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The Nutritional Value of Pasta
the nutritionist’s opinion
Carlo Cannella, Alessandro Pinto
Institute of Food Science and Nutrition
“La Sapienza” University, Rome, Italy
Function of carbohydrates
An adult subject needs about 180 g/die of glucose to meet nervous system and erythrocytes energy requirements
Essentiality Necessity
Carbohydrates are necessary but not essential nutrients because the human body
can produce glucose from aminoacids (gluconeogenesis)
In a low carbohydrate diet, when the catabolism of glucose is active, acetyl-CoA from lipids is burned
otherwise it accumulates to form ketone bodies/fatty acids
Starch
Starch consists of linked glucose units arranged in either
straight or branched chains
Amylose
straight-chain form of starch based on several hundred glucose residues linked
by alpha-glucosidic bonds between carbons 1 and 4 of adjacent glucose
molecules
Amylopectin
branched-chain component of starch based on straight-chain form plus side-branches (by additional bonds between carbons 1 and 6 of two adjacent glucose
molecules)
Metabolic Pathway
Glucose and other absorbed monosaccharydes (fructose, galactose and mannose) are isomerised
and phosphorilated to glucose-6-P
Bloodglucose
Hepatic and muscleglycogen
CO2 + H2O + ATP Pentose phosphate Adipose tissue
Blood glucose control
blood glucose - normal range 110 mg/dl
70 mg/dl
glucose uptaken into cells glycogenosynthesis
Release of Insulinfrom pancreas
High levels ofblood glucose
breakdown of glycogen increase of gluconeogenesis
Release of Glucagonfrom pancreas
Low level ofblood glucose
Glucose Amount from different sources
100 g bread 80 g pasta 60 g sugar
They cause different glucaemia increase rates
G.I. “glycaemic index”
Glycaemic index
It is possible to measure the relative effects of different carbohydrate foods on the blood sugar level. The rise in blood glucose following ingestion of a portion of a test food containing 50 g of
available carbohydrate is compared with the effect on blood glucose of a 50 g available carbohydrate portion of a standard such as glucose or white bread. Comparison of the areas under
the two glucose curves obtained produces a “glycaemic index”
Glycaemic Load = GI x dietary carbohydrate content
Its glycaemic index is suitable for achievements of daily quota of carbohydrates (50-60% total energy uptake)
Its association with different sauces improves nutritional value of proteins (cheese) and exerts an anticancer activity (tomato and onion)
It has a reduced fat content especially of saturated fatty acids and an important source of fiber (affecting other nutrient absorption)
…… but remember portion size of 80 g!
Scientific evidences support pasta daily consumption
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