Cooking Pretreatment Research Articles

Tough and highly conductive deep eutectic solvent-based gel electrolyte strengthened by high aspect ratio of hemp lignocellulosic nanofiber

Flexible electronic sensing and energy storage technology impose heightened demands on the mechanical and stable properties of gel electrolyte materials. Lignocellulosic nanofiber (LCNF) present a promising avenue for improving the properties of electrolyte networks and mechanical strength. In this study, LCNF derived from hemp fibers was prepared using lactic acid/choline chloride deep eutectic solvent (DES) through a combination of cooking and colloid mill mechanical treatment to achieve nanocellulose with a high aspect ratio and uniform dimensions. The outcomes demonstrated that LCNF, a width of below 20 nm and a length of over 5 μm, can be effectively produced through the DES cooking pretreatment in conjunction with colloid mill mechanical treatment. Meanwhile, DES lignin possessed a purity of ∼90 % and was obtained as a by-product. Subsequently, the as-prepared LCNF was integrated as a nanofiller into gel electrolyte. Ag-L NPs/LCNF/DES/PAA exhibited dense porous structures and showcased exceptional properties, including a high conductivity exceeding 10 mS/cm and remarkable adhesion strength surpassing 100 KPa. The presence of LCNF allowed Ag-L NPs/LCNF/DES/PAA to achieve strains above 1000 % and compression properties over 1000 KPa. The supercapacitor based on this assembly had a high specific capacitance of 271 F g−1 at 0.5 A g−1), along with an impressive capacity retention rate reaching ∼100 % after 3000 cycles. This investigation offers valuable insights into the utilization of lignocellulosic multi-component approaches in the development of flexible electronic devices.

Reducing the cadmium, inorganic arsenic and dimethylarsinic acid content of rice through food-safe chemical cooking pre-treatment

Cadmium, inorganic arsenic and, potentially, dimethyl arsenic acid are carcinogens widely elevated in rice. Here it was identified that the food-safe and common cadmium chelator citric acid efficiently removed cadmium from intact grain via pre-soaking procedure, while also reducing arsenic species. A twostep pre-soaking stage was developed whereby rice was first incubated, at ambient temperature, in 1 M citric acid for 12 h, and then in 1 M calcium carbonate for another 12 h, the latter step to neutralize pH, followed by cooking. When 10 different individual types of rice were processed in such a way this resulted in removal rates of 79% for cadmium, 81% for inorganic arsenic and a 66% for DMA. The technology is particularly suitable for bulk food processing and could be deployed in the most cadmium and arsenic impacted regions where rice is a staple.

Combination of ultrasound-assisted aqueous enzymatic extraction and cooking pretreatment for date seed oil recovery

Date seed oil is a good source of natural antioxidants due to the presence of phenols, tocopherols, and sterols. The present research is the first study on the extraction of date seed oil by combining the ultrasound-assisted aqueous enzymatic extraction method and the cooking pretreatment. In this study, the effects of two independent variables namely the sample to solvent ratio (at six levels of 1: 2, 1: 3, 1: 4, 1: 6, 1: 8 and 1:10) and the cooking time (at four levels of 0, 20, 40 and 60) were investigated on dependent variables namely the extraction yield, total phenolic compound, peroxide value, and acid value of date seed oil. The results indicated that optimum conditions for extraction of date seed oil were sample to solvent ratio of 1: 2 and the cooking time of 40 min. Furthermore, the Scanning Electron Microscopy images of date seed powder after selective treatments indicated the destruction and fragmentation of residual pulp structures by increasing the cooking time. In general, results of the present study indicated that it was important to select the appropriate sample to solvent ratio and implement the pretreatment of cooking to extract oil with high yield and quality. Combination of the ultrasound-assisted aqueous enzymatic extraction method and the cooking pretreatment can be proposed as a new extraction method in the oil industry. This new extraction method can improve the oil extraction efficiency and the quality of extracted oil.

Effects of ultrasonication and thermal cooking pretreatments on the extractability and quality of cold press extracted rice bran oil

AbstractThis research investigates the effects of different extraction processes on the extractability and quality of rice bran oil. The extraction processes included hexane extraction (HE) as Control 1, cold press extraction (CE) as Control 2, ultrasonic pre‐treatment combined with cold press extraction (UCE), and thermal cooking combined with cold press extraction (CCE). The results showed that oil extractability was positively correlated to ultrasonic power and duration; and to thermal cooking time. Meanwhile, the oil quality and ultrasonic intensity and thermal cooking period were inversely correlated. Specifically, the oxidative stability, and unsaturated fatty acids of short‐period CCE oil were significantly higher than those of long‐period CCE oil and higher‐power and longer‐duration UCE oil. Similar to HE and CE oils, oleic, linoleic, and palmitic acids were the dominant fatty acids in short‐period CCE oil. Essentially, short‐period CCE is optimal for rice bran oil extraction due to improved oil extractability and quality.Practical applicationsRice bran oil is an excellent source of unsaturated fatty acids and natural antioxidants. It also has many proven health benefits. There are two conventional production methods of rice bran oil: pressing and solvent extraction. While the pressing method achieves low oil extractability, solvent extraction could deteriorate the oil quality. This research, thus, proposes two chemical‐free extraction techniques for rice bran oil that improves the oil extractability and preserves the oil quality: ultrasonic pretreatment combined with cold press extraction (UCE) and thermal cooking pretreatment combined with cold press extraction (CCE). The findings are expected to offer a possible solution to the extractability‐quality challenges associated with the conventional extraction methods.

Simultaneous extraction of lignin and cellulose nanofibrils from waste jute bags using one pot pre-treatment

Cellulose nanofibrils and lignin were simultaneously isolated from waste jute bags using soda cooking pretreatment method. Soda cooking resulted in reduction of recalcitrance of lignocellulose biomass leading to hydrolysis of hemicellulose into sugars, which was subsequently washed, leaving a residue of cellulose and lignin.The chemical composition, yield of lignin and cellulose were assessed using TAPPI method and ASTM standards, respectively. Yields of lignin and cellulose were 58 and 45%, respectively, calculated separately on the basis of their content in the jute bags. FTIR results confirmed the removal of lignin and hemicellulose from raw jute fibers during soda cooking process. HNMR results depicted the aromatic structure of lignin which was further confirmed by UV results which clearly indicated the presence of phenolic compounds. The thermal stability of cellulose nanofibrils and lignin was higher than raw jute fibers. SEM showed cylindrical cellulose nanofibrils and agglomerates of amorphous and crystalline region of lignin. Size of jute fibers decreased to 12–18nm whereas the crystallinity increased after chemical and mechanical treatments studied using TEM and XRD, respectively. The study confirmed the isolation of cellulose nanofibrils and lignin extraction discarding the hemicellulose using single pot treatment.

Effects of hydrodynamic cavitation on dry mill corn ethanol production

In this study, the ability of hydrodynamic cavitation pretreatment (HC) to increase ethanol yields at dry mill corn ethanol plants was investigated at pilot scale. Experiments were conducted at four HC energy densities, with and without jet cooking pretreatment and at a range of alpha-amylase (AA) doses. Corn slurries treated with HC had reduced particle sizes and significantly higher soluble saccharides. After simultaneous saccharification and fermentation (SSF), ethanol yields were 2.6% greater than in uncavitated controls. Jet cooking alone decreased ethanol yield compared to cavitated and control treatments. HC combined with jet cooking resulted in ethanol yields similar to controls. At alpha-amylase dosages 60% lower than those used at commercial scale plants (0.40% w enzyme/w dry corn), there was only a slight, insignificant reduction in ethanol yield. The net energy yield of HC was 47kWh in additional ethanol for each kWh used for HC. In conclusion, HC improved the solubilization of saccharides and ethanol yield from corn, and had a positive net energy yield, thereby improving the efficiency of dry mill corn ethanol production from both an economic and environmental standpoint.

Preparation and characterisation of soya milk enriched with isoflavone aglycone fermented by lactic acid bacteria combined with hydrothermal cooking pretreatment

SummaryA fermented soya milk (FSM) enriched with isoflavone aglycone (FSM‐SPIA) was prepared from heated soya protein isolate (SPI)‐isoflavone complex. After 48 h of fermentation, FSM‐SPIA contained higher contents of living bacteria, free amino acids and aglycone compared with the FSM of SPI (FSM‐SPI) and the FSM of SPI‐isoflavone complex (FSM‐Mix). In the in‐vitro digestion experiment, FSM‐SPIA showed higher antioxidant capacity and isoflavones (ISO) bioavailability than FSM‐SPI and FSM‐Mix. This was likely due to the soya milk containing a higher level of amino acid, peptides and the presence of soya bean isoflavone. The improved protein digestibility, the interaction and binding ability between proteins and ISO may affect the properties of the protein and the fermented products. The FSM enriched with isoflavone aglycone can be used as a functional fermented drink, as well as an auxiliary food for menopausal women during a specific pathological period.

Efficient pretreatment of Vietnamese rice straw by soda and sulfate cooking methods for enzymatic saccharification.

This manuscript presents a study on alkaline pretreatment of Vietnamese rice (Oryza sativa L.) straw that grows in Northern Vietnam for enzymatic saccharification. The NaOH pretreatment (soda cooking) and NaOH/Na2S pretreatment (sulfate cooking) were applied for rice straw pretreatment, which have relatively similar condition with industrial pulping processes but at lower temperature. Pretreated biomass solid was then enzymatic hydrolyzed by commercial enzyme Cellic®CTec2 (Novozymes) with enzyme dosage of 35 FPU/g to achieve reducing sugars. The suitable condition for pretreatment was found at temperature of about 100 °C, pretreatment time of 2 h, and solid/liquid ratio of 1:10 with active alkali dosage of 20 % of dry rice straw. Under this pretreatment condition, sugar yield in enzymatic hydrolysis up to 45.33 and 48.92 % over dry rice straw could be obtained after soda cooking and sulfate cooking pretreatment, respectively. Moreover, the changes of components of rice straw after pretreatment were also studied. The crystallinity of cellulose in pretreated biomass solid was calculated from XRD pattern. And the fibril morphology after treatment was revealed by the microscopic observations performed by scanning electron microscope (SEM).

Simultaneous saccharification and fermentation and economic evaluation of ultrasonic and jet cooking pretreatment of corn slurry

The potential of ultrasonics to replace hydrocooking in corn-to-ethanol plants was examined in this study. Batch and continuous experiments were conducted on corn slurry with sonication at a frequency of 20 kHz. Batch mode used a catenoidal horn operated at an amplitude of 144 μm peak-to-peak (p–p) for 90 s. Continuous experiments used a donut horn operating at inner radius amplitude of 12 μm p–p. Jet-cooked samples from the same ethanol plant were compared with ultrasonicated samples. The highest starch-to-ethanol conversion was obtained by the jet-cooked samples with a yield of 74% of the theoretical yield. Batch and continuous sonication achieved 71.2% and 68% conversion, respectively, however, statistical analysis showed no significant difference between the jet cooking and ultrasonication. On the basis of the similar performance, an economic analysis was conducted comparing jet cooking and ultrasonic pretreatment. The analysis showed that the capital cost for the ultrasonics system was ~10 times higher compared to the capital cost of a hydrocooker. However,due to the large energy requirements of hydrocookers, the analysis showed lower total overall costs for continuous ultrasonication than that for jet cooking, assuming the current energy prices. Because of the high utility cost calculated for jet cooking, it is concluded that ultrasonication poses as a more economical option than jet cooking. Overall, the study shows that ultrasonics is a technically and economically viable alternative to jet cooking in dry-grind corn ethanol plant.

Progress in ethanol production from corn kernel by applying cooking pre-treatment

In order to improve technological properties of corn kernel for ethanol production, samples were treated with a hydrothermal pre-treatment of cooking (steaming), prior to drying. Two types of cooking process parameters were applied; steam pressure of 0.5 bars during a 10 min period, and steam pressure of 1.5 bars during a 30 min period. Afterwards, samples were dried at four different temperatures, 70, 90, 110 and 130 °C. Control sample was also submitted to the afore-mentioned drying parameters. Since the results showed that starch utilization, due to the gelatinization process, was considerably higher in the samples pre-treated before the ethanol production process, it was found that the cooking treatment had a positive effect on ethanol yield from corn kernel. Therefore, the highest ethanol yield was found in the corn kernel samples cooked for 30 min at steam pressure 1.5 bars and dried at 130 °C. Due to the similarity of processes used for starch fermentation, introduction of cooking pre-treatment will not significantly increase the overall ethanol production costs, whereas it will result in significantly higher ethanol yield.

Enzyme-Assisted Extraction of Rice Bran Oil

In the extraction of oil from rice bran, yield and quality of oil between enzyme pretreatment and ordinary cooking pretreatment (heat and dry) were examined. Yield of extracted oil was higher in enzyme pretreatment than in ordinary cooking pretreatment. In addition, total sterol and oryzanol contents were also higher in enzyme pretreatment. Therefore, it was suggested that the condition of rice bran had changed into the one in which the unsaponifiable matters including small amount of components effective for human body were extracted easily through enzyme pretreatment.