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Fatty Acid and Proximate Composition of Bee Bread

 

Muammer Kaplan1, Öznur Karaoglu1, Nazife Eroglu1 and Sibel Silici2*
 

1TUBITAK Marmara Research Center, Food Institute, Gebze, TR-41470 Kocaeli, Turkey
2Erciyes University, Agriculture Faculty, Department of Agricultural Biotechnology, TR-38039 Kayseri, Turkey



Article history:
Received    February 7, 2016
Accepted   July 29, 2016


Key words:
bee bread, fatty acid composition, proximate composition, monofloral pollen, pollen analysis


Summary:
Palynological spectrum, proximate and fatty acid (FA) composition of eight bee bread samples of different botanical origins were examined and significant variations were observed. The samples were all identified as monofloral, namely Castanea sativa (94.4 %), Trifolium spp. (85.6 %), Gossypium hirsutum (66.2 %), Citrus spp. (61.4 %) and Helianthus annuus (45.4 %). Each had moisture content between 11.4 and 15.9 %, ash between 1.9 and 2.54 %, fat between 5.9 and 11.5 %, and protein between 14.8 and 24.3 %. A total of 37 FAs were determined with most abundant being (9Z,12Z,15Z)-octadeca-9,12,15-trienoic, (9Z,12Z)-octadeca- 9,12-dienoic, hexadecanoic, (Z)-octadec-9-enoic, (Z)-icos-11-enoic and octadecanoic acids. Among all, cotton bee bread contained the highest level of ω-3 FAs, i.e. 41.3 %. Unsaturated to saturated FA ratio ranged between 1.38 and 2.39, indicating that the bee bread can be a good source of unsaturated FAs.
 




*Corresponding author:  email3   This e-mail address is being protected from spambots. You need JavaScript enabled to view it.
                                      tel3  +90 352 207 6666
                                      fax2  +90 352 437 6209


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Raw Glycerol and Parboiled Rice Effluent for Carotenoid Production: Effect of the Composition of Culture Medium and Initial pH

 

Carolina Moroni Silva, Thais de Matos de Borba, Susana Juliano Kalil and Janaína Fernandes de Medeiros Burkert*
 

Federal University of Rio Grande (FURG), Chemistry and Food School (EQA), PO Box 474, BR-96203-900 Rio Grande, RS, Brazil



Article history:
Received    August 27, 2015
Accepted   June 29, 2016


Key words:
natural pigments, by-products, Plackett-Burman design, Xanthophyllomonas dendrorhous


Summary:
Search for naturally grown food has stimulated the biotechnological production of carotenoids. Therefore, the use of the yeast Xanthophyllomonas dendrorhous has been researched due to its abilities to assimilate different sources as substrates and to produce high amounts of carotenoids. Furthermore, alternative sources have been used as the culture medium to reduce costs and environmental impact. A potent carotenoid is astaxanthin in view of its health-promoting and antioxidative properties. It consists of different geometrical isomers with trans and cis configuration. In X. dendrorhous this carotenoid is mostly found in the trans form, but cis isomers can also be found. Carotenoid production was investigated in culture medium containing by-products such as raw glycerol (from biodiesel) and parboiled rice effluent. The effects of the culture medium components on biomass concentration and specific and volumetric productions of carotenoids were verified by the Plackett-Burman design. Cultivations were carried out with yeast Xanthophyllomonas dendrorhous NRRL Y-17268 at 25 °C and 150 rpm for 168 h. In this study, maximum production of carotenoids was obtained under the following conditions (in g/L): raw glycerol 10, glucose 10, yeast extract 10, malt extract 10 and peptone 1 at pH=6. Resulting specific and volumetric productions of carotenoids were 326.8 and 4.1 μg/g, respectively.



 


*Corresponding author:  email3   This e-mail address is being protected from spambots. You need JavaScript enabled to view it.
                                      tel3  +55 53 3293 5381
                                      fax2  +55 53 3293 6968



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Prevalence of Thermotolerant Campylobacter spp. in Chicken Meat in Croatia and Multilocus Sequence Typing of a Small Subset of Campylobacter jejuni and Campylobacter coli Isolates

 

Marina Mikulić1*, Andrea Humski1, Bela Njari2, Mario Ostović2, Sanja Duvnjak1 and Željko Cvetnić1
 

1Croatian Veterinary Institute, Savska cesta 143, HR-10000 Zagreb, Croatia
2University of Zagreb, Faculty of Veterinary Medicine, Heinzelova 55, HR-10000 Zagreb, Croatia





Article history:
Received    February 12, 2016
Accepted   May 25, 2016


Key words:
thermotolerant Campylobacter, chicken meat in Croatia, prevalence, multilocus sequence typing (MLST) method


Summary:
In order to detect thermotolerant Campylobacter spp., 241 samples of fresh chicken meat, at retail in Croatia, were analysed according to a standard method, followed by biochemical test and molecular polymerase chain reaction/restriction enzyme analysis for exact species determination. Campylobacter spp. prevalence was 73.86 %. Campylobacter jejuni and Campylobacter coli were isolated from 53.53 and 15.35 % of the samples, respectively. In 4.98 % of isolates thermotolerant Campylobacter spp. were not determined. The multi locus sequence typing method was used to evaluate genetic diversity of eight Campylobacter jejuni and four Campylobacter coli isolates. To our knowledge, these results of genotyping provided the first data on the presence of sequence types (STs) and clonal complexes (CCs) of Campylobacter jejuni and C. coli isolates in Croatia. By applying the multilocus sequence typing, a new allele of tkt gene locus was discovered and marked tkt508. The C. jejuni ST 6182 and C. coli ST 6183 genotypes were described for the first time, and all other identified genotypes were clustered in the previously described sequence types and clonal complexes. These fi ndings provide useful information on the prevalence and epidemiology of Campylobacter jejuni and C. coli in Croatia.


 


*Corresponding author:  email3  This e-mail address is being protected from spambots. You need JavaScript enabled to view it.
                                      tel3  +385 1 612 3611
                                      fax2  +385 1 619 0841



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Processed Meat Protein and Heat-Stable Peptide Marker Identification Using Microwave-Assisted Tryptic Digestion

 

Magdalena Montowska* and Edward Pospiech
 

Institute of Meat Technology, Poznan University of Life Sciences, Wojska Polskiego 31, PL-60-624 Poznan, Poland



Article history:
Received    November 22, 2015
Accepted   May 20, 2016


Key words:
protein aggregation, thermal denaturation, enzymatic cleavage acceleration, microwave irradiation, mass spectrometry, peptide markers


Summary:
New approaches to rapid examination of proteins and peptides in complex food matrices are of great interest to the community of food scientists. The aim of the study is to examine the influence of microwave irradiation on the acceleration of enzymatic cleavage and enzymatic digestion of denatured proteins in cooked meat of five species (cattle, horse, pig, chicken and turkey) and processed meat products (coarsely minced, smoked, cooked and semi-dried sausages). Severe protein aggregation occurred not only in heated meat under harsh treatment at 190 °C but also in processed meat products. All the protein aggregates were thoroughly hydrolyzed after 1 h of trypsin treatment with short exposure times of 40 and 20 s to microwave irradiation at 138 and 303 W. There were much more missed cleavage sites observed in all microwave-assisted digestions. Despite the incompleteness of microwave-assisted digestion, six unique peptide markers were detected, which allowed unambiguous identification of processed meat derived from the examined species. Although the microwave-assisted tryptic digestion can serve as a tool for rapid and high-throughput protein identification, great caution and pre-evaluation of individual samples is recommended in protein quantitation.


 




*Corresponding author:  email3  This e-mail address is being protected from spambots. You need JavaScript enabled to view it.
                                      tel3  +48 61 8487 257
                                      fax2  +48 8487 254


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Genetic Diversity and Symbiotic Efficiency of Indigenous Common Bean Rhizobia in Croatia

 

Ines Pohajda1, Katarina Huić Babić2, Ivana Rajnović3, Sanja Kajić3 and Sanja Sikora3*
 

1Advisory Service, Savska cesta 41, HR-10000 Zagreb, Croatia
2Genera, Svetonedeljska 2, Kalinovica, HR-10436 Rakov Potok, Croatia
3University of Zagreb, Faculty of Agriculture, Department of Microbiology, Svetošimunska 25, HR-10000 Zagreb, Croatia





Article history:
Received    April 13, 2016
Accepted   July 29, 2016


Key words:
nitrogen fixation, Rhizobium leguminosarum, common bean, indigenous strains, RAPD, ERIC-PCR, symbiotic efficiency


Summary:
Nodule bacteria (rhizobia) in symbiotic associations with legumes enable considerable entries of biologically fixed nitrogen into soil. Efforts are therefore made to intensify the natural process of symbiotic nitrogen fixation by legume inoculation. Studies of field populations of rhizobia open up the possibility to preserve and probably exploit some indigenous strains with hidden symbiotic or ecological potentials. The main aim of the present study is to determine genetic diversity of common bean rhizobia isolated from different field sites in central Croatia and to evaluate their symbiotic efficiency and compatibility with host plants. The isolation procedure revealed that most soil samples contained no indigenous common bean rhizobia. The results indicate that the cropping history had a significant impact on the presence of indigenous strains. Although all isolates were found to belong to species Rhizobium leguminosarum, significant genetic diversity at the strain level was determined. Application of both random amplification of polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus–polymerase chain reaction (ERIC-PCR) methods resulted in similar grouping of strains. Symbiotic efficiency of indigenous rhizobia as well as their compatibility with two commonly grown bean varieties were tested in field experiments. Application of indigenous rhizobial strains as inoculants resulted in significantly different values of nodulation, seed yield as well as plant nitrogen and seed protein contents. The most abundant nodulation and the highest plant nitrogen and protein contents were determined in plants inoculated with R. leguminosarum strains S17/2 and S21/6. Although, in general, the inoculation had a positive impact on seed yield, differences depending on the applied strain were not determined. The overall results show the high degree of symbiotic efficiency of the specific indigenous strain S21/6. These results indicate different symbiotic potential of indigenous strains and confirmed the importance of rhizobial strain selection. These are the first studies of indigenous common bean rhizobia in Croatia that provide the basis for further characterization and selection of highly efficient indigenous strains and their potential use in agricultural practice and future research


 



*Corresponding author:  email3   This e-mail address is being protected from spambots. You need JavaScript enabled to view it.
                                      tel3  +385 1 239 3880


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