Elżbieta Wojtowicz

Comparative Analysis of the Antioxidant Capacity of Selected Fruit Juices and Nectars: Chokeberry Juice as a Rich Source of Polyphenols

The bioactive compounds, and hence the antioxidant capacity, of fruit juice are affected by a given type of juice and fruit processing conditions. In this study, some polyphenol-rich juices and nectars were compared, considering the manufacturing conditions (Stage I). Organic chokeberry juice was determined to possess the highest antioxidant capacity, which was 4- to 10-fold higher than in other popular juices. Subsequently, this juice was analyzed for selected flavonoids (flavanols, flavonols, flavones) and phenolic acids (Stage II). The results showed that chokeberry juice was a rich source of chlorogenic and neochlorogenic acids. The high total content of polyphenols and high antioxidant capacity encourage further clinical research on chokeberry juice, in the context of cardiovascular diseases prophylaxis.

Odor Active Compounds Content in Spices and Their Microencapsulated Powders Measured by SPME

Within this study, main odorants of marjoram and thyme (linalool and thymol) were determined in spices and microencapsulated powders using solid-phase microextraction (SPME). Analyses were conducted on selected batches of spices before and after decontamination and on microencapsulated powders prepared for technological purposes (improvement of aroma in decontaminated spices). Conditions of SPME analyses were determined for individual compounds and matrices. Determination of total and surface contents of compounds and the percentage dependencies between encapsulated and surface aroma made it possible to identify the best powders in terms of their quality.

Phenolic compounds reduce formation of Nε-(carboxymethyl)lysine and pyrazines formed by Maillard reactions in a model bread system

This study had the objective of determining the antiglycation activity of phenolic compounds (PCs) ((+)-catechin, quercetin, gallic, ferulic, and caffeic acids) added to a model bread with regards to the inhibition of Nε-(carboxymethyl)lysine (CML) formation. PCs were found to significantly reduce CML (31.77%-87.56%), even at the lowest concentration, with the exception of ferulic acid (FA). The strongest inhibitory effect of FA (∼62%) appeared when concentration was increased to 1.0g/100g of flour. The available lysine losses (0.00%-90.51%) showed a significant correlation (0.853-0.990) with effectiveness of CML inhibition, except in the case of samples with FA. (+)-Catechin reduced CML levels the most, probably due to its structure-antioxidant activity relationship, its thermal stability (∼51% loss), and its reactivity with ε-lysine side chains (∼40.77% loss). Although the bread supplemented with PCs contained low levels of CML, this process may adversely affect bread flavor, reducing the formation of pyrazines (1.10%-80.77%).

Bioactive β-carbolines norharman and harman in traditional and novel raw materials for chicory coffee

The β-carboline compounds norharman and harman exhibit neuroactive activity in the human body. Chicory coffee has proved to be a source of β-carboline compounds. This study assessed the norharman and harman contents of traditional and novel raw materials for the production of chicory coffee, as well as in samples of chicory coffee with novel additives. The highest content of the β-carbolines among the traditional raw materials was recorded in roasted sugar beet (2.26 μg/g), while roasting the chicory caused a 25-fold increase in the content of norharman in this raw material (from 0.05 to 1.25 μg/g). In novel raw materials not subjected to the action of high temperature, β-carboline was not detected. Among the roasted novel raw materials, the highest contents of harman and norharman were found in artichokes. High harman levels were also recorded in roasted chokeberry.

Chlorogenic acid in raw materials for the production of chicory coffee.

BACKGROUND Chicory coffee is produced from traditional raw materials. Other materials are added to improve its aroma. The aim of this study was to test new raw materials with a high content of chlorogenic acid (CGA) as the criterion for their selection. This acid is degraded in the course of roasting and is a source of phenolic compounds affecting coffee aroma. For this reason, contents of CGAs were analyzed in traditional and new materials before and after roasting and compared with the chemicals formed in the roasted pure standard of chlorogenic acid (5-CQA). RESULTS It was shown that the novel raw materials contained considerable amounts of 5-CQA, frequently higher than in traditional chicory. The roasting process caused significant losses of 5-CQA in the tested raw materials, amounting to 55-91%. In turn, the analysis of volatile compounds in roasted materials showed the presence of certain phenolic and heterocyclic compounds that were also formed as degradation products of the pure 5-CQA chemical standard. CONCLUSION Novel raw materials, mainly chokeberry, artichoke and lovage, are rich sources of CGAs, particularly 5-CQA. Their application in the production of chicory coffee may result in an increased content of primarily phenolic compounds in its aroma.

Essential oil content and its composition in herb of lemon balm (Melissa officinalis L.) breeding strains

Abstract The evaluation of essential oil content and its composition in the herb of lemon balm breeding strains was the goal of the research, with the aim of selecting appropriate genotypes for further breeding programs. In 2013–2014, at the beginning of flowering, the herb was collected from ten randomly selected plants of eight strains bred in the nursery. The essential oil content was estimated after hydrodistillation of dried lemon balm herb, in accordance with the method recommended by the European Pharmacopoeia VI; the essential oil was then subjected to gas chromatography. Both the yield of lemon balm essential oil and its composition showed significant differentiation among the investigated strains. These differences were associated with fluctuations in weather conditions in the years of the research. Higher levels of the main components (neral and geranial), though not of essential oil itself, were observed under higher insolation.

Aroma of Decontaminated Leaf and Fruit Spices

Selected leaf and fruit spices were steam decontaminated by original continuous process. Aroma compounds of spices were analyzed before and after decontamination. A total of identified 24 volatiles were identified in marjoram, 21 volatiles in thyme, 8 volatiles in caraway and 14 in coriander, as it was also mentioned by other authors. The GC/O analysis showed that the primary compounds responsible for aroma in analyzed spices were linalool and cis-sabinene hydrate in marjoram, thymol in thyme, carvone in caraway and linalool in coriander, which received the highest dilution factor values (FD) both before and after decontamination. It was determined that the content of the main odorants may be estimated by a SPME/GC method. On the basis of these compounds it was found that steam decontamination caused considerable losses in leaf spices. No significant changes were found in the content of volatile compounds in fruit spices as a result of decontamination. Also, chiral analysis of key odorants in spices did not show changes in the enantiomeric distributions (linalool in marjoram, carvone in caraway and limonene in coriander) as a result of decontamination.

Antioxidant Properties and Phenolic Compounds of Vitamin C-Rich Juices: Antioxidant properties of vit.-C juices…

Many studies have shown that bioactive compounds, for example, polyphenols, and so on can play an important role in reducing oxidative stress and protect against various diseases. The sources of these compounds in the human diet include mainly fruit and good quality fruit juices, which may contain polyphenols but also other phytochemicals such as vitamin C. The purpose of the study was to analyze the antioxidant properties of vitamin C-rich juices, which underwent mild processing. The content of total polyphenols (TP, FBBB), total flavonoids (TF), total anthocyanins (TA), and vitamin C as well as the antioxidant capacity (DPPH, ABTS) were evaluated in commercial fruit juices rich in vitamin C (acerola, gojiberry, sea buckthorn, wild rose, cranberry, Japanese quince). Moreover, phenolic acids and selected flavonoids were determined by HPLC methods. Among the examined fruit juices, acerola and wild rose juices contained the highest amounts of vitamin C and total polyphenols, and had the highest antioxidant capacity. Acerola owes its high antioxidant properties mainly to vitamin C, whereas the antioxidant capacity of wild rose is also attributed to its rich content of flavonoids and phenolic acids. Sea buckthorn juice and Japanese quince juice had a lower antioxidant capacity, yet higher than determined for gojiberry and cranberry juices. Total anthocyanins were the highest in cranberry juice. The results showed that the analyzed juices were a valuable source of natural antioxidants. Generally, vitamin C-rich juices are also good source of polyphenols. Vitamin C and polyphenols act synergistically and define the antioxidant properties of juices. PRACTICAL APPLICATION Bioactive compounds, for example, polyphenols play an important role in reducing oxidative stress and protect against various diseases. Sources of natural antioxidants in human diet include mainly fruit and good quality fruit juices. The study showed that the juices from acerola, gojiberry, sea buckthorn, wild rose, cranberry, Japanese quince were a valuable source of natural polyphenols and vitamin C. These compounds act synergistically and define the antioxidant properties of juices. Among all examined samples, acerola and wild rose juices seem to be the most valuable. Moreover, its worth noticing that juices underwent mild processing (cold pressed and low pasteurization) retained more bioactive compounds, which affected their higher quality.

The antioxidant properties of exotic fruit juices from acai, maqui berry and noni berries

Various natural sources of antioxidants, which may help defy oxidative stress and thereby reduce the risk of many diseases, are being searched for. Exotic fruits and good quality exotic fruit juices can be an alternative to many berries grown in Europe. This paper presents the antioxidant properties and composition of polyphenols of acai, maqui berry and noni juices. Then they were compared to local juices rich in polyphenols, such as elderberry, raspberry and blueberry juices. The research has shown that the highest antioxidant capacity possessed acai juice among the exotic juices and elderberry juice among the local ones. The same two juices had the highest content of polyphenolic compounds, including flavonoids. Noni and maqui berry juices were inferior to acai and elderberry juices in this respect, and did not surpass considerably the qualities of raspberry and blueberry juices. The highest content of total anthocyanins was detected in elderberry juice. Exotic acai juice contains the highest levels of flavonols (mainly catechins) as well as ferulic and chlorogenic acids. Concluding, juices from exotic acai, noni and maqui berry fruits, because of their antioxidant properties, can be an interesting alternative to local juices. Acai juice seems to be the most valuable, in particular.

Antioxidant activity and free radicals of roasted herbal materials

Summary Introduction: Novel raw materials are being constantly searched for chicory coffee, which thanks to their specific composition can influence human health, thus promoting properties and of course the attractive aroma. Prior to their addition herbs – sea buckthorn (Hippophaë rhamnoides L.), rowanberry (Sorbus aucuparia L.), lovage roots (Levisticum officinale Koch) and dandelion (Taraxacum officinale coll.) – are roasted, which may change their antioxidant properties and generate free radicals with pro-oxidative properties. Objective: The characteristic of antioxidant activity of roasted herbal raw materials (sea buckthorn fruits, rowanberry, lovage roots and dandelion roots) for the production of chicory coffee and to determine the level of free radicals formed under the influence of roasting. Methods: Total phenolic contents were determined before and after the roasting process using the Folin-Ciocalteu phenol reagent and antioxidant activity by ABTS and DPPH assays. Free radicals were examined using electron paramagnetic resonance (EPR) spectroscopy. Results: The roasted materials were good sources of bioactive compounds, estimated at the total phenolic levels from 23.9 to 38.8 mg GAE/g. The highest antioxidant activity by ABTS and DPPH at 109.6 and 71.0 mg Tx/g was determined in roasted sea buckthorn. Free radicals were present in both the raw and roasted herbal materials. Roasted materials were characterised by markedly higher free radical concentrations when compared with the corresponding samples. The lowest free radical concentrations were recorded for roasted sea buckthorn fruits (0.031 × 1015 spin/g). Conclusion: Despite a high content of compounds with potent antioxidant activity, free radicals were present in novel roasted herbal materials. The formation of both antioxidant molecules and free radicals during the roasting process demonstrates that the two processes were not inversely related.