The chemistry and metabolism of the starch based sweeteners

Glycaemia and phosphatemia after oral glucose and maltitol ingestion in subjects from two different race groups: preliminary evidence of inter-race differences in metabolism and possible implications for urinary stone disease

PURPOSE

Glucose (Glu) and maltitol (Mal) ingestion affect calciuria and phosphaturia. Renal phosphate leak involving hypophosphatemia is thought to be a mechanism. Inter-race differences in carbohydrate metabolism are known. We investigated the effects of Glu and Mal ingestion on glycaemia and phosphatemia in subjects from two race groups to better understand potential implications for nephrolithiasis.

METHODS

Healthy black (B) (n = 8) and white (W) (n = 8) males followed a self-selected standardized diet for 7 days and a strictly controlled standardized diet on Day 8. After an overnight fast, subjects provided blood samples prior to and 30 min after ingestion of a randomly assigned solution of Glu or Mal. Blood Glu and serum phosphate were measured. Protocols were swapped after a 1-week washout period.

RESULTS

Following Glu ingestion, glycaemia increased significantly in W (4.8 vs 6.2 mmol/l) but not in B (4.7 vs 5.3 mmol/l) while phosphatemia decreased significantly in B (1.16 vs 1.01 mmol/l) but not in W (1.24 vs 1.15 mmol/l). After Mal ingestion, glycaemia increased significantly in B (4.7 vs 5.2 mmol/l) but not in W (4.6 vs 5.9 mmol/l), while phosphatemia decreased significantly in W (1.24 vs 1.18 mmol/l) but not in B (1.17 vs 1.06 mmol/l).

CONCLUSIONS

Our results suggest that enzymes which regulate glycolysis may be less active in B than in W, or expression of renal transcellular Glu transporters may be relatively inhibited in B. Effects on phosphatemia are carbohydrate- and race-dependent, thereby prohibiting speculation of a general algorithm linking these variables. Inter-race differences in metabolic handling of carbohydrates might impact on respective nephrolithiasis risk factors in such groups.

Chemical interactions between additives in foodstuffs: a review

This paper critically reviews the key literature on food additive-additive chemical interactions published over the last 30 years together with appropriate relevant information on food additive-food component interactions. Five main classes of food additive are included, reflecting the research effort to date: the sulfur (IV) species of preservatives, synthetic food colouring materials, nitrate and nitrite, ascorbic acid, and sorbic acid. Within each class, aspects of the chemistry (reactivity), functionality, stability, use and reactions with other specific food additives are reviewed. Where appropriate, the importance of interactions of food additives with other components of food (i.e. nutrients and non-nutrients) has been assessed and certain aspects of toxicology included. The practical outcome of this review is presented as a set of recommendations for future research in this area. The use of the data in this review is proposed as a training set to develop the framework into a diagnostic tool. This might be used ultimately for the development of a multilevel framework, operating systematically, to understand the important parameters that dictate the outcome of additive interactions.