggest that the alteration of the spatial structure of yellow tea polysaccharide can enhance its antioxidant activity which is an important property for functional foods or medicines.

Flavonoid glycosides from the nectar of Camellia reticulata Lindl

The nectar of Camellia reticulata Lindl. contains sugar, amino acids and other nutritional components, suggesting that it could be developed for food and food additives. To understand the effects of the nectar on human health, we investigated its chemical constituents. Two new flavonoid glycosides, cameretiins A and B (1 and 2), and two known flavonoid glycosides, kaempferol 3-O-(2''-O-E-p-coumaroyl)-β-D-glucopyranoside (3) and tiliroside (4) were obtained from the nectar of Camellia reticulata Lindl. Their structures were determined based on analysis of their spectroscopic data and by comparison with 1D NMR spectroscopic data of known compounds reported in the literature. Compounds (1-4) were first isolated from the nectar of Camellia reticulata Lindl.

Analysis of taste characteristics and identification of key chemical components of fifteen Chinese yellow tea samples

In order to explore the taste characteristics and molecular sensory basis of Chinese yellow tea, in this study, quantitative descriptive analysis (QDA) and partial least squares regression (PLSR) were used to analyze the sensory characteristics and chemical components of 15 yellow tea samples from different regions of China. The results showed that: 11 sensory descriptors and their definitions were obtained by QDA, namely, sweet, umami, bitter, sour, astringent, sweet after taste, mellow, neutral, after-taste, thick and tainted taste. The results of variance indicated that there were significant variation in taste sub-attributes of different samples (p <0.05). Principal component analysis indicated that there was a positive correlation between bitter and astringent, between sweet, umami and sour, and between mellow, thick, after-taste and neutral. All yellow tea samples were divided into four categories according to cluster analysis. The results of PLSR showed that there were 22 chemical components that had an important contribution to the taste characteristics of yellow tea, and the chemical components that had an important influence on each taste component were obtained. The identification of key contribution components of taste characteristics in yellow teas will provide a theoretical basis for further research on the directional adjustment and control of tea taste quality.

Comparative Evaluation of the Inhibitory Potential of Synthetic N-Heterocycles, Cu/Fe3O4@SiO2 Nanocomposites and Some Natural Products against Non-Resistant and Antibiotic-Resistant Acinetobacter baumannii

Background: Acinetobacter baumannii is a common infectious agent in hospitals. New antimicrobial agents are identified and prepared to combat these bacterial pathogens. In this context, the blocking potentials of a series of synthesized N-heterocyclic compounds, Cu/Fe3O4@SiO2 nanocomposites, glycine, poly-L-lysine, nisin and hydroalcoholic extracts of Trachyspermum ammi, Curcuma longa and green tea catechins were evaluated against non-resistant and multidrug-resistant strains of A. baumannii. Methods: Solutions of heterocyclic derivatives and hydroalcoholic extracts of Trachyspermum ammi, Curcuma longa and green tea catechins were prepared at initial concentration of 10240 μg ml-1 in 10% DMSO. Other compounds were dissolved in water at the same concentrations. Their in vitro inhibitory activity was assessed by determination of IZD, MIC and MBC values. Results: Glycine, poly-L-lysine, nisin, Curcuma longa and green tea catechins extracts, and thiazoles 3a, 3d and 3f were ineffective at their initial concentrations. Heterocyclic derivatives 7a-f, 3c, 3e and 3h, Cu/Fe3O4@SiO2 nanocomposites and Trachyspermum ammi extract could block the growth of bacterial strains with IZDs (7.40-15.51 mm), MICs (32-1024 µg ml-1) and MBCs (128-2048 µg ml-1). Conclusion: Among synthetic chemicals and natural products, the best antimicrobial effects were recorded with (E)-2-(5-acetyl-4-methylthiazol-2-yl)-2-(thiazolidin-2-ylidene)acetonitrile (7b) and the extract of Trachyspermum ammi. It is imperative that their toxic and histopathologic effects were assessed in future researches. It is predicted that the essential oil of Trachyspermum ammi will improve its antibacterial activities.

Risk assessment of fluoride daily intake from preference beverage

Background/purpose

Tea, coffee and alcohol beverages are called preference beverage and are drunk habitual and in large quantities. Therefore, there is a high possibility that a health risk is caused by the contained components, and risk assessment of intake is essential. However, the risk assessment of fluoride intake from preference beverages has not been sufficiently performed.

Materials and methods

This study estimated the daily fluoride intake from preference beverages by measuring the fluoride concentration of infusion liquid and measuring the total fluoride content by the microdiffusion method. In addition, Hazard Quotient (HQ) was calculated for children and adults to assess the risk of fluoride intake.

Results

As a result of this study, tea was the highest in all sample species, the infusion of tea was 1.06-6.68 mg/L and the total fluoride content of tea was 47.05-291.98 mg/kg. Green tea showed the next highest value, 0.26-4.09 mg/L, 21.91-83.68 mg/kg. Herbal tea fluoride levels were 0.07-0.17 mg/L and 0.05-1.90 mg/kg, Unique tea was 0.03-0.60 mg/L and 0.03-32.37 mg/kg, Coffee was 0.03-0.15 mg/L and 0.04-0.64 mg/kg.

Conclusion

The HQ values calculated from the average daily fluoride intake (DFI) of preference beverages were all within the safe range. Some products made from Camellia sinensis, such as tea and green tea, had 1.66 mg/day as DFI at maximum, and the Child's HQ exceeded 1. These results suggest that habitual consumption of some products requires risk management of dental fluorosis.

Effect of fortification with calcium from eggshells on bioavailability, quality, and rheological characteristics of traditional Polish bread spread

Hen eggshells are a rich and natural source of calcium and can serve as a biofunctional food ingredient. Enriching the traditional Polish bread spread (sersmażony) with micronized eggshell is an attractive proposition for consumers who require easily available calcium. The present study aimed to evaluate the use of micronized eggshells as a source of bioavailable calcium in bread spread. The study evaluated the effect of selected biocomponents on calcium bioavailability by using an in vitro digestion model. The enrichment of bread spread with eggshell, lysine, vitamin D₃, and vitamin K enhanced all examined physicochemical variables except water activity. Enrichment with eggshells increased calcium levels >2.5-fold compared with the control sample. As an ingredient of bread spread, lysine is an important rheological factor. The bioavailability of calcium was higher in samples with lysine and vitamin K compared with samples that contained eggshell alone.

Black Chokeberry Fruit Polyphenols: A Valuable Addition to Reduce Lipid Oxidation of Muffins Containing Xylitol

The study aimed at assessing effects of black chokeberry polyphenol extract (ChPE) added (0.025-0.075%) to xylitol-containing muffins to reduce lipid oxidation, especially in preventing degradation of hydroperoxides throughout the storage period. Among polyphenolic compounds (3092 mg/100 g in total) in ChPE, polymeric procyanidins were the most abundant (1564 mg/100 g). ChPE addition resulted in a significantly increased capacity of scavenging free radicals and markedly inhibited hydroperoxides decomposition, as reflected by low anisidine values (AnV: 3.25-7.52) throughout the storage. On the other hand, sucrose-containing muffins had increased amounts of primary lipid oxidation products and differed significantly from other samples in conjugated diene hydroperoxides (CD values), which was in accordance with the decrease of C18:2 9c12c in those muffins after storage. In addition, sucrose-containing muffins were found to be those with the highest level of contamination with toxic carbonyl lipid oxidation products. Throughout the storage, no yeast or moulds contamination were found in higher enriched muffins. The incorporation of polyphenols to xylitol-containing muffins resulted in preventing decomposition of polyunsaturated fatty acids (PUFAs), and in reducing the content of some toxic aldehydes. ChPE could be regarded as a possible solution to xylitol-containing muffins to extend their shelf life. The results support the use of xylitol in muffin manufacture as being favourable in terms of suitability for diabetics.

The Effect of Thiamine Concentration on the Antioxidative Activity Indices in Tea Extracts

The aim of the study was to determine correlations between the concentration of thiamine in systems and indicators of the antioxidative activity of ethanol tea extracts in the presence of soybean oil. Variability of the thiamine form was assumed by comparison of the influence of thiamine hydrochloride or thiamine pyrophosphate and fermentation of ethanol tea extracts. The study provides practical knowledge about the antioxidative activity of ethanol tea extracts in products containing fat and thiamine. The study showed that all tea extracts exhibited higher antioxidative activity in the presence of thiamine amounts of 0.1 and 0.8 mg/100 g. The antioxidative activity of ethanol tea extracts was significantly reduced when the concentrations were higher than the natural level for foods (over 1.0 mg/100 g). The systems containing white tea extract were the most vulnerable, whereas those with black tea were the least vulnerable. The presence of thiamine pyrophosphate in the system was more strongly correlated with reduced activity of the extracts than the presence of thiamine hydrochloride.

Partial rpoB Gene Sequencing Identification and Probiotic Potential of Floricoccus penangensis ML061-4 Isolated from Assam Tea (Camellia sinensis var. assamica)

Assam tea or Miang is a local name of Camellia sinensis var. assamica in northern Thailand. By the local wisdom, Assam tea leaves are used as the raw material in tea fermentation to produce “Fermented Miang” consumed by people in northern Thailand and the countries nearby. In this study, twenty-eight bacterial isolates were obtained from Assam tea leaf samples collected from Nan province, Thailand. Bacterial isolates were identified within 6 genera including Bacillus, Floricoccus, Kocuria, Lysinibacillus, Micrococcus and Staphylococcus. Among these, the strain ML061-4 shared 100.0 and 99.4% similarity of 16S rRNA and rpoB gene sequence with F. penangensis JCM 31735^T, respectively. This is the first discovery of F. penangensis in Thailand. F. penangensis ML061-4 exhibited probiotic characteristics including lactic acid production (9.19 ± 0.10 mg/ml), antibacterial activities (Escherichia coli ATCC 25922 and E. coli O157:H7 DMST 12743), acid and bile salt tolerance (71.1 and 54.9%, respectively), autoaggregation (97.0%), coaggregation (66.0% with E. coli O157:H7), cell surface hydrophobicity (90.0%), bacterial adhesion (82.9% with Lactobacillus plantarum FM03-1), competitive inhibition (17.8% with E. coli O157:H7) and competitive exclusion (34.9% with E. coli O157:H7). Overall, the data suggested that F. penangensis ML061-4 had a great potential to be a probiotic.

Citric acid-enhanced dissolution of polyphenols during soaking of different teas

This study examined the dissolution kinetics and antioxidant activity of tea polyphenols during the soaking of white, yellow, green, oolong, black, and dark teas. All these teas were, respectively, soaked with either freshly boiled distilled water (DW) or 10 mmol/L citric acid-water solution. The residue obtained from one extraction was used for the next extraction and this process was performed consecutively 10 times, soaking for 30 s each time. UHPLC-QqQ-MS measurement identified epigallocatechin gallate as the major polyphenol in white, yellow, green, oolong, and black tea infusions. As soaking times increased, the polyphenol concentrations rose initially and then dropped. Antioxidant activity was noted to decrease as soaking times increased in all tea infusions except for the DW-soaked oolong and dark teas. These findings suggested that citric acid could increase the polyphenol content in tea infusions. Specifically, the cumulative contents of epigallocatechin gallate was noted to increase 2.1-5.1 times. PRACTICAL APPLICATIONS: After water, tea is one of the most consumed beverages in the world. Drinking tea has been linked to the reduced risk of various diseases, including cancer, cardiovascular system disease, obesity, and neurodegenerative diseases, largely due to its rich polyphenol content. Moreover, the addition of citrus to a tea infusion provides an interesting and feasible method for increasing the dissolution of tea polyphenols, a finding that offers extensive potential for applications in the development of compound tea drinks.

Synthesis and characterization of a (+)-catechin and L-(+)-ascorbic acid cocrystal as a new functional ingredient for tea drinks

Tea (Camellia Sinensis) is one of the most popular drink, consumed as infusion or bottled ready to drink beverages. Although tea leaves contain many antioxidants compounds, after processing they can drastically decrease, sometimes up to a full degradation, as in the case of catechin, a very healthy flavan-3-ol. In this context, the synthesis of a cocrystal between (+)-catechin and L-(+)-ascorbic acid, was proved to be a useful strategy to make a new ingredient able to ameliorate the antioxidant profile of both infusions and bottled teas. The obtained cocrystal showed a three-fold higher solubility than (+)catechin and its formation was elucidated unambiguously by FT-IR, thermal (DSC) and diffraction (PXRD) analyses. Antioxidant characteristics of the samples were evaluated by colorimetric assays. As expected, infusions showed much better antioxidant features than ready-to-use lemon and peach teas. The same trend was confirmed after the addition of the cocrystal at two concentration levels. In particular, supplementation at concentration of 2 mg mL-1 improved the bottled tea antioxidant values to the level showed by the not-added infusion tea.

The Chemical Composition and Nutritional Value of Chia Seeds-Current State of Knowledge

Chia (Salvia hispanica) is an annual herbaceous plant, the seeds of which were consumed already thousands of years ago. Current research results indicate a high nutritive value for chia seeds and confirm their extensive health-promoting properties. Research indicates that components of chia seeds are ascribed a beneficial effect on the improvement of the blood lipid profile, through their hypotensive, hypoglycaemic, antimicrobial and immunostimulatory effects. This article provides a review of the most important information concerning the potential application of chia seeds in food production. The chemical composition of chia seeds is presented and the effect of their consumption on human health is discussed. Technological properties of chia seeds are shown and current legal regulations concerning their potential use in the food industry are presented.

Oxidative stability of lipid fractions of sponge-fat cakes after green tea extracts application

Oxidative stability of lipid fractions extracted from sponge-fat cakes enriched with green tea extracts and synthetic antioxidant (BHA) directly after baking and after 28 days of storage was investigated. This was achieved by the determination of peroxide (PV), p-anisidine (p-AnV) and acid values (AV), and using Rancimat test or differential scanning calorimetry method, respectively. The results showed that the lipid fractions extracted from sponge-fat cakes containing the addition of BHA (0.02%) and green tea extract at concentrations of 1% exhibited a greater resistance to oxidation than those from cakes without additives. AV values were the lowest for lipids extracted from sponge-fat cakes enriched with 1% green tea extract up to the end of storage. The incorporation of BHA and green tea extract (1%) into cakes caused a gradual increase of PV and p-AnV values during 21 days of sample storage. The values of these parameters increased significantly for samples without any additives, especially in regard to PV. What is more, thermal analysis showed that samples enriched with 1% green tea extract and with BHA were characterized by higher onset temperature (tON), activation energy, and induction time (τ) than samples without any additives, especially during 21 days of storage. The increase of green tea extract concentration to 1% in cookies reduced L* (from 63.85 to 51.15) and b* (from 34.64 to 29.11) values, while a* value showed an increase from 8.43 to 11.17.

Effect of yellowing time on bioactive compounds in yellow tea and their antiproliferative capacity in HepG2 cells

Several studies have shown potent antineoplastic effects of tea, which can induce apoptosis and inhibit proliferation of cancer cells. Yellow tea is one of the six major types of tea, and yellowing time, a key factor in its processing, is known to improve its quality and bioactivity. However, the effects of yellowing on the composition of the bioactive substances of tea are poorly understood. We analyzed the biochemical composition and the antioxidant and anticancer activities of the extracts of yellow tea (EYTs) subjected to different yellowing durations. Prolonged yellowing increased the content of water extracts, amino acids, soluble sugars, theaflavins, and nonesterified catechins (p < 0.05, p < 0.01) and decreased that of polyphenols, flavonols, thearubigins, caffeine, GA, and esterified catechins (p < 0.05, p < 0.01). In addition, yellowing also slightly increased the antioxidant capacity of the EYTs, but did not significantly affect their ability to inhibit the proliferation of the hepatocarcinoma HepG2 cells. Mechanistically, the EYTs significantly downregulated the phosphorylation of PI3K and AKT and upregulated the Bax/Bcl-2 ratio in the HepG2 cells. Taken together, the yellowing time influences the bioactive components of yellow tea, and the resulting yellow tea may have more potent antioxidant and anticancer effects.