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24 pages, 2267 KiB  
Review
Evaluating Bioactive-Substance-Based Interventions for Adults with MASLD: Results from a Systematic Scoping Review
by Deepa Handu, Kim Stote and Tami Piemonte
Nutrients 2025, 17(3), 453; https://doi.org/10.3390/nu17030453 - 26 Jan 2025
Cited by 3 | Viewed by 2085
Abstract
Objective: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a chronic condition affecting a broad population. This review aimed to identify and summarize the current evidence on bioactive-substance-based interventions for adults with MASLD, formerly known as nonalcoholic fatty liver disease (NAFLD), covering publications [...] Read more.
Objective: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a chronic condition affecting a broad population. This review aimed to identify and summarize the current evidence on bioactive-substance-based interventions for adults with MASLD, formerly known as nonalcoholic fatty liver disease (NAFLD), covering publications from 2000 to 2023. Methods: A search was conducted across six databases (MEDLINE, CINAHL, Cochrane CENTRAL, Cochrane Database of Systematic Reviews, Food Science Source, and SPORTDiscus) for randomized controlled trials and other study types (e.g., prospective cohort studies and systematic reviews), reflecting the scoping nature of this review. The search was limited to studies in adults (>18 years old), with an intervention of interest and at least one comparator group. Results: A total of 4572 articles were retrieved, with 201 full-text articles screened for eligibility. Of these, 131 primary studies and 49 systematic reviews were included in the scoping review. The most studied bioactive substances were Curcumin (Turmeric) (n = 25), Silymarin (Milk Thistle) (n = 17), Resveratrol (n = 10), Coffee (n = 7), Green Tea (n = 5), and Berberine (n = 5 each). Moreover, 46 studies reported on 36 other bioactive substances with 2 or fewer articles each. Among the included systematic reviews, 13 focused on Curcumin, 12 on Coffee or Tea, 10 on bioactive substance combinations, 6 on Resveratrol, and 2 each on Silymarin and Artichoke Leaf. The included studies showed substantial heterogeneity in reported outcomes, which primarily focused on hepatic health, body weight, adverse events, glycemic control, blood lipids, and body composition. Conclusions: This scoping review highlights a range of bioactive substances used in the treatment of MASLD. While evidence is abundant for bioactive substances like Curcumin and Silymarin, further research and synthesis of findings is necessary to establish the clinical efficacy of all bioactive substances. Full article
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30 pages, 8489 KiB  
Article
Volatilome, Microbial, and Sensory Profiles of Coffee Leaf and Coffee Leaf-Toasted Maté Kombuchas
by Amanda Luísa Sales, Sara C. Cunha, Isabel M.P.L.V.O. Ferreira, Jéssika Morgado, Lauro Melo, Juliana DePaula, Marco Antonio L. Miguel and Adriana Farah
Foods 2024, 13(3), 484; https://doi.org/10.3390/foods13030484 - 2 Feb 2024
Cited by 7 | Viewed by 3083
Abstract
Kombucha is a fermented beverage traditionally made from the leaves of Camelia sinensis. The market has drastically expanded recently, and the beverage has become more elaborated with new, healthy food materials and flavors. Pruning and harvesting during coffee production may generate tons [...] Read more.
Kombucha is a fermented beverage traditionally made from the leaves of Camelia sinensis. The market has drastically expanded recently, and the beverage has become more elaborated with new, healthy food materials and flavors. Pruning and harvesting during coffee production may generate tons of coffee leaves that are discarded although they contain substantial amounts of bioactive compounds, including those found in maté tea and coffee seeds. This study characterized the changes in volatilome, microbial, and sensory profiles of pure and blended arabica coffee leaf tea kombuchas between 3–9 days of fermentation. Acceptance was also evaluated by consumers from Rio de Janeiro (n = 103). Kombuchas (K) were prepared using black tea kombucha starter (BTKS) (10%), sucrose (10%), a symbiotic culture of Bacteria and Yeasts (SCOBY) (2.5%), and a pure coffee leaf infusion (CL) or a 50:50 blend with toasted maté infusion (CL-TM) at 2.5%. The RATA test was chosen for sensory profile characterization. One hundred volatile organic compounds were identified when all infusions and kombucha samples were considered. The potential impact compounds identified in CL K and CL-TM K were: methyl salicylate, benzaldehyde, hexanal, nonanal, pentadecanal, phenylethyl-alcohol, cedrol, 3,5-octadien-2-one, β-damascenone, α-ionone, β-ionone, acetic acid, caproic acid, octanoic acid, nonanoic acid, decanoic acid, isovaleric acid, linalool, (S)-dihydroactinidiolide, isoamyl alcohol, ethyl hexanoate, and geranyl acetone. Aroma and flavor descriptors with higher intensities in CL K included fruity, peach, sweet, and herbal, while CL-TM K included additional toasted mate notes. The highest mean acceptance score was given to CL-TM K and CL K on day 3 (6.6 and 6.4, respectively, on a nine-point scale). Arabica coffee leaf can be a co-product with similar fingerprinting to maté and black tea, which can be explored for the elaboration of potentially healthy fermented beverages in food industries. Full article
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2 pages, 161 KiB  
Abstract
Sensorial and Aroma Profiles of Coffee By-Products—Coffee Leaves and Coffee Flowers
by Marina Rigling, Marc C. Steger, Dirk W. Lachenmeier, Steffen Schwarz and Yanyan Zhang
Proceedings 2023, 89(1), 5; https://doi.org/10.3390/ICC2023-14837 - 14 Aug 2023
Cited by 1 | Viewed by 1076
Abstract
The utilization of coffee leaves and flowers has been underestimated over the years. Both by-products can be obtained from coffee trees without adversely affecting the production of coffee beans. To gain fundamental knowledge of their sensorial and aroma profiles, it becomes essential to [...] Read more.
The utilization of coffee leaves and flowers has been underestimated over the years. Both by-products can be obtained from coffee trees without adversely affecting the production of coffee beans. To gain fundamental knowledge of their sensorial and aroma profiles, it becomes essential to reintroduce them into the food chain. Accordingly, 24 different coffee leaf samples generated from diverse processing as well as 38 varied species of coffee flowers were analyzed for their sensory characteristics by descriptive analysis and liking tests, and their corresponding aroma profiles were decoded by means of gas chromatography–mass spectrometry–olfactometry. For the coffee leaves, a wide range of different flavors could be detected in the sensory evaluation. The fermented coffee leaf samples clearly showed more sweetish and fruity aroma notes compared to the intense green and vegetable aroma of the non-fermented samples. β-Ionone (honey-like), decanal (citrus-like, floral), α-ionone (floral), octanal (fruity), and hexanal (green) were identified as key volatile compounds but distributed in different ratios. In the predominant coffee flowers, hay-like, hop-like, sage-like, dried apricot-like, and honey-like impressions were identified as major aroma descriptors in addition to a basic floral note. 2-Heptanol (fruity), 2-ethylhexanol (green), nerol (floral), and geraniol (floral) were identified as representative aroma compounds. All in all, a great variety of flavors was detected from the coffee leaves and flowers, which will not only provide an insight into the potential applications for the food market (i.e., coffee leaf tea and coffee flower tea) but will also help make coffee growing more sustainable. Full article
(This article belongs to the Proceedings of International Coffee Convention 2023)
7 pages, 222 KiB  
Proceeding Paper
Validation of an HPLC Method for the Determination of Epigallocatechin Gallate, Caffeine and Chlorogenic Acid in Coffee Leaves
by Aaron Münch and Dirk W. Lachenmeier
Biol. Life Sci. Forum 2022, 18(1), 13; https://doi.org/10.3390/Foods2022-13012 - 30 Sep 2022
Viewed by 1730
Abstract
An existing reference HPLC method (ISO 14502-2) was applied and validated for the matrix of coffee leaves (genus Coffea), which can be used to prepare a tea-like infusion. This method is usually used to measure conventional Camellia sinensis teas with high-performance liquid [...] Read more.
An existing reference HPLC method (ISO 14502-2) was applied and validated for the matrix of coffee leaves (genus Coffea), which can be used to prepare a tea-like infusion. This method is usually used to measure conventional Camellia sinensis teas with high-performance liquid chromatography (HPLC). For the purposes of method validation, robustness, applicability, measurement precision and linearity were investigated. The focus was kept on the ingredients epigallocatechin gallate (EGCG), caffeine and chlorogenic acid. It was possible to determine a high level of robustness, applicability and measurement precision of this method through the measurement of caffeine and chlorogenic acid in authentic sample matrices. The repeatability standard deviation of caffeine was lower than 0.09 g/100 g, and that of chlorogenic acid was lower than 0.08 g/100 g. The repeatability coefficient of variation (CV) of caffeine ranged between 0.93% and 4.52%, and that of chlorogenic acid was between 1.20% and 21.10%. The reproducibility standard deviation of caffeine was lower than 0.03 g/100 g, and that of chlorogenic acid was lower than 0.03 g/100 g. The reproducibility CV of caffeine was between 0.68% and 2.92%, and that of chlorogenic acid was between 0.91% and 5.36%. These results show a high level of robustness and measurement precision in each case. However, the used samples were unsuitable for determining the robustness, applicability and measurement precision of EGCG because its amount in coffee leaves was too low or even undetectable. A detection limit (LOD) for EGCG in coffee leaf of 0.02 g/100 g, and a quantification limit (LOQ) of 0.04 g/100 g were determined. Overall, this method was judged as suitable for the regulatory analysis of coffee leaves. Full article
15 pages, 4699 KiB  
Article
Brewer’s Spent Grain Biochar: Grinding Method Matters
by Arvind K. Bhakta, Youssef Snoussi, Mohamed El Garah, Souad Ammar and Mohamed M. Chehimi
C 2022, 8(3), 46; https://doi.org/10.3390/c8030046 - 15 Sep 2022
Cited by 11 | Viewed by 5112
Abstract
The present work is based on the principle of biomass waste valorization. Brewer’s spent grains (BSG) come from breweries as by-products. Their huge amount of production on an industrial scale should focus our attention on their valorization, which creates challenges as well as [...] Read more.
The present work is based on the principle of biomass waste valorization. Brewer’s spent grains (BSG) come from breweries as by-products. Their huge amount of production on an industrial scale should focus our attention on their valorization, which creates challenges as well as opportunities. One way to valorize BSG by-products is to convert them into biochar, a functional material with multiple potential applications. With an emphasis on sustainable development and the circular economy, in this work, we focused on a comparative study of the different mechanical processes of BSG grinding and their effect on the resulting biochar formed after pyrolysis. Home appliances such as blenders, coffee mills, and mortar and pestles were used for this purpose. FESEM images confirmed the successful creation of five different morphologies from the same BSG under the same pyrolysis conditions. Interestingly, a novel Chinese tea leaf egg-like biochar was also formed. It was found that a series of physical pretreatments of the biomass resulted in the reduced roughness of the biochar surface, i.e., they became smoother, thus negatively affecting the quality of the biochar. XRD revealed that the biomass physical treatments were also reflected in the crystallinity of some biochar. Via a Raman study, we witnessed the effect of mechanical pressure on the biomass for affecting the biochar features through pressure-induced modifications of the biomass’s internal structure. This induced enhanced biochar graphitization. This is a good example of the role of mechanochemistry. DSC revealed the thermochemical transformation of the five samples to be exothermic reactions. This study opens up an interesting possibility for the synthesis of biochar with controlled morphology, crystallinity, degree of graphitization, and heat capacity. Full article
(This article belongs to the Special Issue Advanced Carbon Based Nanomaterials)
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34 pages, 9953 KiB  
Article
Coffee Leaf Tea from El Salvador: On-Site Production Considering Influences of Processing on Chemical Composition
by Marc C. Steger, Marina Rigling, Patrik Blumenthal, Valerie Segatz, Andrès Quintanilla-Belucci, Julia M. Beisel, Jörg Rieke-Zapp, Steffen Schwarz, Dirk W. Lachenmeier and Yanyan Zhang
Foods 2022, 11(17), 2553; https://doi.org/10.3390/foods11172553 - 23 Aug 2022
Cited by 14 | Viewed by 6274
Abstract
The production of coffee leaf tea (Coffea arabica) in El Salvador and the influences of processing steps on non-volatile compounds and volatile aroma-active compounds were investigated. The tea was produced according to the process steps of conventional tea (Camellia sinensis [...] Read more.
The production of coffee leaf tea (Coffea arabica) in El Salvador and the influences of processing steps on non-volatile compounds and volatile aroma-active compounds were investigated. The tea was produced according to the process steps of conventional tea (Camellia sinensis) with the available possibilities on the farm. Influencing factors were the leaf type (old, young, yellow, shoots), processing (blending, cutting, rolling, freezing, steaming), drying (sun drying, oven drying, roasting) and fermentation (wild, yeast, Lactobacillus). Subsequently, the samples were analysed for the maximum levels of caffeine, chlorogenic acid, and epigallocatechin gallate permitted by the European Commission. The caffeine content ranged between 0.37–1.33 g/100 g dry mass (DM), the chlorogenic acid was between not detectable and 9.35 g/100 g DM and epigallocatechin gallate could not be detected at all. Furthermore, water content, essential oil, ash content, total polyphenols, total catechins, organic acids, and trigonelline were determined. Gas chromatography—mass spectrometry—olfactometry and calculation of the odour activity values (OAVs) were carried out to determine the main aroma-active compounds, which are β-ionone (honey-like, OAV 132-927), decanal (citrus-like, floral, OAV 14-301), α-ionone (floral, OAV 30-100), (E,Z)-2,6-nonadienal (cucumber-like, OAV 18-256), 2,4-nonadienal (melon-like, OAV 2-18), octanal (fruity, OAV 7-23), (E)-2 nonenal (citrus-like, OAV 1-11), hexanal (grassy, OAV 1-10), and 4-heptenal (green, OAV 1-9). The data obtained in this study may help to adjust process parameters directly to consumer preferences and allow coffee farmers to earn an extra income from this by-product. Full article
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9 pages, 274 KiB  
Article
Morpho-Physiological Traits, Phytochemical Composition, and Antioxidant Activity of Canephora Coffee Leaves at Various Stages
by Yudithia Maxiselly, Pisamai Anusornwanit, Adirek Rugkong, Rawee Chiarawipa and Pin Chanjula
Int. J. Plant Biol. 2022, 13(2), 106-114; https://doi.org/10.3390/ijpb13020011 - 23 May 2022
Cited by 17 | Viewed by 3816
Abstract
Coffee leaves contain a wide range of leaf compounds, which vary by growth stage. Recently, the importance of coffee leaf metabolites with beneficial phytochemicals has been widely identified. This research investigated Canephora coffee’s morphological and physiological development and analyzed the phytochemical composition of [...] Read more.
Coffee leaves contain a wide range of leaf compounds, which vary by growth stage. Recently, the importance of coffee leaf metabolites with beneficial phytochemicals has been widely identified. This research investigated Canephora coffee’s morphological and physiological development and analyzed the phytochemical composition of the main leaf stage. Canephora coffee leaves were harvested and classified into the following five growth stages: S1 (leaf age of 1–4 days), S2 (leaf age of 5–8 days), S3 (leaf age of 9–14 days), S4 (leaf age of 15–20 days), and S5 (leaf age of 21–27 days). The antioxidant activity, total phenol content, flavonoids, and tannin content of coffee leaves at different stages were observed. The results indicated that the highest values for the leaf area, dry weight, greenness, chlorophyll content, and carotenoid content were found at the last stage (S5). The specific leaf area (SLA) differences had higher values in the S3 and S1 growth stages. The youngest leaf phase (S1) was less green, more yellow, and brighter in color than the mature phase. By comparing the assays, it was found that a significant increase in the antioxidant activity and the contents of phenolic compounds, flavonoids, and tannins were observed in the S1 and S2 growth stages. Full article
20 pages, 7890 KiB  
Review
Risk Assessment of Caffeine and Epigallocatechin Gallate in Coffee Leaf Tea
by Nadine Tritsch, Marc C. Steger, Valerie Segatz, Patrik Blumenthal, Marina Rigling, Steffen Schwarz, Yanyan Zhang, Heike Franke and Dirk W. Lachenmeier
Foods 2022, 11(3), 263; https://doi.org/10.3390/foods11030263 - 19 Jan 2022
Cited by 18 | Viewed by 7312
Abstract
Coffee leaf tea is prepared as an infusion of dried leaves of Coffea spp. in hot water. It is a traditional beverage in some coffee-producing countries and has been authorized in 2020 within the European Union (EU) according to its novel food regulation. [...] Read more.
Coffee leaf tea is prepared as an infusion of dried leaves of Coffea spp. in hot water. It is a traditional beverage in some coffee-producing countries and has been authorized in 2020 within the European Union (EU) according to its novel food regulation. This article reviews current knowledge on the safety of coffee leaf tea. From the various ingredients contained in coffee leaves, only two were highlighted as possibly hazardous to human health, namely, caffeine and epigallocatechin gallate (EGCG), with maximum limits implemented in EU legislation, which is why this article focuses on these two substances. While the caffeine content is comparable to that of roasted coffee beans and subject to strong fluctuations in relation to the age of the leaves, climate, coffee species, and variety, a maximum of 1–3 cups per day may be recommended. The EGCG content is typically absent or below the intake of 800 mg/day classified as hepatotoxic by the European Food Safety Authority (EFSA), so this compound is suggested as toxicologically uncritical. Depending on selection and processing (age of the leaves, drying, fermentation, roasting, etc.), coffee leaf tea may exhibit a wide variety of flavors, and its full potential is currently almost unexplored. As a coffee by-product, it is certainly interesting to increase the income of coffee farmers. Our review has shown that coffee leaf tea is not assumed to exhibit risks for the consumer, apart from the well-known risk of caffeine inherent to all coffee-related beverages. This conclusion is corroborated by the history of its safe use in several countries around the world. Full article
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10 pages, 278 KiB  
Proceeding Paper
An Update on Sustainable Valorization of Coffee By-Products as Novel Foods within the European Union
by Dirk W. Lachenmeier, Tabata Rajcic de Rezende and Steffen Schwarz
Biol. Life Sci. Forum 2021, 6(1), 37; https://doi.org/10.3390/Foods2021-10969 - 14 Oct 2021
Cited by 16 | Viewed by 3598
Abstract
The coffee plant Coffea spp. offers much more than the well-known drink made from the roasted coffee bean. During its cultivation and production, a wide variety of by-products are accrued, most of which are currently unused, thermally recycled, or used as animal feed. [...] Read more.
The coffee plant Coffea spp. offers much more than the well-known drink made from the roasted coffee bean. During its cultivation and production, a wide variety of by-products are accrued, most of which are currently unused, thermally recycled, or used as animal feed. The modern, ecologically oriented society attaches great importance to waste reduction, so it makes sense to not dispose of the by-products of coffee production but to bring them into the value chain. The aim of this presentation is to provide an updated overview of novel coffee products in the food sector and their current legal classification in the European Union (EU). Coffee flowers, leaves, cascara, coffee cherry spirit, silver skin, and coffee wood are among the materials considered in this article. Some of these products may have, at least, an indirect history of consumption in Europe (silver skin), while others have already been used as traditional foods in non-EU-member countries (coffee leaves, flowers, cascara, and coffee cherry spirit). Of these, coffee leaf tea and cascara have already been approved by the European Commission. Following a consultation with EU member states, spent coffee grounds were determined as being not novel. For the other products, toxicity and/or safety data need to be gathered to further advance novel food applications. Full article
4 pages, 986 KiB  
Proceeding Paper
Evaluation of Analytical Methods to Determine Regulatory Compliance of Coffee Leaf Tea
by Valerie Segatz, Marc C. Steger, Patrik Blumenthal, Vera Gottstein, Marina Rigling, Steffen Schwarz, Yanyan Zhang and Dirk W. Lachenmeier
Biol. Life Sci. Forum 2021, 6(1), 45; https://doi.org/10.3390/Foods2021-10937 - 13 Oct 2021
Cited by 4 | Viewed by 1848
Abstract
The leaves of the coffee plant Coffea are traditionally used in several countries worldwide to prepare tea-like beverages using aqueous infusion in hot water. There are currently no tested methods available to check the regulatory compliance of coffee leaf tea according to the [...] Read more.
The leaves of the coffee plant Coffea are traditionally used in several countries worldwide to prepare tea-like beverages using aqueous infusion in hot water. There are currently no tested methods available to check the regulatory compliance of coffee leaf tea according to the European Union (EU) novel food authorization. This study shows that standard ISO methods for tea analysis could be transferred without modifications to coffee leaf tea analysis. The only difference found was a much lower content of some catechins in coffee leaf tea compared to Camellia sinensis tea, but the methods were clearly applicable for use in controlling the EU’s maximum limits for coffee leaf tea. Full article
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17 pages, 4625 KiB  
Article
The Nutrient Status of Plant Roots Reveals Competition Intensities in Rubber Agroforestry Systems
by Junen Wu, Huanhuan Zeng, Fan Zhao, Chunfeng Chen, Xiaojin Jiang, Xiai Zhu, Pingyuan Wang, Zhixiang Wu and Wenjie Liu
Forests 2020, 11(11), 1163; https://doi.org/10.3390/f11111163 - 31 Oct 2020
Cited by 13 | Viewed by 3890
Abstract
Controversial competition theories may confuse the current understanding of belowground plant competition and thus result in incorrect diagnoses and mitigation strategies for nutrient competition. As such, the management of nutrient competition is a major challenge in the application and development of rubber agroforestry [...] Read more.
Controversial competition theories may confuse the current understanding of belowground plant competition and thus result in incorrect diagnoses and mitigation strategies for nutrient competition. As such, the management of nutrient competition is a major challenge in the application and development of rubber agroforestry systems (AFSs). To explore the effects of plant competition on the nutrient status of rubber AFSs, this study measured the carbon, nitrogen, and phosphorus concentrations of the litter and soil and in plant leaves, stems, and roots from five rubber plantations (i.e., rubber monocultures and rubber mixed with cocoa, coffee, tea, and Flemingia macrophylla (Willd.) Merr., 1910)). The relative competition intensity indexes were calculated to evaluate the competition intensity of each mixed-species system, and Bayesian networks were established to investigate the linkage effects of interspecific competition for nutrients. This study demonstrated that rubber trees had weak competition with cocoa trees, moderate competition with F. macrophylla and tea trees, and intense competition with coffee trees. With the increase in competition intensity, the negative effects of interspecific competition on soil gradually offset the improvement in soil nutrients achieved with intercropping. Nitrogen and phosphorous translocation from the stems to the roots was enhanced by competition. However, enhanced nutrient allocation to roots may have led to insufficient nitrogen and phosphorous supplies in plant leaves. The quality of the litter therefore decreased because the nutrient status of fallen leaves determines the initial litter conditions. Such consequences may reduce the release of nutrients from the litter to the soil and thus increase soil nutrient depletion. This study revealed that competition effects were most obvious for the root nutrient status, followed by the stem and leaf nutrient statuses. Moreover, this study further demonstrated that the nutrient concentration of plant roots can better indicate the intensity of nutrient competition than the nutrient concentration of other plant organs. Full article
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18 pages, 704 KiB  
Article
Phytochemical Profile and Antioxidant Capacity of Coffee Plant Organs Compared to Green and Roasted Coffee Beans
by Robert Acidri, Yumiko Sawai, Yuko Sugimoto, Takuo Handa, Daisuke Sasagawa, Tsugiyaki Masunaga, Sadahiro Yamamoto and Eiji Nishihara
Antioxidants 2020, 9(2), 93; https://doi.org/10.3390/antiox9020093 - 22 Jan 2020
Cited by 82 | Viewed by 9771
Abstract
The current study investigates the phytochemical composition of coffee plant organs and their corresponding antioxidant capacities compared to green and roasted coffee beans. HPLC analysis indicated that the investigated compounds were present in all organs except mangiferin, which was absent in roots, stems [...] Read more.
The current study investigates the phytochemical composition of coffee plant organs and their corresponding antioxidant capacities compared to green and roasted coffee beans. HPLC analysis indicated that the investigated compounds were present in all organs except mangiferin, which was absent in roots, stems and seeds, and caffeine, which was absent in stems and roots. Total phytochemicals were highest in the green beans (GB) at 9.70 mg g−1 dry weight (DW), while roasting caused a 66% decline in the roasted beans (RB). This decline resulted more from 5–CQA and sucrose decomposition by 68% and 97%, respectively, while caffeine and trigonelline were not significantly thermally affected. Roasting increased the total phenolic content (TPC) by 20.8% which was associated with an increase of 68.8%, 47.5% and 13.4% in the antioxidant capacity (TEAC) determined by 2,2–diphenyl–1–picryl hydrazyl radical (DPPH), 2,2–azino bis (3–ethyl benzothiazoline–6–sulphonic acid) radical (ABTS) and Ferric ion reducing antioxidant power (FRAP) assays, respectively. Amongst the leaves, the youngest (L1) contained the highest content at 8.23 mg g−1 DW, which gradually reduced with leaf age to 5.57 mg g−1 DW in the oldest (L6). Leaves also contained the highest TPC (over 60 mg g−1 GAE) and exhibited high TEAC, the latter being highest in L1 at 328.0, 345.7 and 1097.4, and least in L6 at 304.6, 294.5 and 755.1 µmol Trolox g−1 sample for the respective assays. Phytochemical accumulation, TPC and TEAC were least in woody stem (WS) at 1.42 mg g−1 DW; 8.7 mg g−1 GAE; 21.9, 24.9 and 110.0 µmol Trolox g−1 sample; while herbaceous stem (HS) contained up to 4.37 mg g−1 DW; 27.8 mg g−1 GAE; 110.9, 124.8 and 469.7 µmol Trolox g−1 sample, respectively. Roots contained up to 1.85 mg g−1 DW, 15.8 mg−1 GAE and TEAC of 36.8, 41.5 and 156.7 µmol Trolox g−1 sample. Amongst the organs, therefore, coffee leaves possessed higher values than roasted beans on the basis of phytochemicals, TPC and TEAC. Leaves also contain carotenoids and chlorophylls pigments with potent health benefits. With appropriate processing methods, a beverage prepared from leaves (coffee leaf tea) could be a rich source of phytochemicals and antioxidants with therapeutic and pharmacological values for human health. Full article
(This article belongs to the Special Issue Phenolic Profiling and Antioxidant Capacity in Plants)
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16 pages, 524 KiB  
Article
Dietary Antioxidants in Coffee Leaves: Impact of Botanical Origin and Maturity on Chlorogenic Acids and Xanthones
by Ângelo Monteiro, Silvia Colomban, Helena G. Azinheira, Leonor Guerra-Guimarães, Maria Do Céu Silva, Luciano Navarini and Marina Resmini
Antioxidants 2020, 9(1), 6; https://doi.org/10.3390/antiox9010006 - 20 Dec 2019
Cited by 48 | Viewed by 5120
Abstract
Natural polyphenols are important dietary antioxidants that significantly benefit human health. Coffee and tea have been shown to largely contribute to the dietary intake of these antioxidants in several populations. More recently, the use of coffee leaves to produce tea has become a [...] Read more.
Natural polyphenols are important dietary antioxidants that significantly benefit human health. Coffee and tea have been shown to largely contribute to the dietary intake of these antioxidants in several populations. More recently, the use of coffee leaves to produce tea has become a potential commercial target, therefore prompting studies on the quantification of polyphenols in coffee leaves. In this study a variety of coffee leaf species, at different development stages, were analyzed using ultra-high pressure liquid chromatography. The results demonstrate that both the botanical origin of the samples and their maturity influence significantly the concentration of the antioxidants; for total chlorogenic acids a two-fold difference was found between different species and up to a three-fold variation was observed between young and mature leaves. Furthermore, the range of concentrations of chlorogenic acids in young leaves (35.7–80.8 mg/g of dry matter) were found to be comparable to the one reported for green coffee beans. The results provide important data from which potential new commercial products can be developed. Full article
(This article belongs to the Section Natural and Synthetic Antioxidants)
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13 pages, 3134 KiB  
Article
Determination of Phenolic Compounds, Procyanidins, and Antioxidant Activity in Processed Coffea arabica L. Leaves
by Samuchaya Ngamsuk, Tzou-Chi Huang and Jue-Liang Hsu
Foods 2019, 8(9), 389; https://doi.org/10.3390/foods8090389 - 4 Sep 2019
Cited by 78 | Viewed by 7281
Abstract
The effects of dry processing and maturity on antioxidant activity, total phenolic content, total procyanidins, and identity of phenolic compounds in coffee leaves were evaluated. Fresh coffee leaves were tray-dried at 40 °C for 8 h before total phenolic content, total procyanidins, and [...] Read more.
The effects of dry processing and maturity on antioxidant activity, total phenolic content, total procyanidins, and identity of phenolic compounds in coffee leaves were evaluated. Fresh coffee leaves were tray-dried at 40 °C for 8 h before total phenolic content, total procyanidins, and antioxidant activity were analyzed. The drying process significantly (p < 0.05) improved the release of total phenolic content and total procyanidins compared with the fresh leaves. The results showed that the young leaves exposed to drying processes had the highest total phenolic content, total procyanidins, and DPPH radical scavenging activity. Therefore, the effect of different drying temperatures (30, 40, and 50 °C) in the young leaves were further analyzed. The results indicated that DPPH radical scavenging activity, total phenolic content, and total procyanidins were increasingly generated when exposed to an increase in drying temperatures, whereby the highest bioactivity was evident at 50 °C. The DPPH radical scavenging activity of the coffee leaf teas was significantly correlated with total phenolic content and total procyanidins. Identification of Coffea arabica L. bioactive compounds by LC-MS showed the presence of catechin or epicatechin, mangiferin or isomangiferin, procyanidin B, caffeoylquinic acids (CQA), caffeine, quercetin-3-O-glucoside, procyanidin C, rutin, and 3,4-diCQA. Coffea arabica L. leaf tea was confirmed to be a potential functional food rich in phenolic compounds with strong antioxidant activity. Full article
(This article belongs to the Section Food Nutrition)
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9 pages, 483 KiB  
Article
Evaluation of Caffeine Consumption among Pregnant Women from Southern Poland
by Ewa Błaszczyk-Bębenek, Beata Piórecka, Monika Kopytko, Zuzanna Chadzińska, Paweł Jagielski and Małgorzata Schlegel-Zawadzka
Int. J. Environ. Res. Public Health 2018, 15(11), 2373; https://doi.org/10.3390/ijerph15112373 - 26 Oct 2018
Cited by 16 | Viewed by 4963
Abstract
Caffeine is the most widely consumed stimulant worldwide, including by pregnant women. Products containing caffeine should be limited in accordance with the recommendations for pregnancy. The purpose of this study was to evaluate consumption of caffeinated products and daily caffeine intake from food [...] Read more.
Caffeine is the most widely consumed stimulant worldwide, including by pregnant women. Products containing caffeine should be limited in accordance with the recommendations for pregnancy. The purpose of this study was to evaluate consumption of caffeinated products and daily caffeine intake from food by pregnant women. The study was conducted on a group of healthy pregnant women: attendees of antenatal classes (n = 70) and patients of an outpatient gynecological clinic (n = 70) from Krakow (Southern Poland). A questionnaire about the frequency of consumption of selected foods and drinks containing caffeine was used. The average caffeine content in food products obtained from other Polish studies was used to estimate average daily caffeine intake in our study group. Mean daily caffeine intake was 49.60 ± 59.15 mg/day and the maximum was 498.0 mg/day. The main sources of caffeine were as follows: black tea (bags, leaf), instant coffee and ground coffee. No statistically significant differences in caffeine intake between the groups were found. A weak negative correlation (rs) = −0.28 (p = 0.0208) between month of pregnancy and caffeine intake was observed among attendees of antenatal classes. Mean daily caffeine intake did not exceed the maximum recommended dose in our study group. Full article
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