Volume 16 Issue 3

Three types of phenolic acids (caffeic, ferulic, and chlorogenic acid) were identified and quantified in two halophytic plants (Salicornia bigelovii and Salicornia sinus-persica). Analysis was performed using a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) system via the standard addition method. The matrix effect (ME), recovery efficiency (RE), and process efficiency (PE) parameters were evaluated for S. bigelovii extracts, which revealed a strong ME on the ionization of the three acids. The matrix had little to no effect on the extraction step for all samples. The quantitation results revealed that S. bigelovii was more abundant in the acids analyzed (total of 319.2 µg/g dry water extract) when compared to S. sinus-persica (117.2 µg/g dry water extract), and chlorogenic acid was the dominant component. The extractives content was high in both plants, representing over 35% of the dry plant weight. All the extracts exhibited antioxidant activity toward both DPPH and ABTS radicals at levels comparable to other medicinal plants.

Extensive comparative characterization was performed to explore halophytes native to the Persian (Arabian) Gulf. Ten species collected from the Western region of Abu Dhabi, United Arab Emirates (UAE) were analyzed for their lignocellulosic components as well as for ash and extractives content. It was found that the species significantly differ in the content of carbohydrates, lignin, total ash-free extractives and total ash. The total ash content was found to negatively influence the content of carbohydrates. Based on the characteristics, it is concluded that Cornulaca aucheri is the most attractive as a source of carbohydrates, and Tetraena (Zygophyllum) qatarensis has the potential to produce the highest yield of the extractives fraction.

Enhancing the mechanical, thermal, and degradation properties of a poly(lactic acid) (PLA) blend without deteriorating its other useful features was the goal of this work. The isolation of cellulose nanocrystals (CNCs) from Agave angustifolia fibers was carried out, and the properties of the bio-nanocomposites comprising these CNCs were evaluated, which included PLA, natural rubber (NR), and liquid NR (LNR). Transmission electron microscopy and zeta potential analysis confirmed the successful isolation of CNCs from agave fibers after several chemical treatment steps. The effects of different CNC loadings on the properties of the bio-nanocomposites were investigated using tensile tests, thermal analysis, morphological analysis, and water absorption tests. Bio-nanocomposites containing 5 wt% and 7.5 wt% CNC had the optimal tensile modulus and strength, respectively. Different levels of CNC did not noticeably affect the thermal stability of the bio-nanocomposites, although the thermogram curves increased slightly as CNC content increased. The addition of CNC at different loadings affects the crystallization rate of PLA blend. The water absorption capacity increased as CNC level increased, and 5 wt% CNC gave rise to the highest water absorption. The four-component bio-nanocomposites created in this study provided an alternative for producing new green materials with tunable physical, mechanical, and thermal properties.

Edible coatings (EC) are a biodegradable alternative for food preservation. In this work EC based on extracellular compounds of Humphreya coffeata and pectin (PHC) were elaborated and characterized through testing on strawberries. Two PHC types were obtained (PHC1, which settled, and PHC2, which floated during the first separation). The conservation period of the strawberry and the phenol content and antioxidant activity in strawberries with the EC were determined. Four EC were prepared (EC1, EC2, EC3, and EC4), in which EC1 did not contain any PHC, EC2 contained PHC1, EC3 contained PHC2, and EC4 contained both PHCs. Three EC types (EC2, EC3, and EC4) delayed the decay of strawberries approximately 90% at 20 °C during the first 10 days of evaluation, and at 4 °C the effect was between 75 and 90% after 25 days of experimentation. However, EC3 and EC4, both of which contained PHC2, presented the best results. The content of total phenols (approximately 55 mg (gallic acid equivalent (GAE)/mL) and the free radical scavenging activity were 35% with ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 75% with DPPH (2,2-diphenyl-1-picrylhydrazyl) in strawberries with EC. Thus, EC are an alternative for preserving strawberries without losing their antioxidant capacity.

Color changes were tested and compared for heat-treated Paulownia tomentosa and Pinus koraiensis wood treated with hot oil or hot air for further utilization of these species. Hot oil and hot air treatments were conducted at 180, 200, and 220 °C for 1, 2, and 3 h. Heat-treated wood color changes were determined using the CIE-Lab color system. Weight changes of the wood before and after heat treatment were also determined. The weight of the oil heat-treated wood increased considerably but it decreased in air heat-treated wood. The oil heat-treated samples showed a greater decrease in lightness (L*) than air heat-treated samples. A significant change in L* was observed in Paulownia tomentosa. The red/green chromaticity (a*) of both wood samples increased at 180 and 200 °C and slightly decreased at 220 °C. The yellow/blue chromaticity (b*) in both wood samples increased at 180 °C, but it rapidly decreased with increasing treatment durations at 200 and 220 °C. The overall color change (ΔE*) in both heat treatments increased with increasing temperature, being higher in Paulownia tomentosa than in Pinus koraiensis. In conclusion, oil heat treatment reduced treatment duration and was a more effective method than air heat treatment in improving wood color.

Entrepreneurs and small and medium enterprises are the foundation of the Malaysian furniture industry. Yet, in a multi-ethnic society such as Malaysia, the success factors of entrepreneurs and small and medium enterprises (SMEs) in the furniture industry have not been studied. Therefore, this study evaluated the success factors of entrepreneurs of the Malay and Chinese ethnic groups in the furniture industry and discerned the growth trajectory of young entrepreneurs from wood science and technology programs in the furniture industry. A questionnaire-based survey was used with the assistance of relevant trade associations and universities. The results were statistically analyzed to establish the significant differences between the two ethnic groups in their perceived success factors. The results revealed that Malay entrepreneurs pay more attention to political and socio-cultural factors to gain success, whereas Chinese entrepreneurs focus on enhancing their competitiveness to remain viable. Further, young graduates showed a reduced desire to pursue a career in the furniture industry, as they deem it not environmentally sustainable in addition to limited career growth. These results suggested that current entrepreneurship development programs may need to be revised, so as to assist in producing more resilient and successful entrepreneurs in the future in the furniture industry.

This study proposed action scenarios for urban solid waste management in six municipalities in the Corumbataí River Basin. The operating scenarios were designed for organic waste treatment and for the shared disposal of urban solid waste. Six municipalities were studied, five of which had less than 30,000 inhabitants (Analândia, Charqueada, Corumbataí, Ipeúna, and Santa Gertrudes). In addition, Rio Claro had 199,000 inhabitants. Thus, the transport and transshipment stages, general infrastructure, and final disposal in landfills were analyzed. Further, the three scenarios for organic waste treatment were conducted separately. The items and the cost of implementation were estimated for decentralized composting, centralized composting, and biomethanization of waste with electricity recovery. The biomethanization scenario included the commercialization of electricity, so it generated revenues that decreased costs. This cost reduction was especially notable in the last years of the project when the goals of diversion of organic waste through selective collection were higher. The results suggested that the investigated scenarios could improve organic waste treatment and that the biomethanization scenario with electricity generation presented lower average costs per inhabitant than the centralized and decentralized composting scenarios.

Effects of soaking aqueous ammonia pretreatment were considered for fast-growing poplar wood in the context of bioethanol production. The milled Populus trichocarpa wood with a particle size of 0.43 to 1.02 mm was pretreated at two temperatures (50 °C and 90 °C) and two concentrations of ammonia solution (15% and 20% w/w) for 20 h. The lignin content decreased by 46% in the biomass treated with the most severe conditions. After enzymatic hydrolysis, the sugar yield was analysed, and the results indicated that increased temperature and ammonia concentration during pretreatment resulted in higher glucose content. Additionally, changes in the degree of polymerization and available pore volume were investigated.

Arsenic and other heavy metal contaminants in water are a significant global health threat. In this study, low-cost, sulfur-free, sustainable, water-insoluble materials with heavy metal remediation properties were produced from renewable resources such as starch, xylan, citric acid, and chitosan. Synthesized starch citrate-chitosan (SCC) foam and xylan citrate-chitosan (XCC) foam were flexible, porous, and elastic. The foams’ arsenic uptake in water was significantly greater than five different commercial metal remediating agents. The mercury and lead uptakes with the synthesized foams were similar to the performance of a commercial sulfur-based product, SorbaTech 450 (ST450). However, the cadmium and selenium uptakes were comparatively lower. The complexation of arsenic with oxygen and nitrogen of the SCC foam was shown with time-of-flight secondary ion mass spectrometry (TOF-SIMS). The XCC foam was also shown to adsorb potassium iodide (KI) at a similar rate to sodium chloride. This may be used to remediate water contaminated with radioactive materials, such as iodine 131.

Sulfomethylation of radiata pine kraft lignin was performed using formaldehyde and sodium sulfite under alkaline conditions to determine its potential as a mineral depressant for the separation of molybdenite and chalcopyrite by froth flotation. Optimal conditions for the sulfomethylation reaction were 20% (w/w) Na2SO3 at 130 °C for 4.2 h, which resulted in lignin with a sulfonate content of 2.2 mmol/g. Microflotation assays showed that the optimized sulfomethylated kraft lignin (OSKL) depressed the molybdenite in flotation by 93% using 200 mg/L OSKL, while only 5% chalcopyrite depression was achieved. The performance of OSKL was compared with those of commercial lignosulfonates, and the OSKL displayed a better ability to separate molybdenite and chalcopyrite, even at lower concentration doses. FTIR and 1H-NMR analyses showed that sulfonic groups were incorporated into the C5 position of the aromatic ring and into the aliphatic chain of the OSKL. The hydroxymethyl content of the OSKL was increased, and most β-O-4′, β-1′ and β-5′ bonds were broken, with the exception of the β-β’ bond. Sulfomethylation gives kraft lignin the chemical characteristics of a wood-based molybdenite depressant, making it an alternative to current reagents used in the chalcopyrite-molybdenite flotation process.