Evaluation of Oil Palm Empty Fruit Bunch for Cellulose Production

Oil palm empty fruit bunch (OPEFB) with a cellulose content of 39 wt% is a good promise to be an alternative lignocellulosic feedstock for cellulose production through environmentally friendly extraction process. Therefore, this research was aimed to establish an effective cellulose extraction scheme from OPEFB via introduction of ultrasonication in the alkaline pulping stage for process intensification. The process could greatly reduce alkali solvent usage for cellulose extraction, hence alleviating the environmental impact caused by chemical disposal. Firstly, four distinct pre-treatment techniques had been used to pre-treat the OPEFB powder, namely autoclave, organosolv, acid and microwave pre-treatments. Afterwards, the pre-treated samples further underwent ultrasonic-assisted alkali extraction to extract the cellulose content. It was observed that the autoclave pre-treated ultrasonic extract achieved the highest cellulose content of 77.14 wt% at optimum KOH concentration of 0.75 M, ultrasonic amplitude of 30%, duration of 30 min and temperature of 80 °C. Therefore, the introduction of ultrasonication in alkali extraction of cellulose was indeed an effective approach in establishing a green production scheme of cellulose from lignocellulose.

Pretreatment Techniques and Green Extraction Technologies for Agar from Gracilaria lemaneiformis

Optimizing the alkali treatment process alone without tracking the changes of algae and agar quality with each pretreatment process will not achieve the optimal agar yield and final quality. In this study, we monitored the changes of the morphology and weight of algae with each treatment process, and comprehensively analyzed the effects of each pretreatment process on the quality of agar by combining the changes of the physicochemical properties of agar. In conventional alkali-extraction technology, alkali treatment (7%, w/v) alone significantly reduced the weight of algae (52%), but hindered the dissolution of algae, resulting in a lower yield (4%). Acidification could solve the problem of algal hardening after alkali treatment to improve the yield (12%). In enzymatic extraction technology, agar with high purity cannot be obtained by enzyme treatment alone, but low gel strength (405 g/cm2) and high sulfate content (3.4%) can be obtained by subsequent acidification and bleaching. In enzyme-assisted extraction technology, enzyme damage to the surface fiber of algae promoted the penetration of low-concentration alkali (3%, w/v), which ensured a high desulfurization efficiency and a low gel degradation rate, thus improving yield (24.7%) and gel strength (706 g/cm2), which has the potential to replace the traditional alkali-extraction technology.

Effect of strains and extraction methods on β-glucan production, antioxidant properties, and FTIR Spectra from mushroom fruiting bodies of Schizophyllum commune Fr. in Thailand

Schizophyllum commune Fr., a native mushroom of Thailand, has a high nutritional value and is classified as a mushroom with medicinal properties that can neutralize the growth of many cancer cells. This research aimed to study the effect of S. commune strains and the extraction methods on the quantity and properties of β-glucan. The five S. commune Fr. strains used in this research consisted of Chanthaburi, 85-022, 85-023, 85-031, and 85- 043. There were two different β-glucan extraction methods employed: hot water (M1) and hot alkali extraction (M2), which were compared with the control (native-MR). The results indicated that the Chanthaburi strain has the highest β-glucan content 49.20±0.35% (w/w), and high potential antioxidant activity (79.14±0.77 DPPH% and 50.92±0.48 ABTS%) (p < 0.05). The extraction methods did not affect the yield of β-glucan, except the antioxidant properties and chemical structure of the extract substance. The extract substance from M2 has significantly the highest potential antioxidant activity (80.22±0.51). A mushroom juice drink in cans was developed using 1-day-old MR and adjusted pH of more than 7, which can increase the antioxidant properties of the product.

Optimized isolation method of humin fraction from mineral soil material

Humic substances, including humin fraction, play a key role in the fate of organic and inorganic xenobiotics contaminating the environment. Humin is an important fraction of humic substances, which has been the least studied to date. This is due to the difficulties connected with its isolation that pose a number of methodological problems. Methods of humin fraction isolation can be divided into following main groups: (1) digestion of mineral soil components with HF/HCl followed by alkali extraction of HA and FA; (2) alkali extraction of HA and FA followed by extraction of humin by different organic solvents; and (3) alkali extraction of HA and FA followed by HF/HCl digestion of mineral soil components. Nevertheless, each of these methods has different limitations. We described in detail a useful procedure of humin isolation, in which this fraction was not extracted, but isolated from the soil by removing its soluble organic and mineral components. A modified method of HA and FA extraction with 0.1 M NaOH, according to the International Humic Substances Society, was used in the first step. Then, the mineral components in the residue were digested with the 10% HF/HCl. Unlike the procedures oriented to increase the concentration of organic matter, samples were treated several times with the HF/HCl mixture until the mineral fraction was almost completely digested. The main assumption of the method modification was to obtain the highest yield with the lowest possible ash content, but without affecting humin chemical structure. The results showed that the proposed procedure is characterized by a high efficiency and recovery and, therefore, it can be used to isolate high amounts of humin from soil.

Preparation of Heat-Sensitivity Proteins from Walnut Meal by Sweep Frequency Ultrasound-Assisted Alkali Extraction

Sweep frequency ultrasound- (SFU-) assisted alkali extraction was conducted to increase the yield and content of heat-sensitive protein of walnut meal under a relatively mild condition. The physicochemical and structural characteristics of the proteins obtained by SFU-assisted alkali extraction and the conventional alkali extraction were compared. It was found that the optimal parameters for the SFU-assisted extraction were the solid-liquid ratio of 1 : 12, pH value of 9, initial temperature of 25°C, ultrasonic frequency of 28 kHz, sweep frequency amplitude of 1.5 kHz, sweep frequency cycle of 100 ms, duty ratio of 77%, and ultrasonic time of 90 min. Under this condition, a vast improvement in the walnut protein yield (34.9%) and the walnut protein content (9.8%) was observed. Such improvement was due to the structural changes of the sonicated protein; e.g., SFU decreased the intermolecular/intramolecular hydrogen bond force of proteins and, therefore, caused more order secondary structures and more loosen microstructures. This helped to improve the thermoplastic and solubility of the heat-sensitivity protein. Thus, SFU treatment could be an effective auxiliary technology in the alkali extraction of heat-sensitivity walnut protein. It might also be a promising technology for the extraction of heat-sensitivity protein from other agricultural by-products.

Study of oxygen compounds of acid character of Garbi Absheron field oil

The paper presents the results of fraction and structural-group composition of acids and phenols of Garbi Absheron field oil. Studied oil is heavy, tarry, low paraffinic. The acids and phenols have been purified from the oil with their differentiation on the free and associated (in the form of compound esters) forms. Free acids and phenols were purified from the oil via alkali extraction. Their associated forms were purified after saponification of the oil released from the samples. To study the structure-group content of acids and phenols, proton-magnetic resonance spectroscopy method was used. Obtained results showed that acidic oxygen-containing compounds in Garbi Absheron field oil predominantly consist of associated acids and phenols in the form of compound esters. Middle molecules of these phenols contain condensed naphtenic-aromatic cycles, the acids by their structure belong to the derivatives of hydrocarbons of paraffin series of CH3 residual-substitutes.