Curcumin is a phenolic compound derived from turmeric roots (Curcuma longa L.). This research studied the effects of curcumin extract on the properties of chitosan films. The film characteristics measured included mechanical properties, visual aspects, color parameters, light transmission, moisture content, water solubility, water vapor permeability, infrared spectroscopy, and antioxidant activity. The results suggest that adding curcumin to chitosan-based films increases yellowness and light barriers. Infrared spectroscopy analysis showed interactions between the phenolic compounds of the extract and the chitosan, which may have improved the mechanical properties and reduced the moisture content, water solubility, and water vapor permeability of the films. The antioxidant activity of the films increased with increasing concentrations of the curcumin extract. This study shows the potential benefits of incorporating curcumin extract into chitosan films used as active packaging.

Tomatoes are one of the most nutritionally and economically important crops in New Zealand and around the world. Tomatoes require large amounts of water to grow well and are adversely affected by drought stress. However, few studies have evaluated the physicochemical characteristics of commercial tomatoes grown under water stress conditions. Four tomato cultivars (Incas, Marmande, Scoresby Dwarf, and Window Box Red) were grown in a greenhouse under well-watered and drought stress conditions and the tomatoes were harvested when ripe. The physicochemical properties and antioxidant contents of the fruits were compared. There were significant differences between cultivars in quality characteristics—such as dry matter, total soluble solids, and pH parameters—but there were no differences in the quality characteristics between the two treatments of the fruits (p > 0.05); however, there were significant differences (p < 0.05) in the antioxidant compositions (lycopene, total phenolics, and flavonoids) and antioxidant activities (DPPH and ABTS) of the fruits of both cultivars and treatments. Overall, these results indicated that tomatoes increased their bioactive compounds without changing any quality characteristics when exposed to water stress conditions.

Cellulose from Asparagus officinalis stalk end was extracted and synthesized to carboxymethyl cellulose (CMC_as) using monochloroacetic acid (MCA) via carboxymethylation reaction with various sodium hydroxide (NaOH) concentrations starting from 20% to 60%. The cellulose and CMC_as were characterized by the physical properties, Fourier Transform Infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). In addition, mechanical properties of CMC_as films were also investigated. The optimum condition for producing CMC_as was found to be 30% of NaOH concentration for the carboxymethylation reaction, which provided the highest percent yield of CMC_as at 44.04% with the highest degree of substitution (DS) at 0.98. The melting point of CMC_as decreased with increasing NaOH concentrations. Crystallinity of CMC_as was significantly deformed (p < 0.05) after synthesis at a high concentration. The L* value of the CMC_as was significantly lower at a high NaOH concentration compared to the cellulose. The highest tensile strength (44.59 MPa) was found in CMC_as film synthesized with 40% of NaOH concentration and the highest percent elongation at break (24.99%) was obtained in CMC_as film treated with 30% of NaOH concentration. The applications of asparagus stalk end are as biomaterials in drug delivery system, tissue engineering, coating, and food packaging.

Bacterial cellulose from nata de coco was prepared from the fermentation of coconut juice with Acetobacter xylinum for 10 days at room temperature under sterile conditions. Carboxymethyl cellulose (CMC) was transformed from the bacterial cellulose from the nata de coco by carboxymethylation using different concentrations of sodium hydroxide (NaOH) and monochloroacetic acid (MCA) in an isopropyl (IPA) medium. The effects of various NaOH concentrations on the degree of substitution (DS), chemical structure, viscosity, color, crystallinity, morphology and the thermal properties of carboxymethyl bacterial cellulose powder from nata de coco (CMCn) were evaluated. In the carboxymethylation process, the optimal condition resulted from NaOH amount of 30 g/100 mL, as this provided the highest DS value (0.92). The crystallinity of CMCn declined after synthesis but seemed to be the same in each condition. The mechanical properties (tensile strength and percentage of elongation at break), water vapor permeability (WVP) and morphology of CMCn films obtained from CMCn synthesis using different NaOH concentrations were investigated. The tensile strength of CMCn film synthesized with a NaOH concentration of 30 g/100 mL increased, however it declined when the amount of NaOH concentration was too high. This result correlated with the DS value. The highest percent elongation at break was obtained from CMCn films synthesized with 50 g/100 mL NaOH, whereas the elongation at break decreased when NaOH concentration increased to 60 g/100 mL.

The objective of this study was to characterize the properties of cellulose and CMC synthesized from young and mature coconut coir with different bleaching times (bleaching for the first time; 1 BT, bleaching for a second time; 2 BT, and bleaching for the third time; 3 BT) using hydrogen peroxide (H₂O₂). The surface morphology, structural information, chemical compositions, and crystallinity of both cellulose and CMC were determined. H₂O₂ bleaching can support delignification by reducing hemicellulose and lignin, as evidenced by FTIR showing a sharp peak at wave number 1260 cm⁻¹. The cellulose and CMC from coconut coir can be more dispersed and have greater functional characteristics with increasing bleaching times due to the change in accessibility of hydroxyl groups in the structure. The CMC diffraction patterns of coconut coir after the bleaching process showed the destruction of the crystalline region of the original cellulose. The SEM images showed that the surface of CMC was smoother than that of cellulose. The CMC_y had a higher water holding capacity (WHC) compared to the CMC_m as the bleaching can increase interaction between the polymer and water molecules. Therefore, the best quality of CMC corresponds to CMC_y. Based on these findings, bleaching time has a strong effect on the functional properties of cellulose and CMC from coconut coir.