Agris category codes: Q04
COBISS Code 1.01 Language: English
RELATION OF
MYOFIBRIL FRAGMENTATION TO TEXTURAL AND CHEMICAL PARAMETERS OF AGED PORK Longissimus dorsi[1]
a),
Tomaž POLAK, Božidar ŽLENDER and Lea GAŠPERLIN
a)Univ. of Ljubljana,
Biotechnical Fac., Dept. of Food Science and Technology, Jamnikarjeva 101,
SI-1111 Ljubljana, Slovenia
ABSTRACT
The relation
of myofibrilar fragmentation (length of myofibrilar fragments, myofibrilar
fragmentation index) to textural (Warner-Bratzler share force) and chemical
parameters (non-protein nitrogen changes) of pork Longisimus dorsi
muscles(acquired 24 h post mortem, normal meat quality) were
investigated over a 16-day ageing period at 2 °C (± 1 °C). Ageing time
significantly affected all parameters at
the 1% level or less. The pH
value for 16-day aged samples was slightly higher; the average values being
5.61 for nonaged and 5.67 for aged samples. Length of myofibrilar
fragments being in average the highest (73 mm)
for nonaged samples, and the lowest (15.7 mm
and 12.4 mm)
for 11 and 16 days aged ones. Myofibrilar fragmentation index increases
significantly with storage: for nonaged samples below 30, after a 2-day
ageing about 50, and after 5-day ageing 63.7 (determined as described by
Olson et al., 1976), or after 11-day ageing 56.9 (determined as
described by Hopkins et al., 2004) Indexes for Hopkins procedure were
about 7% lower (P ≤ 0.001) compared to those for Olson procedure. Non-protein
nitrogen after 11 and 16 days of storage was higher (10.78% and 10.93% of
total nitrogen) compared to the nonaged pork (9.39% of total nitrogen).
Warner-Bratzler share force was markedly affected by 16-day ageing (nonaged
51.3 N, 16 days 29.2 N). On the basis of instrumentally measured texture
differences in thermally treated aged pork we concluded that myofibrilar
fragmentation index was a suitable proteolysis rate pointer already from the
second day on. The increase in non-protein nitrogen content indicates a
release of free amino acids; so, it is a suitable measure of proteolysis
after 5 days of ageing.
[1]This article is
part of a dissertation thesis 'Effects of quality, proteolysis and
degree of doneness on heterocyclic aromatic amines formation in
thermal aged pork Longissimus dorsi', issued by Dejan Došler,
supervisor Assoc. Prof. Lea Gašperlin, Ph.D.
Agris category
codes: L20
COBISS Code 1.02
Language: English
Phenotypic
heterogeneity in bacterial populations
a)
a)Univ. of
Ljubljana, Biotechnical Fac., Dept. of Biology, Večna pot 111, SI-1000
Ljubljana, Slovenia, Prof., Ph.D.
ABSTRACT
Genetically uniform
bacterial cells exhibit heterogeneity such as intrapopulation differences in
metabolism as well as variation in growth rate. Additionally, phenotypic
heterogeneity in more complex developmental processes where a portion of a
population performs specialized functions has been described. Heterogeneity
within populations of bacterial cells ensures that a small fraction of the
population is prepared to survive adverse environmental conditions.
Phenotypic heterogeneity is mediated by two mechanisms: (i) genotypic
alterations such as, mutations and rearrangements of specific DNA fragments
or (ii) epigenetic phenomenon. Here examples of genotypic as well as
epigenetically regulated phenotypic heterogeneity from several bacterial
species are presented.
Agris
category codes:
L20
COBISS Code 1.01 Language: English
THE
RELATIONSHIP BETWEEN TOTAL AND CULTURABLE BACTERIA IN COLD SOILS
a)
a) Univ.
of Ljubljana, Biotechnical Fac., Zootechnical Dept., Groblje 3, SI-1230
Domžale, Slovenia, Ph.D., M.Sc.
ABSTRACT
Cold ecosystems are
essential to global ecology. Microbial activities are predicted to increase
in low temperature regions due to global warming thus further affecting the
green gas emissions and stored carbon overturn. This all has led to
increased awareness how minute is our understanding of bacterial assemblages
in the cold soils and also other environments, spurring the idea of
standardization of research protocols. This work focused on comparison of
recently published data on culturability of bacteria from 23 cold soils in
the frame of International polar Year 2007 (IPY 2007). The results show that
linear relationship exists between direct counts and numbers of cultured
bacteria. 11 environmental parameters were reported in these studies.
However, only two categories were present in all, preventing attempt to
identify governing environmental factors. As there is such heterogeneity in
reporting and performing research in microbial ecology, standardization of
approaches and protocols in microbial ecology could improve comparability of
results substantially.
Agris
category codes: F30
COBISS Code 1.01 Language: English
GENETIC VARIABILITY OF SOME QUALITY TRAITS IN Lathyrus spp. GERMPLASM
a), Abd El-Zahar MUSTAFA, Salwa BADR and Walla
TAHR
a)
Tanta
Univ., Fac. of Science, Botany Dept., Tanta, Egypt
ABSTRACT
Sixty-six
accessions representing eighteen species of the genus Lathyrus
collected from different geographic regions were evaluated for variations of
quality traits (100 seeds weight, ash, total seed proteins and 3-(-N-oxayl)-L-2,3
diaminopropoinc acid – ODAP contents). High variability of ODAP levels was
exhibited at both inter-specific and intra-specific levels. This variability
was attributed to genetic and environmental factors. No significant
correlation was found between ODAP and each of total protein content, ash
content and 100 seeds weight. Cluster analysis of C.V. (Coefficient of
variance) values for each accession identified the sixty-six accessions into
eight groups. The most promising accession for breeding programs was L.
sativus from Tunisia. This accession has good grain quality due to
relatively low ODAP level and high protein content. The variations of
protein content, ash content and 100-seeds weight were also discussed.
Agris category codes: E10
COBISS Code 1.01 Language: English
optimisation of
production activities on individual agricultural holdings IN THE FRAME OF
DIFFERENT direct payments OPTIONS
a), Emil ERJAVEC and Stane KAVČIČ
a) Univ.
of Ljubljana, Biotehnical Fac., Dept. of Animal Science, Groblje 3, SI-1230
Domžale, Slovenia
ABSTRACT
Linear programming model has been developed and applied to the hypothetical
agricultural holding in the hilly part of Slovenia in order to find optimal
production plans by maximizing total gross margins. The model covers
especially those sectors of Slovenian agriculture, for which the most
drastic changes due to the actual reform of CAP in the field of direct
payments – in Slovenia implemented in 2007 – are anticipated. On the basis
of developed model the economic impacts of CAP reform and importance of agri-environmental
measures have been evaluated. Model results lead to the conclusion that the
reform will have the most unfavorable impacts for agricultural holdings with
intensive production practice, especially those with animal production
activities which are under the standard scheme eligible for relatively high
production coupled direct payments (up to 70% of achieved total gross
margin). Negative impacts of the reform can be mitigated by combining
different production activities and technologies. Economic results markedly
improve (up to 28%) if farming management complies with agri-environmental
measures.
Key words:
agriculture / linear programming / CAP reform / direct payments / Slovenia
