<p>U ovom radu su ispitani hemijski sastav, antioksidativna, antihiperglikemijska, antiproliferativna i antimikrobna aktivnost liofiliziranih metanolnih ekstrakata tropa<br />maline (Rubusidaeus L) sorti Meeker (ETMM) i Willamette (ETMW), kupine (RubusfruticosusL) sorti Čačanska bestrna (ETKČ) i Thornfree (ETKT) i divlje borovnice<br />(Vacciniummyrtillus L) (ETB). Sadržaj ukupnih polifenola (TPh), flavonoida (TF) i antocijana (TAc) u ekstraktima tropova određeni su spektrofotometrijskim metodama.<br />Identifikacija i kvantifikacija fenolnih jedinjenja (fenolnihkiselina, flavonola i cijanidina) i vitamina C u ekstraktima tropova izvedena je HPLC analizom. Spektrofotometrijskim<br />testovima određena je antioksidativna aktivnostna DPPH i ABTS+ radikale i redukciona sposobnost ekstrakata. ESR spektroskopijom utvrđen je uticaj ekstrakata na reaktivne hidroksil i superoksid anjon radikale. Antihiperglikemijska aktivnost ekstrakata određena<br />je testom inhibicije &alpha;-glukozidaze. Antiproliferativna aktivnost ekstrakata tropova ispitana je in vitro, njihovim delovanjem na rast četiri histolo&scaron;ki različite humane ćelije:<br />HeLa (epitelni karcinom cerviksa), MCF7 (adenokarcinom dojke), HT-29 (adenokarcinom debelog creva) i MRC-5 (humani fetalni fibroblasti pluća). Antimikrobna aktivnost ekstrakata tropova bobičastog voća ispitana je na odabrane sojeve Gram-pozitivnih i Gram-negativnih bakterija, kvasaca i plesni disk difuzionom metodom i metodom &bdquo;bunarčića&rdquo;. Ispitana je i mogućnost primene liofiliziranih ekstrakata tropova bobičastog voća kao funkcionalnog dodatka sokovima od voća. Laboratorijski proizvedenim obogaćenim sokovima je određen sadržaj TPh, TF i TAc i utvrđena antioksidativna aktivnost testom redukcione sposobnosti i DPPH testom. Rezultati ispitivanja hemijskog sastava, antioksidativne, antihiperglikemijske, antiproliferativne i antimikrobne aktivnosti ETMM, ETMW, ETKČ, ETKT i ETB ukazuju da su svi ispitivani ekstrakti tropova potencijalni izvor prirodnih<br />bioaktivnih jedinjenja, a antioksidativna aktivnost obogaćenih sokova ukazuje na mogućnost kori&scaron;ćenja ovih ekstrakata, kao funkcionalnih aditiva u proizvodnji različitih<br />visoko vrednih prehrambenih proizvoda.</p> / <p>This work examined the chemical composition, the antioxidant,<br />antihyperglycaemic, antiproliferative and antimicrobial<br />activity of the freeze-dried raspberry (Rubus idaeus L.)<br />varieties Meeker (ETMM) and Willamette (ETMW), blackberry<br />(Rubus fruticosus L.) varieties (ETKČ) and Thornfree<br />(ETKT), and wild blueberry (Vaccinium myrtillus L.) (ETB)<br />pomaces methanol extracts. The content of total polyphenols<br />(TPh), total flavonoids (TF) and total anthocyanins (TAc) in<br />the pomace extracts were determined spectrophotometrically.<br />Identification and quantification of the phenolic compounds<br />(phenol acids, flavonols and cyanidins) and ascorbic acid in<br />the pomace extracts was performed by HPLC analysis. The<br />antioxidant activities of the extracts was determined spectrophotometrically<br />using DPPH and ABTS+ free radicals and<br />reducing ability assay. ESR spectroscopy is used for determination<br />of pomace extracts&rsquo; influence on reactive hydroxyl<br />and superoxide anion radicals. Antihyperglycaemic activity of<br />the pomace extracts was determined using &alpha;-glucosidase inhibition<br />assay. The antiproliferative activity of the pomace extracts<br />was tested in vitro, testing their influence on the growth<br />of four histologically different human tumor cells: HeLa<br />(cervix epithelioid carcinoma), MCF7 (breast adenocarcinoma),<br />HT-29 (colon adenocarcinoma) and MRC-5(human fetal<br />lung fibroblasts). Antimicrobial activity of berry pomace extracts was tested on selected strains of Gram-positive and<br />Gram-negative bacteria, yeasts and molds with the disc diffusion<br />method and the method of &ldquo;wells&rdquo;. The possibility of<br />freeze dried berry pomace extracts application as a fruit functional<br />additive was investigated as well. Laboratory produced<br />enriched juice was tested in terms of TPH, TF and TAc content,<br />reducing ability and DPPH scavenging ability as well.<br />The results of testing the chemical composition, the antioxidative,<br />antihyperglycaemic, antiproliferative and antimicrobial<br />activities of ETMM, ETMW, ETKČ, ETKT and ETB, indicate<br />that all investigated pomace extracts are a potential source of<br />natural bioactive compounds, and that the antioxidant activity<br />enriched juice indicates the possibility of using these extracts,<br />as a functional additive in the production of various high-value<br />food products.</p>

Outbreaks of food-born illness associated with the consumption of unpasteurized juice and apple cider have resulted in a rule published by the U.S. Food and Drug Administration (FDA) in order to improve the safety of juice products. The rule (21 CFR120) requires manufacturers of juice products to develop a Hazard Analysis and Critical Control Point (HACCP) plan and to achieve a 5-log reduction in the number of the most resistant pathogens. Ultraviolet (UV) disinfection is one of the promising methods to reach this 5-log reduction of pathogens. The absorption coefficients of juices typically vary from 10 to 40 1/cm and can be even higher depending on brand and processing conditions. Thin film reactors consisting of two concentric cylinders are suitable for inactivating pathogens in juices. When the two concentric cylinders are fixed, the flow pattern in the gap can be laminar Poiseuille flow or turbulent flow depending on flow rates. If the inner cylinder is rotating, and the rotating speed of the inner cylinder exceeds a certain value, the flow pattern can be either laminar or turbulent Taylor-Couette flow. UV disinfection between concentric cylinders in laminar Poiseuille flow, turbulent flow and both laminar and turbulent Taylor-Couette flow was investigated experimentally and numerically. This is the first systematic study done on UV disinfection between concentric cylinders in all three flow patterns. The present work provides new experimental data for pathogen inactivation in each of the three flow patterns. In addition, the present study constitutes the first systematic numerical CFD predictions of expected inactivation levels. Proper operating parameters and optimum gap widths for different flow patterns are suggested. It is concluded that laminar Poiseuille flow provides inferior (small) inactivation levels while laminar Taylor-Couette flow provides superior (large) inactivation levels. The relative inactivation levels are: laminar Poiseuille flow < turbulent flow < laminar Taylor-Couette flow.

Orientador: Roger Darros-Barbosa / Banca: Maria Aparecida Mauro / Banca: José Fernando Durigan / Resumo: A recuperação dos sólidos solúveis presentes na membrana central da laranja, separada durante a etapa de extração industrial do suco, normalmente produz um suco contendo de 5 a 6ºBrix e uma série de outros compostos insolúveis (cerca de 9%), muitos dos quais contribuem para a baixa qualidade do suco, sendo responsáveis pelo amargor e adstringência. O presente trabalho propôs-se a clarificar esse suco contendo sólidos recuperados, empregando um pré-tratamento com enzimas pectinolíticas seguido por tratamento por flotação por injeção de ar comprimido auxiliada por agentes clarificantes: bentonita, sílica sol e colágeno hidrolisado. Constituíram-se os objetivos: (i) a determinação das melhores condições (tipo de enzima pectinolítica, duas hidrolases e duas pectinases, e tempo de incubação) para a degradação enzimática da pectina presente; (ii) a determinação da melhor combinação dos agentes clarificantes visando obter um subproduto clarificado através do monitoramento de parâmetros físico-químicos (capacidade floculante e transmitância) e (iii) a avaliação do processo de flotação com diferentes concentrações de bentonita (500, 1.000 e 1.500 mg L-suco-1 e pressões (490, 680 e 880 kPa) pela determinação do grau de clarificação através de monitoramento da transmitância do clarificado, pela determinação da velocidade de flotação/separação das fases, através da verificação das frações volumétricas das fases separadas (clarificado, sedimentado e flotado), em intervalos de tempos regulares durante o processo de flotação e pela análise do produto final clarificado. Os produtos clarificados foram analisados com relação ao conteúdo de sólidos solúveis e insolúveis, pH, acidez titulável, polpa, transmitância, cor (parâmetros L*, a*, b*) proteína, pectina total, sódio, hesperidina, polifenóis e bioflavonóides. Para o tratamento... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Core membrane of the orange fruit separated during the juice extraction step in the citrus processing industrial plant, is currently submitted to a soluble solids recovery process, normally producing a by product (secondary) juice containing about 5 to 6º Brix and other insoluble components (about 9%), which contribute to the juice's low quality, since many are responsible for the bitterness and adstringency. This research aimed to clarify this by-product juice containing recovered solids, by enzyme pre-treatment with pectic enzymes, followed by a flotation treatment with compressed air injection using fining agents: bentonite, silica sol and hydrolyzed collagen. The objectives were (i) to determine the best conditions (enzyme type, two hydrolyses and two pectin-liases and incubation time) for the enzyme treatment for pectin degradation; (ii) to determine the best combination of the fining agents to obtain a clarified by-product through monitoring physical chemical parameters (flocculating ability and product transmittance); and (iii) to evaluate the flotation process and the effects of bentonite concentration (500, 1.000 and 1.500 mg L-juice-1) and saturation pressure (490, 680 and 880 kPa) by determining the degree of clarification through monitoring the product transmittance and by determining the flotation rate (and phase separation) through measurements of volumetric fractions of the separated phases (clarified, floated and sediment) over time during the flotation and phase separation processes. Both untreated and clarified juices were analyzed for soluble and insoluble solid contents, pH, total titratable acidity, pulp content, transmittance, color (parameters L*, a* and b*), protein and pectin contents, sodium, hesperidine, poliphenols and bioflavonoids. The results indicates a purified poligalacturonase as the adequate for the enzyme treatment in 1 hour, 45ºC, with 0,05 mL... (Complete abstract click electronic access below) / Mestre

<p>Nesavesna upotreba antibiotika izazvala je razvoj antimikrobne rezistencije zabrinjavajućih razmera. Porast rezistencije prema konvencionalnim antimikrobicima nametnuo je potrebu pronalaska novih supstanci, koje će biti delotvorne protiv otpornih sojeva. U poslednje četiri decenije, dominira trend da se lekovi i lekovita sredstava prave na bazi prirodnih proizvoda, a naročito biljnog materijala. Hemijski sastav plodova porodice ruža (Rosaceae) upućuje na to da bi određene vrste ove porodice biljaka mogle ispoljavati antimikrobno dejstvo. Plodovi voća porodice Rosaceae istraživani u okviru ove disertacije su: malina (Rubus idaeus), kupina (Rubus fruticosus), tre&scaron;nja (Prunus avium), vi&scaron;nja (Prunus cerasus) i aronija (Aronia prunifolia). Predmet istraživanja ove doktorske disertacije je antimikrobno tj. antibakterijsko, antigljivično, antialgalno i antivirusno dejstvo sokova i ekstrakata plodova odabranog voća porodice Rosaceae gajenog i prikupljenog na teritoriji Srbije na &scaron;irok spektar humanih i animalnih patogenih mikroorganizama.Sokovi su dobijeni ceđenjem svežih plodova voća. Ekstrakti su dobijeni iz ostataka voća nakon ceđenja (tropa) metodom dvostruke etanolne ekstrakcije. Nakon ceđenja i ekstrakcije sprovođeno je uparavanje do suva sokova i ekstrakata. HPLC metodom je ispitano prisutstvo 23 hemijske komponente u svakom od sokova i ekstrakata. Antimikrobna analiza je sprovedena na 21 mikroorganizmu, od čega su 15 bile bakterije, 2 gljivice, 2 alge i 2 virusi. Od navedenih mikroorganizama 14 je bilo autohtonih izolata, a 7 referentnih sojeva. Ispitivanje antibakterijskog, antifungalnog i antialgalnog dejstva plodova odabranog voća je sprovedeno difuzionom i mikrodilucionom metodom. Analiza antivirusne aktivnosti plodova odabranog voća je sprovedena posmatranjem inhibicije citopatogenog efekta (CPE) virusnih čestica na ćelijsku kulturu. Sve studije su sprovedene u triplikatu. Rezultati hemijske analize su obrađeni statistikom metodom srednje vrednosti, uz računanje standardne devijacije. Eksperimentalno dobijeni podaci u okviru ispitivanja antibakterijskog, antigljivičnog i antialgalnog dejstva su uvr&scaron;teni u statističku analizu. Metodom aproksimacije je utvrđena tačna koncentracija soka ili ekstrakta koja daje željeni efekat na ispitivani mikroorganizam. Rezultati analize antivirusnog dejstva su statistički obrađeni metodom srednje vrednosti. Kako bi se utvrdio stepen povezanosti rezultata dobijenih u okviru antimikrobnih analiza sa hemijskim supstancama prisutnim u plodovima odabranog voća sprovedena je regresiona analiza za vaki pojedinačni slučaj. Antibakterisjko, antiungalno i antialgalno dejstvo sokova i ekstrakata je upoređeno sa istim dejstvima konvencionalnih antimikrobnih lekova. Najveću ukupnu količinu ispitivanih supstanci je sadržao ekstrakt kupine (3965,56 mg/ml), a najmanju ekstrakt tre&scaron;nje (161,44 mg/ml). Od svih ispitivanih hemijskih supstanci, samo su: antocijani, katehin, galna kiselina i vitamin C, prisutni u svim ispitivanim sokovima i ekstraktima. Sve ispitivane biljke sadrže veću količinu supstanci u ekstraktu, osim kod tre&scaron;nje, kod koje se veća količina supstanci nalazi u soku. U najvećoj meri su u sokovima i ekstraktima plodova biljaka prisutni antocijani i to najvi&scaron;e kod kupine od ekstrakata, a kod maline od sokova. Antimikrobno (antibakterijsko, antifungalno, antialgalno i antivirusno) dejstvo je dokazano za svaki od sokova i/ili ekstrakata plodova odabranog voća. Po prosečnim vrednostima rezultata dilucione analize antimikrobnog i dejstva na MDBK ćelije, protiv najvećeg broja mikroorganizama najdelotvorniji je bio ekstrakt kupine, a neaktivan ili najslabije aktivan (aktivan u najvećoj koncentraciji) sok tre&scaron;nje. Prosečne vrednosti antimikrobnog i dejstva na MDBK ćelije su bile u opsegu od 0,71 mg/ml do 100 mg/ml. Sve ispitivane supstance su pokazale antibakterijsku aktivnost u ispitivanim koncentracijama na sve ispitivane bakterije, osim soka maline na Escherichia-u coli i soka aronije na Klebsiella-u pneumoniae. Ekstrakti su bolje delovali u većini slučajeva, uz nekoliko izuzetaka. Sve ispitivane supstance su pokazale antfiungalnu aktivnost na Candida-u albicans ATCC 24433, osim soka aronije. Na autohtoni soj Candida-e albicans su delovali samo ekstrakti kupine i tre&scaron;nje. Ekstrakti su bolje delovali u većini slučajeva, osim kupine na Candida-u albicans ATCC 24433, u kojem je dejstvo soka bilo jednako sa dejstvom ekstrakta. Iako su skoro svi ispitivani sokvi i ekstrakti ispoljili antialgalno dejstvo, na Prototheca-u wickerhamii nisu delovali vi&scaron;nja i sok maline, dok sok aronije nije delovao antialgalno ni na jednu od ispitivanih Prototheca. Ekstrakti su bolje delovali u većini slučajeva, osim maline kod koje je, u oba slučaja, bolje delovao sok. Sve ispitivane supstance su pokazale antivirusnu aktivnost na Bovine herpesvirus i Bovine viral diarrhea virus, kao i toksičnost na MDBK ćelije, osim sokova maline i tre&scaron;nje, koji su bili neaktivni protiv Bovine herpesvirus-a. Ekstrakti su bolje delovali u većini slučajeva, osim tre&scaron;nje na MDBK ćelije i Bovine viral diarrhea virus, na koje je jače delovao sok. U potpunosti jednako delovanje soka i ekstrakta je uočeno kod aronije za sva tri dejstva i maline za toksičnost na MDBK ćelije. Pri ispitivanju difuzionom metodom antibiotik je ispoljio jače dejstvo u odnosu na sokove i ekstrakte, osim ekstrakata kupine, maline i vi&scaron;nje na Trueperella-u pyogenes. Pri ispitivanju dilucionom metodom, dejstvo ekstrakata i sokova na Gram pozitivne bakterije je bilo uporedivo sa dejstvom Streptomicina, dok je dejstvo antibiotika na Gram negativne bakterije bilo jače u odnosu na sokove i ekstrakte, izuzetev jačeg dejstva ekstrakta maline protiv Escherichia-e coli. Nistatin je sve antifungalne i antialgalne efekte na gljivice i alge obuhvaćene istraživanjem ispoljio u manjim koncentracijama u odnosu na ispitivane sokove i ekstrakte.Najpovezanije sa antibakterijskim dejstvom sokova i ekstrakata na odgovarajuće mikroorganizme su bile: kumarinska, ferulna i galna kiselina, katehin. Najveći procenat povezanosti sa antimikrobnom aktivnosti ploda imali su antocijani na Enterococcus faecalis (71,94%). Najmanje povezani sa antimikrobnom aktivnosti na odgovarajuće mikroorganizme su bili: hlorogenska kiselina, kempferol, kumarinska i siringinska kiselina, vitamin C, vanilinska kiselina, epikatehin, katehin, rutin, krisin, elaginska i p-hidroksibenzoeva kiselina. Saznanja dobijena u okviru ove disertacije pro&scaron;iruju obim znanja o antimikrobnom dejtvu voća i predstavljaju osnovicu za svrsishodniju primenu voća kako u ishrani tako i u terapiji. Međutim, dalja istraživanja u smislu pro&scaron;irenja spektra ispitivanih mikroorganizama, antimikrobnih studija pojedinačnih komponenti iz plodova i mehanizama dejstva su potrebna.</p> / <p>Nonconscientious use of antibiotics has caused the development of antimicrobial resistance of worrying proportions. The increase in resistance to conventional antimicrobials has imposed a need to find new substances that will be effective against resistant strains. Over the last four decades, the trend is to medicines and medicinal products be made on the basis of natural products, and especially plant material. The chemical composition of the Rose family (Rosaceae) fruits suggests that certain species of this family of plants may exhibit an antimicrobial effect. The fruits of the Rosaceae family studied in the framework of this dissertation are: Raspberry (Rubus idaeus), Blackberry (Rubus fruticosus), Cherry (Prunus avium), Cherry (Prunus cerasus) and Aronia (Aronia prunifolia). The subject of the research of this doctoral dissertation is antimicrobial ie. antibacterial, antifungal, antialgal and antiviral effects of juices and fruit extracts, of the selected fruit of the Rosaceae family collected on the territory of Serbia, on a wide range of human and animal pathogenic microorganisms. Juices were obtained by the process of squeezing fresh fruits. The extracts were obtained from residues of fruits after extraction (pomace) by the double ethanol extraction method. After squeezing and extraction, evaporation to dryness of juices and extracts was carried out. The presence of 23 chemical components in each of the juices and extracts was examined by the HPLC method. Antimicrobial analysis was carried out on 21 microorganisms, of which 15 were bacteria, 2 fungi, 2 algae and 2 viruses. 14 of these microorganisms were autochthonous isolates and 7 reference strains. The antibacterial, antifungal and antialgal effect of the selected fruit was tested by the diffusion and microdilution method. The analysis of the fruits antiviral activity was carried out by observing the inhibition of cytopathogenic effect (CPE) of viral particles per cell culture. All studies were conducted in triplicate. The results of the chemical analysis were processed by means of a mean value method, with calculation of the standard deviation. The experimentally obtained data within the antibacterial, antifungal and antialgal examination were included in the statistical analysis. The method of approximation was used in order to determine the exact concentration of the juice or extract, which gives the desired effect on the examined microorganisms. The results of the antiviral analysis were statistically processed using the mean value method. In order to determine the degree of correlation of the results obtained in the framework of antimicrobial analysis with the chemical substances present in the fruits of the selected fruit, regression analysis was carried out for each individual case. Antibacterial, antifungal and antialgic effects of juices and extracts are compared with he same effects of conventional antimicrobial drugs, Streptomycin and Nystatin. The largest total amount of test substances was contained by blackberry extract (3965.56 mg/ ml), and the smallest by extract of sweet cherry (161.44 mg/ ml). Of all the investigated chemicals, only: anthocyanins, catechins, gallic acids and vitamin C were present in all examined juices and extracts. All investigated plants contain a higher amount of substances in the extract, except for sweet cherries, in which a greater amount of substances is present in the juice. In the juices and extracts of fruits anthocyanins are present to the greatest extent, mostly in the blackberry extract, and in raspberry juices. According to the average values of the results of the dilution analysis of the antimicrobial and the effect on the MDBK cell, the most effective was the blackberry extract and the most active inactive (active in the highest concentration) cherry juice against the most numerous microorganisms. The average antimicrobial values and effects on the MDBK cells were in the range of 0.71 mg/ ml to 100 mg/ ml. All investigated substances showed antibacterial activity in the tested concentrations on all examined bacteria, except raspberry juice on Escherichia coli and aronia juice on Klebsiella pneumoniae. Extracts acted better in most cases, with few exceptions. All investigated substances showed antifungal activity on Candida albicans ATCC 24433, except aronia juice. On the autochthonous Candida albicans, only blackberry and sweet cherry extracts were active. Extracts worked better in most cases, except for blackberry on Candida albicans ATCC 24433, in which the effect of the juice was equally efficient as the extract. Although almost all of the examined juices and extracts exhibited an antialgal effect, the sour cherry and raspberry juice did not work on the Prototheca wickerhamii, while the aronia juice did not express antialgal activity to any of tested Prototheca isolates. Extracts worked better in most cases, apart from raspberries, wich juice was stronger in both cases. All investigated substances showed antiviral activity on Bovine herpesvirus and Bovine viral diarrhea virus, as well as the toxicity to MDBK cells, except for raspberry and cherry juices, that were inactive against Bovine herpesvirus. The extracts worked better in most cases, except sweet cherries on MDBK cells and Bovine viral diarrhea virus, whose juice had stronger effect. The equally effective action of juice and extract was observed in aronia for all three effects and raspberries for toxicity to MDBK cells. In the diffusion test, antibiotic showed a stronger effect than juices and extracts, except for extracts of blackberry, raspberry and sour cherries on Trueperella pyogenes. In a dilution study, the effect of extracts and juices on Gram-positive bacteria was comparable to that of Streptomycin, while the effect of the antibiotic on Gram negative bacteria was stronger than juices and extracts, with exception of the stronger effect of raspberry extract against Escherichia coli. Nystatin has expressed its all antifungal and antialgal effects on fungi and algae included in the study in smaller concentrations compared to the examined juices and extracts. The most consistent with the antibacterial effect of juices and extracts on the appropriate microorganisms were: coumarin, ferulan and gallic acid, catechin. The highest percentage of association with antimicrobial activity of the fruits was given by anthocyanins to Enterococcus faecalis (71.94%). The least related to the antimicrobial activity on the appropriate microorganisms were: chlorogenic acid, champferol, coumarin and saringic acid, vitamin C, vanillic acid, epicatechin, catechin, rutin, chrysin, elaginic and p-hydroxybenzoic acid. The knowledge gained through this dissertation expands the scope of knowledge on antimicrobial activity of fruits and forms the basis for more effective use of fruits in both therapy and nutrition. However, further research in terms of extending the range of examined microorganisms, antimicrobial studies of individual fruits components and mechanisms of action are required.</p>

South Africa has over 19 500 different indigenous plant species. Most of these are of ethnobotanical significance and are still used by local rural communities as medicine, food and for making beverages. The relatively little research that has been conducted on indigenous plant species has focused mainly on their medicinal potential. However, in view of the rapidly growing size of the global and local beverage industry and their constant search for new products, beverage-making indigenous plant species may have commercial development potential. To date, no detailed studies have been conducted on these plants, especially in the species-rich Limpopo province. The aim of this study was, therefore to evaluate the potential of indigenous plants for commercial beverage production. In order to achieve this, a survey was conducted in the Limpopo province to identify beverage-making plants and to document beverage preparation methods. Selected beverages were analysed and evaluated for their nutrient and sensory characteristics and a market product acceptability survey was conducted to identify those beverages with the greatest potential for development. Sixty three different beverage-plant species were identified in three study areas within the Limpopo province. These were used for the preparation of teas, fruit juices and alcoholic beverages. Plants that received further research attention were selected on the basis of their status as indigenous plants, frequency of use, nature of harvesting methods and availability. Some of the selected beverages were found to be rich in nutrients, especially with respect to vitamin C and mineral content. Furthermore, sensory analyses and market surveys indicated that four species, namely, Doyvalis caffra, Garcinia livingstonei, Grewia flavescens and Englerophytum magalismontanum have potential for further development for the beverage industry while Athrixia phylicoides has commercialisation potential as a herbal tea. However, further research is required to improve and refine preparation methods and to ensure compliance with quality standards. The availability of sufficient plant material for the industry must also be ensured. This research has indicated that South African indigenous plants have untapped market potential for the beverage industry which, if developed sustainably, could contribute to economic growth of the rural parts of South Africa. / Environmental Sciences / D. Ed. (Environmental Management)

South Africa has over 19 500 different indigenous plant species. Most of these are of ethnobotanical significance and are still used by local rural communities as medicine, food and for making beverages. The relatively little research that has been conducted on indigenous plant species has focused mainly on their medicinal potential. However, in view of the rapidly growing size of the global and local beverage industry and their constant search for new products, beverage-making indigenous plant species may have commercial development potential. To date, no detailed studies have been conducted on these plants, especially in the species-rich Limpopo province. The aim of this study was, therefore to evaluate the potential of indigenous plants for commercial beverage production. In order to achieve this, a survey was conducted in the Limpopo province to identify beverage-making plants and to document beverage preparation methods. Selected beverages were analysed and evaluated for their nutrient and sensory characteristics and a market product acceptability survey was conducted to identify those beverages with the greatest potential for development. Sixty three different beverage-plant species were identified in three study areas within the Limpopo province. These were used for the preparation of teas, fruit juices and alcoholic beverages. Plants that received further research attention were selected on the basis of their status as indigenous plants, frequency of use, nature of harvesting methods and availability. Some of the selected beverages were found to be rich in nutrients, especially with respect to vitamin C and mineral content. Furthermore, sensory analyses and market surveys indicated that four species, namely, Doyvalis caffra, Garcinia livingstonei, Grewia flavescens and Englerophytum magalismontanum have potential for further development for the beverage industry while Athrixia phylicoides has commercialisation potential as a herbal tea. However, further research is required to improve and refine preparation methods and to ensure compliance with quality standards. The availability of sufficient plant material for the industry must also be ensured. This research has indicated that South African indigenous plants have untapped market potential for the beverage industry which, if developed sustainably, could contribute to economic growth of the rural parts of South Africa. / Environmental Sciences / D. Ed. (Environmental Management)

Tesis por compendio / [ES] Los componentes de los aceites esenciales (CAEs) han demostrado ser eficaces contra una amplia variedad de microorganismos. Sin embargo, su aplicación plantea desafíos debido a su baja solubilidad y alteración de las propiedades organolépticas en los alimentos. Por tanto, la búsqueda de nuevas formas de dosificación es fundamental para promover su uso en la industria alimentaria. La presente tesis doctoral está centrada en el desarrollo y aplicación de sistemas antibacterianos y antivirales basados en la inmovilización covalente de CAEs para mejorar la calidad y seguridad de alimentos líquidos. El primer capítulo evaluó el efecto de la adición de componentes naturalmente presentes en los alimentos (proteínas, lípidos, carbohidratos, ácidos orgánicos y etanol) sobre la actividad antimicrobiana de diferentes CAEs (carvacrol, eugenol, geraniol, timol y vainillina) en su forma libre. Además, se evaluó la influencia de los componentes alimentarios sobre la vainillina inmovilizada. Los resultados mostraron que la albúmina sérica bovina (BSA), el aceite de girasol y algunos carbohidratos fueron los componentes que más inhibieron la actividad antimicrobiana de los CAEs libres, con algunas excepciones. En los medios que contienen BSA, no se inhibió la actividad antimicrobiana del geraniol. Lo mismo ocurrió con eugenol en aceite de girasol, o con carvacrol, eugenol, geraniol y timol en presencia de D-lactosa. La vainillina inmovilizada confirmó el efecto inhibidor de las proteínas, lípidos y carbohidratos sobre la actividad antimicrobiana, pero el ácido cítrico y el etanol mejoraron la actividad antimicrobiana. Estos resultados demuestran la importancia de considerar la composición de la matriz alimentaria al seleccionar un compuesto antimicrobiano. El segundo capítulo evaluó la aplicación de CAEs frente al crecimiento y producción de guaiacol por un microorganismo alterante y termorresistente como Alyciclobacillus acidoterrestris en zumo de naranja. Para ello, se utilizaron CAEs inmovilizados con dos enfoques diferentes: como aditivos y como coadyuvantes tecnológicos. La presencia de CAEs provocó una reducción microbiana y una inhibición de la producción de guayacol, que fue mantenida tras la inmovilización. Este hecho es de gran interés, ya que la inmovilización evita el problema de alteración organoléptica del producto, derivado de la aplicación de estos antimicrobianos en forma libre. En el tercer capítulo se estudió la actividad antiviral de los CAEs, tanto en forma libre como inmovilizada, frente al virus Tulane en agua. La aplicación de CAEs en forma libre logró una reducción de la infectividad de sólo 1 log10, mientras que concentraciones equivalentes de antimicrobiano inmovilizado redujeron la infectividad a más de 4,5 log10. Por otro lado, el mecanismo antiviral se basó en la modificación o alteración de cápside viral. Además, se determinó que los CAEs inmovilizados no son citotóxicos en concentraciones antivirales efectivas. A pesar de la eficacia observada tras la inmovilización de los CAEs, su aplicación práctica en la industria alimentaria presenta varios desafíos, siendo uno de ellos la aceptación de esta tecnología por parte de los consumidores. El último capítulo estudió la percepción de los consumidores sobre el uso de la nanotecnología en el procesamiento de alimentos. La valoración de los distintos alimentos en los que se había aplicado nanotecnología en su procesamiento o envasado fue en general positiva. De todos los productos, aquellos en los que la nanotecnología no formaba parte de los alimentos recibieron la mejor valoración. Teniendo en cuenta este resultado, los CAEs inmovilizados aplicados como coadyuvantes tecnológicos serían los más valorados y, por tanto, podrían ser una excelente alternativa a los tratamientos de conservación convencionales, para controlar tanto virus como bacterias durante la producción y el almacenamiento de alimentos. / [CA] Els components dels olis essencials (COEs) han demostrat ser eficaços en fornt d'una àmplia varietat de microorganismes. Tot i això, la seua aplicació planteja desafiaments a causa de la seua baixa solubilitat i alteració de les propietats organolèptiques en els aliments. Per tant, la recerca de noves formes de dosificació és fonamental per promoure'n l'ús a la indústria alimentària. Aquesta tesi doctoral està centrada en el desenvolupament i l'aplicació de sistemes antibacterians i antivirals basats en la immobilització covalent de COEs per a millorar la qualitat i la seguretat d'aliments líquids. El primer capítol va avaluar l'efecte de l'addició de components naturalment presents als aliments (proteïnes, lípids, carbohidrats, àcids orgànics i etanol) sobre l'activitat antimicrobiana de diferents COEs (carvacrol, eugenol, geraniol, timol i vainillina) en la seua forma lliure. En aquesta primera part també es va avaluar la influencia dels components alimentaris sobre la vainillina immobilitzada. Els resultats van mostrar que l'albúmina sèrica bovina (BSA), l'oli de gira-sol i alguns carbohidrats van ser els components que van inhibir més l'activitat antimicrobiana dels COEs lliures, amb algunes excepcions. Als mitjans que contenen BSA no es va inhibir l'activitat antimicrobiana del geraniol. El mateix va passar amb eugenol en oli de gira-sol, o amb carvacrol, eugenol, geraniol i timol en presencia de D-lactosa. La vainillina immobilitzada va confirmar l'efecte inhibidor de les proteïnes, els lípids i els carbohidrats sobre l'activitat antimicrobiana, però l'àcid cítric i l'etanol van millorar l'activitat antimicrobiana. Aquests resultats demostren la importància de considerar la composició de la matriu alimentària quan s'ha de seleccionar un compost antimicrobià per a una aplicació concreta. El segon capítol va avaluar l'aplicació de COEs en front del creixement i la producció de guaiacol per un microorganisme alterant i termorresistent com Alyciclobacillus acidoterrestris en suc de taronja. Per això, es van utilitzar COEs immobilitzats amb dos enfocaments diferents: com a additius i com a coadjuvants. La presència de COEs provoca una reducció microbiana i una inhibició de la producció de guaiacol, així com manté la seua eficàcia després de la immobilització. Aquest fet és de gran interès, ja que la immobilització evita el problema d'alteració organolèptica del producte, derivat de l'aplicació d'aquests antimicrobians en forma lliure. Al tercer capítol es va estudiar l'activitat antiviral dels COEs, tant en forma lliure com immobilitzada, davant del virus Tulane en aigua. L'aplicació de COEs en forma lliure va aconseguir una reducció de la infectivitat de només 1 log10, mentre que concentracions equivalents d'antimicrobià immobilitzat van reduir la infectivitat a més de 4,5 log10. D'altra banda, es va comprobar que el mecanisme antiviral es va basar en la modificació o alteració de la càpside viral. A més, es va determinar que els COEs immobilitzats no són citotòxics en concentracions antivirals efectives. Tot i l'eficàcia observada després de la immobilització dels COEs, la seua aplicació pràctica a la indústria alimentària presenta diversos desafiaments, un dels quals és l'acceptació d'questa tecnologia per part dels consumidors. El darrer capítol va estudiar la percepció dels consumidors sobre l'ús de la nanotecnologia en el processament d'aliments. La valoració dels diferents aliments en que s'havia aplicat nanotecnologia al seu processament o envasat va ser en general positiva. De tots els productes, aquells en que la nanotecnologia no formava part dels aliments van rebre la millor valoració. Tenint en compte aquest resultat, els COEs immobilitzats aplicats com a coadjuvants de processament serien els més valorats i, per tant, podrien ser una alternativa excel·lent als tractaments de conservació convencionals, per controlar tant virus com bacteris durant la producció i l'emmagatzematge d'aliments. / [EN] Essential oil components (EOCs) have proven to be effective against a wide variety of microorganisms. However, the direct application of these compounds poses challenges due to their low solubility and alteration of the organoleptic properties of foods. Therefore, the search for new dosage forms of these promising antimicrobials is essential to promote their use in the food industry. The present doctoral thesis is focused on the development and application of antibacterial and antiviral systems based on the covalent immobilization of EOCs to improve the quality and safety of liquid foods. The first chapter evaluated the effect of the addition of components naturally present in food (proteins, lipids, carbohydrates, organic acids and ethanol) on the antimicrobial activity of certain EOCs (carvacrol, eugenol, geraniol, thymol and vanillin) in their free form. In this first part, the influence of these food components on the antimicrobial activity of vanillin immobilized on silicon oxide particles was also evaluated. The results showed that bovine serum albumin (BSA), sunflower oil and some carbohydrates were the food components that most inhibited the antimicrobial activity of the free EOCs, with some exceptions. In media containing BSA the antimicrobial activity of geraniol was not inhibited. The same occurred with eugenol in media containing sunflower oil, or with carvacrol, eugenol, geraniol and thymol in media with D-lactose. Immobilized vanillin confirmed the inhibitory effect of the proteins, lipids and carbohydrates on the antimicrobial activity, but citric acid and ethanol enhanced the antimicrobial activity. These results demonstrate the importance of considering the composition of the food matrix when selecting an antimicrobial compound. The second chapter evaluated the application of EOCs against the growth and production of guaiacol by a spoilage and heat-resistant microorganism such as Alyciclobacillus acidoterrestris in orange juice. For this purpose, EOCs immobilized on silicon oxide particles were used with two different approaches: as additives and as processing aids. The presence of EOCs causes a microbial reduction and an inhibition of guaiacol production, maintaining their effectiveness after immobilization. This fact is of great interest, since immobilization avoids the problem of organoleptic alteration of the product, derived from the application of these antimicrobials in free form. In the third chapter, the antiviral activity of EOCs, both in free and immobilized form, against Tulane virus in water was studied. The application of EOCs in free form achieved a reduction in infectivity of only 1 log10, equivalent concentrations of immobilized antimicrobial reduced infectivity to more than 4.5 log10. On the other hand, it has been demonstrated that the antiviral mechanism is based on the ability of immobilized antimicrobials to modify or disrupt the viral capsid. Furthermore, it was determined that immobilized EOCs are not cytotoxic at effective antiviral concentrations. Despite the efficacy observed after immobilization of EOCs against bacteria and viruses, their practical application in the food industry presents several challenges, one of them is the acceptance of this technology by consumers. Thus, the last chapter studied the perception of consumers regarding the use of nanotechnology in food processing. The evaluation of the different foods in which nanotechnology had been applied in their processing or packaging was generally positive, and most consumers would buy them. Of all the products, those in which nanotechnology was not part of the food received the best evaluation. Considering this result, immobilized EOCs applied as processing aids would be the most highly valued, and therefore could be an excellent alternative to conventional preservation treatments, to control both viruses and bacteria during food production and storage. / This research forms part of project PID2021-128141OB-C21 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. H.G.LL. acknowledges the Universitat Politécnica de València for his predoctoral fellowship. The authors acknowledge native English translator Helen Warburton for editing the text. The authors gratefully acknowledge the financial support from the project PID2021-128141OB-C21 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. This work is also granted by the project TED2021- 132035B-I00, funded by MCIN/AEI/10.13039/501100011033 and by “European Union NextGenerationEU/PRTR”. CG-B thanks the financial support received from the Spanish State Agency of Research (PID2022-136963OBI00/AEI/10.13039/501100011033), the Xunta de Galicia [ED431C 2021/29 and Centro singular de investigación de Galicia accreditation 2019-2022 (ED431G 2019/03)], and the European Regional Development Fund (ERDF). H.G.LL. acknowledges the Universitat Politècnica de València for his predoctoral fellowship. The authors gratefully acknowledge the financial support from the project PID2021- 128141OB-C21 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. This work is also granted by the project TED2021-132035B-I00, funded by MCIN/AEI/10.13039/501100011033 and by “European Union NextGenerationEU/PRTR”. H.G.LL. acknowledges the Universitat Politècnica de València for his predoctoral fellowship.The authors gratefully acknowledge the financial support for the experiment reported herein from the Spanish Government (RTI2018-101599-B-C21-AR). Héctor Gómez Llorente wishes to thank the Universitat Politècnica de València for the FPI Grant. / Gómez Llorente, H. (2024). New Strategies to Enhance the Quality and Safety of Liquid Foods Based on the Use of Natural Antimicrobial Compounds [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/207284 / Compendio