Nutritional and Health Aspects of Sweeteners - Sweeteners: Nutritional Aspects, Applications, and Production Technology - page 332

isomaltulose, 75-g carbohydrate equivalents) following an overnight fast (08.40 h) and with a stan-
dardized meal (12.30 h; 25% of the total energy content was provided as either a sucrose or an
isomaltulose drink). Blood samples were taken before ingestion and every 30 min thereafter for a
period of 3 h, substrate use was assessed by indirect calorimetry, and breath samples were collected.
Ingestion of carbohydrates with a mixed meal resulted in a lower peak glucose and insulin response
and a lower change in area under the curve [difference in area under the curve (dAUC)] following
isomaltulose when compared with sucrose. Together with the lower glucose and insulin responses,
postprandial fat oxidation rates were higher (14%) with isomaltulose compared with sucrose when
ingested with a mixed meal. The attenuated rise in glucose and insulin concentrations following
isomaltulose results in reduced inhibition of postprandial fat oxidation. The metabolic response
to isomaltulose coingestion suggests that this may represent an effective nutritional strategy to
counteract overweight-induced metabolic disturbances. The intake of isomaltulose in combina-
tion with a mixed meal resulted in an attenuated rise in the plasma glucose and insulin responses
compared with sucrose and, subsequently, less inhibition of postprandial fat oxidation. The greater
postprandial fat use was accompanied by higher circulating plasma nonesteriied fatty acid (NEFA)
concentrations. The latter is probably attributed to a greater supply of plasma NEFA, resulting from
a reduced insulin-mediated suppression of lipolysis (Wolever 2003). These data seem consistent
with two other research papers that highlighted the stimulating effect of isomaltulose ingestion
on fat oxidation and/or lipid deposition compared with sucrose in rats and healthy men. Sato et al.
(2007) observed signiicant reductions in visceral fat mass, adipocyte cell size, hyperglycemia, and
hyperlipidemia after 8 weeks of isomaltulose feeding compared with sucrose feeding in Zucker
fatty (fa/fa) rats. Arai et al. (2007) showed that peak plasma glucose and insulin levels were lower
30 min after the ingestion of the isomaltulose-containing liquid meal compared with the control
formula ingestion in healthy men. Postprandial fat oxidation rates following the ingestion of the
isomaltulose meal group were higher compared with the control formula group.
The slow digestible disaccharide isomaltulose (palatinose) is available as a novel functional car-
bohydrate ingredient for the manufacturing of low-glycemic foods and beverages. Although basi-
cally characterized, various information on physiological effects of isomaltulose is still lacking.
Thus, Holub et al. (2010) expanded scientiic knowledge of the physiological characteristics of
isomaltulose by a set of three human intervention trials. Using an ileostomy model, isomaltulose
was found to be essentially absorbed, irrespective of the nature of food (beverage and solid food).
The apparent digestibility of 50-g isomaltulose from two different meals was 95.5% and 98.8%;
the apparent absorption was 93.6% and 96.1%, respectively. In healthy volunteers, a single-dose
intake of isomaltulose resulted in lower postprandial blood glucose and insulin responses than did
sucrose while showing prolonged blood glucose delivery over a 3-h test. In a 4-week trial with
hyperlipidemic individuals, regular consumption of 50 g/day of isomaltulose within a Western-type
diet was well tolerated and did not affect blood lipids. Fasting blood glucose and insulin resis-
tance were lower after the 4-week isomaltulose intervention compared with baseline. This would be
consistent with possible beneicial metabolic effects as a consequence of the lower and prolonged
glycemic response and lower insulinemic burden. However, there was no signiicant difference at
4 weeks after isomaltulose compared with sucrose. In conclusion, Holub et al. (2010) showed that
isomaltulose is completely available from the small intestine, irrespective of the food matrix, lead-
ing to a prolonged delivery of blood glucose. Regular isomaltulose consumption is also well toler-
ated in subjects with increased risk of vascular diseases. With a calculated GI of 32, isomaltulose is
a low-glycemic carbohydrate, as veriied by Atkinson et al. (2008).
The insulin response for the saccharides was directly proportional to their glycemic response,
both in the magnitude and shape of the response curve [incremental area under the curves: 15,208
[standard deviation (SD) 8639] versus 23,347 (SD 14,451) min × pmol/L; P = 0.005]. Isomaltulose
evoked the lowest insulin response with a maximum of 227.8 pmol/L, which is more than 50%
lower compared with sucrose (470.1 pmol/L) (Holub et al. 2010).