Advance of Food Chemistry and nutrition 2/2006. Bioenergetics and the Science of Ribose –Rate and...

Preview:

Citation preview

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Unpublished data on file - Bioenergy, Inc.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

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