半制备高效液相色谱-离子色谱法检测婴幼儿配方食品中低聚半乳糖的含量

目的 优化并建立半制备高效液相色谱法-离子色谱法测定婴幼儿配方食品中低聚半乳糖含量的方法.方法 以乳粉、特殊医学配方奶粉和液态奶为实验对象,利用半制备高效液相色谱法分别收集婴幼儿配方食品中的二糖和三糖及聚合度(degree of polymerization,DP)3以上的糖,再利用β-半乳糖苷酶水解收集聚合度3及3以...     

低聚半乳糖分离纯化研究进展

低聚半乳糖（GOS）是一种功能性低聚糖,因其具有独特的理化性质及生理功能,被广泛地应用于食品、医药等领域,市场前景十分广阔。该文综述了低聚半乳糖的性质及制备方法,对其分离纯化方法进行重点介绍,最后对高纯度的GOS的制备进行了展望。     

母乳中的低聚半乳糖研究和应用的最新进展

本详述了低聚半乳糖的研究和应用的最新进展,并简述了低聚半乳糖的特性。     

Sensory evaluations and stability determinations of goat milk containing galactooligosaccharides

The objectives of this study were to evaluate the feasibility of producing goat milk containing galactooligosaccharides (GOS) by β‐galactosidase and to determine the sensory attribute and stability of goat milk containing GOS. The results indicated that the maximum GOS obtained were approximately 13.9% of total sugars at pH 4.5 and temperature 40 °C. The sensory attribute of the obtained GOS was determined using a 5‐point hedonic scale in terms of taste, flavour, appearance and overall acceptability. There were significant increases in taste and overall acceptability of goat milk containing higher GOS concentration when compared to regular goat milk (control). Also, goat milk containing GOS presented a good stability over the acidic conditions. GOS in goat milk were also stable after the high heat treatment and shelf life conditions.     

Wheat aleurone: separation, composition, health aspects, and potential food use

Over the last three decades substantial attention has been given to the role of dietary fiber in health and disease, in particular diabetes, cardiovascular disease, intestinal health, and some types of cancer. As a result the food industry started to add back fiber to refined foods and develop fiber rich foods. Scientists suggested that whole grain foods are superior to foods enriched with fibers obtained/synthesized using enzyme treatment, and thermal or chemical processing because the content of bioactive components and micronutrients in whole grain is more abundant. This triggered interest in how to isolate the micronutrient rich aleurone fiber fraction from wheat. Aleurone is a single cell layer at the inner site of the bran. It contains most of the minerals, vitamins, phenolic antioxidants, and lignans of the wheat grain. Novel milling and dry-fractionation techniques have recently allowed for full-scale separation of aleurone cells from the other layers of wheat bran, yielding a fiber rich concentrate which potentially contains many of the "whole grain kernel bioactives," which recently have been used in a variety of studies. The present review highlights available data on aleurone isolation, composition, intestinal physiology, and its metabolism and potential health benefits as well as its use in food.     

Seaweed proteins: biochemical,nutritional aspects and potential uses

Seaweeds are traditionally used in human and animal nutrition. Their protein contents differ according to the species and seasonal conditions. Little information is available on the nutritional value of algal proteins and, especially, on the compounds that decrease their digestibility. This paper is a short review of the biochemical and nutritional aspects associated with seaweed proteins. Some perspectives on the potential uses of algal proteins for the development of new foods or additives for human or animal consumption are also discussed.     

Avocado oil: Production and market demand,bioactive components,implications in health,and tendencies and potential uses

Avocado is a subtropical/tropical fruit with creamy texture, peculiar flavor, and high nutritional value. Due to its high oil content, a significant quantity of avocado fruit is used for the production of oil using different methods. Avocado oil is rich in lipid-soluble bioactive compounds, but their content depends on different factors. Several phytochemicals in the oil have been linked to prevention of cancer, age-related macular degeneration, and cardiovascular diseases and therefore have generated an increase in consumer demand for avocado oil. The aim of this review is to critically and systematically analyze the worldwide production and commercialization of avocado oil, its extraction methods, changes in its fat-soluble phytochemical content, health benefits, and new trends and applications. There is a lack of information on the production and commercialization of the different types of avocado oil, but there are abundant data on extraction methods using solvents, centrifugation-assisted aqueous extraction, mechanical extraction by cold pressing (varying concentration and type of enzymes, temperature and time of reaction, and dilution ratio), ultrasound-assisted extraction, and supercritical fluid to enhance the yield and quality of oil. Extensive information is available on the content of fatty acids, although it is limited on carotenoids and chlorophylls. The effect of avocado oil on cancer, diabetes, and cardiovascular diseases has been demonstrated through in vitro and animal studies, but not in humans. Avocado oil continues to be of interest to the food, pharmaceutical, and cosmetic industries and is also generating increased attention in other areas including structured lipids, nanotechnology, and environmental care.     

Flaxseed proteins: food uses and health benefits

Flaxseed proteins are potent multi‐functional ingredients for food formulation owing to their techno‐functionalities, food preservation capacity, and health benefits. A possible synergistic effect with mucilage on their functionalities could be valuable even though this co‐product in flaxseed may limit the protein yield during their production processes. Their techno‐functional properties could also be considered in mixture with other flax bioactive components such as lignans and fibre to enhance the value of the flaxseed meal. The present paper reviews flaxseed protein uses in food and their health benefits. New perspectives according to consumers’ demand for products with health promoting bioactive components are also suggested.     

Effect of inulin and galactooligosaccharides on particle size distribution and rheological properties of prebiotic ketchup

The aim of this study was to evaluate the effects of different combinations of long-chain inulin and short-chain galactooligosaccharides mixed with different hydrocolloids on the physical/rheological attributes of prebiotic ketchup. Novel prebiotic ketchup was produced in which modified starch, xanthan, and guar gum was incorporated. Results showed that modified starch negatively influenced the physical properties of prebiotic samples and the optimum condition was 7.5% long-chain inulin and 2.5% galactooligosaccharides along with 0.4 % xanthan and 0.18% guar gum. Under these conditions, smaller hysteresis loop area, higher values of the linear viscoelastic region, larger G₀, η₀ in the creep test, and smaller sized suspended particles as compared to the other prebiotic samples were observed. In addition, galactooligosaccharides may interfere with the elastic behavior due to its high water solubility. Therefore, an appropriate amount (2.5%) of this ingredient may be used to produce a nutritive prebiotic ketchup with desirable textural properties. Environmental scanning electron microscopic images confirmed larger and inter-connected air bubbles entrapped into the semi-solid matrix of prebiotic sample produced under optimum condition.     

Rice bran and its constituents: Introduction and potential food uses

Rice bran (RB) is one of the by-products during the milling of rice. RB is underutilised due to its ease of susceptibility towards enzymatic activity. RB contains various bioactive compounds such as γ-oryzanol, phytosterols, tocols and squalene. High nutritional properties make RB, and its constituents play their different roles in the food industry, such as gluten flour substitutes, alternate shortening, organogelators, stabilisers and other types of additives. This review will briefly introduce the RB and its constituents and discuss their potential applications in the food industry.     

粮油加工副产物在微生物群导向型食品研发中的应用潜力

人体肠道上皮附着着数以亿计的菌群,它们是人体健康和生理功能实现的参与者,也是大健康概念所涵盖的一个重要靶点。到目前为止,补充益生元仍是调节肠道菌群和促进有益菌群生长的有效手段之一。粮油加工副产物产量大,种类丰富,且其中很多成分可被寄居人体的肠道菌群利用,是优质益生元的来源之一,亦是"微生物群导向型食品"开发中重要的物质基础与原料来源。     

Fructo-oligosaccharides: Production,Purification and Potential Applications

The nutritional and therapeutic benefits of prebiotics have attracted the keen interest of consumers and food processing industry for their use as food ingredients. Fructo-oligosaccharides (FOS), new alternative sweeteners, constitute 1-kestose, nystose, and 1-beta-fructofuranosyl nystose produced from sucrose by the action of fructosyltransferase from plants, bacteria, yeast, and fungi. FOS has low caloric values, non-cariogenic properties, and help gut absorption of ions, decrease levels of lipids and cholesterol and bifidus-stimulating functionality. The purified linear fructose oligomers are added to various food products like cookies, yoghurt, infant milk products, desserts, and beverages due to their potential health benefits. This review is focused on the various aspects of biotechnological production, purification and potential applications of fructo-oligosaccharides.     

Comparative composition,diversity, and abundance of oligosaccharides in early lactation milk from commercial dairy and beef cows

Prebiotics are nondigestible dietary ingredients, usually oligosaccharides (OS), that provide a health benefit to the host by directly modulating the gut microbiota. Although there is some information describing OS content in dairy-source milk, no information is available to describe the OS content of beef-source milk. Given the different trait emphasis between dairy and beef for milk production and calf survivability, it is plausible that OS composition, diversity, and abundance differ between production types. The goal of this study was to compare OS in milk from commercial dairy and beef cows in early lactation. Early-lactation multiparous cows (5–12 d in milk) from 5 commercial Holstein dairy herds and 5 Angus or Angus hybrid beef herds were sampled once. Milk was obtained from each enrolled cow and frozen on the farm. Subsequently, each milk sample was assessed for total solids, pH, and OS content and relative abundance. Oligosaccharide diversity and abundance within and between samples was transformed through principal component analysis to reduce data complexity. Factors from principal component analysis were used to create similarity clusters, which were subsequently used in a multivariate logistic regression. In total, 30 OS were identified in early-lactation cow milk, including 21 distinct OS and 9 isomers with unique retention times. The majority of OS detected in the milk samples were present in all individual samples regardless of production type. Two clusters described distribution patterns of OS for the study sample; when median OS abundance was compared between the 2 clusters, we found that overall OS relative abundance was consistently greater in the cluster dominated by beef cows. For several of the structures, including those with known prebiotic effect, the difference in abundance was 2- to 4-fold greater in the beef-dominated cluster. Assuming that beef OS content in milk is the gold standard for cattle, it is likely that preweaning dairy calves are deprived of dietary-source OS. Although supplementing rations with OS is an approach to rectify this deficiency, understanding the health and productivity effects of improving OS abundance being fed to preweaning calves is a necessary next step before recommending supplementation. These studies should account for the observation that OS products are variable for both OS diversity and structural complexity, and some products may not be suitable as prebiotics.     

Effects of probiotic,prebiotic and synbiotic follow‐up infant formulas on large intestine morphology and bone mineralisation in rats

The effects of powder functional follow‐up infant formulas on the morphology of the large intestine and the bone mineral content in rats were investigated. Infant formulas were supplemented with probiotics (Bifidobacterium bifidum and Bifidobacterium longum), prebiotics (galacto‐oligosaccharides (4′‐GOS) at 12, 50 and 100 g kg^?1) or synbiotics (bifidobacteria and 4′‐GOS) and administered to seven groups of weanling rats over 30 days. After sacrificing the animals, the caecum and colon were removed and the luminal content pH and the crypt depth and cell density within the epithelial layer were measured. Results showed that groups fed synbiotic diets had significantly (P < 0.05) lower caecal and colonic content pH values compared with the control group. However, no test diet significantly modified the crypt depth or cell density in the caecum. In contrast, all seven test diets significantly increased (P < 0.05) the crypt depth in both the proximal and distal portions of the colon. There was a high correlation (Pearson correlation coefficient 0.870) between caecal and colonic content pH values. On the other hand, colonic content pH was negatively correlated with crypt depth in both the proximal and distal colon and with cell density in the distal colon. The authors previously reported increases in calcium, magnesium and phosphorus absorption using the same infant formulas. In the present study it was concluded that the increase in calcium absorption took place in the distal colon whereas magnesium absorption increased in both the proximal and distal colon, and their contents (especially that of calcium) increased in both the femur and tibia. Copyright © 2007 Society of Chemical Industry     

Production, purification, and characterization of a potential thermostable galactosidase for milk lactose hydrolysis from Bacillus stearothermophilus

β-Galactosidase, commonly named lactase, is one of the most important enzymes used in dairy processing; it catalyzes the hydrolysis of lactose to its constituent monosaccharides glucose and galactose. Here, a thermostable β-galactosidase gene bgaB from Bacillus stearothermophilus was cloned and expressed in B. sub-tilis WB600. The recombinant enzyme was purified by a combination of heat treatment, ammonium sulfate fractionation, ion exchange, and gel filtration chromatography techniques. The purified β-galactosidase appeared as a single protein band in sodium dodecyl sulfate-PAGE gel with a molecular mass of approximately 70 kDa. Its isoelectric point, determined by polyacryl-amide gel isoelectric focusing, was close to 5.1. The optimum temperature and pH for this β-galactosidase activity were 70°C and pH 7.0, respectively. Kinetics of thermal inactivation and half-life times for this thermostable enzyme at 65 and 70°C were 50 and 9 h, respectively, and the K_m and V_max values were 2.96 mM and 6.62 μmol/min per mg. Metal cations and EDTA could not activate this thermostable enzyme, and some divalent metal ions, namely, Fe²⁺, Zn²⁺, Cu²⁺, Pb²⁺, and Sn²⁺, inhibited its activity. Thiol reagents had no effect on the enzyme activity, and sulfhydryl group blocking reagents inactivated the enzyme. This enzyme possessed a high level of transgalactosylation activity in hydrolysis of lactose in milk. The results suggest that this recombinant thermostable enzyme may be suitable for both the hydrolysis of lactose and the production of galactooligosaccharides in milk processing.     

Production of functional probiotic, prebiotic, and synbiotic ice creams

In this work, 3 types of ice cream were produced: a probiotic ice cream produced by adding potentially probiotic microorganisms such as Lactobacillus casei and Lactobacillus rhamnosus; a prebiotic ice cream produced by adding inulin, a prebiotic substrate; and a synbiotic ice cream produced by adding probiotic microorganisms and inulin in combination. In addition to microbial counts, pH, acidity, and physical and functional properties of the ice creams were evaluated. The experimental ice creams preserved the probiotic bacteria and had counts of viable lactic acid bacteria after frozen storage that met the minimum required to achieve probiotic effects. Moreover, most of the ice creams showed good nutritional and sensory properties, with the best results obtained with Lb. casei and 2.5% inulin.     

Bioavailability of calcium,magnesium and phosphorus in rats fed probiotic,prebiotic and synbiotic powder follow‐up infant formulas and their effect on physiological and nutritional parameters

The effect of infant formulas supplemented with functional ingredients on calcium (Ca), magnesium (Mg) and phosphorus (P) bioavailability was investigated in rats. Seven follow‐up infant formulas containing probiotics (Bifidobacterium bifidum and Bifidobacterium longum), prebiotics (galactooligosaccharides at 12, 50 and 100 g kg^?1) or synbiotics (bifidobacteria and galactooligosacccharides) were administered to weanling rats for 30 days. A 3 day mineral balance was performed over three periods (8–10, 18–20 and 28–30 days) to monitor mineral apparent absorption and retention ratios and physiological and nutritional parameters. Feeding rats on infant formula‐based diets showed high feed efficiency (≥0.46). It was found that infant formulas supplemented with probiotics and/or prebiotics for 30 days increased Ca, Mg and P bioavailability in rats. Mineral apparent absorption and retention ratios were higher than 90% for Ca and P and 80% for Mg during the first balance period regardless of the infant formula used, but they decreased during the next two balance periods. Although it was not possible to select one infant formula as the best to improve mineral absorption, the 100 g kg^?1 prebiotic and 50 and 100 g kg^?1 synbiotic infant formulas were the most efficient at increasing Ca, Mg and P bioavailability compared with the control group. Copyright © 2006 Society of Chemical Industry