813 research outputs found
Exogenous proteinases in dairy technology
Glavna primjena proteinaza u mljekarskoj tehnologiji je u proizvodnji sira. Prikazana je prva enzimatska te druga ne-enzimatska faza koagulacije mlijeka sirilom. Ukratko su prodiskutirane mogućnosti zamjene telećeg sirila, a u detalje razvoj imobilizirajućih sirila. Razmatrana je također mogućnost ubrzanja zrenja sira dodavanjem proteinaza. Dat je pregled sporedne upotrebe proteinaza uključujući proizvodnju proteinskih hidrolizata, modifikaciju proteina i proizvodnju dječje hrane.The principal applications of proteinases in dairy technology are in cheese manufacture. The enzymatic primary phase and non-enzymatic secondary phase of rennet coagulation of milk are reviewed. Aspects of veal rennet substitutes are briefly discussed and developments in immobilized rennets considered in detail. The possibility of accelerating cheese ripening via added proteinases is also considered. Minor applications of proteinases including production of protein hidrolyzates, protein modification and baby food manufacture are reviewed
Proprietary Creameries in Ireland
While Irish creameries today are popu larly associated wi th co-operative ownership, in fact
over the first forty years of the development of the creamery system in Ireland, the majority
of creameries were in private ownersh ip. These so-called "proprietary" creameries are the
main focus of this chapter, which is structured as follows. Init ially, the traditional method of
making butter on farms is described briefly and compared with the new creamery technology.
This is followed by a general account of the spread of the creamery system in Ire land. The
chapter then provides a profi le of the proprietary creamery sector, focu si ng firstly on some
of the individual entrepreneurs who played key roles in the development of the sector and
then on the corporate groupings (bot h Irish and Bri tish owned) which came to dominate
the sector. The chapter concludes with an account of major legislative and organisational
changes instigated by the Irish Free Sta te Government in the 1920s which elimi nated the
proprietary sector from the Irish creamery industry, thereby leaving it almost completely
cooperatively-owned
Biochemical and Functional Relationships in Cheese.
End of Project ReportCheese is used extensively in cooking applications, mainly because of its
flavour and heat-induced functionality, which is a composite of different
attributes such as softening, flow and stretch. The functional attributes of
cooked cheese generally have a major impact on the quality of foods in
which cheese is included as an ingredient, e.g. pizza pie. Owing to its
importance in cookery applications, numerous studies have been
undertaken on the effects of different factors on the age-related changes in
the functionality of cooked cheese, especially Mozzarella, and to a lesser
extent, Cheddar and processed cheese. These studies have shown that the
functionality of natural cheese is dynamic, with the different functional
attributes undergoing marked changes during ripening, and, for a given
cheese variety, the desired functional attributes are optimum within a
specific time frame during maturation. The time at which the cheese
becomes functional and the width of the window - and hence the functional
shelf-life, are affected by the extent of chemical changes, including the
increase in proteolysis and the ratio of bound to free moisture.
The main aims of this project were to investigate the effects of the following
on the age-related changes in heat-related functional attributes (e.g.
stretchability, fluidity) of cheese:
* fat reduction,
* the degree of fat emulsification,
* the pH and calcium content and their interaction,
* the correlation between proteolysis and functional attributes,
especially attributes other than flowability, e.g. rheological
properties of raw cheese, stretchability of heated cheese, and
* the age-related changes in the functionality of cheeses other
than Mozzarella, e.g. analogue pizza cheese and Emmental.
At the outset of this project, comparatively little information was available on
the effects of the above parameters on the age-related changes in heatinduced
functional attributes (e.g. stretchability, fluidity) of cheese,
especially for varieties other than Mozzarella.Department of Agriculture, Food and the Marin
Role of Lactobacilli in Flavour Development of Cheddar Cheese.
End of Project ReportCheddar cheese is a complex microbial ecosystem. The internal
cheese environment, in particular of hard and semi-hard cheeses, is
not conducive to the growth of many microorganisms.
At the beginning of ripening the dominant microorganisms are the
starter bacteria which are present at high levels (~109/g). However,
during ripening, non-starter lactic acid bacteria (NSLAB) grow from
relatively low levels (<103/g) at the beginning of ripening, to 108/g
within 6 - 8 weeks. Other bacteria, e.g. enterococci and staphylococci,
may also be present but in much lower numbers.
In a previous study of mature and extra mature Cheddar cheeses from
different manufacturers (see End of Project Report No. 1), it was
found that the NSLAB population was dominated by strains of Lb.
paracasei. However, their contribution to cheese flavour and their
source(s) are still unclear, nor is it known if the NSLAB flora is unique
to each plant. Hence, understanding the growth of this group of
organisms in cheese is a key to defining their role in flavour
development.
The biochemistry of flavour development in cheese is poorly
understood. For most cheese varieties, including Cheddar,
proteolysis, which results in the accumulation of free amino acids, is
of vital importance for flavour development. Increasing evidence
suggests that the main contribution of amino acids is as substrates for
the development of more complex flavour and aroma compounds.
The manner by which such compounds are generated in cheese is
currently the focus of much research.
Starter bacteria have been shown to contain a range of enzymes
capable of facilitating the conversion of amino acids to potential
flavour compounds. However, the potential of lactobacilli (NSLAB) to
produce similar enzymes has only recently been investigated. Hence, although, it is generally accepted that the cheese starter flora
is the primary defining influence on flavour development, the
contribution of NSLAB is also considered significant.
The objectives of these studies were:
- to develop a greater understanding of the behaviour of NSLAB in
cheese, and
- to identify suitable strains, and other cheese bacteria, to be used as
starter adjuncts for flavour improvement.Department of Agriculture, Food and the Marin
The mu-rhythm can mirror: Insights from experimental design, and looking past the controversy.
Development Psychopathology in context: famil
Exploring nu signals in dark matter detectors
We investigate standard and non-standard solar neutrino signals in direct
dark matter detection experiments. It is well known that even without new
physics, scattering of solar neutrinos on nuclei or electrons is an irreducible
background for direct dark matter searches, once these experiments each the ton
scale. Here, we entertain the possibility that neutrino interactions are
enhanced by new physics, such as new light force carriers (for instance a "dark
photon") or neutrino magnetic moments. We consider models with only the three
standard neutrino flavors, as well as scenarios with extra sterile neutrinos.
We find that low-energy neutrino--electron and neutrino--nucleus scattering
rates can be enhanced by several orders of magnitude, potentially enough to
explain the event excesses observed in CoGeNT and CRESST. We also investigate
temporal modulation in these neutrino signals, which can arise from geometric
effects, oscillation physics, non-standard neutrino energy loss, and
direction-dependent detection efficiencies. We emphasize that, in addition to
providing potential explanations for existing signals, models featuring new
physics in the neutrino sector can also be very relevant to future dark matter
searches, where, on the one hand, they can be probed and constrained, but on
the other hand, their signatures could also be confused with dark matter
signals.Comment: 38 pages, 8 figures, 1 table; v3: eq 3 and nuclear recoil plots
corrected, footnote added, conclusions unchange
Updated tests of scaling and universality for the spin-spin correlations in the 2D and 3D spin-S Ising models using high-temperature expansions
We have extended, from order 12 through order 25, the high-temperature series
expansions (in zero magnetic field) for the spin-spin correlations of the
spin-S Ising models on the square, simple-cubic and body-centered-cubic
lattices. On the basis of this large set of data, we confirm accurately the
validity of the scaling and universality hypotheses by resuming several tests
which involve the correlation function, its moments and the exponential or the
second-moment correlation-lengths.Comment: 21 pages, 8 figure
The -dependence of the generalised Gerasimov-Drell-Hearn integral for the deuteron, proton and neutron
The Gerasimov-Drell-Hearn (GDH) sum rule connects the anomalous contribution
to the magnetic moment of the target nucleus with an energy-weighted integral
of the difference of the helicity-dependent photoabsorption cross sections. The
data collected by HERMES with a deuterium target are presented together with a
re-analysis of previous measurements on the proton. This provides a measurement
of the generalised GDH integral covering simultaneously the nucleon-resonance
and the deep inelastic scattering regions. The contribution of the
nucleon-resonance region is seen to decrease rapidly with increasing . The
DIS contribution is sizeable over the full measured range, even down to the
lowest measured . As expected, at higher the data are found to be in
agreement with previous measurements of the first moment of . From data on
the deuteron and proton, the GDH integral for the neutron has been derived and
the proton--neutron difference evaluated. This difference is found to satisfy
the fundamental Bjorken sum rule at GeV.Comment: 12 pages, 10 figure
Measurement of the Proton Spin Structure Function g1p with a Pure Hydrogen Target
A measurement of the proton spin structure function g1p(x,Q^2) in
deep-inelastic scattering is presented. The data were taken with the 27.6 GeV
longitudinally polarised positron beam at HERA incident on a longitudinally
polarised pure hydrogen gas target internal to the storage ring. The kinematic
range is 0.021<x<0.85 and 0.8 GeV^2<Q^2<20 GeV^2. The integral
Int_{0.021}^{0.85} g1p(x)dx evaluated at Q0^2 of 2.5 GeV^2 is
0.122+/-0.003(stat.)+/-0.010(syst.).Comment: 7 pages, 3 figures, 1 table, RevTeX late
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