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Advance of Food Chemistry and nutrition
2/2006
•Bioenergetics and the Science of Ribose
–Rate and efficiency of energy supply (turnover)
–Volume (concentration) of energy substrates in the
cell
“[The] distinction between ATP concentration and ATP turnover rate is central to our understanding of
molecular bioenergetics”
Role of ATP in Tissue Function
Ion pumps • Electrochemical gradients • Ca+2 pump
ATP
Contractile mechanisms
• (Systolic) contraction• (Diastolic) relaxation• Energy reserve
Biosynthesis• Proteins & macromolecules• Genetic material• de novo ATP
Adenine
Ribose
Phosphates
ATP
ATP – The Energy Currency of the Cell
ADP
Normal ATP Turnover
ATP
ADP
Glucose
Fatty Acid
+ O2
(Yield 36 ATP)
(Yield 128 ATP)
ADPADPADPADP
ATP Turnover in Hypoxia
ATP
ADP
+ O2
Glucose
Fatty AcidXYield = 4 ATP
ATP catabolism depletes the purine pool and reduces the
energy status of the cell
Energy is Lost with Hypoxia
ATP catabolism depletes the purine pool and reduces the
energy status of the cell
Hypoxia depletes the cell’s energy pool and reduces its energy status
ATP Recovery Rate Following Ischemia
-4.0
-2.0
0.0
2.0
4.0
6.0
0-4 4-24 24-48
NS Control
Time (hrs)
ATP
Reco
very
Rat
e
(nm
ol. m
g w
et w
t-1) Ribose Treated
*p<0.005
*
*
Unpublished data on file - Bioenergy, Inc.
Ribose Drives Nucleotide Recovery in Hearts
Brault JJ, RL Terjung. J Appl Physiol 2001;91:231-238.
~ 5-gm dose(+300%)
~ 0.5 - 1-gm dose(+100%)
Ribose Regulates Nucleotide Salvage in Muscles
Ribose captures purine nucleotides before they can be washed out of the cell.
Cellular energy status is preserved.
Ribose stimulates energy synthesis in all muscle fiber types
Accelerates energy recovery and puts muscle in better physiological condition
Brault JJ, RL Terjung. J Appl Physiol 2001;91:231-238.
Ribose is…
•Fundamental energy regulating compound
• Foundation of ATP, FAD, acetyl-CoA
• Energy limiter in oxygen reduced states
• Critical to cellular energy stasis
D-Ribose
How?
O2
EnergyX
Supplemental Ribose
• Rebuilds cellular energy
• Improves physiological condition of stressed tissue
• Enhances cell and tissue function
• Increases exercise tolerance and physical performance
• Improves diastolic cardiac function
6/7/05
Riboseproducts
6/7/05
2. Oligosaccharidesa. Properties and Reactionsreducing sugar: a free lactol group at C1
Non-reducing sugar : no free lactol group
b. Mutarotation of sugarSaccharose non-reducing It hydrolysis is denotedas invert sugar mutarotation change form positive to negative
β-anomer lower specific rotation ,cleavage of β-glycosides in
creases specific rotation;
α-anomer higher specific rotation ,cleavage of α-glycosides decreases specific rotation
β-cyclodextrin: prepared by the action of cyclomaltodextrin glucanotransferase (E.C. 2.4.1.19,from bacillus macerans) maltodextrin are made by the degradation of starch with α-amylase, cyclodextrin : non-hygroscopic ,slightly sweet.
Cyclodextrins are cyclic (a-1,4)-linked oligosaccharides of a-D-gluco-pyranose
c. β-cyclodextrin
containing a relatively hydrophobic central cavity
hydrophilic outer surface
In the food industry:
It is suitable agent for stabilizing vitamins and aroma substance and for neutralizing the taste of bitter substances
In the pharmaceutical industry:
It been used as complexing agents to increase the aqueous solubility of poorly water-soluble drugs, and to increase their bioavailability and stability.
In addition, cyclodextrins are used to reduce or prevent gastrointestinal or ocular irritation, reduce or eliminate unpleasant smells or tastes, prevent drug-drug or drug-additive interactions, or even to convert oils and liquid drugs into microcrystalline or amorphous powders
3.Polysaccharides
(1) Properties( General remarks)
Structure-forming skeletal substances (cellulose,pectin)
Assimilative reserve substances (starch)
Water-binding substance (agar, mucopolysaccharides)
(2) Functions of polysaccharides in food.
Functions: Physical compactness, crispness, good mouth feel, thickening, viscosity, adhesiveness, gel-forming.
A. Structure and function.
a. Molecules arrangement structure.
In a glucan there five oxygen per chain unit that can form hydrogen bonds, hydrate and solubility depend on their arrangement of the molecule.
Crystalline regions: hydrate difficulty
Amorphous regions: hydrate easy
b. Linear and branched molecule
At same molecule weight solution of linear more viscous than branched.
Branched form short junction , It simply form viscous, stable solution, but It is not develop retrogradation
Linear , easy to move together in a zipperlike manner to form long junction zone , ( retrogradation ).
c. Molecule size and charge Viscosity depend on molecule size, bigger molecule more viscous.
Liner molecule not stable during cooling
Difuntional group that cross linking polysaccharides such as: epoxide, some acids, ( succinic anhydrides ) and some ion (Ca2+) .
B. Functional property changes after different treatment
a. Heat treatment
After heat treatment:Higher the gelatinization T and water binding capacityLower the swelling capacity
Pregelatinized starch
Heating of starch suspensions, followed by drying, provides products that are swellable in cold water and form pastes or gels on heating, these products are used in instant foods
b. Chemically treatment
Acid treatment starch
H2Cl, H2SO4, treat it at 25—55oC, 6- 24 hr.
decreased hot-paste viscosity
decreased intrinsic viscosity
decreased gel strength
increased gelatinization T
Gel firmly on cooling ,used in gum candies.
Hydroxyethylated
Ethylene oxide or propylene oxide in the presence of hydroxides of alkali or alkali earth metals (pH 11-13 ) at 50oC
The DS, (degree of substitute) can be controlled over a wide range( 0.05—1.0) by adjusting process parameters ..
Increased paste clarity
reduced retrogradation.
Used in salad dressing, pie filling and other food thickening
Phosphate treatment
ortho-, pyro-, tripolyphosphate , such as sodium trimetaphosphate
at 50-60oC, DS <0.25, reduced retrogradation
reduced gelatinization T
excellent freeze-thaw stability. used in frozen food
(3) occurrence and Isolate some of polysaccharides
A . Starch
Isolation of starch
(1) Plant material is disintegrated
(soft material 50oC water contain 0.2% SO2 for 36-48 hr in order
to loosen protein matrix)
(2) Starch granules are washed
Starch milk sedimented or separated in hydrocyclones ,the separation is based on density difference (protein < starch)
most starches contain 20-30% amylose, 70-80% amylopectin
amylose isolate by crystallization of a starch dispersion in the presence of salts (MgSO4) or by precipitation with a polar organic c
ompound (alcohols, such as n-butanol or lower fatty acids such as caprylic acids.
B . pectin
produced commercially from peels of citrus fruits and from apple pomace
it is 20-40% of the dry matter content in citrus fruit peel
10-20% in apple pomace
Extraction at pH 1.5-3 at 60-100oC, the extract is concentrated to a liquid pectin product or is dried by spray or drum-drying into a powered product.
Purified preparations are obtained by precipitation of pectin with ions which form insoluble pectin salts (e.g. Al3+), followed by washing with acidified alcohol to remove the added ions, or by alcoholic precipitation using isopropanol and ethanol
(4) uses of polysaccharides in food
Recommended