Diss. Alnarp : Sveriges lantbruksuniv., 2001. / Härtill 5 uppsatser.

Saving energy is considered about by much more people nowadays. The energy use of industrial drying occupies a large part of total energy usage. Not only the governments, but also the industry owners are trying to find ways to cut down the usage of energy. The aim of this work is to find suitable technologies for industrial drying of berries which can be energy-efficient at the same time. More specifically, to find suitable dryers for drying aronia berry in Sweden. The research is based on secondary data collected by literature review. Good options for other circumstances like fluidized bed drying, freeze drying and solar drying were not discussed in detail. After the study, a continuous hot air dryer with explosion puffing system and heat pumping system seems to be the best solution for drying aronia berry in Sweden. It is easy to be controlled, cost acceptable (both capital and operational costs), environmental friendly and has high drying rate and high product quality. The extra means for improve drying process such as combined with dielectric or conductive dryer, adding pre-treatment such as osmotic drying were also discussed. Combined dryers can reduce the drying time and osmotic drying can cut the operation cost. Careful experiments shall be done before large amount of investment due to the complexity of dehydration.

Strawberries can be considered a functional food because their consumption has been associated with several health benefits. They are important sources of bioactive compounds, such as vitamins and polyphenolic compounds, with recognized antioxidant capacity (AOC). However, strawberry overall quality and bioactive content are greatly affected by environmental conditions during pre- and post-harvest and, little is known about the stability of its bioactive compounds, specifically ascorbic acid (AA) and polyphenolics compounds. Furthermore, additional research that addresses the impact of polyphenolic compounds on in vitro and in vivo models is needed to understand the mechanisms behind their potential health benefits. Therefore, the objectives of the work presented in this thesis were to: 1) evaluate the impact of different disease control treatments on strawberry bioactive compounds and AOC; 2) understand the relationship between bioactive compounds and AOC in strawberries and fruit juices; 3) investigate the origin of AOC in strawberries by identifying their major polyphenolic compounds and, 4) explore the effects of polyphenol-rich fruits and fruit juices on the proliferation of cancer cells and lifespan of Caenorhabditis elegans. Conscientious consumers are aware of the health benefits of substantial fruit and vegetable consumption but are also concerned about the amount of pesticide residues that can be found in conventionally grown produce, with pesticide-free produce (i.e., organic) becoming more popular. However, the market price for organic strawberries can be more than twice that of conventionally grown fruit which discourages the average American from purchasing this fruit on a regular basis. Therefore, in the first study presented in this thesis, we hypothesized that reducing pesticide usage would provide the consumer with a “sustainable strawberry” that would have better or similar quality at a lower cost than organic fruit while it would also reduce environmental impact and risk to pesticide applicators. Results from this study showed that strawberries from a reduced fungicide treatment, had better or similar bioactive content and AOC than fruit from the conventional disease control treatment. After cold storage, strawberries from the reduced or conventional disease control treatments showed comparable amounts of bioactive compounds and AOC. These results indicate that growing strawberries with a reduced number of fungicide applications can be an alternative to the conventional disease control or organic practices as it may reduce residual fungicides in the fruit, decrease production costs while still retaining important bioactive compounds. In order to understand the relationship between bioactive compounds and AOC in strawberries and fruit juices, 56 different types of commercial beverages were chosen for the second study presented in this thesis. Overall, results showed that the higher the total phenolic contents (TPC) in the beverage the higher their AOC. Amongst all beverages studied, aronia, blackcurrant, and pomegranate juices contained the highest amount of TPC and AOC. Furthermore, after opening the bottles, these juices were maintained for 14 days at 4 °C, to test the stability of their TPC which was in general relatively stable throughout storage. Further investigation on individual polyphenolic compounds and their possible contribution to the overall AOC of fruits and fruit juices, led to a third study. Overall, results showed that the AOC of major individual polyphenolic compounds found in strawberries (i.e., pelargonidin, cyanidin, ellagic acid, quercetin, kaempferol, catechin, epicatechin, caffeic acid, p-coumaric acid, ferulic acid) was significantly higher than that of mixtures of the same compounds. In addition, the AOC of strawberries correlated with its major bioactive compounds (i.e., polyphenolic compounds and ascorbic acid) in a form of a synthetic bioactive strawberry model (“Powerberry”) composed of major strawberry polyphenolic compounds, vitamin C, fructose and glucose in the same ratios found in a real strawberry. These results suggest that even though strawberries contain many different polyphenolic compounds and vitamins, their AOC might only depend on few compounds that are found in significant quantities in the fruit. Finally, using cell and worm models we were able to demonstrate that conventional and organic strawberry, raspberry and blueberry fruits, and aronia, blackcurrant and pomegranate juices successfully inhibited the proliferation of HeLa cervical cancer cell lines. In addition, when introduced in low doses (0.75 mg ml-1 or lower) to the C. elegans diet, aronia, blackcurrant and pomegranate juices promoted longevity. Overall, results suggest that using whole fruit or fruit juices might constitute an alternative of treating cancer cells in vivo and that polyphenolic compounds contained in fruits and fruit juices displayed significant bioactivity in a worm model.

De nombreuses études ont indiqué que la consommation régulière d’aliments riches en polyphénols comme le vin rouge, le thé, ou les fruits est associée à une réduction du risque de pathologies cardiovasculaires chez l’homme et les animaux. L’effet bénéfique des polyphénols sur le système cardiovasculaire est dû, au moins en partie, à leur action directe sur les vaisseaux sanguins en améliorant la fonction endothéliale. En effet, de nombreuses études indiquent que les polyphénols induisent des relaxations dépendantes de l’endothélium dans les artères isolées en stimulant la formation endothéliale de monoxyde d’azote (NO). La comparaison des relaxations induites par 13 jus et purées de fruits différents dans les artères coronaires de porc a permis de sélectionner l’Aronia melanocarpa en raison de sa grande activité et de sa forte teneur en polyphénols. L’Aronia melanocarpa est un puissant inducteur de relaxations dépendantes de l’endothélium en stimulant la formation endothéliale de NO. Cette formation accrue de NO implique l’activation rédox-sensible de la voie Src/PI3-kinase/Akt qui va phosphoryler la NO synthase sur son site activateur entraînant une formation rapide de NO. A plus long terme, l’Aronia melanocarpa stimule l’expression de la NO synthase via un mécanisme rédox-sensible impliquant les voies PI3-kinase/Akt, JNK, et p38 MAPK, et entraînant la phosphorylation inactivatrice des facteurs de transcription FoxO1 et Fox3a; cet effet prévient la régulation négative de l’expression de la NO synthase endothéliale. En conclusion,nos études révèlent le potentiel d’Aronia melanocarpa à améliorer la protection vasculaire par la stimulation soutenue de la formation de NO. / Many studies indicated that the regular consumption of drink or food rich in polyphenols like red wine, green tea, fruits, vegetables and chocolate is associated with a reduction of the risk of cardiovascular pathologies in human and animals. The beneficial effect of polyphenols, well known as antioxidants, on the cardiovascular system is due at least partly to their direct action on the blood-vessels by improving the endothelial function. Indeed, many studies indicate that the polyphenols induce the endothelium-dependent vasorelaxation in the isolated arteries by stimulating the formation of endothelial nitric oxide (NO). Comparing the endothelium-dependent relaxations induced by 13 different fruit juices and purees in the isolated porcine coronary arteries, Aronia melanocarpa was selected due to its high activity and the highest polyphenol content. Aronia melanocarpa is a potent inducer of endothelium-dependent relaxation in coronary artery by stimulating the formation of endothelial NO. This increased formation of NO involves the redox-sensitive activation of the Src/PI3-kinase/Akt pathway leading to the phosphorylation of eNOS at the activation site, Ser1177, during the rapid formation. Further for the long-term, Aronia melanocarpa stimulates the expression of eNOS via a redox-sensitive mechanism involving PI3-kinase/Akt, JNK, p38 MAPK pathways and the subsequent inactivation of transcription factors FoxO1 and FoxO3a by phosphorylation; this effect prevents their negative regulation of eNOS expression. In conclusion, our studies reveal the potential of Aronia melanocarpa to improve vascular protection by stimulating in a constant way the formation of endothelial NO.

The diploma thesis deals with the preparation of extract and concentrate of anthocyanin dyes from aronia moldings (Aronia melanocarpa). It also determines chemical properties important for human´s health, which are important also for further possible use of extract/concentrate as natural red food coloring. A series of extractions of dried and powdered aronia moldings was carried out in the experimental part of the thesis, aiming for the optimization the conditions of the extraction. Extracts were characterized by content of total anthocyans, content of total fenolic substances and total antioxidant activity. The best laboratory conditions for extraction were determined as follows: amount of moldings 12,5 g, composition of extraction agent ethanol:water 1:1, volume of extraction mixture 60 ml and time of the extraction 11 hours. Prepared extracts were concentrated on vacuum evaporator. It has been found that the temperature of the water bath in the vacuum evaporator can not exceed 40 °C. At higher temperatures there is significant degradation of anthocyanins. Furthemore, the content of individual anthocyanic dyes in extract and concentrate, from aronia moldings, was quantified by HPLC. The major anthocyanin, cyanidine-3-galactoside, was contained in the concentrate at 923,6 ± 8,5 mg·l-1, the other specified anthocyanin, minor cyanidine-3-glucoside, was present at a concentration of 53,5 ± 0,3 mg·l-1.

In recent years, the use of natural medicinal properties of plants has again come to the forefront of interest of the public. Because of their therapeutic properties, these plants are commonly used in alternative treatments for minor ailments. This thesis deals with the determination of polyphenolic acids in extracts from aronia, echinacea, tetradenia and centella. One of the aims of the thesis was to compare the amount of polyphenolic acids in individual plants with their antioxidant properties. The theoretical part includes a general introduction to flavonoids, introduction to polyphenolic acids, introduction to the principles of capillary zone electrophoresis and a summary of selected foreign studies for the determination of flavonoids. An important chapter of the theoretical part is a description of individual plants with an explanation of their possible therapeutic use. The experimental part is devoted to the process of optimization of electrophoretic determination of selected polyphenolic acids and evaluation of their content. It was found that in the extracts six representatives of polyphenolic acids occur in minimal amounts, often below the limit of quantification or detection of the method.

This diploma thesis deals with comparison of the properties of chokeberry spreads of different origins, composition and different production technologies. The theoretical part contains a brief description of the chokeberry – Aronia melanocarpa, an overview of the most important substances contained in the chokeberry and examples of the use of aronia, not only in the food industry. Furthermore, the legislative requirements for the production of spreads and the production technology itself are described. In this thesis is also described a new patented technology of spread production using HTD technology. Another part of the theoretical part is a literature review of the determination of anthocyanins in chokeberry by HPLC method. The experimental part describes the laboratory procedures used for determination of dry matter, carbohydrates by HPLC with ELSD detector, anthocyanin dyes, total phenolic compounds and antioxidant activity. Another part of the work was a questionnaire survey and sensory analysis of selected chokeberry spreads. The panel members prefered the Lowicz chokeberry spread, for which was determined 29,39% dry matter, 15,15 mg.g-1 anthocyanins, 9,20 mg.g-1 total phenolic compounds, 158,42 mg.g-1 fructose and 151,26 mg.g-1 glucose and the antioxidant activity was determined to be 5,94 mg.g-1.

This diploma thesis deals with chemical analysis of selected frozen, dried and lyophilized fruit, specifically Mirabelle de Nancy, Aronia Nero and blackcurrant varieties Gairn Ben and Ben Lomond. In the theoretical part taxonomy and botanical characteristics of selected fruit are given. Subsequently the utilization of fruit in food industry is described. In common the theoretical part focuses on lyophilisation and drying of fruit and raw food. Further in this part the methods of phenolic substances, anthocyanins, antioxidant capacity and finally ascorbic acid and carbohydrates value measurements are specified. In the experimental part the value were determined measurements of biologically active substances: total phenols, total anthocyanins, antioxidant capacity, ascorbic acid and carbohydrates. For all value measurements were compared the frozen, dried and lyophilised samples of every single fruit. Further, the every sort of fruit were compared to each other. Following the raw food preparaon a product of lyophilised fruit was made.

This diploma thesis deals with possibilities of using of aronia fruit pomace. The theoretical part is focused on botanical characteristics of aronia fruit, description of HPLC and anthocyanins dyes. The effects of various extraction condition on content of some polyphenolic compounds (gallic and vanilla acids, katechin and rutin) in aronia berry pomace are investigated in the experimental part. The mentioned compounds were detected with HPLC. Thanks to this method the content of carbohydrates was also detected. A quantity of anthocyanins dyes was determined by pH differential method.

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniv. / Härtill 9 uppsatser.