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 EssentialityNecessity 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

Carbohydrate: classification SimpleComplex Available or not available

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 Blood glucose Hepatic and muscle glycogen CO 2 + H 2 O + ATPPentose phosphateAdipose tissue

Blood glucose control blood glucose - normal range 110 mg/dl 70 mg/dl  glucose uptaken into cells  glycogenosynthesis Release of Insulin from pancreas High levels of blood glucose  breakdown of glycogen  increase of gluconeogenesis Release of Glucagon from pancreas Low level of blood glucose

Glucose Amount from different sources 100 g bread80 g pasta60 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