Soluble Polysaccharides Research Articles

Application of a Designed Mixed Model Approach for Antioxidant Extraction from Pomace

Pomace is a residue of juice production, but still holds many valuable compounds, such as antioxidants. However, efficient extraction proves to be challenging, as extractability is highly dependent on experimental conditions. Furthermore, antioxidants are also often retained by structural polysaccharides. Consequently, this study investigates the extractability of antioxidants in five different types of pomace in a 2 × 2 × 2 × 3 full factorial fully replicated design to determine the most efficient way of extraction. Therefore, extracting agent, temperature, extraction method and use of enzyme to break down structural components were alternated to investigate the effects of these parameters on the extractability. Main effects as well as interaction effects were estimated with linear mixed models. To study the effects of polysaccharides on the retention of antioxidants, the amount of soluble polysaccharides was measured and connected to the antioxidant capacity at each experimental condition. The experiments showed that acetone was most suitable as an extracting agent and that the use of pectinase significantly increased the amount of extracted antioxidants. Additionally, ultrasound-assisted extraction is advantageous compared to extraction in water bath. Temperature showed the lowest effect in this experimental design. Lastly, the results also highlight that the amount of soluble polysaccharides does not correlate with the extractability of antioxidants.

Effects of microplastics on the growth, photosynthetic efficiency and nutrient composition in freshwater algae Chlorella vulgaris Beij

Microplastics, plastic particles and fragments smaller than 5 mm are ubiquitous in various aquatic environments, but the hazards of microplastics with different particle sizes, concentrations and materials are not well understood. This study investigated the toxicity of polyethylene microplastics (PE-MPs) with different concentrations and particle sizes or polystyrene microplastics (PS-MPs) on freshwater algae Chlorella vulgaris Beij (C. vulgaris) for 11 days. Results indicated that the growth, colony formation, photosynthetic pigment contents and soluble intracellular polysaccharides were unaffected, whereas the photosynthetic efficiency and the total soluble protein (TSP) contents were remarkably decreased at 11 d with the increased concentration of PE-MP exposure. The growth, photosynthetic efficiency, soluble intracellular polysaccharides and TSP contents were unaffected after exposure to PE-MPs with different particle sizes or PS-MPs. By contrast, the colony formation and photosynthetic pigment contents were remarkably decreased after exposure to PS-MPs compared with the control or PE-MPs with the same particle size. The C. vulgaris colonization on microplastics was proven by scanning electron microscopy, indicating that the adsorption effects were the main harmful pathways of different microplastics to algal. Our results suggested that microplastics have limited harmful effects on algae, mainly in adsorption and shading.

Refining the metabolisable energy value of field beans for turkeys

ABSTRACT 1. This study examined the feeding value of ten UK grown field bean (Vicia faba L. var. minor) cultivar samples from the same harvest year on nitrogen corrected apparent metabolisable energy (AMEn) and nutrient retention coefficients when fed to young female turkeys. 2. A balancer feed (BF) was formulated to contain 12.39 MJ/kg ME and 269 g/kg crude protein. Ten nutritionally complete, mash diets were prepared by mixing 200 g/kg of each ground field bean cultivar with 800 g/kg of the BF, totalling eleven diets. Diets were fed to female BUT Premium turkeys from 40 to 50 d of age. Each diet was fed to eight raised floor pens, housing two birds, following randomisation. The AMEn was determined by the total collection technique over the last 4 d of the study. Relationships were examined between AMEn, chemical composition and quality variables of the field bean samples. 3. The overall determined AMEn value of the beans ranged from 7.72 MJ/kg DM to 9.87 MJ/kg DM, giving an average AMEn of 8.80 MJ/kg DM (P < 0.05). The soluble non-starch polysaccharide (NSP) content of the beans negatively correlated with their determined AMEn (r = −0.730; P < 0.05). Bean flour lightness-darkness degree (L*) correlated positively with the AMEn (r = −0.643; P < 0.05) 4. A positive correlation was observed between the degree of yellowness-blueness of bean flour and condensed tannins content (r = 0.696; P < 0.05). Step-wise regression indicated that soluble NSP + L* of field beans provided explanatory variables suitable for estimating the AMEn value for turkeys (r2 = 0.737; P < 0.05).

Influence of hydrocolloids and natural emulsifier in the physical stability of UHT oat beverage.

This study aimed to improve the physical stability of ultra-high temperature (UHT) oat beverage by adding hydrophilic colloids (guar gum [GG] and xanthan gum [XG]) and a natural emulsifier (soluble soybean polysaccharide [SSPS]). The stability of the oat beverage was characterized by particle size, zeta potential, rheological properties, Fourier-transform infrared (FTIR) spectroscopy, backscattered light intensity (ΔBS), and microstructure. The results indicated that XG reduced the average particle size and size distribution of the beverage, indicating that XG could prevent particle aggregation. GG increases the apparent viscosity of the oat beverage without affecting the zeta potential. When SSPS was added to the oat beverage, it increased the absolute value of the zeta potential and the infrared absorption peak intensity, while the average particle size and backscattered light intensity (ΔBS) decreased, resulting in a more uniform microstructure. The zeta potential reached a maximum value of 32.12 when GG, XG, and SSPS were combined, indicating that the physical stability of the oat beverage was effectively improved when all three were present simultaneously. This study may provide some suggestions for the industrial production of low-viscosity cereal beverages with good stability.

A sequential recovery extraction and biological activity of water-soluble sulfated polysaccharides from the polar red macroalgae Sarcopeltis skottsbergii

Algal biomass is comprised of a variety of biochemical components that make it a viable raw material for use in a variety of applications using a biorefining process. From the residual supernatant generated by high-pressure homogenization for the extraction of the R-phycoerythrin pigment, two soluble polysaccharides (neutral and acid fractions) were obtained. The composition of total carbon (C), hydrogen (H), nitrogen (N), and sulfur (S), gas chromatography–mass spectrometry (GC–MS), Fourier transform infrared (FTIR-ATR) spectroscopy, antioxidant capacity (ABTS) and antiproliferative in vitro and in vivo activities were evaluated. The two polysaccharides, which had a relatively high sulfate content, exhibited significant antioxidant activity in superoxide radical assay (ABTS) and high anti-proliferative effects on G-361, U-937, HCT-116 cancer cells. High selectivity index (>3) was observed for the acid extract on G-361 and U-937 cell lines, but a significant inhibitory effect on the growth of 1064sK healthy fibroblast cells was measured too. On the other hand, neutral fraction polysaccharides, with the lowest sulfate content and relatively lower radical scavenging rates, showed scarce antitumor activity, a high selectivity index on G-361 melanoma cancer cells and non-toxicity on healthy cells. This differential behavior was verified by testing toxicity and lethality of both polysaccharide extracts in and in vivo zebrafish embryo acute toxicity test. Following this method, the LC50 of the neutral fraction resulted much higher (1.477 mg mL−1, p ≈ 0.0000) than that of the acid fraction (0.080 mg mL−1, p ≈ 0.0000) at 72 h post-fertilization. During this period, a slight growth delay and/or rare teratogenic effects were also induced by these fractions at concentrations lower than their LC50. Overall, this study indicates that the antitumor, antioxidant and toxicity effects of polysaccharides may be related to the combined effects of sulfate and galactose contents from the residual supernatant bioprocess. The nutraceutical potential of the acid fractions is thus finally discussed.

Application of electron beam irradiation for selenium nanoparticles production using gum Arabic as stabilizer

In this work, selenium nanoparticles (SeNPs) stabilized by gum arabic (GA), a highly water soluble natural polysaccharides, were succesfully synthesized by irradiation using electron beam accelerator. The obtained gum arabic coated nanoparticles (SeNPs/GA) were characterized by various analytical techniques including UV–Vis, Transmission Electron Microscope (TEM), Energy Dispersive X-Ray (EDX), X-ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The stability of SeNPs/GA over time at two different storage conditions was also determined by Dynamic Light Scattering (DLS). The SeNPs/GA powder was also prepared by freeze drying. Results showed that the SeNPs/GA were spherical with an average size of 27.3 ± 4.8 nm and were crystalline with hexagonal structure. Furthermore, the resultant SeNPs/GA solution was fairly stable up to 6 months when storing at 5 °C.The SeNPs/GA powder was of high purity containing only Se and GA components. These results indicated that SeNPs/GA synthesized by electron beam irradiation could be potential selenium source for various applications.

Hempseed polysaccharide (Cannabis sativa L.): Physicochemical characterization and comparison with flaxseed polysaccharide

The whole hempseed contains about 27.6% of fiber, of which 5.4% and 22.2% are soluble and insoluble fiber, respectively. The defatted hempseed meal contains about 42.6% of total fiber. Despite the abundant amount of fiber in the hempseed, the application of hempseed polysaccharides (HSP) is currently limited in the food industry. It is necessary to understand their physicochemical properties to extend their food applications. Hence, the objective of the current study is to investigate the physicochemical properties of soluble hempseed polysaccharides in comparison with flaxseed polysaccharides. The physicochemical properties, including molecular weight distribution, shape conformation, total sugar content, uronic acid content, rheological properties, and emulsification properties, were evaluated. The results indicated that the HSP contains about 33% uronic acids, 53% total sugars, and possesses an oblate ellipsoidal shape (Rg = 23.07 nm, Rh = 22.61 nm). Compared to flaxseed polysaccharides and pectin, the HSP showed a high surface active behavior at concentrations above 0.5% (w/v). The dynamic flow curves demonstrated the shear thinning behavior of HSP at the low shear rate range (0.01–10 s−1), followed by a Newtonian behavior at the high shear rate range. The HSP exhibited a weak gel property and an elastic nature. The emulsion stability of HSP and flax polysaccharide did not show a significant difference. The effects of pH and heat treatment on HSP stabilized emulsion were insignificant compared to flax polysaccharides. Finally, the freeze-thaw stability of HSP was inferior compared to flaxseed polysaccharides and pectin. The study has revealed that the HSP could be a potential emulsifying agent in the food system.

Preparation and digestive characteristics of myricitrin-loaded nanoemulsion delivery systems with glycated soybean oil body and κ-carrageenan as emulsifiers

Myricitrin (MYR) exhibits anxiolytic, analgesic, anti-inflammatory, antioxidant, hypoglycemic and antiapoptotic activities, but its use in food is currently limited due to poor water solubility, low bioavailability and chemical instability. In order to improve the MYR bioavailability, the soybean oil body (SOB) and its glycated forms were firstly used as emulsifiers to prepare four MYR nanoemulsions: (1) MYR/SOB-e: MYR monolayer nanoemulsions with SOB; (2) MYR/G-SOB-e: MYR monolayer nanoemulsions with the soy soluble polysaccharide (SSPS) glycated SOB; (3) MYR/SOB/κ-Car-e: MYR bilayer nanoemulsions with SOB and κ-carrageenan (κ-Car); (4) MYR/G-SOB/κ-Car-e: MYR bilayer nanoemulsions with soybean glycated SOB and κ-Car. The sizes, zeta potentials and microstructures of MYR nanoemulsions were examined to determine hydrolysis during gastrointestinal digestion and MYR bioavailability. The results showed that the bioavailabilities of emulsions prepared from glycated SOB were generally higher than those of emulsions prepared from unglycated SOB (p < 0.05). The highest bioavailability was 19.09% for MYR/G-SOB/κ-Car-e when κ-Car was of 2 mg/mL, which was much higher than the MYR/SOB-e bioavailabilities of 10.77%. In addition, MYR/G-SOB-e and MYR/G-SOB/κ-Car-e were stable and not visually changed after 14 days of storage, suggesting that the glycated SOB effectively improved the storage stabilities of MYR nanoemulsions.

Development and characterization of a new active and intelligent packaging system based on soluble soybean polysaccharide-Malva sylvestris extract.

This work aimed to develop an active and intelligent film based on soluble soybean polysaccharide (SSPS)/Malva sylvestris extract (MSE) to extend the shelf life of foodstuff and detect indirectly the food spoilage. The influence of MSE content on physico-mechanical properties, biological activity, and pH sensitivity of the SSPS-based films was examined. When the MSE concentration increased from 0 to 6% (w/w), water solubility and water vapor permeability of the films decreased (p ˂ 0.05). Clear antioxidant and antibacterial capacities were observed for SSPS films incorporated with different concentrations of MSE. SSPS/MSE films could sense the pH variation in a pH range of 7 to 8. SSPS/MSE film was used to detect the spoilage of shrimp and showed a pH-sensitive highly distinctive color variation from grey to dark green as the shrimp's quality altered. Overall, SSPS/MSE film can be introduced as a promising candidate for application as active and intelligent packaging.

Synergistic effect of nano zinc oxide and tea tree essential oil on the properties of soluble soybean polysaccharide films

Soluble soybean polysaccharide (SSPS)-based composite films with the addition of nano zinc oxide (nZnO, 5 wt% based on SSPS) and tea tree essential oil (TTEO, 10 wt% based on SSPS) were developed by the casting method. The effect of the combination of nZnO and TTEO on the microstructure and physical, mechanical and functional properties of SSPS films was evaluated. The results showed that the SSPS/TTEO/nZnO film exhibited enhanced water vapor barrier properties, thermal stability, water resistance, surface wettability, and total color difference, and almost completely prevented ultraviolet light transmission. The addition of TTEO and nZnO had no significant effect on the tensile strength and elongation at break of the films, but decreased the percentage of light transmittance of the films at 600 nm from 85.5 % to 10.1 %. The DPPH radical scavenging activity of the films significantly increased from 46.8 % (SSPS) to 67.7 % (SSPS/TTEO/nZnO) due to the presence of TTEO. Scanning electron microscopy analysis indicated that nZnO and TTEO were evenly dispersed in the SSPS matrix. The synergistic effect of nZnO and TTEO endowed the SSPS film with excellent antibacterial activity against E. coli and S. aureus, suggesting that the SSPS/TTEO/nZnO film could be a promising material for active packaging applications.

Microalgae as next generation plant growth additives: Functions, applications, challenges and circular bioeconomy based solutions.

Sustainable agriculture practices involve the application of environment-friendly plant growth promoters and additives that do not negatively impact the health of the ecosystem. Stringent regulatory frameworks restricting the use of synthetic agrochemicals and the increase in demand for organically grown crops have paved the way for the development of novel bio-based plant growth promoters. In this context, microalgae biomass and derived agrochemicals offer novel sources of plant growth promotors that enhance crop productivity and impart disease resistance. These beneficial effects could be attributed to the presence of wide range of biomolecules such as soluble amino acid (AA), micronutrients, polysaccharides, phytohormones and other signaling molecules in microalgae biomass. In addition, their phototrophic nature, high photosynthetic efficiency, and wide environmental adaptability make them an attractive source of biostimulants, biofertilizers and biopesticides. The present review aims to describe the various plant growth promoting metabolites produced by microalgae and their effects on plant growth and productivity. Further, the effects elicited by microalgae biostimulants with respect to different modes of applications such as seed treatments, foliar spray and soil/root drenching is reviewed in detail. In addition, the ability of microalgae metabolites to impart tolerance against various abiotic and biotic stressors along with the mechanism of action is discussed in this paper. Although the use of microalgae based biofertilizers and biostimulants is gaining popularity, the high nutrient and water requirements and energy intensive downstream processes makes microalgae based technology commercially unsustainable. Addressing this challenge, we propose a circular economy model of microalgae mediated bioremediation coupled with biorefinery approaches of generating high value metabolites along with biofertilizer applications. We discuss and review new trends in enhancing the sustainability of microalgae biomass production by co-cultivation of algae with hydroponics and utilization of agriculture effluents.

Green Chemistry Education Concept Transited by a Comprehensive Experiment of Citrus Peel Conversion and Utilization

To improve the comprehensive experimental skill of undergraduate and penetrate the concept of green chemistry education, we combined with the teaching needs of applied chemistry and designed a comprehensive experiment of preparing green drilling fluid treatment agent with waste citrus peel as raw material. Citrus fruit peel contains a lot of plant phenols, cellulose, soluble polysaccharides and other components, which can be used as drilling fluid to increase viscosity and reduce filtration loss. However, the proportion of water-soluble substance in citrus peel is low and the effect is poor. Therefore, to improve its utilization efficiency, we have applied different methods to modify the raw material, including the pretreatment, crosslinking, carboxymethylation to increase the proportion of water-soluble substance and improve its performance in drilling fluid. This experiment has introduced knowledge of organic chemistry to oilfield chemistry and combined experimental skills with field work, which will help to improve students' professional skills and field adaptability. In addition, using discarded citrus fruit peels as raw material in the experiment can practice the concept of green environmental protection, which is helpful to guide the future clean production of the oilfield and promote green and low-carbon development.

The Benefits of Exogenous Xylanase in Wheat–Soy Based Broiler Chicken Diets, Consisting of Different Soluble Non-Starch Polysaccharides Content

Four wheat-based diets with either a low soluble content of non-starch polysaccharides (NSPs, 13 g/kg); low viscosity, LV) or a high content of NSPs (33.5 g/kg; high viscosity, HV), with and without exogenous xylanase (XYL), were fed to male Ross 308 broiler chickens from 7 to 21 days age. The enzyme was supplemented at 100 FXU/kg diet, and its preparation was based on endo-1,4-beta-xylanase produced by Aspergillus oryzae. Each diet was fed to eight pens, with five birds in each pen, following randomisation. Chicks fed XYL had an improved feed efficiency, hepatic coenzyme Q10, caecal butyric acid concentration, nitrogen digestibility (p &lt; 0.05) and increased dietary ME (p &lt; 0.001). Compared to HV, birds fed LV diets had reduced weight of proventriculus, gizzard and the pancreas and higher blood glutathione peroxidase and dietary ME (p &lt; 0.05), but no differences were observed on nutrient digestibility and growth performance variables. This also suggests that birds may tolerate a greater dietary NSPs content; thus, further benefits may be obtained by the application of XYL in low energy wheat-based diets.

Effect of soluble soybean polysaccharides on the short- and long-term retrogradation properties of instant rice.

Rice starch retrogradation is prone to occur during instant rice storage, which contributes to reduced viscosity, poor sensory characteristics, and shortened shelf life. The purpose of this study was to explore the anti-retrogradation effect of soybean soluble polysaccharides (SSPS) on instant rice and the possible interaction between SSPS and high-moisture starch products. We studied the effects of SSPS on the retrogradation of instant rice, using hardness as an index. The optimal amount of SSPS was 0.2%. Hardness, enthalpy, relative crystallinity, and full width at half maximum values were lower in the SSPS-treated group than in the control group (no SSPS) during storage. The weight loss rate of instant rice had the following trend: SSPS-treated group (0 day) < control group (0 day) < SSPS-treated group (28 days) < control group (28 days). The lower the weight loss rate, the lower was the material loss. Scanning electron microscopy results showed that the gaps between starch granules were less obvious in the control group than in the SSPS-treated group during storage. The SSPS-treated group presented a starch network with uniform chambers. SSPS might compete with starch molecules for water absorption, thereby improving water retention and limiting starch retrogradation. The results showed that adding SSPS to instant rice could effectively inhibit starch retrogradation, because the interaction of SSPS and amylopectin side chains inhibited the crosslinking of starch molecules through hydrogen bonds, which hindered the formation of ordered structures. It was helpful to understand the anti-retrogradation mechanism of SSPS during the storage of instant rice, and provided the basis for the industrial production of high-water-content starch foods. © 2023 Society of Chemical Industry.

Soluble polysaccharides decrease inhibitory activity of banana condensed tannins against porcine pancreatic lipase

The inhibition of soluble polysaccharides (SPs) (arabic gum, dextran and pectin from citrus) on the binding between banana condensed tannins (BCTs) and pancreatic lipase (PL) was studied from variant aspects. Molecular docking simulations predicted that BCTs strongly bound SPs and PL through non-covalent interactions. The experimental results showed that SPs reduced the inhibition of BCTs on PL, and the IC50 value increased. However, the addition of SPs did not change the inhibitory type of BCTs on PL, which all were non-competitive inhibition. BCTs quenched PL fluorescence through static quenching mechanism and changed the secondary structure of PL. The addition of SPs alleviated the trending. The effect of SPs on the binding of BCTs-PL was mainly due to the strong non-covalent interaction between SPs and BCTs. This study emphasized that attention should be paid to the counteracting effects of polysaccharides and polyphenols in dietary intake to maximize their respective roles.

Effects of nanocomposite packaging on postharvest quality of mushrooms (Stropharia rugosoannulata) from the perspective of water migration and microstructure changes

AbstractStropharia rugosoannulata, a high‐value mushroom, exhibits high nutritional value and flavor characteristics; however, the mushroom is susceptible to spoilage, water loss and texture deterioration, which renders its safety and edibility a challenge. To improve the shelf life of fresh mushrooms during storage, a novel nanocomposite packaging (NP) was applied for the first time to maintain the freshness of S. rugosoannulata. The results showed that compared to other groups, NP effectively delayed the deterioration of sensory quality, postponed the decrease in firmness, and inhibited the degradation of soluble protein (caps 54.58 mg g−1 and stipes 31.45 mg g−1) and crude polysaccharide (caps 5.06 mg g−1 and stipes 3.53 mg g−1). Moreover, NP significantly reduced weight loss (0.41%) and water content loss (caps 90.93% and stipes 89.80%), as confirmed by low‐field nuclear magnetic resonance and magnetic resonance imaging; thus, water loss was inhibited. Additionally, the results of scanning electron microscopy and transmission electron microscopy indicated that NP helped preserve intact cell structure and retard organelle disintegration, helping prevent water from escaping to some extent. The overall research indicated that the application and performance of the novel NP, which is convenience, suitable for scale application and improves postharvest quality, is a promising approach for extending the shelf life of fresh S. rugosoannulata.

Benign treatment and resource utilization characteristics of doramectin fermentation residues

Doramectin is a commonly used antiparasitic drug. The biopharmaceutical process to produce doramectin can generate substantial amounts of doramectin fermentation residues, causing environmental risks and increasing economic burden of pharmaceutical enterprises. In the present work, the residual doramectin in the fermentation residues was removed through a low-temperature thermal treatment (LTT) method with temperatures from 160 °C to 220 °C. The degradation products of doramectin and toxicity prediction were assessed, and the impacts of LTT on bioresource properties of doramectin fermentation residues were investigated. The high efficiency for doramectin degradation was achieved by the LTT method, and reached more than 97% at 180–200 °C for 30 min and at 220 °C for 15 min. The olefin, ether and ester groups of doramectin molecule were broken during the LTT process, and higher temperature promoted the production of degradation products with smaller molecular structure. The toxicity prediction demonstrated that the LTT method could mitigate overall acute toxicity for rats of doramectin, and the toxicity of all degradation intermediates was observably reduced at 180 °C. All things considered, the optimal condition for disposing doramectin fermentation residues was recommended at 180 °C for 30 min. The results of synchrotron-based Fourier transform infrared spectroscopy revealed that LTT had little influence on organic functional groups of solid components in doramectin fermentation residues. Under the optimal operating condition of LTT, the contents of soluble total organic carbon, soluble total nitrogen and soluble polysaccharides in doramectin fermentation residues increased by 45.83%, 19.76% and 117.87%, respectively, and the formation and release of humic acid-like matters were also promoted. Generally, the LTT technology may be a promising approach to practically and safely treat doramectin fermentation residues.

Changing the ratio of phenolic compounds to saccharides is an approach to the regulation of antioxidant properties of polysaccharides

Rice straw is an agricultural waste rich in lignocellulose. Soluble polysaccharides (SPs) and phenolic compounds are released from rice straw during bioethanol production. In this study, the composition of the SPs was analyzed using HPLC. It was found that phenolic compounds were another major component in the SPs besides saccharides. FT-IR of the SPs indicates that the phenolic compounds were covalently linked to the SPs in the form of ester or ether bonds. GPC analysis showed that the ratio of phenolic compounds to saccharides (P/S) was related to the molecular weight. The SPs with higher P/S exhibit stronger antioxidant capacities. The relationships between the molecular weight, P/S, and antioxidant capacity were identified by regulating the P/S of the SPs using a laccase oxidation method. The results indicate that the oligosaccharides in the SPs have a higher P/S and were the major contributor to the antioxidant capacity. The SPs derived from rice straw exhibit much higher antioxidant capacities than commercial SPs, suggesting that lignocellulosic biomass is a suitable material for the preparation of SPs with high antioxidant properties.

Homogenized soybean hull suspension as an emulsifier for oil/water emulsions: Synergistic effect of the insoluble fiber and soluble polysaccharide

In this study, the functional properties of the soybean hull soluble fractions and insoluble fiber in stabilizing oil-in-water emulsions were investigated by changing the soluble fraction (SF) content in the soybean hull suspensions. High-pressure homogenization (HPH) caused the release of soluble materials (Polysaccharides and proteins) and the deagglomeration of insoluble fibers (IF) from soybean hulls. The apparent viscosity of the soybean hull fiber suspension increased as the SF content of the suspension increased; The absolute value of ζ-potential increased from 18 to 28 mV. In addition, the IF individually stabilized emulsion had the largest emulsion particle size (32.10 μm), but decreased as the SF content in the suspension increased to 10.53 μm. The microstructure of the emulsions showed that surface-active SF adsorbed at the oil-water interface formed an interfacial film, and microfibrils in IF formed a three-dimensional network in the aqueous phase, which synergistically stabilized the oil-in-water emulsion. The findings of this study are important for understanding emulsion systems stabilized by agricultural by-products.

Feeding Australian Acacia Gums and Gum Arabic Leads to Non-Starch Polysaccharide Accumulation in the Cecum of Rats

Exudative gums from two Australian Acacia species (A. pycnantha and A. baileyana) and gum arabic (from A. senegal) were fed to rats at graded levels (0, 20, 40, 80 g/kg), replacing cellulose in purified diets containing cholesterol plus cholic acid. Compared with consumption of the control diet containing cellulose only, consumption of the gums had no significant effects on concentrations of plasma or liver cholesterol. Plasma triacylglycerol concentrations were higher in rats fed gum arabic, whereas liver triacylglycerols were lower in rats fed the gums. The gums did not affect the total pool of volatile fatty acids in the ceca, as compared with results in controls, but did promote the relative contribution of propionate at the expense of acetate. In rats fed the diet containing cellulose (80 g/kg) the proportions of cecal acetate:propionate:butyrate were 76:15:9, whereas in the rats fed A. pycnantha gum, gum arabic and A. baileyana gum (80 g/kg) the ratios were 42:54:4, 35:46:19 and 43:53:4, respectively. The low apparent fermentability of the gums was confirmed by the accumulation of non-starch polysaccharides in cecal digesta. In rats fed 80 g/kg A. pycnantha gum, 3.44 g of soluble non-starch polysaccharides was measured in the ceca, which was 58% of the dry weight of the cecal contents. We conclude that the biological activities of the Australian Acacia gums were similar to those of gum arabic and that these gums may have potential value as human food ingredients.