Isolation of cellulose nanofibers from rapeseed straw via chlorine-free purification method and its application as reinforcing agent in carboxymethyl cellulose-based films.

In this study, cellulose nanofibers (CNFs) were successfully isolated from rapeseed straw (RS) whose valorization has been rarely investigated to date. A combined bleaching method without chlorine was applied for the purification of cellulose fibers, previously unexplored for RS. Chemical composition analysis and Fourier-transform infrared spectroscopy (FTIR) indicated that the purification method eliminated hemicellulose and reduced lignin content from 24.4 % to 1.8 %. The isolation of CNFs was performed using sulfuric acid hydrolysis under different acid concentrations (55 and 60 % v/v) and hydrolysis times (15, 30, and 45 min). The isolated CNFs were characterized by FTIR, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The formation of CNFs was confirmed by a significant increase in crystallinity index from 46.45 % of RS to >79.41 % of CNFs, depending on acid concentration and isolation duration. Carboxymethyl cellulose (CMC) films with different contents of CNFs were prepared by casting method. The mechanical properties and cytotoxicity of the prepared films were investigated. The CNFs obtained from RS via a chlorine-free purification method showed promising results for their usage as reinforcement in CMC matrix and film fabrication for various applications such as transdermal medicine and food packaging.

Development of Plantago ovata seed mucilage and xanthan gum-based edible coating with prominent optical and barrier properties.

This study investigates the fabrication of edible coating based on Plantago ovata seed mucilage (POSM). The films were prepared from POSM (1 %, w/v), glycerol (75 %, based on POSM mass), and xanthan gum (XG: 20, 30 and 40 %, based on POSM mass) by a casting method, and their physicochemical, mechanical, thermal, morphological, and barrier properties were determined. Results indicated the development of highly transparent (transparency values: 1.36 ± 0.05 to 2.42 ± 0.09) and hydrophobic films (contact angle: 101.57 ± 0.34 to107.08 ± 0.55o) with very low water vapor permeability (WVP: 2.77 ± 0.02 × 10-12 to 1.98 ± 0.04 × 10-12 g s-1m-1Pa-1), slight water solubility (31.14 ± 0.46 to 23.08 ± 0.82 %), and good mechanical properties (tensile strength: 30.87 ± 0.96 to 61.80 ± 0.71 MPa). Morphological studies also indicated smooth and uniform surfaces without pores and cracks. In addition, the films showed good antioxidant activity (61.46 to 68.71 %), and their antibacterial activity against E. coli, S. aureus and P. aeruginosa was also demonstrated. The applicability of the developed films to extend the shelf life of strawberries was shown by comparing the appearance of dip-coated strawberries and the control sample within 8 days at room temperature. Based on the results, the developed biofilms have great potential for edible coating and packaging applications.

Nanocellulose-based sensors in medical/clinical applications: The state-of-the-art review.

In recent years, the considerable importance of healthcare and the indispensable appeal of curative issues, particularly the diagnosis of diseases, have propelled the invention of sensing platforms. With the development of nanotechnology, the integration of nanomaterials in such platforms has been much focused on, boosting their functionality in many fields. In this direction, there has been rapid growth in the utilisation of nanocellulose in sensors with medical applications. Indeed, this natural nanomaterial benefits from striking features, such as biocompatibility, cytocompatibility and low toxicity, as well as unprecedented physical and chemical properties. In this review, different classifications of nanocellulose-based sensors (biosensors, chemical and physical sensors), alongside some subcategories manufactured for health monitoring, stand out. Moreover, the types of nanocellulose and their roles in such sensors are discussed.

Xanthan gum production from acid hydrolyzed broomcorn stem as a sole carbon source by Xanthomonas campestris.

Xanthan gum is an exo-polysaccharide industrially produced by fermentation using simple sugars. In this study, broomcorn stem was introduced as a low-cost- and widely available carbon source for xanthan gum fermentation. Broomcorn stem was hydrolyzed using sulphuric acid to liberate reducing sugar which was then used as a carbon source for biosynthesis of xanthan gum by Xanthomonas campesteris. Effects of hydrolysis time (15, 30, 45 and 60 min), sulphuric acid concentration (2, 4, 6 and 8% v/v) and solid loading (3, 4, 5 and 6% w/v) on the yield of reducing sugar and consequent xanthan production were investigated. Maximum reducing sugar yield (55.2%) and xanthan concentration (8.9 g/L) were obtained from hydrolysis of 4% (w/v) broomcorn stem with 6% (v/v) sulphuric acid for 45 min. The fermentation product was identified and confirmed as xanthan gum using Fourier transform infrared spectroscopy analysis. Thermogrvimetric analysis showed that thermal stability of synthesized xanthan gum was similar to those reported in previous studies. The molecular weight of the produced xanthan (2.23 × 106 g/mol) was determined from the intrinsic viscosity. The pyruvate and acetyl contents in xanthan gum were 4.21 and 5.04%, respectively. The chemical composition results indicated that this biopolymer contained glucose, mannose and glucoronic acid with molecular ratio of 1.8:1.5:1.0. The kinetics of batch fermentation was also investigated. The kinetic parameters of the model were determined by fermentation results and evaluated. The results of this study are noteworthy for the sustainable xanthan gum production from low-value agricultural waste.

Piperine-The Bioactive Compound of Black Pepper: From Isolation to Medicinal Formulations.

Piperine is the major bio-active component of pepper, which imparts pungency and biting taste to it. This naturally occurring alkaloid has numerous demonstrated health effects and beneficial therapeutic properties; nevertheless, its biological applications are limited due to its poor solubility in aqueous environments. This emphasizes an implementation of advanced extraction approaches which could enhance the extraction yield of piperine from pepper and also the development of new formulations containing piperine to improve its in vivo bioavailability. This paper presents a review on the therapeutic and medicinal effects of piperine, its isolation from pepper fruit and the development of new formulations for its medicinal (pharmaceutical) applications. A thorough review on conventional and advanced separation techniques for the extraction of piperine from pepper is presented and an outline of the most significant conditions to improve the extraction yield is provided and discussed. Different methods used to measure and quantify the isolated piperine are also reviewed. An overview of biotechnological advancements for nanoparticle formulations of piperine or its incorporation in lipid formulations, which could enhance its bioavailability, is also presented.