scholarly journals Cross-Linking of Wheat Bran Arabinoxylan by Fungal Laccases Yields Firm Gels

Processes ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 36 ◽  
Author(s):  
Sanaz Khalighi ◽  
Ralf G. Berger ◽  
Franziska Ersoy

The native extractable arabinoxylans (AX) from wheat bran were cross-linked by the commercial laccase C (LccC) and self-produced laccases from Funalia trogii (LccFtr) and Pleurotus pulmonarius (LccPpu) (0.04 U/µg FA, each). Dynamic oscillation measurements of the 6% AX gels demonstrated a storage modulus of 9.4 kPa for LccC, 9.8 kPa for LccFtr, and 10.0 kPa for LccPpu. A loss factor ≤ 0.6 was recorded in the range from 20 to 80 Hz for all three laccases, and remained constant for four weeks of storage, when LccFtr and LccPpu were used. Arabinoxylan gel characteristics, including high water holding capacity, swelling ratio in saliva, and heat resistance indicated a covalently cross-linked network. Neither the mediator compounds caffeic acid and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), nor citrus pectin, enhanced the elastic properties of the gels. Using laccases as an oxidant provided gels with a solid and stable texture, comparable in firmness to traditional gelatin gels. Thus, AX gels can be presented in the vegan, halal, and kosher food markets. They may also find use in pharmaceutical and other industrial applications.

Processes ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 16 ◽  
Author(s):  
Sanaz Khalighi ◽  
Ralf G. Berger ◽  
Franziska Ersoy

Sugar beet fibre (fibrex) is an abundant side-stream from the sugar refining industry. A self-produced laccase from Funalia trogii (LccFtr) (0.05 U/µg FA) successfully cross-linked fibrex to an edible gel. Dynamic oscillation measurements of the 10% fibrex gels showed a storage modulus of 5.52 kPa and loss factors ≤ 0.36 in the range from 20 to 80 Hz. Comparing storage stability of sweetened 10% fibrex gels with sweetened commercial 6% gelatin gels (10% and 30% d-sucrose) indicated a constant storage modulus and loss factors ≤ 0.7 during four weeks of storage in fibrex gels. Loss factors of sweetened gelatin gels were ≤0.2, and their storage modulus decreased from 9 to 7 kPa after adding d-sucrose and remained steady for four weeks of storage. Fibrex gel characteristics, including high water holding capacity, swelling ratio in saliva, and heat resistance are attributed to a covalently cross-linked network. Vanillin, as a mediator, and citrus pectin did not enhance covalent cross-links and elastic properties of the fibrex gels. Thus, laccase as an oxidative agent provided gels with a solid and stable texture. Fibrex gels may find uses in pharmaceutical and other industrial applications, which require a heat-resistant gel that forms easily at room temperature. They also represent an ethical alternative for manufacturing vegan, halal, and kosher food.


Author(s):  
Hellen S. Santos ◽  
Karine L. Buarque da Silva ◽  
Ariel E. Zanini ◽  
Danilo S. Coelho ◽  
Marcelo Embiruçu ◽  
...  

Background: Brazilian bentonites have a low sodium concentration in their interlayer structure. This is a problem with most of the industrial applications that demand the characteristics of sodium bentonites. Objective: As a solution for this limitation, sodium carbonate is added to in natura clays, promoting ion exchange between other interlayer cations with sodium. Methods: A process was used based on the principle of Stokes’ Law (BR Patent 10 2013 016298). For this, we used four glass columns in series, in which a high water flow was considered to obtain purified clays. It was proposed as a simple, fast and economical method for sodium determination that was developed and applied in bentonites by flame photometry. The equipment calibration was performed with a NaCl standard solution in concentrations between 80 and 110 ppm. The bentonites in the suspension were separated by means of centrifugation, being thus analyzed by a flame photometer. Results: The samples were prepared according to the manufacturer’s specifications to contain detectable amounts of sodium by means of flame photometry. A resulting linear relationship between the average value readings versus sodium standard content solution (both in ppm) was obtained by the logarithmic scale, as expected. Conclusion: The procedure allowed to define a method that could be used in the sodification control process, thus making it possible to differentiate the sodium cation content in terms of the value of cation exchange capacity (CEC) from bentonite. X-ray analysis of in natura and the sodified clays showed nanostructural differences related to interlayer distance.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 412
Author(s):  
Sam Swingler ◽  
Abhishek Gupta ◽  
Hazel Gibson ◽  
Marek Kowalczuk ◽  
Wayne Heaselgrave ◽  
...  

Bacterial cellulose (BC) is an extracellular polymer produced by Komagateibacter xylinus, which has been shown to possess a multitude of properties, which makes it innately useful as a next-generation biopolymer. The structure of BC is comprised of glucose monomer units polymerised by cellulose synthase in β-1-4 glucan chains which form uniaxially orientated BC fibril bundles which measure 3–8 nm in diameter. BC is chemically identical to vegetal cellulose. However, when BC is compared with other natural or synthetic analogues, it shows a much higher performance in biomedical applications, potable treatment, nano-filters and functional applications. The main reason for this superiority is due to the high level of chemical purity, nano-fibrillar matrix and crystallinity. Upon using BC as a carrier or scaffold with other materials, unique and novel characteristics can be observed, which are all relatable to the features of BC. These properties, which include high tensile strength, high water holding capabilities and microfibrillar matrices, coupled with the overall physicochemical assets of bacterial cellulose makes it an ideal candidate for further scientific research into biopolymer development. This review thoroughly explores several areas in which BC is being investigated, ranging from biomedical applications to electronic applications, with a focus on the use as a next-generation wound dressing. The purpose of this review is to consolidate and discuss the most recent advancements in the applications of bacterial cellulose, primarily in biomedicine, but also in biotechnology.


Author(s):  
Girisha Malhotra ◽  
Shilpa S. Chapadgaonkar

Abstract Background Xylanase is one of the widely applied industrial enzymes with diverse applications. Thermostability and alkali tolerance are the two most desirable qualities for industrial applications of xylanase. In this paper, we reveal the statistical Taguchi optimization strategy for maximization of xylanase production. The important process parameters pH, temperature, concentration of wheat bran, and concentration of yeast extract were optimized using the Taguchi L8 orthogonal array where the 4 factors were considered at 2 levels (high and low). Results The optimized conditions given by model were obtained as follows: (i) pH 6, (ii) culture temperature 35 °C, (iii) concentration of xylan 2% w/v, (iv) concentration of wheat bran 2.5% w/v. The production was scaled upto 2.5 L bioreactor using optimized process parameters. A high xylanase titer of 400 U/ml could be achieved in less than 60 h of culture in the reactor. Conclusion Optimization was successful in achieving about threefold increase in the yield of xylanase. The optimized conditions resulted in a successful scale up and enhancement of xylanase production.


2015 ◽  
Vol 1 (2) ◽  
pp. 67
Author(s):  
Haq Nawaz ◽  
Muhammad Aslam Shad ◽  
Rabia Mehmood ◽  
Tanzila Rehman ◽  
Hira Munir

<p>Functional properties such as protein solubility, swelling capacity, water holding capacity, gelling ability, bulk density and foaming capacity of flours of some commonly used cereals and legume (wheat, refined wheat, maize and chickpea) and their blends were studied. Blends of flours were prepared by mixing equal proportions of selected floors. Statistically significant difference  in studied functional properties except bulk density was observed among cereal flours and their blends. Chickpea flour was found to possess comparatively high water holding capacity, protein solubility index and swelling capacity. The functional properties of maize and wheat flours were found to be improved when blended with chickpea. Chickpea flour and its blends with cereal flours were found to possess good functional score and suggested as favorable candidates for use in the preparation of viscous foods and bakery products. The data provide guidelines regarding the improvement in functional properties of economically favorable cereal flours.<strong></strong></p>


2021 ◽  
Vol 11 (23) ◽  
pp. 11347
Author(s):  
Elisha Munsu ◽  
Hana Mohd Zaini ◽  
Patricia Matanjun ◽  
Noorakmar Ab Wahab ◽  
Nurul Shaeera Sulaiman ◽  
...  

The effect of the addition of three types of tropical edible seaweeds, Kappaphycus alvarezii (KA), Sargassum polycystum (SP), and Caulerpa lentilifira (CL), on sausages were studied. Nine sausage formulations with three levels of inclusion (2%, 4%, and 6%) of each seaweed were prepared, analysed, and compared with the control sample (without seaweed) in terms of their physicochemical properties, total phenolic content, and lipid oxidation. The modified sausages had low moisture and fat content (p < 0.05) but high ash and dietary fiber content (p < 0.05) compared to the control sausage. The addition of seaweed powder changed the texture of the sausages, mainly its hardness and chewiness (p < 0.05), but no significant difference in cohesiveness and springiness was found (p < 0.05). The modified sausages were shown to have high water holding capacities and cooking yields. The different types of seaweed modified the colour of the chicken sausages differently. In general, the L* (brightness) and b* (yellowness) values was low for all sausage samples containing seaweed powder (p < 0.05), while the a* (redness) value increased with the addition of the KA and SP seaweed powder but decreased for the sausage sample with added CL seaweed powder (p < 0.05). Moreover, the modified sausages have higher total phenolic contents and high antioxidant capacities, which contributed to slowing the oxidation of lipid in sausages during storage (p < 0.05). Sensory evaluation showed that the panellists found up to 4% of KA and 2% of SP to be acceptable. Overall, the seaweeds, especially KA and SP, could potentially be developed as excellent additives for the manufacture of highly technological high-quality meat products.


Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 267 ◽  
Author(s):  
Katharine Valéria Saraiva Hodel ◽  
Larissa Moraes dos Santos Fonseca ◽  
Isa Moreira da Silva Santos ◽  
Jamile Costa Cerqueira ◽  
Raimundo Evangelista dos Santos-Júnior ◽  
...  

Bacterial cellulose (BC) has received considerable attention due to its unique properties, including an ultrafine network structure with high purity, mechanical strength, inherent biodegradability, biocompatibility, high water-holding capacity and high crystallinity. These properties allow BC to be used in biomedical and industrial applications, such as medical product. This research investigated the production of BC by Gluconacetobacter hansenii ATCC 23769 using different carbon sources (glucose, mannitol, sucrose and xylose) at two different concentrations (25 and 50 g∙L−1). The BC produced was used to develop a biocomposite with montmorillonite (MMT), a clay mineral that possesses interesting characteristics for enhancing BC physical-chemical properties, at 0.5, 1, 2 and 3% concentrations. The resulting biocomposites were characterized in terms of their physical and barrier properties, morphologies, water-uptake capacities, and thermal stabilities. Our results show that bacteria presented higher BC yields in media with higher glucose concentrations (50 g∙L−1) after a 14-day incubation period. Additionally, the incorporation of MMT significantly improved the mechanical and thermal properties of the BC membranes. The degradation temperature of the composites was extended, and a decrease in the water holding capacity (WHC) and an improvement in the water release rate (WRR) were noted. Determining a cost-effective medium for the production of BC and the characterization of the produced composites are extremely important for the biomedical applications of BC, such as in wound dressing materials.


2006 ◽  
Vol 34 ◽  
pp. 479-485 ◽  
Author(s):  
Hiroyuki YAMADA ◽  
Akinori TANAKA ◽  
Yoshio OKUDA
Keyword(s):  

2015 ◽  
Vol 29 (4) ◽  
pp. 423-432 ◽  
Author(s):  
Ran Hu ◽  
Min Zhang ◽  
Benu Adhikari ◽  
Yaping Liu

AbstractWheat bran is rich in dietary fibre and its annual output is abundant, but underutilized. Insoluble dietary fibre often influences food quality negatively; therefore, how to improve the physical and chemical properties of insoluble dietary fibre of wheat bran for post processing is a challenge. Insoluble dietary fibre was obtained from wheat bran and micronized using high-pressure homogenization, high-intensity sonication, and a combination of these two methods. The high-pressure homogenization and high-pressure homogenization+high-intensity sonication treatments significantly (p<0.05) improved the solubility, swelling, water-holding, oil-holding, and cation exchange capacities. The improvement of the above properties by high-intensity sonication alone was marginal. In most cases, the high-pressure homogenization process was as good as the high-pressure homogenization+high-intensity sonication process in improving the above-mentioned properties; hence, the contribution of high-`intensity sonication in the high-pressure homogenization+high-intensity sonication process was minimal. The best results show that the minimum particle size of wheat bran can reach 9 μm, and the solubility, swelling, water-holding, oil-holding, cation exchange capacities change significantly.


Sign in / Sign up

Export Citation Format

Share Document