Immunological Properties of Inulin-Type Fructans

Beneficial effects of inulin-type fructans are discussed in view of studies that applied the oligosaccharides in colon cancer, chronic inflammatory diseases, vaccination efficacy, and prevention of infection and allergy. In the present paper, we discuss their immunomodulating effects. It is suggested that immunomodulation is elicited through indirect and direct mechanisms. Indirect mechanisms encompass stimulation of growth and activity of lactic acid bacteria, but can also be caused by fermentation products of these bacteria, i.e., short chain fatty acids. Evidence for direct effects on the immune system generally remains to be confirmed. It is suggested that inulin-type fructans can be detected by gut dendritic cells (DCs), through receptor ligation of pathogen recognition receptors (PRRs) such as Toll-like receptors, nucleotide oligomerization domain containing proteins (NODs), C-type lectin receptors, and galectins, eventually inducing pro- and anti-inflammatory cytokines. DCs may also exert antigen presenting capacity toward effector cells, such as B cells, T cells, and natural killer cells locally, or in the spleen. Inulin-type fructans may also ligate PRRs expressed on gut epithelium, which could influence its barrier function. Inulin-type fructans are potent immunomodulating food components that hold many promises for prevention of disease. However, more studies into the mechanisms, dose-effect relations, and structure-function studies are required.     

冷藏中低聚果糖对发酵乳中微生物的影响

对添加低聚果糖的原料奶，使用嗜酸乳杆菌、双歧杆菌和嗜热链球菌作为快速发酵剂进行发酵后．在4℃条件下储存42d。每周对发酵乳进行微生物分析和酸度测试。结果表明，低聚果糖质量浓度在10—50g／L时对嗜酸乳杆菌和嗜热链球菌的存活都没有太大影响。双歧杆菌活菌数下降幅度比嗜酸乳酸杆菌和嗜热链球菌要快。但添加低聚果糖对双歧杆菌的存活起到重要作用。结论是低聚果糖产品对双歧杆菌有益生作用，因此在冷藏发酵乳制品中有助于提高双歧杆菌活菌数。     

Alginate coating as carrier of oligofructose and inulin and to maintain the quality of fresh-cut apples

The aim of this study was to apply an edible coating containing prebiotics such as oligofructose and inulin to fresh-cut apple wedges. An assessment of the quality, sensory, polyphenol, and volatile attributes of coated and uncoated fresh-cut apple wedges was also undertaken. Fructan analysis showed that all prebiotics remained stable over the 14-d storage period and an intake of 100 g of apple supplies 1 to 3 g of prebiotics. Browning index, firmness, acidity remained stable throughout the 14 d compared to the control while applying prebiotic coatings resulted in an increase in soluble solids. Sensory and visual assessment indicated acceptable quality of apple wedges coated with prebiotics. HPLC analysis showed that levels of polyphenolic compounds were more stable in coated apple wedges (without prebiotic inclusions) than in uncoated control apples. No difference was found between O(2) and CO(2) headspace concentration of coated and uncoated samples. Significant differences (P < 0.001) were found for headspace volatile production between the samples. Most coated samples showed lower volatile production in the headspace than uncoated samples.     

Antioxidative capacity produced by Bifidobacterium‐ and Lactobacillus acidophilus‐mediated fermentations of konjac glucomannan and glucomannan oligosaccharides

BACKGROUND: Konjac glucomannan (KGM) has been shown to stimulate the growth of bifidobacteria and lactobacilli in the human and rat colon. This study investigated the antioxidative effects produced after 48 h in vitro fermentation of unhydrolysed KGM and two hydrolysed KGM fractions (KH1 and KH2 with degree of polymerisation 10 and 5 respectively) by Bifidobacterium adolescentis, B. bifidum, B. breve, B. longum and Lactobacillus acidophilus respectively. The inhibitory effect on conjugated diene formation, ferric‐chelating capacity, α,α‐diphenyl‐β‐picrylhydrazyl (DPPH) radical‐scavenging ability and thiobarbituric acid‐reactive substances (TBARS) concentration produced by these fermentations were compared with those of oligofructose (OF) fermentation. RESULTS: The fermentation of KGM by each bacterial strain produced higher ferric‐chelating capacity of the culture supernatant compared with KH2 or OF fermentation. In contrast, the fermentation of KGM by each bacterial strain led to lower inhibition of conjugated diene formation and lower radical‐scavenging ability compared with KH2 fermentation. The fermentation of KH2 produced the lowest amount of TBARS. CONCLUSION: The fermentation of unhydrolysed KGM by colonic lactic acid bacteria in vitro produced antioxidative capacity mainly by preventing the initiation of ferrous ion‐induced peroxidation, whereas the fermentation of konjac oligosaccahrides did so by increasing the radical‐scavenging ability and eliminating lipid peroxide formation. Copyright © 2008 Society of Chemical Industry     

Short communication: Rising and lying behavior of heifers before and after alimentary oligofructose overload

The aim of this experiment was to describe the rising and lying behavior of heifers in the first 5 d after alimentary oligofructose overload to 1) acquire information about consequences of this experimental disease model in terms of animal behavior; and 2) contribute to the evaluation of the influence of disease on cattle welfare. Eight tethered Holstein-Friesian heifers were used and their behavior was observed for 10.5 ± 2.7 hours of light per day. Occurrence of rising and lying behavior and parts thereof were recorded. Clinical and physiological examinations were conducted throughout to confirm presence of ruminal acidosis and lameness. The duration of pre-lying intention movements were increased on d 3 after oligofructose overload compared with d −1 [28 (20 to 40) vs. 13 (10 to 16) s, respectively], and the duration of the total lying sequence was increased on d 1 and 3 compared with the control day [27 (22 to 33) and 36 (25 to 48) vs. 17 (13 to 21) s, respectively]. The frequency and duration of getting up did not differ between days. These results suggest that disease induced by oligofructose overload (i.e., ruminal acidosis and lameness) can affect lying behavior in heifers as shown by increased duration of lying intentions and difficulty in lying down, which may indicate that lying motivation was thwarted, possibly by pain or discomfort.     

On the presence of Inulin and Oligofructose as natural ingredients in the western diet

The classic definitions of inulin and oligofructose are constructively criticized. It is observed that inulin cannot unequivocally be described as a polydisperse 1‐kestose‐based (GF_n) β(2 ? 1) linear fructan chain, but that inulin always contains small amounts of F_m and branched molecules. This review article describes the presence of inulin and oligofructose in common foodstuffs. Historical data on human consumption add an extra dimension.

Modern analytical techniques (HPLC, LGC, HPAEC‐PAD) are used to check the variety of data mentioned in the literature throughout the past century. Methods to determine inulin and oligofructose in natural foodstuffs (cereals, fruit, and vegetables) are optimized and used to determine the loss of inulin during storage and during preparation of the food.

These findings allow quantification of the amount of inulin and oligofructose in the average daily western diet. The daily per capita intake is estimated to range from 1 to 10 g, depending on geographic, demographic, and other related parameters (age, sex, season, etc.).

Inulin and oligofructose are not measured by classic methods of dietary fiber analysis and consequently are often not mentioned in food tables. Their significant contribution (1 to 10 g/d/per capita) to the dietary fiber fraction (recommended at 25 g/d/per capita) is not taken into account in any nutritional recommendations. In view of this, inulin and oligofructose deserve more attention, both in food composition tables and in diet or nutrition studies.     

Dietary fiber,inulin, and oligofructose: A review comparing their physiological effects

Dietary fiber is a general terra. It covers a wide variety of substances that belong to the family of carbohydrates that resist hydrolysis by human alimentary enzymes but are fermented by colonie microflora.

The main physiological effects of dietary fiber are primarily on gastric emptying and small intestinal transit time, resulting in an improved glucose tolerance and a decreased digestion of starch; second, on colonie transit time and large bowel functions due to fermentation by ceco‐colonic microbial flora or bulking action.

The so‐called soluble dietary fibers are fermented to a large extent by a wide variety of anaerobic bacteria that result in an increase in bacterial biomass, an increase in fecal mass, a change in intracolonic pH, and production of short chain fatty acids and various gases as metabolic end products. The insoluble fibers are only marginally fermented; they serve almost exclusively as bulking agents that result in shorter transit time and increased fecal mass.

The short chain fatty acids resulting from the colonie fermentation of dietary fiber are largely absorbed via the portal blood and reach both the liver and the peripheral tissues. They induce changes in glucose and fat metabolism leading to post‐prandial hypoglycemia and long‐term hypolipidemia.

Inulin and oligofructose are fructans with a degree of polymerization of 2 to 60 and 2 to 20. respectively. Due to the structural conformation of their osidic bridge ((3 2–1), they both resist the hydrolysis by human alimentary enzymes. Moreover, when reaching the colon, both inulin and oligofructose are almost quantitatively fermented almost exclusively by colonie bifidobacteria and bacteroides. Such an extensive fermentation causes an increase in fecal bacterial biomass, a decrease in ceco‐colonic pH. and produces a large amount of fermentation products among which the short chain fatty acids that exert systemic effects on lipid metabolism.

Thus, both inulin and oligofructose have most of the characteristics of a dietary fiber and the proposal is made to classify them as such. Moreover, they are bifidogenic factors, because, due to still unknown reasons, they are primarily fermented by bifidobacteria.

It is concluded from this review that “nondigestible fructooligosaccharides.” even though they arc not included in the carbohydrate fraction that is quantified as dietary fiber by classic analytical methods, have most of the physiological effects of a dietary fiber. Because it has become necessary for the consumer to be informed clearly and specifically on the nature and the beneficial effects of all fermentable carbohydrates that will “feed” their colon, it is suggested that food labeling should be extended to include such products in the dietary liber fraction.     

Optimization of the Acceptance of Prebiotic Beverage Made from Cashew Nut Kernels and Passion Fruit Juice

The aim of this research was to develop a prebiotic beverage from a hydrosoluble extract of broken cashew nut kernels and passion fruit juice using response surface methodology in order to optimize acceptance of its sensory attributes. A 2² central composite rotatable design was used, which produced 9 formulations, which were then evaluated using different concentrations of hydrosoluble cashew nut kernel, passion fruit juice, oligofructose, and 3% sugar. The use of response surface methodology to interpret the sensory data made it possible to obtain a formulation with satisfactory acceptance which met the criteria of bifidogenic action and use of hydrosoluble cashew nut kernels by using 14% oligofructose and 33% passion fruit juice.     

Acute bovine laminitis: a new induction model using alimentary oligofructose overload

Twelve dairy heifers were used to examine the clinical response of an alimentary oligofructose overload. Six animals were divided into 3 subgroups, and each was given a bolus dose of 13, 17, or 21 g/kg of oligofructose orally. The control group (n = 6) was sham-treated with tap water. Signs of lameness, cardiovascular function, and gastrointestinal function were monitored every 6 h during development of rumen acidosis. The heifers were euthanized 48 and 72 h after administration of oligofructose. All animals given oligofructose developed depression, anorexia, and diarrhea 9 to 39 h after receiving oligofructose. By 33 to 45 h after treatment, the feces returned to normal consistency and the heifers began eating again. Animals given oligofructose developed transient fever, severe metabolic acidosis, and moderate dehydration, which were alleviated by supportive therapy. Four of 6 animals given oligofructose displayed clinical signs of laminitis starting 39 to 45 h after receiving oligofructose and lasting until euthanasia. The lameness was obvious, but could easily be overlooked by the untrained eye, because the heifers continued to stand and walk, and did not interrupt their eating behavior. No positive pain reactions or lameness were seen in control animals. Based on these results, we conclude that an alimentary oligofructose overload is able to induce signs of acute laminitis in cattle. This model offers a new method, which can be used in further investigation of the pathogenesis and pathophysiology of bovine laminitis.     

The effect of alternative sweeteners on batter rheology and cake properties

BACKGROUND: The aim of this research was to investigate whether certain polyols (mannitol, maltitol, sorbitol, lactitol), fructose, oligofructose and polydextrose can replace sugar (by an equal amount of each substitute) in cake formulations. The rheological behaviour of the cake batter and the physical characteristics of the cakes containing sugar substitutes were compared with the respective attributes of the control cake. Differential scanning calorimetry was used to investigate the effect of sugar substitutes on starch gelatinisation. Furthermore sensorial characteristics were evaluated by instrumental measurements and sensory evaluation. The correlation of the batter characteristics with the textural attributes of the final product was also attempted. RESULTS: The best results were obtained by using oligofructose, lactitol or maltitol as sugar replacers, which exhibited similar behaviour to sucrose in terms of batter rheology and increased starch gelatinisation temperature. Fructose and mannitol led to cakes of poor quality characteristics, as was demonstrated by instrumental measurements and sensory evaluation. CONCLUSIONS: Batter rheological behaviour as well as the ability of sugar substitutes to increase starch gelatinisation temperature proved to be controlling factors of the textural properties and volume of the cakes. The sensory evaluation indicated that overall acceptance followed closely the scores of tenderness and taste. Copyright © 2011 Society of Chemical Industry