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but improved effects on plasma lipids. The aim of the present
study was to compare the effects on plasma lipoproteins and
haemostatic variables of two hard test margarines with similar
functional properties, one traditional margarine based on PHFO
and one based entirely on vegetable oils. (1500)
Abbreviations:
PHFO – partially hydrogenated fish oil.
Lp(a) – lipoprotein (a)
LDL – Low – density lipoprotein
HDL – High-density lipoprotein
5. Influence of water activity on growth of
microorganisms
We have already emphasized that water takes part in two major
transformations in foodstuffs: enzymatic and oxidative changes.
Its role is equally important in the growth of microorganisms.
Many studies have addressed this. It emerges that the growth
and metabolic activity of microorganisms, including bacteria,
yeasts, and moulds, depend essentially on available water. A
reduction in the activity of water causes the following
modifications to the growth curve obtained at optimal activity
Aw
1
for microbial growth:
(i) increased duration of the lag phase;
(ii) reduced rate of growth (exponential phase);
(iii) reduced number of organisms during the stationary
phase.
Different groups of microorganisms have different values of
A
W1
, the optimal activity for growth. Table 3.7 gives details, as
we can see, the optimum range is between 0.92 and 0.99. By
contrast, growth of microorganisms is impossible below a
limiting value of A
w1
. In addition to A
w
, a number of other
parameters influence the growth of microorganisms. The most
important of these, for meat technology, are: the oxygen partial
pressure, pH, temperature, and the presence of nitrite and
sodium chloride. The data for the parameters referred to above
(optimum and limiting values of A
w
are thus not absolute, owing
to the influence of these other factors. (1200)
Section II
Texts for home translation in writing
6. Environmental Problems: Why the Concern?
Americans are concerned about environmental problems for
two general reasons. First, many environmental problems are
public health problems. Increased air and water pollution may
compromise the health of the entire population. The second
reason for concern is a growing fear that human societies are
creating so many environmental problems that the overall
stability of the earth's ecosystems may be threatened, rendering
the planet unfit for human habitation.
Because many environmental problems, like exposure to
toxic chemicals, are relatively invisible, they are easy to ignore.
However, as we all know, ignoring a problem does not make it
go away. Picture in your mind a warm summer day. Imagine
you are outside mowing a lawn, washing your car, or having a
barbecue with friends. Months ago a contractor hired by your
state's department of transportation resurfaced the street in front
of your house. Unbeknownst to you, ash from a municipal
but improved effects on plasma lipids. The aim of the present contrast, growth of microorganisms is impossible below a
study was to compare the effects on plasma lipoproteins and limiting value of Aw1. In addition to Aw, a number of other
haemostatic variables of two hard test margarines with similar parameters influence the growth of microorganisms. The most
functional properties, one traditional margarine based on PHFO important of these, for meat technology, are: the oxygen partial
and one based entirely on vegetable oils. (1500) pressure, pH, temperature, and the presence of nitrite and
sodium chloride. The data for the parameters referred to above
Abbreviations: (optimum and limiting values of Aw are thus not absolute, owing
to the influence of these other factors. (1200)
PHFO – partially hydrogenated fish oil.
Lp(a) – lipoprotein (a)
LDL – Low – density lipoprotein
HDL – High-density lipoprotein
5. Influence of water activity on growth of Section II
microorganisms Texts for home translation in writing
We have already emphasized that water takes part in two major 6. Environmental Problems: Why the Concern?
transformations in foodstuffs: enzymatic and oxidative changes.
Its role is equally important in the growth of microorganisms. Americans are concerned about environmental problems for
Many studies have addressed this. It emerges that the growth two general reasons. First, many environmental problems are
and metabolic activity of microorganisms, including bacteria, public health problems. Increased air and water pollution may
yeasts, and moulds, depend essentially on available water. A compromise the health of the entire population. The second
reduction in the activity of water causes the following reason for concern is a growing fear that human societies are
modifications to the growth curve obtained at optimal activity creating so many environmental problems that the overall
Aw1 for microbial growth: stability of the earth's ecosystems may be threatened, rendering
the planet unfit for human habitation.
(i) increased duration of the lag phase; Because many environmental problems, like exposure to
(ii) reduced rate of growth (exponential phase); toxic chemicals, are relatively invisible, they are easy to ignore.
(iii) reduced number of organisms during the stationary However, as we all know, ignoring a problem does not make it
phase. go away. Picture in your mind a warm summer day. Imagine
you are outside mowing a lawn, washing your car, or having a
Different groups of microorganisms have different values of barbecue with friends. Months ago a contractor hired by your
AW1, the optimal activity for growth. Table 3.7 gives details, as state's department of transportation resurfaced the street in front
we can see, the optimum range is between 0.92 and 0.99. By of your house. Unbeknownst to you, ash from a municipal
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