Evaluation of the Antioxidant Capacity, Antimicrobial and Antiproliferative Potential of Fir (Abies alba Mill.) Honeydew Honey Collected from Gorski kotar (Croatia).

The paper examines the antiproliferative, antimicrobial and antioxidative effects of fir (Abies alba Mill.) honeydew honey from mountain region of Croatia (Gorski kotar) as a potential replacement for standard antibiotics and chemotherapeutic agents. Cell viability, annexin V assay and flow cytometry analysis served to analyse the antiproliferative effect on, apoptosis induction in and cell death of cancer cell lines: HeLa, MCF-7, SW620, CFPAC-1, MIA PaCa-2 and normal diploid human fibroblasts (BJ). Antimicrobial activity was tested against Staphylococcus and Acinetobacter strains by agar well diffusion and microdilution assays. The DPPH˙ assay determined the radical scavenging activity, while mathematical models helped to evaluate the kinetic data of DPPH˙ inhibition. Antiproliferative effect on all tested cell lines and the prominent effect on normal diploid human fibroblasts (BJ), colorectal adenocarcinoma (SW620, metastatic) and breast epithelial adenocarcinoma (MCF-7, metastatic) was observable. The mechanisms of antiproliferative effect included accumulation of cells in the sub-G1 phase in all tested cells and induction of apoptosis in SW620 and MCF-7 cells predominantly. The antibacterial assays showed that antibiotic-resistant strains of both bacteria, including multi-resistant strain A. baumannii ATCC® BAA-1605™, were sensitive to all tested honey samples. Radical scavenging assay suggests that antioxidants present in the honey possess different radical suppressing abilities and that they react at different rates with radicals, thereby causing two steps of reaction. The results of the study indicate that Croatian fir honeydew honey has a therapeutic potential due to the strong biological activity and can serve to protect human health.

Volatiles from a rare Acer spp. honey sample from Croatia.

A rare sample of maple (Acer spp.) honey from Croatia was analysed. Ultrasonic solvent extraction (USE) using: 1) pentane, 2) diethyl ether, 3) a mixture of pentane and diethyl ether (1:2 v/v) and 4) dichloromethane as solvents was applied. All the extracts were analysed by GC and GC/MS. The most representative extracts were 3) and 4). Syringaldehyde was the most striking compound, being dominant in the extracts 2), 3) and 4) with percentages 34.5%, 33.1% and 35.9%, respectively. In comparison to USE results of other single Croatian tree honey samples (Robinia pseudoacacia L. nectar honey, Salix spp. nectar and honeydew honeys, Quercus frainetto Ten. honeydew as well as Abies alba Mill. and Picea abies L. honeydew) and literature data the presence of syringaldehyde, previously identified in maple sap and syrup, can be pointed out as a distinct characteristic of the Acer spp. honey sample. Headspace solid-phase microextraction (HS-SPME) combined with GC and GC/MS identified benzaldehyde (16.5%), trans-linalool oxide (20.5%) and 2-phenylethanol (14.9%) as the major compounds that are common in different honey headspace compositions.

Occurence of Ochratoxin A and Biogenic Amines in Croatian Commercial Red Wines.

Food safety is one of the main concerns in the world and in wine it depends mostly on metabolites of microbial origin. The aim of this study was to investigate the occurrence of natural contaminants, ochratoxin A and biogenic amines (cadaverine, histamine, putrescine and tyramine), in Croatian commercial red wines originating from different Croatian wine-making regions. Ochratoxin A was detected in 92.8% of samples, however its concentrations in all samples were more than 10-fold lower than the limit set by the European Union (2 µg/kg), marking these wines as safe for consumption. The frequency of occurrence and measured concentrations of ochratoxin A were higher in wines produced in southern regions with highest values obtained in wines from southern Dalmatian islands. All samples were contaminated with cadaverine and putrescine, while 88.2% and 82.7% were contaminated with histamine and tyramine, respectively. Histamine concentrations ranged from below the limit of detection to 8.5 mg/L. Higher histamine concentrations were measured in wines with higher pH values which coincided with southern geographic origin. These results reinforce the need for routine detection and quantification of biogenic amines in Croatian wines to achieve better control of vinification and minimize their formation.

Deoxynivalenol and zearalenone in unprocessed cereals and soybean from different cultivation regions in Croatia.

The aim of this study was to investigate the occurrence of deoxynivalenol (DON) and zearalenone (ZEN) in unprocessed cereals and soybean sampled in 2014 and 2015 from different fields located in Croatian regions. A total of 306 samples were analysed for DON and 415 samples for ZEN concentrations using quantitative ELISA methods. In 2014, DON and ZEN were determined in all samples in the mean concentrations of 1,461 ± 2,265 µg/kg and 656 ± 853 µg/kg, respectively, while in 2015 these means were 2,687 ± 2,731 µg/kg and 1,140 ± 1,630 µg/kg, respectively. The cultivation year significantly (p < 0.05) influenced mycotoxin concentrations, whereas the influence of cultivation region was seen with ZEN for all cereals except soybean, and not seen with DON at all. A higher contamination determined during 2015 could be explained by high to extreme humidity evidenced in the period of cereals' growth and harvesting.