Variations of Total Phenolic Content in Honey Samples Caused by Different Calibration Lines

In the review of total phenolic contents (TPCs) of acacia, lime, and chestnut honey samples from several literature sources, large differences were noticed, which cannot be attributed only to seasonal or geographical variations. The dependence of TPC on the process of construction of the calibration line is illustrated in the measurement of acacia, lime, and chestnut honey types from Croatia and neighbouring countries (Serbia, Italy, and Hungary). TPCs are determined for 39 uni-floral honey samples by four calibration lines and four TPC values are obtained for each honey sample. Obtained results are compared mutually, as well as with the literature results for honey samples of the same type. For each honey type, the average of all determined TPCs determined in this study is in the middle of literature values. The average TPC values for chestnut honey samples were found to be 1.5 and 3 times higher than those for lime and acacia, respectively. The effects of two factors regularly considered in the determination of calibration lines are analyzed: (1) the concentration range of the standard chemical and (2) whether the calibration line is drawn through the origin, or not. The final results strongly depend on these two factors that should be considered in future TPC estimations. This work is licensed under a Creative Commons Attribution 4.0 International License

Influence of the Beehive Type on the Quality of Honey

Agricultural producers apply numerous technological procedures, and enlarging efforts to produce the high-quality products. This initiative is present in the beekeeping, too. The quality of the honey produced by the honey bee colonies depends of various factors, but prevailing are the ecological conditions and the floristic composition of the honeyfull plants. The aim of our research was to discover the influence of the beehive type on the quality of honey, which is produced at apiaries under the similar environmental conditions. The whole studied honey bee colonies belong to the European race, Apis mellifera carnica, and they used the same honeyfull plants pastures. The results indicate that different beehive type used at apiaries influenced on the quality of honey

Influence of the Beehive Type on the Quality of Honey

Agricultural producers apply numerous technological procedures, and enlarging efforts to produce the high-quality products. This initiative is present in the beekeeping, too. The quality of the honey produced by the honey bee colonies depends of various factors, but prevailing are the ecological conditions and the floristic composition of the honeyfull plants. The aim of our research was to discover the influence of the beehive type on the quality of honey, which is produced at apiaries under the similar environmental conditions. The whole studied honey bee colonies belong to the European race, Apis mellifera carnica, and they used the same honeyfull plants pastures. The results indicate that different beehive type used at apiaries influenced on the quality of honey

Vitisin-Type Pigments: Possible Novel Food Colors

Spectral properties of different forms of several vitisin-type pigments, recently found in red wines and grapes, were studied. These orange-red tone compounds seem to be promising anthocyanin based food colors

Effect of pH on α-Amylase Activity and Early Seedling Growth of Red Clover (Trifolium pratense L.)

The pH of the surrounding media is one of the environmental factors that can severely limited legume growth and development. We preliminary examined the effect of four pH levels of germination media (4, 5, 6 and 7) on α-amylase activity, seed germination and radicle length of red clover (Trifolium pratense L.) and traits correlations to evaluate the significance of obtained relationships in development of an screening method for pH tolerance in the earliest phases of plant growth. The pH of germination media significantly affected red clover α-amylase activity (P<0.01), germination (P<0.05) and radicle length (P<0.05).The overall α -amylase activity was higher at 5 and 6 of pH than at pH 4 and 7. The activity of α -amylase at the same pH was most intensive during the first two days of germination. The highest seed germination percentage was found at pH 5. Length of radicle was higher at pH 5 and 6 than at 4 and 7. The occurrence of positive correlations (P<0.01) among tested traits suggested that the α-amylase activity might serve as a parameter for the pH tolerance testing

Structure-Radical Scavenging Activity Relationships of Flavonoids

The relationship between the structural characteristics of 29 flavonoids and their antiradical activity was studied. The obtained results suggest that the free radical scavenger potential of these polyphenolic compounds closely depends on the particular substitution pattern of free hydroxyl groups on the flavonoid skeleton. The possible mechanism of action of flavonoids lacking B ring OHs as free radical scavengers has been proposed

A Simple QSAR Model for Trypsin Aminopeptidase Inhibitory Flavonoids

A simple QSAR model of the trypsin aminopeptidase inhibitory flavonoids has been developed which enables prediction of the inhibitory potency of flavonoids as a function of their molecular properties. Based upon the results obtained, a possible mode of interaction between the flavonoid and its target receptor is proposed

Variability of milk urea, milk urea nitrogen, and ammonia emission from dairy Simmental and Holstein cows based on the milk recording month

The subject of this paper was to define the variability of milk urea, milk urea nitrogen, and ammonia emission from dairy Simmental and Holstein cows relating to months of milk recording through the precision farming methodology. Test-day records of dairy cows used in the statistical analysis were collected over five years. Regarding the parity, the animals were divided into four classes; regarding the recording date, test-day records were divided into twelve recording months, from January to December. The analysis was performed separately for each breed. The significance of the differences between the recording months was tested by the Scheffe's method of multiple comparisons (using the PROC GLM procedure in SAS). In terms of results, lower ammonia emission per cow was determined in the winter, while the ammonia emission was higher in the summer. Also, higher values of milk urea, milk urea nitrogen, as well as higher ammonia emission per animal, were determined in the Holstein than in Simmental cows