Desenvolvimento de um aditivo natural à base de catequina: otimização da extração e estabilização a partir de frutos de Arbutus unedo L.

Mestrado com dupla diplomação com a Universidade Tecnológica Federal do ParanáThe common Mediterranean ornamental strawberry-tree (Arbutus unedo L.) produces an edible reddish sweet berry that is found to be bland and tasteless unless it is consumed overripe, otherwise it is discarded or used as basic agricultural sub residue. The bioactive properties of this fruit have been reported and related with phenolic compounds, mainly flavan-3-ols, such as catechin and procyanidins, which has opened the opportunity to exploit their extraction from alternative sources.The common Mediterranean ornamental strawberry-tree (Arbutus unedo L.) produces an edible reddish sweet berry that is found to be bland and tasteless unless it is consumed overripe, otherwise it is discarded or used as basic agricultural sub residue. The bioactive properties of this fruit have been reported and related with phenolic compounds, mainly flavan-3-ols, such as catechin and procyanidins, which has opened the opportunity to exploit their extraction from alternative sources. This study compares and optimizes the maceration, microwave and ultrasound extraction techniques in the recovery of a catechin extract from Arbutus unedo L. fruits and evaluate the stability of flavan-3-ols during storage and application processes. To obtain conditions that maximize the catechin extraction yield, a response surface methodology was used. Maceration and microwave extractions were found to be the most effective methods, capable of yielding 1.38±0.1 and 1.70±0.3 mg of catechin/g dry weight (dw) in the corresponding optimal extraction conditions. The optimal conditions for maceration were 93.2±3.7 min, 79.6±5.2 ºC and 23.1±3.7 % of ethanol, while for the microwave extraction were 42.2±4.1 min, 137.1±8.1 ºC and 12.1±1.1 % of ethanol. The microwave system was a quicker solution, conducting to slightly higher yields of catechin than maceration, but this one needed lower temperatures to reach similar yields. The ultrasound method was the least effective solution in terms of catechin yield extraction (0.71±0.1 mg/g at 42.4±3.6 min, 314.9±21.2 W and 40.3±3.8 %. ethanol). The stability was tested with of the catechin-enriched extract (60% flavan-3-ols and 22% catechin), obtained under the best maceration conditions, was tested. Therefore, catechin-enriched extracts were submitted to physical and chemical stability studies, considering the main affecting variables (time, temperature and pH): i) a stability study of the extracts during storage as powder system; and ii) a stability study of the extracts in simulated food environment (aqueous solution system). The measured responses were the flavan-3-ols and catechin contents, determined by HPLC-DAD, and the antioxidant activity of the extracts evaluated by hydrophilic assays. Mechanistic and phenomenological equations were used to describe the responses, and the optimal conditions for flavan-3-ols (including catechin) stability as powder extract during a month were pH= 5.4 and T= -20ºC; while its stability in aqueous solution remained during the 24 h of application at pH<4 and T<30ºC. This study compares and optimizes the maceration, microwave and ultrasound extraction techniques in the recovery of a catechin extract from Arbutus unedo L. fruits and evaluate the stability of flavan-3-ols during storage and application processes. To obtain conditions that maximize the catechin extraction yield, a response surface methodology was used. Maceration and microwave extractions were found to be the most effective methods, capable of yielding 1.38±0.1 and 1.70±0.3 mg of catechin/g dry weight (dw) in the corresponding optimal extraction conditions. The optimal conditions for maceration were 93.2±3.7 min, 79.6±5.2 ºC and 23.1±3.7 % of ethanol, while for the microwave extraction were 42.2±4.1 min, 137.1±8.1 ºC and 12.1±1.1 % of ethanol. The microwave system was a quicker solution, conducting to slightly higher yields of catechin than maceration, but this one needed lower temperatures to reach similar yields. The ultrasound method was the least effective solution in terms of catechin yield extraction (0.71±0.1 mg/g at 42.4±3.6 min, 314.9±21.2 W and 40.3±3.8 %. ethanol). The stability was tested with of the catechin-enriched extract (60% flavan-3-ols and 22% catechin), obtained under the best maceration conditions, was tested. Therefore, catechin-enriched extracts were submitted to physical and chemical stability studies, considering the main affecting variables (time, temperature and pH): i) a stability study of the extracts during storage as powder system; and ii) a stability study of the extracts in simulated food environment (aqueous solution system). The measured responses were the flavan-3-ols and catechin contents, determined by HPLC-DAD, and the antioxidant activity of the extracts evaluated by hydrophilic assays. Mechanistic and phenomenological equations were used to describe the responses, and the optimal conditions for flavan-3-ols (including catechin) stability as powder extract during a month were pH= 5.4 and T= -20ºC; while its stability in aqueous solution remained during the 24 h of application at pH<4 and T<30ºC.O medronho (Arbutus unedo L.) é uma árvore ornamental comum no Mediterrâneo que produz frutos comestíveis avermelhados e doces quando maduros. As propriedades bioativas destes frutos têm sido descritas e relacionadas com a sua composição em compostos fenólicos, principalmente flavan-3-óis, tais como catequinas e procianidinas, o que torna interessante explorar esta matriz como fonte alternativa para extrair estes compostos. O presente estudo visou otimizar as técnicas de extração de catequina a partir de frutos de A. unedo por maceração, micro-ondas e ultrassons e avaliar a estabilidade desses compostos durante os processos de armazenagem e aplicação, simulando uma matriz alimentar. Para obter as condições de maximização do rendimento da extração de catequina, utilizou-se uma metodologia de superfície de resposta. As técnicas de extração por maceração e micro-ondas foram consideradas mais eficazes, capazes de produzir 1,38±0,1 e 1,70±0,3 mg de catequina/g matéria seca (ms), respetivamente, nas condições ótimas de extração. Essas condições foram para a maceração 93,2±3,7 min, 79,6±5,2 ºC e 23,1±3,7 % de etanol, enquanto para o micro-ondas foram 42,2±4,1 min, 137,1±8,1 ºC e 12,1±1,1 % de etanol. O sistema de extração por micro-ondas ofereceu uma resposta ótima mais rápida e com rendimentos de extração de catequina ligeiramente mais elevados do que os da maceração, mas esta necessitou de temperaturas mais baixas para atingir rendimentos de extração semelhantes. O método de extração por ultrassons foi menos eficaz em termos de rendimento de extração de catequina (0,71±0,1 mg/g em 42,4±3,6 min, 314,9±21,2 W e 40,3±3,8 % de etanol). Foi também testada a estabilidade do extrato enriquecido em catequina (60% flavan-3-óis e 22% de catequina), obtido nas melhores condições de maceração. Assim, os extratos enriquecidos em catequina foram submetidos a estudos de estabilidade química e física, considerando as principais variáveis que afetam os compostos (tempo, temperatura e pH): i) um estudo de estabilidade dos extratos durante o armazenamento do sistema em pó; e ii) um estudo de estabilidade dos extratos em ambiente que simula um alimento (sistema de solução aquosa). Os resultados foram determinados pelo conteúdo de flavan-3-óis e catequina, utilizando HPLC-DAD, e pela atividade antioxidante dos extratos avaliada por ensaios hidrofílicos. Utilizaram-se equações mecanicistas e fenomenológicas para descrever as condições ideais para garantir a XII estabilidade de flavan-3-óis (incluindo catequina). As condições de estabilidade adequadas para o extrato em pó durante um mês foram: pH=5,4 e T=-20ºC; enquanto a sua estabilidade em solução aquosa permaneceu durante as 24h de aplicação a um pH <4 e T <30ºC. Estes resultados fornecem informações úteis para: i) potencial utilização industrial dos frutos de A. unedo como fontes alternativas de flavan-3-óis e ii) cálculos de vida de prateleira e previsões de perda de catequina em condições específicas de temperatura e pH. Finalmente, os resultados obtidos estão de acordo com estudos de estabilidade de catequina em sistemas em pó ou em solução realizados anteriormente por outros autores, mas o presente estudo valida uma nova fonte alternativa: frutos de A. unedo

Could fruits be a reliable source of food colorants? Pros and cons of these natural additives

Color additives are important for the food industry to improve sensory quality lost during food process and to expand the variety of products. In general, artificial colorants have lower cost and better stability than the natural ones. Nevertheless, studies have reported their association with some health disorders. Furthermore, consumers have given greater attention to food products with health beneficial effects, which has provided a new perspective for the use of natural colorants. In this context, fruits are an excellent alternative source of natural compounds, that allow the obtainment of a wide range of colorant molecules, such as anthocyanins, betalains, carotenoids, and chlorophylls. Furthermore, in addition to their coloring ability, they comprise different bioactive properties. However, the extraction and application of natural colorants from fruits is still a challenge, since these compounds show some stability problems, in addition to issues related to the sustainability of raw-materials providing. To overcome these limitations, several studies have reported optimized extraction and stabilization procedures. In this review, the major pigments found in fruits and their extraction and stabilization techniques for uses as food additives will be looked over.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013), L. Barros contract. To: The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020); L. Barros thanks the national funding by FCT, P.I., through the institutional scientific employment program-contract.info:eu-repo/semantics/publishedVersio

Anthocyanin-rich extract of jabuticaba epicarp as a natural colorant: Optimization of heat- and ultrasound-assisted extractions and application in a bakery product

Heat- and ultrasound-assisted extractions of anthocyanins from jabuticaba epicarp were optimized and the colouring potential of the developed extract was tested on macarons. The independent variables time (t), solvent concentration (S), and temperature (T) or power (P) were combined in a five-level central composite design coupled with response surface methodology. The delphinidin-3-O-glucoside and cyanidin-3-O-glucoside levels monitored by HPLC-DAD-ESI/MS were used as response criteria. The developed models were successfully fitted to the experimental data and used to determine optimal extraction conditions. HAE was the most efficient method yielding 81 ± 2 mg/g extract under optimal conditions (t = 21.8 min, T = 47.1 °C and S = 9.1% ethanol, v/v). Macarons were then produced using the optimized anthocyanin-rich colouring extract and their colour parameters and nutritional profile were monitored during shelf-life. The obtained results provided useful information for the development of anthocyanin-rich extracts from a bio-waste with potential use as natural food colorants.info:eu-repo/semantics/publishedVersio

Phenolic compounds: current industrial applications, limitations and future challenges

Phenolic compounds are natural bioactive molecules found mainly in plant tissues that have shown interesting bioactivities, such as antioxidant, antimicrobial, anti-inflammatory, and antiproliferative activities, among others, which has led to great interest in their use by several industries. However, despite the large number of scientific studies on this topic, some issues still need to be studied and solved, such as the understanding of the main actions of these compounds in organisms. Besides their large potential applicability in industry, phenolic compounds still face some issues making it necessary to develop strategies to improve bioavailability, sustainable technologies of extraction and refinement, and stability procedures to increase the range of applicability. This review focuses on the most recent advances in the applications of phenolic compounds in different technological and medicinal areas. In addition, techniques to improve their sustainable resourcing, stability and bioavailability will be presented and discussed. This journal isFoundation for Science and Technology (FCT, Portugal) is acknowledged for financial support by national funds FCT/ MCTES to CIMO (UIDB/00690/2020). National funding by FCT, P. I., through the institutional scientific employment programcontract for Lillian Barros contract and through the individual scientific employment program-contract for Sandrina A. Heleno, and B. Albuquerque Research grant (SFRH/BD/136370/2018 ). European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project NORTE-01-0145-FEDER-023289: DeCodE and project Mobilizador Norte-01-0247-FEDER-024479: ValorNatural®. FEDER-Interreg España-Portugal programme is acknowledged for financial support through the project 0377_Iberphenol_6_E.info:eu-repo/semantics/publishedVersio

Chemical characterization and antioxidant proprieties of Myrciaria jaboticaba bioresidues

Jabuticaba (Myrciaria jaboticaba (Vall.) O. Berg) is a Brazilian berry very appreciated for in natura consumption. However, its epicarp is not normally consumed, and in manufacture of products from jabuticaba fruit, it is responsible for the generation of large amounts of residues [1,2]. The exploration of by-products is becoming important for the obtainment of valuable bioactive compounds for food and pharmaceutical industries [2]. In this context, the present work aimed in the characterization of the main bioactive compounds present in jabuticaba epicarps and its potential antioxidant.Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020); national funding by FCT, P.I., through the institutional scientific employment program-contract for M.I. Dias, L. Barros, and C. Pereira contract; and B. Albuquerque (SFRH/BD/136370/2018) PhD grant; ERDF through the Regional Operational Program North 2020, within the scope of Project NORTE-01-0145-FEDER-023289: DeCodE and project Mobilizador Norte-01-0247-FEDER-024479: ValorNatural®; FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E.info:eu-repo/semantics/publishedVersio

Recovery of bioactive compounds from Arbutus unedo L. fruits: Comparative optimization study of maceration/microwave/ultrasound extraction techniques

The aim of this work was to produce an extract rich in different bioactive compounds from Arbutus unedo L. fruits to enhance its possible valorization and commercialization. The conditions of the main variables of maceration, microwave, and ultrasound assisted extractions (MA, MAE and UAE, respectively) were optimized and compared in terms of its composition (based on the total material extracted, total content in carbohydrates, phenolic and flavonoid compounds) and its preservative potential (based on the response of four in vitro antioxidant assays). The key variables of each extraction technique (time, temperature or power and hydroalcoholic mixture) were evaluated by specific experimental designs using response surface methodology. Mathematical models were developed and numerical optimal values for each extraction technique and response were achieved. Regarding the extraction of target compositional compounds, MAE was the most efficient, closely followed by MA. In terms of its preservative potential, MAE was the most suitable solution, but MA gave similar results at lower temperatures (~90 °C). Globally, MA and MAE were the best options conducting to optimal solutions using reduced amounts of ethanol. UAE required higher ethanol contents (~60%). The results showed alternatives to obtain extracts of A. unedo fruits, supporting their potential to be exploited at industrial level.The authors thank the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013) and L. Barros contract. The authors are also grateful to FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E; and to the European Structural and Investment Funds (FEEI) through the Regional Operational Program North 2020, within the scope of Project NORTE- 01-0145-FEDER-023289: DeCodE. To POCI-01-0145-FEDER-006984 (LA LSRE-LCM), funded by FEDER, through POCI-COMPETE2020 and FCT. To Xunta de Galicia for financial support for the post-doctoral researcher of M.A. Prieto. B. Albuquerque thanks Celeide Pereira (UTFPR, Brazil) for her master co-supervision. Finally, the authors want to express their gratitude to Araceli Menduiña Santomé (Instituto de Investigacións Mariñas, IIM-CSIC) for her professional work and dedication on the production of the laboratory results.info:eu-repo/semantics/publishedVersio

Stability assessment of extracts obtained from Arbutus unedo L. fruits in powder and solution systems using machine-learning methodologies

Arbutus unedo L. (strawberry tree) has showed considerable content in phenolic compounds, especially flavan-3-ols (catechin, gallocatechin, among others). The interest of flavan-3-ols has increased due their bioactive actions, namely antioxidant and antimicrobial activities, and by association of their consumption to diverse health benefits including the prevention of obesity, cardiovascular diseases or cancer. These compounds, mainly catechin, have been showed potential for use as natural preservative in foodstuffs; however, their degradation is increased by pH and temperature of processing and storage, which can limit their use by food industry. To model the degradation kinetics of these compounds under different conditions of storage, three kinds of machine learning models were developed: i) random forest, ii) support vector machine and iii) artificial neural network. The selected models can be used to track the kinetics of the different compounds and properties under study without the prior knowledge requirement of the reaction system.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO, Portugal (UIDB/00690/2020); L. Barros thanks the national funding by FCT, P.I., through the institutional scientific employment program-contract. The authors are also grateful to FEDER-Interreg VA España-Portugal (POCTEP) programme for financial support through the project 0377_Iberphenol_6_E and TRANSCoLAB 0612_TRANS_CO_LAB_2_P. G. Astray thanks to the University of Vigo for his contract “Programa de retención de talento investigador da Universidade de Vigo para o 2018” with budget application 0000 131H TAL 641. M.A. Prieto thanks to the MICINN for the financial support for the Ramón and Cajal grant. G. Astray thanks to RapidMiner GmbH. for the Free and Educational version of RapidMiner Studio software.info:eu-repo/semantics/publishedVersio

Jabuticaba residues (Myrciaria jaboticaba (Vell.) Berg) are rich sources of valuable compounds with bioactive properties

The main environmental issue associated with compost production is the production of a liquid leachate. Leachate from municipal wastes contains carbon, nitrogen, phosphorus, potassium and trace elements that can be used as nutrients by plants. The advantages of the use of organic wastes such as compost leachate as fertilizers are evident. Their use would reduce the consumption of commercial fertilizers, which need, with their production, high cost and energy. This work aims to determine the physical and chemical properties of a specific leachate with a variable composition, collected from the composting line of a mechanical and biological treatment facility. The goal is to assess if the leachates can be used as a potential source for fertilizers, and thus develop and design a sequence of processes which could effectively convert the leachates to commercial fertilizers according to the requirements of the proposal of regulation of the European Parliament of 2016 for fertilizers. Preliminary results show that the leachate samples qualitatively meet the requirements established for the composition of commercial fertilizers, especially organo-mineral fertilizers. Furthermore, there is no production cost of leachate as a raw material. The results show that the leachate is characterized by manageable concentrations of heavy metals which can be removed by adsorption processes, and it presents suitable amounts of organic carbon after a water removal procedure. However, the establishment of the conditions for suitable conversion processes are still under investigation considering the high composition variability due to factors like storage and environmental conditions.info:eu-repo/semantics/publishedVersio

Jabuticaba residues (Myrciaria jaboticaba (Vell.) Berg) are rich sources of valuable compounds with bioactive properties

Jabuticaba (Myrciaria jaboticaba (Vell.) Berg) is a Brazilian berry, very appreciated for in natura consumption. However, its epicarp is not normally consumed due to its stiffness and astringent taste, and in manufacture of products from jabuticaba fruit, it is responsible for the generation of large amounts of residues. The exploration of by-products is becoming important for the obtainment of valuable bioactive compounds for food and pharmaceutical industries. In this context, jabuticaba epicarp was studied regarding its chemical composition, namely in terms of phenolic compounds, tocopherols, and organic acids, and its bioactive properties, such as antioxidant, anti-proliferate, anti-inflammatory, and antimicrobial activities. A total of sixteen phenolic compounds, four tocopherols and six organic acids were identified in jabuticaba epicarp. Regarding bioactive properties, it showed high antioxidant activity, also presenting moderate anti-inflammatory, anti-proliferative, and antimicrobial activities. The extract did not present hepatotoxicity, confirming the possibility of its applications without toxicity issues.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2019); national funding by FCT, P.I., through the institutional scientific employment programcontract for M.I. Dias, L. Barros, and R.C. Calhelha contracts; C. Pereira contract though the celebration of program-contract foreseen in No. 4, 5 and 6 of article 23° of Decree-Law No. 57/2016, of 29th August, amended by Law No. 57/2017, of 19th July; and B. Albuquerque (SFRH/BD/136370/2018) PhD grant; to FEDER-Interreg España- Portugal programme for financial support through the project 0377_Iberphenol_6_E; the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project NORTE-01-0145-FEDER-023289: DeCodE and project Mobilizador Norte-01-0247-FEDER-024479: ValorNatural®. The authors thank Dra. Cyanthia J. Kunigk (Instituto Mauá de Tecnologia, Brazil) for her collaboration.info:eu-repo/semantics/publishedVersio

Valorization of sicana odorifera (Vell.) naudin epicarp as a source of bioactive compounds: Chemical characterization and evaluation of its bioactive properties

Fruit bio-residues can be interesting for the recovery of bioactive molecules, such as phenolic compounds, tocopherols, vitamins, among others. These compounds can be targeted at the food industry and used for the development of functional foods or as food additives. In some cases, fruit epicarps are converted into by-products with non-commercial value, and generally, these fruit parts have a higher content in bioactive compounds than the fruit pulp. From this perspective, S. odorifera, a Brazilian fruit, has an inedible epicarp that could be explored to obtain biological compounds. Therefore, the aims of this study were to evaluate the chemical composition and the antioxidant, anti-proliferative, anti-inflammatory, and antimicrobial bioactivities of this by-product. S. odorifera epicarp showed a total of four organic acids, four phenolic compounds, highlighting the high concentration of anthocyanins (24 ± 1 mg/g dry weight (dw)) and high content of tocopherols (366 ± 2 mg/100 g dw). The hydroethanolic extract showed considerable antioxidant activity (EC50 values of 48.2 ± 0.5 and 27 ± 1 µg/mL for TBARS and OxHLIA assays, respectively), as also antibacterial and antifungal activities (minimal inhibitory concentrations (MICs) ≤ 2.2 mg/mL). The results obtained in this study suggest that Sicana odorifera epicarp represents a reliable option for the development of novel natural-based colorants with functional/bioactive proprieties.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020) and B.R. Albuquerque research grant (SFRH/BD/136370/2018). National funding by FCT, P.I., through the individual scientific employment program-contract for M.I.D., C.P., R.C.C., and L.B. contracts. The authors are grateful to FEDER-Interreg España-Portugal programme for financial support through the project TRANSCoLAB 0612_TRANS_CO_LAB_2_PT and to the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project GreenHealth: Norte-01-0145-FEDER-000042 and the Project Mobilizador Norte-01-0247- FEDER-024479: ValorNatural®. This work has also been supported by the Ministry of Education, Science and Technological Development of Republic of Serbia (451-03-68/2020-14/200007).info:eu-repo/semantics/publishedVersio