L. is a wild relative of garlic, and it is abundant in many antioxidant compounds. Sulfur compounds, primarily cysteine sulfoxides (CSOs), are converted through several reactions into various ...volatile molecules, which are considered the principal flavor compounds of Alliums. In addition to secondary metabolites, wild garlic is abundant in primary compounds, such as amino acids, which serve not only as building blocks for the health-promoting sulfur compounds but also as antioxidants. The aim of this study was to investigate the link between individual amino acid contents, the total phenolic content, and the profile of volatile compounds as well as their influence on the antioxidant capacity of both the leaves and bulbs of wild garlic populations in Croatia. Both univariate and multivariate methods were used to study the differences in the phytochemical compositions among the wild garlic plant organs and the link between individual compounds and antioxidant capacity. Both the plant organ and location, as well as their interaction, have a significant impact on the content of total phenolic content, amino acids, volatile organic compounds, and the antioxidant capacity of wild garlic.
Total flavonoid and total phenolic content were studied in acacia and multifloral honey for 12 months in 6-month intervals. DPPH (1,1-diphenyl-2-picrylhydrazyl) and FRAP (ferric reducing antioxidant ...power) methods were used to determine total antioxidant activity in honey samples during the same period of time. Samples were stored in transparent glass containers at room temperature, on shelves exposed to natural light during daytime and in the dark during nighttime. Two types of honey from four different regions in Varazdin county, Croatia, were investigated: monofloral--acacia (Robinia pseudoacacia L.) and multifloral. Of the total of 40 samples, there were 20 of each type of honey (5 from each region). The goal of this study is primarily to demonstrate the changes in the antioxidant activity of the two investigated types of honey during one year of storage, and not to make comparisons between them. According to the obtained data, the rate of decrease in the content of total flavonoids and phenolics was determined and changes in the antioxidant activity in honey samples were measured. After one year of storage, total phenolic content decreased by 91.8 % in acacia honey, and by 88.6 % in multifloral honey. Total flavonoid content also decreased in both types of honey, by 45.6 % in acacia honey and by 43.8 % in multifloral honey. During the same period, an increase from 12.20 to 16.73 mg/mL (i.e. by 37.1 %) was recorded in the IC50 values in multifloral honey, while in acacia honey this increase was from 44.64 to 407.01 mg/mL (i.e. by 811.7 %). Decrease in the antioxidant activity measured by FRAP method was also bigger in acacia honey than in multifloral honey (by 428.0 and 72.5 %, respectively), which corresponds well with the results obtained by DPPH method. Simple correlations were made to determine how each of the investigated parameters affects the others. The analysis of variance was used in order to determine the influence of the region, honey type and storage time on different parameters of antioxidant activity as well as on the total phenolic and total flavonoid content in honey samples. Key words: antioxidant activity, phenolic compounds, honey, storage
Ultrasonication is a nonthermal food processing method that is used in several applications (extraction, treatment before drying, freezing, inactivation of microorganisms, etc.) in ultrasound ...processing. The objective of this study is to investigate the effect of high power ultrasound and pasteurisation on the aroma profile and sensory properties of apple juice and nectar. Samples were treated according to the experimental design, with high power sonicator at ultrasound frequency of 20 kHz under various conditions (treatment time: 3, 6 and 9 min, sample temperature: 20, 40 and 60°C, and amplitude: 60, 90 and 120 mm). The aromatic profiles of juices showed that, compared to the untreated samples of juices and nectars, ultrasonic treatment led to the formation of new compounds (which were not present in the untreated samples) or to the disappearance of compounds that were found in the untreated samples. Samples treated at the highest amplitude (120 mm) were used for evaluation and comparison with untreated and pasteurised samples using electronic tongue study. Principal component analysis confirmed the results of electronic tongue study, which showed that the ultrasound-treated and pasteurised juices had different scores compared to the untreated samples. Key words: high power ultrasound, apple juice and nectar, aroma profile, sensory properties, electronic tongue
Novel approach in food fortification by using natural deep eutectic solvent (NADES) was studied. Cocoa by-products were chosen as sustainable source of polyphenols and extracts were prepared ...following the green extraction principles by using NADES. Antioxidative and biological activities of prepared extracts rich in polyphenols were determined and they were used for fortification of chocolate milk. Furthermore, electronic tongue analysis combined with SIMCA multivariate data analysis was used for the first time, to evaluate the sensory acceptability of chocolate/cocoa drinks with addition of NADES extracts, which is after safety issues, surely one of the most important features for possible application of those extracts in food industry. Based on presented results it is evident that carefully selected NADES could be used for efficient extraction of polyphenols from cocoa by-products and that obtained NADES extracts could be used for fortification in food industry, without removal of extraction solvent, since they are proven safe and estimated as sensory acceptable.
•Efficient extraction of cocoa waste polyphenols with natural deep eutectic solvents (NADES).•NADES based extracts could be directly used for food fortification.•Potential cosmetic applications of NADES extracts is showed by in-vitro study on keratinocytes.•Guidance for the legislation and application of NADES extracts were given.
The aim of this study is to characterise 8 different monofloral and multifloral types of Croatian honey (a total of 254 samples from 2003, 2004, and 2005 harvesting seasons) based on 11 common ...physicochemical parameters (water mass fraction, total reducing sugar mass fraction, sucrose mass fraction, ash mass fraction, electrical conductivity, acidity, diastase and invertase activity, hydroxymethylfurfural (HMF) mass fraction, proline mass fraction and optical rotation). Differences in the above-mentioned parameters, established among the honey samples, are influenced by different factors, such as botanical origin, climate and regional circumstances. After the sample characterisation, results obtained for 2 monofloral (acacia (Robinia pseudoacacia) and chestnut (Aesculus hippocastanum)), and 2 multifloral (floral and meadow) honey types were subjected to the pattern recognition procedures. In this regard, unsupervised methods such as cluster and principal component analyses were employed, with the goal of evaluating the possibility of differentiation of Croatian honey stemming from different botanical origins, based on their physicochemical profile. Cluster analysis (CA) revealed the existence of two clusters, in the first of which is acacia honey as the best grouped, and the second corresponds to the dispersed group constituted of the remaining three honey types under investigation (chestnut, floral, and meadow). Principal component analysis (PCA), i.e. its first two components, stood for the average of 50.5 % of the data variance. PCA and CA showed that physicochemical parameters are able to provide enough information to allow for the classification and distinction of the types of honey originating from four botanical origins under investigation (acacia, chestnut, floral and meadow). Key words: honey, physicochemical parameters, botanical origin, cluster analysis (CA), principal component analysis (PCA)
Minerals occur in all foodstuffs as well as in milk and dairy products. The mineral content in milk is influenced by many factors ranging from environmental conditions during pasture, feeding, ...breeding, stage of lactation and climate to post-milking handling, transportation and processing. The aim of the study was to assess whether the intakes comply with Recommended Dietary Allowances (RDA), Adequate Intakes (AIs) or Tolerable Upper Intake Levels (ULs) for essential elements. Milk samples from different producers and with different fat content were purchased from Zagreb’s market four times in year 2007 and analysed. Concentrations of ten minerals (Ca, P, Mg, Fe, Cu, Zn, Mn, Ni, K and Na) were determined by atomic absorption spectrometry. Mean values of mineral contents were in range with the literature data. The daily intakes of these minerals by school children selected in age-gender groups (school children 8-9 years old and adolescents 15-18 years old) through milk consumption were also estimated. The average daily intake of essential minerals ranged from a minimum of 1.36 % of manganese up to 35.27 for phosphorus, irrespective of age and gender of children.
Legume flours can nutritionally enrich gluten-free bread but can also negatively affect its flavour. Although sourdough fermentation can improve bread flavour, its application to legume–cereal ...gluten-free matrices has been scarcely investigated. The aim of this study was to determine the effects of partial replacement (25%) of wholemeal rice with yellow pea flour (YPF) and the addition of sourdough (20%, dough basis) fermented with
Lactobacillus reuteri
DSM 20016,
Lactobacillus fermentum
DSM 20052 or
Lactobacillus brevis
DSM 20054 on the volatile profile and sensory properties of gluten-free bread. The 62 volatile compounds were quantified by HS-SPME/GC–MS. Quantitative descriptive and hedonic sensory analyses of bread odour and flavour were performed. The addition of YPF increased the concentration of undesirable hexanal,
(E,E)
-2,4-decadienal and benzaldehyde in bread. It also decreases the acceptability of crumb odour and bread flavour, mainly by increasing the intensity of the pea crumb odour, bread flavour and aftertaste. The addition of sourdough increased the concentration of desirable 2-methylbutanal, 3-methylbutanal, phenylacetaldehyde, octanal, nonanal and 3-methyl-1-butanol in bread, with the effect depending on the addition of YPF and the starter used for fermentation. It also decreased the concentration of undesirable hexanal and increased bread flavour and crumb odour acceptability of bread with YPF, mainly by decreasing the intensity of pea odour.
L. brevis
sourdough bread with YPF had the highest concentration of the above-mentioned desirable compounds.
Acrolein is a toxic compound present in food. It can be formed by bacterial species isolated from sourdough or applied as sourdough starter cultures, such as
Lactobacillus reuteri
. To the best of ...our knowledge, the content of acrolein in sourdough bread has not yet been determined, neither has a method for its quantification in such a sample been published. The aim of this study was to develop and validate a simple method for determining acrolein in sourdough, batter, and bread by headspace solid-phase microextraction combined with gas chromatography–mass spectrometry. The selected conditions for acrolein extraction were temperature 40 °C and time 20 min. A significant effect of the matrix on acrolein signal was observed. Linearity and precision were achieved within the examined range for all evaluated matrices. The obtained limits of detection and quantification were 1.21 μg/kg of sample and 4.05 μg/kg of sample, respectively. The acrolein solution with the addition of 0.2% hydroquinone was stable for 48 h. The developed method was applied for the quantification of acrolein in gluten-free sourdough (with
L. reuteri
DSM 20016 or
L. brevis
DSM 20054 as a starter culture), and batter and bread with or without added sourdough. Acrolein was not detected in the samples prepared without
L. reuteri
DSM 20016. Acrolein content in bread prepared with
L. reuteri
DSM 20016 sourdough was 161 μg/kg, which is below the WHO provisional tolerable concentration, but its consumption would significantly contribute to the overall acrolein exposure.
•Concentrations of macro-, micro- and toxic elements were measured in 10 honey types.•Honeys were collected in four regions of Croatia in three beekeeping seasons.•Significant differences were found ...in the element levels between different honeys.•Element content differences in honeys were measured between seasons.•Regional element content differences of the same honey types were established.
Concentrations of 20 elements were measured in ten honey types collected from four main geographical regions of Croatia during three beekeeping seasons. The four regions differ by their geography, ecology and climate. Significant differences in the element concentrations between honeys of different botanical origin were found for Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Mo, Na, Pb and Zn (p<0.05). The highest mean concentrations of elements were found in honeys: floral Cd, Cr; acacia Mo; honeydew Al, Cu, K, Ni; chestnut Ba, Ca, Mn, Na; forest Fe, Mg; sunflower Cu; linden Pb, Co; sage Se; lacy phacelia Zn. Differences in the element content of honeys originating from the same region collected in different seasons was found for the honeys: floral Al, Ca, K, Zn; acacia Ba, Ca, Cu, Mg, Mn, Na, Zn; honeydew Cu, K, Mn, Pb; chestnut Al, Ba, Cu, K, Mn, Na, Pb; sunflower Cu; linden Ba, Ca, Mn. Also, regional differences in the element content of honeys collected within the same season was found for: floral Al, Ca, K, Mg; acacia Ca, K, Mg, Mn, Na, Zn; honeydew Cu, K, Mn, Pb; sage Ba, Ca, K, Mg, Mn; chestnut Ba.
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