total dietary fibre????

Question

can anyonr plzzzzzzzzzzzzzzzzzzzzzzz tell me a non enzymatic method for estimation of total dietary fibre in food products, itz vry urgently required.

whatz the difference between true protein and total protein, is crude protein and total protein d same.

Answer 1

Dietary Fibre :
Dietary fibre is usually determined by fractionation procedures and the one proposed by Southgate is now widely used. The estimate of amount of dietary fibre in a food will depend upon the analytical method used for the estimation and the values so obtained need not necessarily be considered always precise. Dietary fibre estimation is still considered to be only semi-quantitative.

True Protein and total Protein :
The Kjeldahl Test
Historically, the Kjeldahl method has
been the primary procedure used to test
milk protein reference samples. These
protein reference samples are used by
milk plants, cooperatives and DHIAs,
among others, to calibrate automatic
milk protein testing equipment.
Milk protein content is not measured
directly by the Kjeldahl. The test instead
measures the nitrogen content of milk.
Milk protein contains 15.65% nitrogen.
To convert the Kjeldahl nitrogen
reading to milk protein, the nitrogen
measurement is multiplied by a factor
of 6.38 (100 ÷ 15.65). For example, if a
milk sample is determined to contain
.55% nitrogen by Kjeldahl analysis,
then its protein content is .55 x 6.38, or
3.5%.
Use of the Kjeldahl method presumes
that all of the nitrogen found in milk is
contained in protein. However, this is
not the case. A portion of the nitrogen
in milk comes from non-protein sources,
such as urea and uric acid. These other
protein sources are called non-protein
nitrogen (NPN). The Kjeldahl method
therefore actually measures what is
termed total protein. Total protein is the
nitrogen in milk multiplied by 6.38.
True Protein
The true protein in milk is the total
nitrogen minus the NPN, then multiplied
by 6.38. The textbook average
level of NPN in milk is about 5%. Dr.
David Barbano of Cornell University
conducted a yearlong national milk
composition study in 1985. His findings
showed an average total protein
value of 3.27%, a true protein value of
3.11%, and average NPN of 4.78%.
Assuming an average NPN value of
5%, then the true protein content of a
milk testing 3.2% total protein would
be calculated as follows:
0.5% x 3.2% = 16% NPN
3.20% Total Protein
– .16% NPN
3.05% True Protein
The 5% NPN is an average. The percent
NPN varies among breeds, seasons
and regions. Table 1 was obtained from
a study showing differences in NPN levels
by breeds. This table shows that Jersey
milk contains less non-protein nitrogen
(3.6%) than other dairy breeds.
A University of Vermont study examined
seasonal variations in NPN among
Vermont cheese plants. The graph in
Figure 1 demonstrates these results. Dr.
Barbano’s work mentioned earlier
showed seasonal and regional variations
in NPN as well. His research revealed
that NPN as a percentage of total nitrogen
varied seasonally from 4.33% to
5.22%. Perfect NPN is the highest in the
summer and lowest in the winter. The
study also found the lowest monthly
regional NPN was 3.9% and the highest
5.6%.
Another Barbano project found significant
variation among farms. In a limited
study on 24 western New York farms,
results were obtained showing NPN
variation from a low of 2.9% to a high
of 6.1%.
What Is The Point?
Why make an issue of whether true
protein or total protein is used? Fifteen
years ago, Vernal Packard, food scientist
at the University of Minnesota, addressed
this question and gave the following
reasons for why true protein
should be used instead of total protein.
1. NPN does not have biological
value as protein. For the most part,
it cannot be used by the body to
perform functions characteristic of
protein.
Table 1. Nitrogen distribution in milk (milk total N equals 100%).
NPN Protein N Casein N
(%) (%) (%)
Jersey 3.6 96.4 80.2
Guernsey 3.9 96.1 77.7
Holstein 4.9 95.1 78.2
Ayrshire 4.9 95.1 78.7
Brown Swiss 5.4 94.6 77.4
Milking Shorthorn 7.5 92.5 74.8
Average 4.9 95.1 77.9
Source: J. Dairy Sci. 58: 417
Figure 1. Variation of mean percentage nonprotein
nitrogen (NPN) of total nitrogen (TN)
in milks from seven Vermont cheese plants
by months (1980-1981).
True vs. Total Protein
(continued from page XX)
2. NPN does not add cheese yield. It
has no place in a purchase plan for
milk in which cheese yield is the
major consideration.
3. If all dairy plants are not on the
same program—either true or total
protein—the difference becomes a
source of confusion.
4. Level of NPN is highly variable in
milk. Because the Kjeldahl method
is used as the official method for
calibration and daily control of infrared
and dye binding testing devices,
NPN becomes a source of
variability in these other methods,
even though they do not measure
NPN as such.
5. Seasonal variations in NPN–and
these are significant–must either be
ignored or adjustments in equipment
made on a seasonal basis.
6. Breeding programs for protein can
be more tightly monitored on true
than total protein. Because increases
in percentage of protein
come very slowly and in very small
increments, NPN may mask these
changes. In other words, true protein
is by far the better basis for
evaluating progress of breeding
programs.
Packard noted, “Of the several factors
that have some influence on NPN level
in milk, feeding practices on the farm
may be the most important. Whenever
the ratio of protein to energy in the feed
goes up, NPN level increases. Feed more
protein and less grain, and not protein
but NPN level (%) increases in milk. This
kind of change in protein/energy ratio
is characteristic, in some parts of the
country, of the change from winter to
summer (pasture) feeding. As a rule, NPN
% increases in summer and drops in the
winter.
“Considering the preceding factors,”
Packard concluded, “compelling reasons
appear to exist for basing protein
purchase on the true rather than total
protein, as is done in most European
nations. In doing so, a regional policy
and, preferably, a national policy to that
effect becomes essential, so that neighboring
plants and states are all testing
on the same basis.”
Testing For True Protein
The Kjeldahl method can still be used
to prepare true protein calibration
samples. The difference in testing for
true protein rather than total protein involves
sample preparation and additional
procedures. As with total protein,
the Kjeldahl procedure for true protein
produces accurate and reliable true protein
calibration samples.
Adjustments In MCP Plans Using
True Protein
In 1988, the New York State Department
of Agriculture and Markets required
all protein payment programs to
use true protein instead of total protein.
Protein pricing programs in New York
state were adjusted accordingly. For example,
Eastern Cooperative previously
paid a protein premium of 10 cents for
each 0.1% of protein above 3.3%. Using
true protein, the cooperative lowered
its base to 3.1%.
On the average, most dairy farmers
did not see any change in their total
protein premium dollars. Their true protein
tests were approximately 5% lower
than their total protein tests. However,
the difference was compensated for by
lowering the protein base.
For those plants using End Product
Pricing (EPP), an adjustment was made
in the percentage of protein that is
casein. The original cheese yield formula
estimates casein to be 78% of total
protein. If true protein is used, casein
is 82% of true protein.
Implications For Jersey Milk
The Federal Order Reform decision
requiring the use of true protein instead
of total protein is a positive one for Jersey
producers, because of the lower percent
of non-protein nitrogen in Jersey
milk compared to average milk. Payment
on the basis of true protein will
make milk pricing more equitable.
Consider the example of a plant paying
a protein premium of 10¢ per 0.1%
above 3.2% based upon total protein.
Jersey milk testing 4.0% total protein
would receive a premium of 80¢ per
hundredweight (8 points x 10¢).
On a true protein basis, using an average
NPN of 5%, the base would be adjusted
to 3.04% to reflect true protein.
Non-protein nitrogen in Jersey milk is
3.6%, leaving a true protein content of
3.86%. At 10¢ for each point of protein,
the premium for Jersey milk increases
from 80¢ to 82¢ per hundredweight.
In addition, cheese yield is more accurately
predicted using true protein
measures. The value of Jersey milk sold
under End Product Pricing therefore increases
when true protein is the basis
for calculating payment.
For example, assume that a plant is
using a cheese yield value of $1.20 per
pound. Jersey milk testing 4.8% butterfat
and 4.0% protein and producing
12.90 lbs. cheese would be valued at
$15.49 under EPP. Jersey milk testing
4.8% butterfat and 3.86% true protein
would yield 12.98 lbs. cheese, which is
worth $15.58 at $1.20 per pound.
Crude Protein and Total protein :
Yes crude protein is sometimes called as total protein content

Answer 2

Try solubility tests.