The development of cost-effective cellulose fibers by utilizing agricultural residues have been attracted by the scientific community in the past few years; however, a facile production route along with minimal processing steps and a significant reduction in harsh chemical use is still lacking. Here, we report a straightforward ultrasound-assisted method to extract cellulose nanofiber (CNF) from fibrous waste sugarcane bagasse. X-ray diffraction-based crystallinity calculation showed 25% increase in the crystallinity of the extracted CNF (61.1%) as compared to raw sugarcane bagasse (35.1%), which is coherent with Raman studies. Field emission scanning electron microscopy (FE-SEM) images revealed thread-like CNF structures. Furthermore, we prepared thin films of the CNF using hot press and solution casting method and compared their mechanical properties. Our experiments demonstrated that hot press is a more effective way to produce high strength CNF films; Young’s modulus of the thin films prepared from the hot press was ten times higher than the solution casting method. Our results suggest that a combination of ultrasound-based extraction and hot press-based film preparation is an efficient route of producing high strength CNF films.

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Agricultural byproducts rich in lignocellulose are considered one of the most promising feedstocks to produce sustainable value-added materials with different industrial applications. However, fractionation into carbohydrates, lignin, and silica is a key challenge in the conversion of plant biomass into value-added products due to its complex structure. This study is designed to develop a novel method for sequential separation and collection of cellulose, hemicellulose, lignin, and silica from agricultural byproducts, peanut shell (PS), rice husk (RH), and sugar cane bagasse (SB), using an integrated approach under mild hydrolysis conditions. Silica and cellulose nanofibers (CNFs) were synthesized using an ultrasonic-assisted chemical method. Pure silica was obtained by further pyrolysis. The yield percent of cellulose was 35%, 39%, and 41% and hemicellulose and lignin combined was 30%, 18%, and 29% from PS, RH, and SB, respectively. The X-ray diffraction results demonstrated that CNFs were semicrystalline from all samples, and CNFs from SB had the highest crystallinity. Similarly, silica nanoparticles (SNPs) were amorphous in RH, while it was crystalline in both PS and SB. The surface morphologies of the CNFs and nanosized fibers were observed by field emission-scanning electron microscopy. It revealed that there were different morphological characteristics such as web-like, parallel, and tangled in PS, RH, and SB, respectively. The surface morphology of SNPs was also varied among the samples. In BET analysis, SNPs from RH had a larger specific surface area of 37.5 m 2 /g and total pore volume of 0.08 cc/g compared to SNPs from both PS and SB. The ascribed method could be a potential approach for comprehensive utilization of agricultural biomass through a relatively simple process, which can then be used for the biorefinery process or as a feedstock for the biomaterials industry. It is also suggested that the structural variations of CNFs/SNPs might be a vital factor to be considered for selecting optimal biomaterials.

Plant-derived biopolymers are renewable and readily available, thus making viable alternatives to synthetic polymers. The present study examined properties of biopolymers from cover crops such as rye, oat, clover, vetch, and barley, which were grown organically in a greenhouse. The yields of cellulose, hemicellulose, and lignin of the cover crops were calculated based on the dry weight. Structural variations and thermal properties of the isolated cellulose were characterized and compared with commercial cellulose using Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and Thermogravimetric analysis (TGA). The average yield percentages of cellulose, hemicellulose, and lignin were 19 to 27%, 9 to 25%, and 1.42 to 4.86%, respectively. The FTIR and Raman spectral analysis indicated that the isolated cellulose had similar peaks and patterns to commercial cellulose, and confirmed the removal of non-cellulosic constituents. The onset decomposition temperature occurred at 270 °C in all samples. Interestingly, the maximum degradation temperature beyond 370 °C in cellulose was isolated from black oat, which was higher than commercial cellulose (350 °C). The findings of this research suggest that cellulose isolated from cover crops may be a benefit to the polymer industry in the development of bio-based materials such as biofuels, bio-composites, and biomedical devices.

This study was carried out to determine the effect of natural antimicrobial washing solutions against microbial growths on fresh produce specifically strawberries. Selected washing solutions used for strawberry washing, and treatments were sterile water (control), white vinegar (VI), crude lemon juice extract (LE), VI+Origanum oil (VIO), LE+Origanum oil (LEO), and VI+LE+Origanum oil (VILEO). From the preliminary study of antimicrobial activity of washing solutions in aqueous model system tested at 2, 5, 10, 15, 20 and 25 min against S. Typhimurium, washing time was determined as 5 min to be used for this study. After the washing, strawberries were stored at 4 °C for 5 days. Results showed that all natural washing solutions exhibited inhibitory effect against total aerobic bacteria, yeast and mold. On day 5, compared to the control, all washing solutions significantly reduced S. Typhimurium by 2.7 Log CFU/g (P<0.05). Color results showed that samples color were slightly changed by washing with VIO and VILEO. However, there was no significant difference in total color change on strawberries compared to the control (P>0.05). Based on the results, it is indicated that the combination of vinegar with crude lemon juice extract and essential oil might be suitable as natural sanitizer for decontamination of fresh produce.