Supplementation of Fructooligosaccharide Mildly Improves the Iron Status of Anemic Rats Fed a Low-Iron Diet

Also known as a prebiotic, fructooligosaccharide (FOS) resists digestion by gastric acid and pancreatic enzymes in vivo, but is preferentially fermented by beneficial intestinal bacteria once it reaches the colon. While some studies suggest that FOS and its fermentation products may influence the iron absorption process, the effects of prolonged FOS supplementation on iron status remain unclear. The objective of this study was therefore to determine the enhancing effects of FOS supplementation on the iron status of anemic rats. Male Sprague-Dawley rats receiving a low-iron diet (12 μg/g) for 14 days showed significantly lower hemoglobin concentration, as well as lower tissue non-heme iron levels than rats receiving a regular diet (45 μg/g), confirming iron-deficiency anemia. On the first day of the feeding trial, two groups of anemic rats (n = 6) were fed the same low-iron diet with or without FOS supplementation, while two other groups of anemic rats were switched to the regular diet with or without FOS supplementation to allow recovery. FOS was provided to the rats by dissolving in water at 5% (w/v). Anemic rats fed the low-iron diet showed a mild increase (p < 0.05) in hemoglobin level after 21 days of FOS supplementation when compared to rats without FOS. For anemic rats switched to the regular diet, hemoglobin level returned to normal after 14 days and FOS supplementation showed no additional effects. Our results suggest that FOS supplementation has a mild enhancing effect on the iron status of anemic subjects on a low-iron diet.

Comparative Analysis of Lactulose and Fructooligosaccharide on Growth Kinetics, Fermentation, and Antioxidant Activity of Common Probiotics

Prebiotics are non-digestible oligosaccharides that selectively stimulate the growth of beneficial bacteria in the human gut. Fructooligosaccharide (FOS) is a common prebiotic found in food products and infant formula. Lactulose is primarily used as a pharmaceutical ingredient but also shows potential prebiotic activities. Our objectives were to determine and compare the effects of FOS and lactulose on: 1) growth kinetics of common probiotics in aerobic condition;2) pH and titratable acidity after fermentation;and 3) antioxidant capacity of the probiotics. Ten probiotic and two non-probiotic strains, representing genera Lactobacillus, Bifidobacterium, Bacillus, and Escherichia were assembled. Media used for prebiotics experiment were modified to contain 2% FOS or lactulose as the sole or main carbohydrate source. All experiments were done in triplicate. In aerobic condition, most strains cultured with FOS or lactulose did not grow optimally compared to dextrose (a non-prebiotic), while all four Bifidobacterium spp. showed little growth regardless of the carbohydrate source. In anaerobic condition, lactulose and FOS fermentation of Bifidobacterium spp. yielded similar pH (p = 0.2723), but percent lactic acid, as determined by titratable acidity, was higher after lactulose fermentation (p = 0.0004). The non-probiotic strains were able to utilize both FOS and lactulose, but displayed weaker acid production and higher pH (p Bifidobacterium spp. (p = 0.0002) and Lactobacillus spp. (p = 0.0447), but not probiotic E. coli and Bacillus spp. (p = 0.2599) or non-probiotics (p = 0.8816). In conclusion, lactulose supported growth activities of probiotics to a similar extent as FOS. Lactulose also stimulated higher acid production for Bifidobacterium spp. than FOS in anaerobic condition, thus it might be considered for incorporation into functional food products containing bifidobacteria.

Milk protein concentrate and reduced-calcium milk protein concentrate as natural emulsifiers in clean label high-protein ice cream manufacture

Clean label food is a rising consumer trend in the food industry.Milk protein concentrate(MPC)and reduced-calcium milk protein concentrate(RCMPC)could serve as natural emulsifiers and increase the total protein content of ice cream products.The objectives of this study were to determine and compare the effects of MPC and RCMPC on ice cream composition,mix viscosity,storage stability,meltdown rate,and texture.A base formulation with 3%non-fat dry milk(NFDM)and no added emulsifiers was set as the control.Three levels of MPC or RCMPC(each powder containing 85%protein)at 1%,2%,and 3%were incorporated by replacing equivalent amounts of NFDM and keeping other ingredients unchanged.All ice cream treatments were processed with a target overrun of 70%and hardened at−25℃in a blast freezer.Additions of MPC or RCMPC at 1%,2%,and 3%corresponded to increases in protein content of ice cream by 15%,30%,and 45%,respectively.The viscosity of the ice-cream mix increased with increasing levels of MPC or RCMPC.In general,higher protein samples had slower meltdown rate and higher values of hardness and adhesiveness,but the trends were inconsistent.No shrinkage in volume was observed in any ice cream stored at−25℃after 180 days.However,an additional storage stability study revealed that the control showed significant shrinkage after 60 days(−6.5%±1.5%),90 days(−7.1%±1.8%),and 180 days(−7.9%±1.1%)in a typical household-style freezer at−13℃.MPC at 1%also showed significant shrinkage after 180 days,while samples with RCMPC at any levels showed no shrinkage at all.Ice cream manufacturers may consider MPC and RCMPC natural alternatives to synthetic emulsifiers,with RCMPC being more effective than MPC in terms of ice cream storage stability.