Prolonged Consumption of glucose syrup enhances glucose tolerance in mice

Individual differences in cephalic-phase insulin response are stable over time and predict glucose tolerance in mice

Oral stimulation by glucose triggers a rapid insulin response, which enhances glucose tolerance. This so-called cephalic-phase insulin response (CPIR) has been documented in many mammal species, but its functional properties are poorly characterized. Here, we studied CPIR in lean C57BL/6 mice. Experiment 1 asked whether the large individual differences in CPIR magnitude were real or reflected experimental noise. We measured CPIR magnitude four times across a period of 30 days in the same mice. The individual differences in CPIR magnitude were remarkably stable across the repeated trials, indicating that they were real. Experiment 2 examined the functional consequences of individual differences in CPIR magnitude. We found that higher CPIR magnitudes contributed to larger postprandial insulin responses and greater glucose tolerance. Experiment 3 examined the observation that the CPIRs in Experiments 1 and 2 were associated with a rapid rise in blood glucose. To determine whether the rapid rise in blood glucose caused the CPIRs, we asked whether mice would generate a CPIR if we prevented cephalic-phase stimulation of beta cells by either delivering the glucose intragastrically or blocking parasympathetic input to the pancreatic beta cells with atropine. The mice subjected to these treatments experienced a rapid rise in blood glucose, but they did not exhibit a CPIR. This indicates that it was the oral glucose stimulation, and not the rise in blood glucose, that triggered the CPIRs in Experiments 1 and 2. We conclude that (i) individual differences in CPIR magnitude are stable over time; (ii) CPIR magnitudes predicted postprandial insulin responses and glucose tolerance; and (iii) a rapid rise in blood glucose is not sufficient to trigger a CPIR in mice.

Chronic sugar exposure increases daily intake of sugars but decreases avidity for sweeteners in mice

Little is known about how chronic sugar consumption impacts avidity for and daily intake of sugars. This issue is topical because modern humans exhibit high daily intakes of sugar. Here, we exposed sugar-naïve C57BL/6 mice (across two 28-day exposure periods, EP1 and EP2) to a control (chow and water) or experimental (chow, water and a 11 or 34% sugar solution) diet. The sugar solutions contained sucrose, glucose syrups, or high-fructose syrups. We used brief-access tests to measure appetitive responses to sucralose and sucrose solutions at three time points: baseline (before EP1), after EP1, and after EP2. We used lick rates to infer palatability, and number of trials initiated/test to infer motivation. Exposure to the control diet had no impact on lick rates or number of trials initiated for sucralose and sucrose. In contrast, exposure to the experimental diets reduced licking for the sweeteners to varying degrees. Lick rates were reduced by exposure to sugar solutions containing the 11% glucose syrups, 34% sucrose, 34% glucose syrups and 34% high-fructose syrups. The number of trials initiated was reduced by exposure to all of the sugar solutions. Despite the exposure-induced reductions in avidity for the sweetener solutions, daily intakes of virtually all of the sugar solutions increased across the exposure periods. We conclude that (i) chronic consumption of sugar solutions reduced avidity for the sweetened solutions, (ii) the extent of this effect depended on the concentration and type of sugar, and (iii) avidity for sweet-tasting solutions could not explain the persistently high daily intake of sugar solutions in mice.

Early-life influences of low-calorie sweetener consumption on sugar taste

Children and adolescents are the highest consumers of added sugars, particularly from sugar-sweetened beverages (SSB). Regular consumption of SSB early in life induces a variety of negative consequences on health that can last into adulthood. Low-calorie sweeteners (LCS) are increasingly used as an alternative to added sugars because they provide a sweet sensation without adding calories to the diet. However, the long-term effects of early-life consumption of LCS are not well understood. Considering LCS engage at least one of the same taste receptors as sugars and potentially modulate cellular mechanisms of glucose transport and metabolism, it is especially important to understand how early-life LCS consumption impacts intake of and regulatory responses to caloric sugars. In our recent study, we found that habitual intake of LCS during the juvenile-adolescence period significantly changed how rats responded to sugar later in life. Here, we review evidence that LCS and sugars are sensed via common and distinct gustatory pathways, and then discuss the implications this has for shaping sugar-associated appetitive, consummatory, and physiological responses. Ultimately, the review highlights the diverse gaps in knowledge that will be necessary to fill to understand the consequences of regular LCS consumption during important phases of development.

Comprehensive Enzymatic Conversion of Starch for the Food Industry

This study demonstrated the feasibility of comprehensive enzymatic conversion of starch for non-waste applications in food industry. Enzymatic conversion of starch gives rise to nano-sized particles that can be used for manufacturing biodegradable and edible packaging materials and glucose syrup for replacing sugar in confectionery formulations. The 96 h enzymatic hydrolysis yielded starch nanoparticles smaller than 100 nm. Films based on nano-sized starch particles have promising physicochemical properties for manufacturing biodegradable and edible packaging materials. Such properties as reduced moisture content, increased homogeneity, crystallinity, and high initial thermal stability improve the mechanical and performance characteristics of the final food packaging materials. During film formation from starch subjected to preliminary mechanical amorphization, the polymer chain is recrystallized. The C-type crystal structure of starch is converted to the B-type structure. The supernatant obtained by starch hydrolysis can be used for producing glucose syrup. The resulting glucose syrup can be used as a sugar substitute in production of confectionery products. No objective technological differences in properties of glucose syrup obtained by comprehensive conversion of starch and the commercially available glucose syrup derived from sucrose were revealed.