Extraction Of Dietary Fiber Research Articles

Optimization of ultrasonic‐assisted extraction of insoluble dietary fiber from wheat bran and its characterization

Ultrasonic-assisted extraction technique by means of response surface methodology was used to study optimized conditions for extraction of insoluble dietary fiber (IDF) from wheat bran varieties, namely Zincol-2016 (ZL), Borlaug-2016 (BG), NARC (NC), and Pakistan-2013 (PN). Optimized parameters for time, temperature, and amplitude ranged from 10 to 11 min for 30–40°C, and 64%–65% for all varieties with extracted IDF (39%–41%). FTIR spectra confirmed the presence of IDF in extracted material. DSC showed endothermic behavior near 100°C during the melting process. TGA showed stability at 99°C and complete degradation at 372°C. Chemical characterization of IDF extract showed a reduction in protein and fat, thus improving purity and IDF content. Tested technique also improved functional properties like cation exchange capacity (meq/kg) 16.30–17.66, emulsifying capacity (%) 32.1–32.98, and swelling capacity (ml/g) 4.43–5.98 to a high level. Briefly, under-tested extraction parameters, the IDF has improved chemical and functional characteristics. Practical applications The study concludes that ultrasonic extraction, under-explored moderate, and optimized conditions will prove an efficient extraction technique yielding considerable quantity and quality of IDF from wheat bran. The above results show the possibility for the application of all tested samples of IDFs in the food industry, especially to expand the thermal stability of food for various purposes. The ultrasonically extracted IDFs have better structural integrity and functional characteristics which play an important part in preparation and quality maintenance of food products, especially cereal food products.

Extraction of dietary fibers from cassava pulp and cassava distiller's dried grains and assessment of their components using Fourier transform infrared spectroscopy to determine their further use as a functional feed in animal diets.

ObjectiveThe present study was to investigate the extraction conditions of dietary fiber from dried cassava pulp (DCP) and cassava distiller’s dried grains (CDG) under different NaOH concentrations, and the Fourier transform infrared (FTIR) was used to determine the dietary fiber components.MethodsThe dried samples (DCP and CDG) were treated with various concentrations of NaOH at levels of 2%, 4%, 6%, and 8% using a completely randomized design with 4 replications of each. After extraction, the residual DCP and CDG dietary fiber were dried in a hot air oven at 55°C to 60°C. Finally, the oven dried extracted dietary fiber was powdered to a particle size of 1 mm. Both extracted dietary fibers were analyzed for their chemical composition and determined by FTIR.ResultsThe DCP and CDG treated with NaOH linearly or quadratically or cubically (p< 0.05) increased the total dietary fiber (TDF) and insoluble fiber (IDF). The optimal conditions for extracting dietary fiber from DCP and CDG were under treatment with 6% and 4% NaOH, respectively, as these conditions yielded the highest TDF and IDF contents. These results were associated with the FTIR spectra integration for a semi-quantitative analysis, which obtained the highest cellulose content in dietary fiber extracted from DCP and CDG with 6% and 4% NaOH solution, respectively. The principal component analysis illustrated clear separation of spectral distribution in cassava pulp extracted dietary fiber (DFCP) and cassava distiller’s dried grains extracted dietary fiber (DFCDG) when treated with 6% and 4% NaOH, respectively.ConclusionThe optimal conditions for the extraction of dietary fiber from DCP and CDG were treatment with 6% and 4% NaOH solution, respectively. In addition, FTIR spectroscopy proved itself to be a powerful tool for fiber identification.

Extraction, physiological function and application of soluble dietary fiber from edible fungi: a review

Soluble dietary fiber has attracted much attention due to its significant health benefits to consumers. Edible fungi are abundant sources of soluble dietary fiber (SDF). The content and composition of soluble dietary fiber in edible fungi variy greatly according to varieties, growth stages and different parts. This review focuses on the extraction methods of soluble dietary fiber from edible fungi, such as Lentinula edodes, Agrocybe cylindracea. The possible health benefits of mushroom soluble dietary fiber in relationship with hypoglycemic effect, regulatory mechanism of pancreatic lipase, gut microbiota and macrophages are also discussed. Finally, the application and development potential of mushroom soluble dietary fiber are pointed out.

MODIFYING THE FUNCTIONALITIES OF DIETARY FIBER IN FOODS BY VARIOUS PROCESSING METHODS

Dietary fiber is that part of plant material in the diet which is resistant to enzymatic digestion which includes cellulose, non-cellulosic polysaccharides such as hemicellulose, pectic substances, gums, mucilages and a non-carbohydrate component lignin. The diets rich in fiber such as cereals, nuts, fruits and vegetables have a positive effect on health since their consumption has been related to decreased incidence of several diseases. Dietary fiber can be used in various functional foods like bakery, drinks, beverages and meat products. Influence of different processing treatments (like extrusioncooking, canning, grinding, boiling, frying) alters the physico- chemical properties of dietary fiber and improves their functionality. An attempt has been made to compile the recent developments in the extraction, applications and functions of dietary fiber in different food products

Optimization of soluble dietary fiber extraction from hulless barley grass

AbstractBackground and objectivesThe key factors determining the extraction conditions of soluble dietary fiber from hulless barley grass (HBG) are still unclear. Impact of enzymatic treatment on the yield of soluble fiber of HBG under different reaction conditions was investigated.FindingsResponse surface methodology (RSM) was carried out to establish the optimal combination of reaction conditions based on Box‐Behnken design (BBD), using xylanase concentration (X1: 400–1200 unit/g), cellulase concentration (X2: 200–600 unit/g), and enzymatic hydrolysis time (X3: 1–5 hr). The optimum reaction condition increased soluble dietary fiber (SDF) of HBG from 1.6% to 22.8%, when HBG was subjected to a combination of xylanase (995 unit/g) and cellulase (392 unit/g) for 2.4 hr. The experimental value (22.8%) was close to the theoretically predicted yield (23.0%), indicating that the model could be used to predict the yield of SDF in HBG.ConclusionsSDF level was correlated to xylanase concentration and cellulase concentration, but the main factor was enzymatic hydrolysis time. Reaction conditions were not significantly related to particle size and water to raw material ratio.Significance and noveltyThis study could provide support for production of SDF‐based functional food products.

Effects of ultrasonic and ozone pretreatment on the structural and functional properties of soluble dietary fiber from lemon peel

AbstractIn this study, the effects of ultrasonic (US), ozone (O3), or ozone‐ultrasonic (O3‐US) pretreatments on the structural and functional properties of soluble dietary fibers (SDFs) obtained from lemon peel were investigated. Scanning electron microscopy observation showed that, US‐SDF, O3‐SDF, and O3‐US‐SDF showed more looser surface and porous characterization, compared to the lemon peel SDF without treatment (untreated‐SDF). Pretreatment led to a significant increases of SDFs yield, which increased by 16.70%, 85.44%, and 92.36% for US‐SDF, O3‐SDF, and O3‐US‐SDF, compared to untreated group, respectively. X‐ray diffraction results showed that the crystal structure of the pretreated‐SDFs was disrupted and possessed lower crystallinity. TGA analysis showed that pretreated‐SDFs exhibited lower thermal stability. All three pretreatments led to a redistribution of monosaccharides in SDFs. In addition, functional properties, including water swelling capacity (WSC), water‐holding capacity (WHC), oil holding capacity (OHC), and binding capacity of SDF for heavy metals ions (Pb, Cd, and Cu), were enhanced by the three different pretreatment methods. Especially, O3‐SDF showed the highest hydration ability. Principal component analysis (PCA) showed that untreated‐SDF and pretreated‐SDFs were effectively distinguished. In summary, our study suggested that the O3 pretreatment could be used as the ideal pretreatment method for lemon peel SDF, and O3‐SDF has the greatest potential to be applied as functional ingredients in food products.Practical ApplicationsUltrasonic (US) treatment is one of the green nonthermal technologies, it has been widely used to assist in the extraction of dietary fiber. Ozone (O3) is commonly used in agricultural waste disposal, while O3 treatment is still in the blank stage in the field of assisting the extraction of dietary fiber, and has great potential for development. In this experiment, the effects of US and O3 pretreatment on the structural and functional properties of SDFs from lemon peel were studied. The results showed that pretreated‐SDFs existed different structural and functional properties compare with the untreated‐SDF. And O3 pretreatment could be used as the ideal pretreatment method for lemon peel SDF.

Prebiotic Potential of Cereal Components.

One type of functional food that has been receiving much attention is food rich in prebiotics. The old but still valid definition of prebiotics defines them as non-digestible food components that selectively stimulate the growth and/or activity of the beneficial bacteria in the colon and, as a result, improve the host health. Cereals, as one of the main components in the human diet, contain substantial levels of dietary fiber with probable prebiotic potential. In addition, dietary fiber, particularly soluble dietary fiber, has recently emerged as a promising natural highly functional food ingredient in food production. This review focuses on the prebiotic potential of cereal dietary fiber types and covers the achievements and developments regarding its isolation. First, the probiotic and prebiotic concepts will be discussed. Next, different components of dietary fiber and their effect on the host bacteria through in vitro and/or in vivo studies will be reviewed. In a last part, this paper also discusses means of boosting the prebiotic properties of cereal components and innovative strategies for the extraction of cereal dietary fiber. The review focuses on wheat as a leading cereal crop that is widely and intensely used throughout the world in food production.

Comparative study on the structure, physicochemical, and functional properties of dietary fiber extracts from quinoa and wheat

Soluble and insoluble dietary fiber (SDF and IDF) were extracted from quinoa and wheat. Results showed that all the dietary fiber (DF) samples exhibited typical infrared spectrum characteristics of polysaccharides. Compared with wheat soluble dietary fiber (WHSDF), quinoa soluble dietary fiber (QUSDF) displayed a compact structure, higher reducing power and digestive enzyme inhibitory activity. WHSDF showed stronger DPPH radical scavenging activity than QUSDF. Quinoa insoluble dietary fiber (QUIDF) and wheat insoluble dietary fiber (WHIDF) displayed similar network structure, but the α-glucosidase inhibitory activity of WHIDF was higher than QUIDF. Moreover, the bound polyphenols in QUIDF and WHIDF also showed better DPPH radical scavenging activity and α-amylase inhibitory activity. In summary, the DF of quinoa and wheat showed different structural, physicochemical and functional properties, and in both samples bound polyphenols had significant contributions to the antioxidant and hypoglycemic capacity of IDF.

Extraction of dietary fibers from bagasse and date seed, and evaluation of their technological properties and antioxidant and prebiotic activity

Dietary fiber (DF) was extracted from plant byproducts (date seed and sugarcane bagasse) by alkaline hydrogen peroxide extraction and their chemical composition, technological properties, antioxidant activity, and prebiotic activity were evaluated. Bagasse had a significantly higher DF content (48.34%) than date seed (39.89%). Bagasse dietary fiber (BDF) had a significantly higher Fe, K, Mg, Na, and Zn (1343 ppm, 274.69 ppm, 640.08 ppm, 643.08 ppm, and 31.74 ppm, respectively) than date seed dietary fiber (DSDF) with 186.84 ppm, 185.88 ppm, 505.64 ppm, 506.72 ppm, and 13.28 ppm, respectively. The results showed that BDF had significantly higher values for oil binding capacity, water-holding capacity, and swelling capacity which equaled 2.73 g/g, 7.12 ml/g, and 12.50 ml/g, respectively, compared to DSDF (0.81 g/g, 4.06 ml/g, and 8.88 ml/g, respectively). The samples containing 5% DSDF and 5% BDF had the highest stimulating effect on Lactobacillus acidophilus growth, respectively. Also, pH reduction in the studied media depended on the type of DF and its concentration and the trend of decrease in pH was variable. Evaluation of the antioxidant activity of the studied DFs indicated that, at a 500 ppm concentration, DSDF with 89.12% had a significantly higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) inhibition rate than ascorbic acid (85.4%), and with increasing the DF concentration, antioxidant activity increased. The findings confirmed that the studied DFs have prebiotic effects. Due to their technological, physicochemical, and antioxidant properties, they can be used as inexpensive DF sources in the food and pharmaceutical industries.

Obtención y caracterización de fibras vegetales para la mejora nutricional de caramelos tipo gummies: avances de tesis doctoral

Considerando que el sobrepeso es una consecuencia de una malnutrición, que afecta a todos los países de la región y tiene alcance global, es importante mantener una buena alimentación mediante el consumo de alimentos saludables y poco calóricos. Consecuentemente, las investigaciones del área de alimentos se orientan a obtener ingredientes con características funcionales a partir de fuentes naturales, para incorporarlos en alimentos que propicien una dieta balanceada y nutritiva, y que prevengan enfermedades crónicas. Uno de estos componentes funcionales es la fibra dietaria, que se encuentra en una gran variedad de hortalizas como las mandiocas, batatas, y jengibres, cultivados en el Nordeste argentino. Por consiguiente, este plan de tesis doctoral consiste en la reformulación de caramelos tipo gummies con el objeto de mejorarlos nutricionalmente a partir de la adición de fibra extraída de vegetales regionales. La misma actuará, además, como agente estructural debido al reemplazo de los azúcares presentes en la formulación por edulcorantes no calóricos con el fin de reducir del aporte calórico.En este trabajo, se presentarán los avances realizados del mencionado plan, que comenzó a mediados del año 2019 y continua hasta la actualidad. Primeramente, se realizó el ensayo de extracción de fibra dietaria de batata utilizando un método tradicional químico con etanol al 85% (v/v) como solvente, y se determinó el rendimiento. Se definieron los parámetros del proceso tales como las condiciones de pre-tratamiento, temperaturas de extracción y secado, ratio, tiempo de secado y tamaño de tamiz, dando como resultado rendimientos de 10% aproximadamente. Además, se llevaron a cabo las determinaciones de los componentes bioactivos: carotenoides totales y capacidad antioxidante de las materias primas batata, jengibre y mandioca, con el fin de caracterizarlas. En ambos casos se utilizaron métodos espectrofotométricos, y se obtuvieron valores del contenido de carotenoides totales de 14.27±0.55 µgβ-caroteno/gmuestra para el jengibre, y de 12.66±1.43 y 1.35±0.06 µgβ caroteno/gmuestra, para la batata y mandioca. Un comportamiento similar ocurrió en el caso de la capacidad antioxidante donde el jengibre fue un 90% y 50% mayor en comparación con la mandioca y la batata, respectivamente.De este modo, se determinó el rendimiento de la extracción química de fibra a partir de batata, y se observó que el jengibre fue el material vegetal con mayor contenido de compuestos bioactivos, lo que lo hace un ingrediente potencialmente utilizable para lograr la mejora nutricional de los alimentos.

반응표면분석법을 이용한 천년초 줄기로부터 식이섬유소 추출을 위한 효소처리 조건의 최적화

This study aimed to optimize the hydrolysis conditions required for extraction of dietary fiber from Opuntia humifusa stem using Viscozyme® (MilliporeSigma, St. Louis, MO, USA) with response surface methodology (RSM). A central composite design was applied to examine the effects of the independent variables, enzyme concentration (0.5-2.5%, X1) and reaction time (1-5h, X2). The hydrolysis conditions were optimized using total yield, total dietary fiber (TDF), water-soluble dietary fiber (SDF), and water-insoluble dietary fiber (IDF) contents of hydrolysates as dependent variables. The total yield was 39.9-53.2% and the coefficient (R2) of the derived equation from the response surface regression for total yield was 0.9073. The TDF and SDF contents in all hydrolysates were 29.02-43.82% and 27.25-40.68%, respectively, which were within the 1% level. The IDF contents in all hydrolysates were 0.98-3.80% (R2 0.8886) and with in 5% significance. The optimal hydrolysis conditions comprised 1.0-1.8% Viscozyme® and an incubation period of 1.0-1.8 h. Our results suggested that O. humifusa could be a source that might extend the application of dietary fiber in functional food industries.

Extraction, modification, and property characterization of dietary fiber from Agrocybe cylindracea.

Dietary fiber (DF) has gained a great attention owing to its potential health benefits. Agrocybe cylindracea is an edible fungus with high protein and low fat contents, which is also an enriched source of DF. However, limited study has been conducted on optimizing the conditions of A. cylindracea‐derived DF extraction and modification as well as characterizing its properties. In this study, ultrasound‐assisted enzymatic method for DF extraction was optimized as the following conditions: liquid material ratio of 29 ml/g, α‐amylase concentration of 1.50%, protamex concentration of 1.20%, and ultrasonic power of 150 W, which improved the DF extraction yield to 37.70%. Moreover, high temperature modification (HTM) and cellulase modification (CEM) were applied to modify A. cylindracea‐derived DF. The results showed that HTM had more potential capacity in converting insoluble DF into soluble DF, and DF with HTM exhibited more advantages in its physicochemical properties than DF with CEM. The DF with both HTM and CEM showed antioxidant activities, reflected by the increased reducing power as well as DPPH radical, hydroxyl radical, and ABTS+ scavenging capabilities in vitro. These findings could offer a reference for the extraction, modification, and characterizing various properties of DF from A. cylindracea, which would establish the foundation for the comprehensive application of fungi‐derived DF.

Performance of growing lambs supplemented with ground licuri (Syagrus coronata).

ObjectiveThe aim of this study was to determine the effect of dietary ground licuri on lamb performance.MethodsForty male lambs were used in a completely randomized design to test the effects of 0, 5, 10, and 15 g/kg of ground licuri added to diets. The trial lasted for 75 days. Intake, digestibility, physically effective neutral detergent fiber, and chewing activity were estimated. Blood samples were taken on day 45 to determine the concentrations of glucose, urea, non-esterified fatty acids, and triglycerides. Average daily gain (ADG) were determined on the last day of the experimental trial.ResultsLicuri inclusion markedly increased dietary neutral detergent fiber and ether extract (EE) content, but it decreased dry matter (DM) intake. However, the intake and digestibility of EE linearly increased. The ADG decreased linearly (p<0.05) with licuri inclusion. Licuri had no effect (p>0.05) on the concentrations of blood metabolites; however, blood urea increased (p<0.05), while serum glucose decreased (p<0.05).ConclusionThe physically effective fiber of ground licuri is similar to Tyfton hay and licuri inclusion decreases lamb performance due to a decreased in DM intake.

Structure, physicochemical and bioactive properties of dietary fibers from Akebia trifoliata (Thunb.) Koidz. seeds using ultrasonication/shear emulsifying/microwave-assisted enzymatic extraction

Dietary fiber extracts from Akebia trifoliata (Thunb.) Koidz. seeds were generated using alkaline extraction, enzymatic hydrolysis as well as physical pretreatments including ultrasonication, shear emulsifying and microwave. Compared with the basic alkaline hydrolysis, cellulase-assisted extraction exhibited the highest water holding capacity (7.99 g/g), cation exchange capacity (0.55 mmol/g), glucose adsorption capacity (1352.33 μmol/g) and pancreatic lipase inhibition (37.69%). Ultrasonication pretreatment before both the preceding procedures increased the oil holding capacity (3.95 g/g) and α-amylase inhibition (6.81%) of the extracted fiber. Microwave pretreatment generated fiber possessing the greatest specific surface area (137.70 m2/kg), water swelling capacity (1.25 mL/g), adsorption capacity (4.14 mg/g, pH = 2) and sodium cholate adsorption capacity (38.68%). However, shear emulsifying gave the lowest crude yields (57.72%), glucose absorption capacity (22.09 mg/g), α-amylase inhibition (2.77%) and pancreatic lipase inhibition (22.61%) though it contained highest levels of soluble fiber (6.40 g/100 g) and lowest crystallinity (33.6%). A fuzzy statistical evaluation indicated that ultrasonication assisted enzymatic hydrolysis was the most efficient improvement in the overall properties of the dietary fiber. These results provide valuable information for the potential use of A. trifoliata seeds as a new food ingredient and for extraction of dietary fiber from this plant.

The anti-lipidemic role of soluble dietary fiber extract from okara after fermentation and dynamic high-pressure microfluidization treatment to Kunming mice.

The present study was conducted to evaluate the anti-hyperlipidemia ability of the dietary fiber extracted from okara in mice fed a high cholesterol diet. The dietary fiber was extracted from okara by combining fermentation with dynamic high-pressure microfluidization. An animal model was established to test the hypothesis that soluble dietary fiber, insoluble dietary fiber and total dietary fiber inhibit the fatty liver could be related to the total lipids and cholesterol including total cholesterol, triglyceride, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol in the serum. Compared with mice fed with simvastatin, mice fed dietary fiber can significantly reduce their serum total cholesterol, low-density lipoprotein cholesterol, triglyceride, and atherogenic index whereas no significant effect on high-density lipoprotein cholesterol was observed. Dietary fiber lowered a high level of liver total cholesterol and triglyceride. The dietary fiber extracted from okara might play an important role in the prevention of hyperlipidemia in high cholesterol mice and could be used as a natural supplement to a high cholesterol diet of functional food, due to the suppression of liver lipid synthesis.

Effect of extraction methods on the physicochemical, structural, functional, and antioxidant properties of the dietary fiber concentrates from male date palm flowers.

The current study evaluates the effect of both aqueous and alkaline extraction methods on the physicochemical, structural, functional, and antioxidant properties of dietary fibers (DF) from male date palm flowers (MDPF). The DF extracted by the alkali treatment (ADF) display a higher DF content as well as lower protein and lipid content than the DF resulting from watery extraction (WDF). The scanning electron microscopy, the Fourier-transform infrared spectroscopy, and the X-ray diffraction show that the alkaline treatment contributes to a slight modification of the structural characteristics of ADF leading to better purity and functional properties. The oil holding capacity and the antioxidant activity of ADF have improved compared to the WDF, which makes this concentrate a promoting functional ingredient and a natural antioxidant. Therefore, these findings confirm the wealth of both concentrates in DF, especially ADF, as well as their potential of functional and antioxidant properties, which emphasize their suitability to be used in food applications as functional ingredients. PRACTICAL APPLICATIONS: Nowadays, studies on the extraction of DF from vegetable waste are of considerable interest in the face of the rising global demand for dietetic food. The male date palm flowers (MDPF), an agricultural waste generated during the period of pollination, are valuable natural sources of DF and antioxidants. The insoluble DF of MDPF could be essential in a balanced diet as they could fight against obesity by creating a feeling of satiety. The presence of antioxidants, which are known for preventing or slowing cell damage caused by free radicals, could contribute to the improvement of the antioxidant properties of the formulated food. The functional properties of DF concentrates from MDPF are able to solve the technical problems of agri-food industries when used as food ingredients. The use of DF from MDPF, consequently, contributes to the minimization of waste and provides value addition to the by-product considered as waste in agricultural processing.

Study on Quality of Soluble Dietary Fiber from Jujube (Z. vulgaris Lam) with Different Treatments

The studies focused on plant soluble dietary fiber. The apparent characteristics of SDF from the Jujube under different treatment methods can provide theoretical support for product development to obtain the best trait products. Optimal extraction conditions, physical properties and antioxidant activity of SDF from the Jujube were investigated. The yield of 20.17 ± 0.16 % for extraction of soluble dietary fiber from Jujube were obtained as extraction temperature was 94 °C, extraction time was 40 min and ratio of raw material to water was 1:21. The physical properties of SDF were ascertained by measuring dissolution time, rehydration, swelling ability and bulk density, respectively. And it was evaluated by FT-IR and scanning electronic microscopy (SEM). Furthermore, it was proved that the soluble dietary fiber extracted by vacuum freeze dried had higher scavenging ability than that of vacuum dried and hot dried against DPPH, ABTS+ and hydroxyl radical. It has good antioxidant function and can slow down intestinal aging as a basis for new food development.

Optimization Techniques for the Extraction of Soluble Dietary Fiber from Okra with Complex Enzymes and Its Physicochemical Properties and Structure Characterization

Soluble dietary fiber from okra pods was obtained by mixed enzyme extraction method. Effects of enzyme content,material-to-water ratio,extraction temperature and extraction time on the extraction of SDF were investigated by single-factor experiments. Based on single-factor experiments,response surface analysis was employed to investigate the optimal parameters of the extraction. Physicochemical properties and structure characterizations of the SDF extracted under optimal conditions were studied. The result showed that the optimal conditions were as follows:Material-to-water ratio 1:24 g/mL,enzyme content 1.8%,extraction time 54 min,extraction temperature 62℃,under these conditions,the yield of SDF achieved 10.94%,the relative error with the predicted value was 1.48%. The SDF from okra exhibited significant water holding capacity(5.61 g/g),swelling capacity(3.35 mL/g)and oil holding capacity(4.88 g/g),which could be developed as ingredient of laxative functional food in the future. Microstructure of SDF from okra showed that starch substances on its surface were removed completely. The crystal structure of okra SDF accorded with crystal form of cellulose I. Fourier transform infrared spectroscopy of SDF accorded with typical characteristics of dietary fibers.

Optimized Extraction of Dietary Fiber from Defatted Rice Bran and Evaluation of the Fiber-fortified Drink Yogurt

The effects of time, temperature and concentration of hydrogen peroxide on the extraction yield of fiber from defatted rice bran, its color, water binding and oil binding capacity were investigated using the central composition design with three variables. Carboxymethyl cellulose (CMC) and extracted fiber were added to drink yogurt in different ratios (0-0, as blank sample, 0-0.05, 0-0.1, 0-0.2, 0.5-0.05 and 1-0.05) and rheological properties of the drink were analyzed weekly for 21 days. The results showed that temperature and hydrogen peroxide concentration significantly affected fiber extraction yield, and hydrogen peroxide concentration had the greatest impact on L*. The process temperature had the greatest impact on oil binding capacity of the fiber. However, water binding capacity was not affected by any parameter. Rheological tests indicated that blank sample was a Newtonian fluid while the drink yogurt fortified with the fiber showed a pseudo-plastic behavior.

Extraction, Purification, and Characterization of Insoluble Dietary Fiber from Oat Bran

The dietary fiber in oats is mainly concentrated in the bran; however, the oat bran is mostly used for livestock and poultry feed and thus has a low utilization rate and low added value. In this study, insoluble dietary fiber (IDF) was extracted by a combination of α-amylase and neutral protease. The optimal extraction conditions of the IDF were obtained by response surface methodology. The material-to-water ratio was 1:12.1, the concentration of α-amylase was 1.85%, and the hydrolysis time was 39.14 min. After purifying the crude fiber with 4% sodium oxide (NaOH), 70 °C hot water, and anhydrous ethanol, the purity of dietary fiber exceeded 95%. X-ray diffraction analysis indicated that the IDF was predominantly amorphous. Scanning electron microscopy showed that the IDF surface exhibited a loose porous network structure. Fourier-transform infrared spectroscopy of the crude IDF showed characteristic absorption peaks at 3626, 2929, 1667, 1538, 1455, 1242, and 1048 cm−1, while the infrared spectrum of the purified IDF showed characteristic absorption peaks at 3401, 2924, 1744, 1643, 1418, and 1040 cm−1, which is consistent with the structure of cellulose polysaccharide. Differential scanning calorimetry analysis showed that there were three exothermic peaks at 270–310 °C, 320–350 °C, and 440–460 °C, which may represent the pyrolysis peaks of hemicellulose, cellulose, and lignin, respectively, indicating that the oat bran IDF had good thermal stability. The results indicate that the oat bran IDF can be used for the production of dietary fiber products and health-care products.