Modifi cation of wheat bran insoluble and soluble dietary fibers with snail enzyme

Insoluble dietary fiber(IDF)and soluble dietary fiber(SDF)extracted from wheat bran were modifi ed by snail enzyme and their physicochemical properties(water retention capacity and oil retention capacity),functional properties(cholesterol adsorption capacity,glucose adsorption capacity and antioxidant activity)and structural characterizations were evaluated.The results showed that snail enzyme modification led to the significant increase in oil retention capacity of IDF,glucose adsorption capacity and cholesterol adsorption capacity of IDF and SDF.Enzymatic modification also markedly improved the DPPH radical scavenging capacity and reducing power of IDF and SDF.Meanwhile,scanning electron microscopy(SEM)analysis indicated the microstructures of IDF and SDF powders were signifi cantly changed.Fourier transfer-infrared spectrometry(FT-IR)showed that snail enzyme modifi cation could degrade the part of cellulose and hemicellulose of IDF and SDF.All these improved physicochemical and functional properties of IDF and SDF might depend on their structural changes.It suggested that snail enzyme modifi cation could effectively improve physicochemical and functional properties of IDF and SDF from wheat bran.

Study on Functional and Structure Properties of Soluble Dietary Fiber Modified by Extrusion-expansion Technology from Peanut Shells

[Objectives] This study was conducted to investigate the feasibility of using modified peanut dietary fiber as a functional food ingredient. [Methods]Using peanut shells as a test material,the process parameters of soluble dietary fiber( SDF) modified by extrusion and expansion were studied,and the functional and structural characteristics of SDF before and after modification were discussed. [Results] The optimum conditions were as follows: screw speed 200 rpm,temperature 130 ℃ and moisture content 20 %,and the SDF extraction yield was 22. 3%. The modified SDF showed BCmax values of( 378. 5 ± 5. 3),( 278. 3 ± 3. 2)and( 167. 2 ± 2. 5) μmol/g and BCmin of( 30. 4 ± 1. 3),( 63. 4 ± 3. 7) and( 71. 3 ± 4. 2) μmol/L,for Pb,As and Cu,respectively,indicating that the adsorption to the three heavy metals was enhanced. The modified SDF had a porous network like honeycomb and swelled structure. [Conclusions]Therefore,it is feasible to modify SDF by extrusion and expansion.

Effects of different ratios of soluble to insoluble dietary fiber on growth performance and intestinal health of piglets

This study investigated the impact of different ratios of soluble to insoluble dietary fiber(SDF:IDF)formulations by sugar beet pulp(SBP)supplementation on piglet growth performance,nutrient digestibility,immune function,intestinal morphology,intestinal microbiota and intestinal health.A total of 60 crossbred piglets(Duroc×[Landrace×Yorkshire])at 40 d old with body weight of 10.0±0.3 kg were randomly assigned to 5 treatments with 6 replicates per treatment and 2 piglets per replicate in a 21-d trial.The dietary treatments included a corn-soybean meal diet(0%SBP supplementation;CON),and diets supplemented with 2%,4%,6%,and 8%SBP,representing different SDF:IDF ratios at 10.16%,13.53%,16.79%,19.86%,and 24.81%,respectively.The results indicated that the 8%SBP treatment had a negative effect on feed-to-gain ratio(linear,P=0.009)compared with the CON treatment(P=0.021).The apparent total tract digestibility(ATTD)of crude protein was lower in treatments supplemented with SBP(P=0.002)and showed a linear decrease(P=0.001),while the ATTD of IDF showed a linear increase(P=0.037)in four SBP treatments compared to the CON treatment.The 4%SBP treatment increased serum concentrations of triglyceride(quadratic,P=0.019)and K(linear,P<0.0037),and decreased alanine transaminase concentration(quadratic,P=0.015)compared with the CON treatment.The concentrations of Cit,Cys,Ile,Leu,Orn,Arg,taurine,urea,1-methylhistidine,α-aminoadipic acid,α-aminobutyric acid and cystathionine in the 4%SBP treatment were highest among all treatments(P<0.05).The serum concentrations of interleukin-6,interleukin-8,interleukin-10,transforming growth factor-β,and tumor necrosis factor-αin the 6%SBP treatment were higher than those in the CON treatment(P<0.05),which also increased mucin-2 and G protein-coupled receptor 41 mRNA expression(P<0.05)in colonic mucosa compared with the CON treatment and improved the intestinal barrier function.Diets containing more than 19.86%SDF:IDF could impair the intestinal health in piglets when SBP was used as the SDF source.Supplementing nursery piglet diets with 16.79%to 19.86%SDF:IDF is recommended for improving intestinal barrier function,increasing short-chain fatty acids concentrations,and improving intestinal microbiota composition.

Long-term follow-up of the effects of fecal microbiota transplantation in combination with soluble dietary fiber as a therapeutic regimen in slow transit constipation

As some studies have reported that strategies targeting the gut microbiota such as fecal microbiota transplantation(FMT) with or without other microecological therapy might have efficacy in treating slow transit constipation(STC), we conducted a singlecenter, open-label trial to study the long-term effect of FMT combined with soluble dietary fiber(pectin) on STC. Thirty-one adult patients with STC were enrolled into the trial. Patients received 6-day FMT procedures repeatedly for the first 3 months and soluble dietary fiber(pectin) daily during the follow-up. The rate of clinical remission and improvement, stool consistency, the Wexner constipation scale, and assessment of constipation-related symptoms were evaluated at week 4 and 1 year later. The clinical remission and improvement rates at week 4 were 69.0%(20/29) and 75.9%(22/29), respectively. At the end of the study,48.3%(14/29) of patients continued to have at least three complete spontaneous bowel movements per week and 58.6%(17/29)of patients showed clinical improvements. Stool consistency, the Wexner constipation scale, and constipation symptoms improved both at short-term and long-term follow-up. The results indicated that FMT in combination with soluble dietary fiber(pectin) had both short-term and long-term efficacy in treating STC.

The effects of dietary fiber level on nutrient digestibility in growing pigs

The objective of this study was to investigate the effects of total dietary fiber level on nutrient digestibility and the relationship between apparent total tract digestibility of total dietary fiber, and soluble dietary fiber, insoluble dietary fiber and available energy. Sugar beet pulp was as the only fiber source. The experiment was designed as a 6 x 6 Latin square with an adaptation period of 7 d followed by a 5-d total collection of feces and urine. Feed intake tended to decrease （P =0.] O） as total dietary fiber level increased. The apparent total tract digestibility of dry matter, crude protein and gross energy decreased （P 〈0.0]） when total dietary fiber increased but the digestibility of soluble dietary fiber and insoluble dietary fiber increased （P 〈0.01）. The digestible energy and metabolizable energy content of diets decreased （P 〈0.01） as the total dietary fiber increased.

A Review of the Associations between Dietary Fiber Intake and Cancer Prevention or Prognosis

The increase in tumor incidence is closely related to dietary factors.In recent years,many researchers have carried out in-depth research to investigate whether increasing the intake of dietary fiber can prevent tumors and improve the prognosis,but the results have been unclear.We herein searched the literature in common academic databases and incorporated and summarized the relevant articles.The literature clearly indicates that dietary fiber can protect against the following cancers:colorectal cancer,breast cancer,pancreatic cancer,ovarian cancer,and head and neck cancer.There is also evidence that dietary fiber intake can exert protective effects against cancers of the liver,lung,stomach,small bowel,kidney,and esophagus,as well as lymphoma,but the data have so far been relatively limited.The effects on endometrial cancer and prostate cancer still remain uncertain.In terms of the effects on the cancer prognosis,dietary fiber does not appear to have an impact on colorectal cancer or breast cancer.Although more research is needed for some kinds of cancer,it is clear that increasing the intake of dietary fiber is beneficial for preventing the occurrence and development of several major types of cancer,with no major adverse effects.We therefore recommend that most of individuals increase their intake of dietary fiber.

Ultrasound-assisted Enzymatic Extraction of SDF on Passion Fruit Seeds

Ultrasound-assisted enzymatic extraction of soluble dietary fiber(SDF) from passion fruit seeds was carried out in order to shorten the extraction time and increase the yield of SDF. The effects of cellulase concentration, ultrasonic power, extraction temperature, solid-liquid ratio and water bath time on the SDF yield of passion fruit were studied by single factor analysis. And the orthogonal experiment was designed to optimize the extraction conditions. The results showed that the optimum conditions for the extraction of SDF from passion fruit by ultrasoundassisted enzymatic method were cellulase concentration 1.5%, ultrasonic power 120 W, solid-liquid ratio(g/mL) 1 ∶ 15, extraction temperature 55 ℃, and water bath time 160 min. The SDF extraction rate was determined to be 5.12%.

Characterization of a new 4,6-α-glucanotransferase from Limosilactobacillus fermentum NCC 3057 with ability of synthesizing low molecular mass isomalto-/maltopolysaccharide

4,6-α-Glucanotransferase(4,6-α-GT)converts starch into product with increasedα(1-6)glycosidic bonds ratio,and this product is a new type of soluble dietary fiber with property of escaping small intestine digestion.4,6-α-GT gained interest recently because of their potential use in enzymatic synthesis of soluble dietary fiber.In this study,a putative GtfB sequence from Limosilactobacillus fermentum NCC 3057 was identified.This sequence was truncated and expressed in Escherichia coli to obtain the protein L.fermentum NCC 3057 GtfBΔN.GtfBΔN showed optimal activity at 35℃and pH 6.0,and it converted amylose V to isomalto-/maltopolysaccharide(IMMP)with low molecular mass(3.1 kDa).This IMMP product contains 72%α(1-6)glycosidic bonds,and it showed 64%indigestible content in vitro digestion experiment.These results indicate that the product of L.fermentum NCC 3057 GtfBΔN is a soluble dietary fiber.Finally the X-ray crystal structure of GtfBΔN(2.4Å)was resolved.Based on the GtfBΔN structure,we offer an insight about that three loops of domain C may be related to the molecular mass of IMMP product.