Physiological and Nutraceutical Perspectives of Fructan

Functional and nutraceutical foods have captured the global market owing to trends and perceptions of consumers on the natural products and diet-health linkages. Health promoting potential of such foods has been attributed to the presence of essential bioactive moieties. Wheat, being staple food in many parts of the world, gained substantial attention of researchers particularly for the extraction of various functional components. Among these, fructan oligosaccharides in nature bestow quality of baked products and provide protection against various physiological disorders. Addition of fructan in various baked products enhances softness and color, especially in bread, and also imparts textural improvement. Moreover, fructans boost mineral absorption, hypocholesterolemic, and hypoglycemic perspectives, bifidogenic nature and controlling cancer insurgence. The benefits allied with fructan are mainly dose and time dependent. In this context, its industrial applications for vulnerable groups are increasing worldwide.     

酶水解-阴离子色谱法联用测定婴幼儿配方奶粉中果聚糖的总含量及平均聚合度

摘 要：目的 建立酶水解—离子色谱法测定婴幼儿配方奶粉中总果聚糖的分析方法。方法 通过酶水解将样品中的果聚糖水解成果糖、葡萄糖,以PA1阴离子交换柱分离,脉冲积分安培检测器进行检测果聚糖总含量,以果糖与葡萄糖产生的比例计算平均聚合度。结果 果糖、葡萄糖在0.25~25.0 mg/L范围内线性关系良好（R2>0.999）,果聚糖的回收率为96.9%~104.4%,方法检出限为195mg/kg,定量限为650mg/kg。实际样品测定中,日间的相对标准偏差（RSD,n=6）为1.15%~3.87%。结论 可用于婴幼儿配方奶粉中果聚糖的总含量及平均聚合度的测定方法。     

Optimization of osmotic dehydration of yacon slices

Osmotic dehydration assisted by ultrasound (ODAU) at low temperatures reduces water activity (a_w) and maintains nutrients. The influence of solution concentration (SC; 20 to 60° Brix, xylitol and sorbitol) and ultrasound application time (t_us, 0 to 40 min) in ODAU of yacon was studied with the aid of a response surface method. The optimum condition with respect to mass transfer parameters, a_w, and fructan retention was SC of 60° Brix for both solutions and t_us of 2.67 min for xylitol samples and 0 min for sorbitol samples. The application of ultrasound improved dehydration but resulted in depolymerization of fructans.     

Optimization of Fish Oil Spray Drying Using a Protein:Inulin System

The aim of this work was to investigate the use of an unconven-tional polymeric material, inulin, in fish oil spray drying. The influence of inlet air temperature, oil load, and carrier substitution (whey protein isolate by inulin) on the physical properties of particles containing fish oil was investigated. Increasing the oil load caused an increase in the surface oil; however, the presence of inulin favorably decreased the particle surface oil when a high oil lad was applied. The parameters hygroscopicity and wettability were also influenced by the inulin fraction. The higher inlet air temperature produced larger particles with lower densities. The best operating conditions were determined to be an air temperature of 185°C, a 40% inulin fraction, and a 6% oil load. The results indicate that inulin is an alternative carrier in the fish oil spray-drying process.     

Synbiotic potential of fresh cream cheese supplemented with inulin and Lactobacillus paracasei in co-culture with Streptococcus thermophilus

The influence of the addition of Lactobacillus paracasei and Streptococcus thermophilus on the fructan content at the beginning and at the end of storage at 4 ± 1 °C of a potentially synbiotic fresh cream cheese manufactured with inulin was investigated. Three cheese-making trials were prepared, all supplemented with a lactic culture of S. thermophilus (T1, T2 and T3). L. paracasei subsp. paracasei was added in T1 and T2. Inulin was added in T2 and the fructan content was measured after 1 and 21 days of storage. Samples of T2 possessed similar mean concentrations of fructans after 1 and 21 days of storage, 7.32% and 7.27%, respectively, and no significant difference was observed. These results indicated that the metabolism of starter and probiotic bacteria did not degrade the fructans present in those cheeses. Additionally, synbiotic cheeses possessed a fructan content higher than 7 g per 100 g, sufficient to confer prebiotic potential during the entire storage period of these products.     

果聚糖的合成与利用

介绍了富有果聚糖的植物种类及利用蔗糖合成果聚糖的微生物。讨论了果聚糖的特性、菊粉与果聚糖的功能及其利用情况。     

Characterisation of dietary fibre components in rye products

In this study, dietary fibre (DF) was characterised in rye products from a local supermarket. Soft breads generally had lower DF contents (8–18%) than had crisp breads (13–20%) due to high inclusion of wheat flour. For some products, the labelled DF values contained fructan, but others did not. However, for most products, the DF values analysed exceeded those declared. Arabinoxylan (AX) and fructan were generally the main DF components in the products, followed by cellulose and resistant starch, β-glucan, Klason lignin and arabinogalactan. In the soft breads, cellulose and resistant starch concentrations were relatively high, due to significant formation of resistant starch. During bread manufacturing, the molecular weight of β-glucan was highly degraded, while that of AX was more resistant. Extruded products had the highest β-glucan extractability and the extracted β-glucan retained its molecular weight most, which may be of nutritional significance. In rye milling fractions, about 50% of the fructan content analysed had a degree of polymerisation below 10, i.e. it comprised oligosaccharides. The crisp breads produced without yeast had the highest DF and fructan contents and the highest proportion of low-molecular weight fructan. These results indicate that, during bread-making, the low-molecular weight fraction of fructan was most available for degradation by yeast or by endogenous enzymes present in the ingredients.     

Anti-influenza A virus effects of fructan from Welsh onion (Allium fistulosum L.)

A fructan that acts as an anti-influenza A virus substance was isolated from hot water extract of the green leafy part of a Welsh onion (Allium fistulosum L.). The structure of the fructan was characterised and elucidated by chemical and spectroscopic analyses. The fructan was composed of terminal (21.0%) and 2,1-linked β-d-Fruf residues (65.3%) with 1,6-linked β-d-Glcp residues (13.7%). The molecular weight of the polysaccharide and polydispersity was estimated to be 1.5 × 10³ and 1.18, respectively. Although the fructan did not show anti-influenza A virus activity in vitro, it demonstrated an inhibitory effect on virus replication in vivo when it was orally administered to mice. In addition, the polysaccharide enhanced the production of neutralising antibodies against influenza A virus. Therefore, the antiviral mechanism of the polysaccharide seemed to be dependent on the host immune system, i.e., enhancement of the host immune function was achieved by the administration of the polysaccharide. From our observations, the fructan from Welsh onions is suggested to be one of the active principles which exert an anti-influenza virus effect.