Residual Cake Research Articles

Harnessing Bacillus subtilis QY5 PP784163 for Bioethanol Production from Potato Peel Waste and Nutrient Recovery for Animal Feed: Maximizing Resource Efficiency

The present work focuses on the utilization of potato peel waste for the production of bioethanol. In the present study, extensive screening was undertaken to isolate amylolytic and cellulolytic microbes using starchy biomass. After confirming the chemical composition of potato peel waste (PPW), several trials were performed to enhance the amylase and cellulase production from Bacillus subtilis to hydrolyze the PPW in submerged fermentation. Optimization of physical parameters was performed using both commercial and indigenous media from enzymatically hydrolyzed PPW. Different routes of various combinations were designed to enhance bioethanol production. The maximum ethanol titer of 0.50% and 0.41% was recorded in Route B and A, i.e., separate saccharification and ethanol fermentation and consolidated fermentation. Simultaneous saccharification and fermentation (SSF) also measured a good ethanol yield of 0.46%. The fermented residual cake was checked for nutritional components and showed a high content of protein and amino acids because of the addition of unicellular yeasts. This cake can be utilized as an animal feed supplement.

Optimization and Study of the Enzymatic Aqueous Extraction of Coffee Beans and Its Residual Cake

ABSTRACT Agroindustrial processes have increasingly focused on sustainability and pressing coffee beans generates a waste known as the residual cake. This study evaluated the effects of aqueous enzymatic extraction with carbohydrases applied in coffee bean and its residual cake. Optimized conditions for enzymatic extraction were 75 min, pH 4.5 and 49°C (CB); 51 min, pH 5.0 and 46 °C(RC). The extracts obtained from aqueous enzymatic extraction, when compared to their respective control groups, showed statistically significant increases in the extraction of caffeine (0.32 ± 0.02 and 0.73 ± 0.10 g/100 g for CB RC, respectively) phenolic compounds (3.06 ± 0.30 and 3.85 ± 0.51 g/100 g, for CB and RC, respectively), oil content and improved antioxidant activity by the DPPH and ABTS methods (184.1 ± 2.5 for CB and 153.6 ± 8.4 µmolTrolox/g for RC). These results also showed the potential of the residual cake as a raw material for the production of extracts rich in bioactive compounds and the use of clean technology.

Preparation of fibrous ceramic-based catalytic membranes by microwave heating and their structural properties and dust and NO removal characteristics

Different drying methods were used to prepare catalytic membranes for the simultaneous removal of dust and NO to explore their effect on the distribution of active components, with the structural properties, filtration performance, catalytic performance, and working mechanism of the preferred prepared catalytic membrane systematically investigated. The results indicated that microwave drying, in contrast to traditional electric drying with blasting, effectively inhibited the migration of the precursor solution to achieve uniform loading of active components, thus endowing the catalytic membrane with excellent catalytic activity. Meanwhile, the pore structure of the fibrous ceramic substrate was not almost affected by the loaded catalyst and still exhibited high porosity. These characteristics contributed to the development of a catalytic membrane with good filtration and catalytic performance, as well as superior adaptable NO concentration and filtration velocity properties. Therefore, fibrous ceramic-based catalytic membranes prepared using microwave assistance offer considerable application prospects for integrated purification of high-temperature flue gases. Furthermore, the removal of dust and NO was determined to follow the Eley–Rideal reaction mechanism and surface filtration mechanism of the residual dust cake, respectively.

The use of small diameter nozzles in temperature-controlled hemp oil extraction allows high oil yields and good quality residual hemp cake feed.

The use of two nozzle diameters (6 and 8 mm) in a cold (50°C) hemp seed oil extraction process was evaluated in terms of extraction efficiency, and chemical composition and in vitro fermentation characteristics of the residual cake. Seeds of the varieties Futura 75 and Uso 31 were pressed using a mechanical press with a cooling device. Five pressings were carried out for each variety and nozzle size, the functional parameters of the extraction processes were recorded, and sample of the residual cakes (n = 20) were analyzed. The 6 mm nozzle determined a higher oil yield (+4%) with a limited increase in temperature in the pressing chamber and in the oil (on average + 3°C compared to the 8 mm nozzle). A lower oil yield and consequently a higher fat content in the corresponding cake was observed when using the 8 mm nozzle. Despite the similar fat content, the two varieties had different oil yields and different residual cake compositions. The gas production kinetic of cakes was influenced by variety but little by nozzle size. Overall, the use of a smaller nozzle in a temperature-controlled extraction process can be a useful option to increase hemp oil yield while maintaining good fermentation characteristics of the residual cakes as ruminant feed.

In Situ Transesterification from Soybean Seed Using Mechanochemical Methods toward Producing Biodiesel.

The research and development of new routes of biodiesel synthesis have been increasingly in line with the principles of green chemistry. In this sense, mechanochemistry is a promising technique, able to ally the energetic potential with reductions in the use of solvents and steps of treatment of the sample and the purification of the product. To date, this is the first work using mechanochemistry directly in extracting soybean oil from its seed and the in situ transesterification reaction by applying a reactive soybean oil extraction process. The presence of n-hexane was studied in different molar proportions (relative to the oil content), and a low solvent consumption in a 3:1 ratio was adopted. Mechanochemistry favored oil diffusion in the n-hexane solvent, resulting in a mean triglyceride content equal to 90%, against 66% obtained in the tests without spheres in the planetary ball mill. The catalyst content was also evaluated, and 4% NaOH (weight, concerning the oil) was the concentration that presented less residue of nontransesterified glycerides in the samples for ethyl ester preparation. Additionally, the protein content was determined on the residual soybean cake, with no loss of nutritional potential when subjected to the mechanochemical process.

Co-Fermentation of Agri-Food Residues Using a Co-Culture of Yeasts as a New Bioprocess to Produce 2-Phenylethanol.

Whey is a dairy residue generated during the production of cheese and yogurt. Whey contains mainly lactose and proteins, contributing to its high chemical oxygen demand (COD). Current environmental regulations request proper whey disposal to avoid environmental pollution. Whey components can be transformed by yeast into ethanol and biomolecules with aroma and flavor properties, for example, 2-phenyethanol (2PE), highly appreciated in the industry due to its organoleptic and biocidal properties. The present study aimed to valorize agri-food residues in 2PE by developing suitable bioprocess. Cheese whey was used as substrate source, whereas crab headshells, residual soy cake, and brewer's spent yeast (BSY) were used as renewable nitrogen sources for the yeasts Kluyveromyces marxianus and Debaryomyces hansenii. The BSYs promoted the growth of both yeasts and the production of 2PE in flask fermentation. The bioprocess scale-up to 2 L bioreactor allowed for obtaining a 2PE productivity of 0.04 g2PE/L·h, twofold better productivity results compared to the literature. The bioprocess can save a treatment unit because the whey COD decreased under the detection limit of the analytical method, which is lower than environmental requirements. In this way, the bioprocess prevents environmental contamination and contributes to the circular economy of the dairy industry.

Isolation and characterization of novel microcellulose from Sesamum indicum agro-industrial residual waste oil cake: conversion of biowaste to wealth approach

Isolation and characterization of novel microcellulose from Sesamum indicum agro-industrial residual waste oil cake: conversion of biowaste to wealth approach

Hemp Seed Oil Extraction and Stable Emulsion Formulation with Hemp Protein Isolates

Industrial hemp (Cannabis sativa L.) is traditionally processed for its high fibre content in the textile industry, but in recent years, it has come to constitute a new raw material in the food industry. Hemp seeds, but also the seed meal, are rich in protein (25%) and oil (30%), the latter consisting of 80–90% of unsaturated fatty acids; they represent a rich and balanced nutritional source to replace the classic animal sources, and they are used in the food industry to supply new food trends. In this work, the hemp oil extraction process was studied, taking advantage of the supercritical CO2 and ultrasounds, and comparing it with the exhaustive Soxhlet technique. The residual cake from extraction is a protein-rich waste that can be used for food formulations. From this perspective, the hemp oil extracted was used to formulate emulsions with the consistency of vegetable drinks, enriched with standard hemp protein isolate and stabilized with the addition of 0.05% w/w of thickening polysaccharides (Gellan gum). The formulated emulsion is stable, and this can encourage the process improvement and the use of the waste from hemp seed extraction for the valorisation of by-products and waste to obtain complete food products with high nutritional value.

Isolation and characterization of novel micro cellulose from Azadirachta indica A. Juss agro-industrial residual waste oil cake for futuristic applications

Isolation and characterization of novel micro cellulose from Azadirachta indica A. Juss agro-industrial residual waste oil cake for futuristic applications

Recycling of Angren coal mining tailings to obtain humic acids and bacterial-humic fertilizers

Coal processing at the Angren deposit in Uzbekistan has led to accumulation of a huge amount of coal tailings, for which an effective and economically viable recycling technology is required. For this purpose, a waste-free technology has been developed, which includes two-stage tailings processing. At the first stage, the tailings are treated with NaOH or KOH hydroxide at the rate of 5–8 g/100 g with the solid/liquid ratio of 1 : 5 for 30 minutes at 80 °C. The humic acid extracts are then filtered, the suspension is adjusted to pH 6.5–7, and dehydration to 50 % moisture is performed to obtain a humate paste. At the second stage, the growth medium is first prepared. First-stage cake is then inoculated with a solution containing an overgrown bacterial medium at a solid/liquid weight ratio of 1 : 3, with the total organic matter present in the form of rice screenings. The resulting mix is placed in waterproof tanks with a layer of up to 2 m and kept for 7–9 days, with six treatments a day. With the mass fraction of bound humic acids (HA) in the residual cake of 13.77 %, bacterial treatment with nine days of cultivation in the active phase results in 11.98 % of free HA passing into the liberated form (available to plants).

Biocarriers facilitated gravity-driven membrane filtration of domestic wastewater in cold climate: Combined effect of temperature and periodic cleaning

In this study, two lava stone biocarrier facilitated gravity-driven membrane (GDM) reactors were operated at ~8 °C and ~22 °C in parallel for treating primary wastewater effluent. Although the biocarrier reactor at 8 °C displayed less efficient removals of biodegradable organics than that at 22 °C, both GDM systems (without cleaning) showed comparable fouling resistance distribution patterns, accompanying with similar cake filtration constants and pore constriction constants by modelling simulation. Compared to the GDM at 8 °C, more foulants were accumulated on the GDM at 22 °C, but they presented similar soluble organics/inorganics contents and specific cake resistances. This indicated the cake layers at 22 °C may contain greater-sized foulants due to proliferation of both prokaryotes and eukaryotes, leading to a relatively less-porous nature. In the presence of periodic cleaning (at 50 °C), the cleaning effectiveness followed a sequence as ultrasonication-enhanced physical cleaning > two-phase flow cleaning > chemical-enhanced physical cleaning > physical cleaning, regardless of GDM operation temperature. However, significantly higher cake resistances were observed in the GDM system at 22 °C than those at 8 °C, because shear force tended to remove loosely-attached foulant layers and may compress the residual dense cake layer. The presence of periodic cleaning led to dissimilar dominant prokaryotic and eukaryotic communities in the cake layers as those without cleaning and in the lava stone biocarriers. Nevertheless, operation temperature did not influence GDM permeate quality, which met EU discharge standards.

Fouling and mitigation mechanisms during direct microfiltration and ultrafiltration of primary wastewater

Direct membrane filtration (DMF) has recently gained attention as an alternative secondary biological wastewater treatment process. This study evaluated direct microfiltration (MF) and ultrafiltration (UF) performance and cleaning protocols during crossflow DMF of primary municipal wastewater effluent. Several types of MF and UF membranes were examined by threshold flux determination, and two types of membranes (MF, 0.08 μm; UF, 100 kDa) were chosen for exploring membrane fouling mechanisms at different feed pressures via both fouling resistance analysis and optical coherence tomography (OCT) observation. The results revealed that both MF and UF displayed three-stage fouling behaviors, i.e., initial intermediate pore blocking followed by two-stage cake filtration. Increasing feed pressure from 8 kPa to 50 kPa could accelerate physically reversible fouling rate (consistent with simulated cake filtration constant). During physical flushing, the cake layer was more readily removed from the UF membrane; while residual porous cake layer was present on the MF membrane, regardless of the feed pressure. With extending filtration-cleaning cycle, shortening filtration duration and elevating cleaning solution temperature to from 25 °C to 50 °C benefited for irreversible fouling alleviation. At 50 °C, the geothermal water performed similar cleaning behaviors as clean water, facilitating lower reversible and irreversible fouling than the geothermal brine. This study shed light on the feasibility of using high temperature geothermal water for periodic physical cleaning during DMF of wastewater under Icelandic scenario.

From solvent extraction to the concurrent extraction of lipids and proteins from green coffee: An eco-friendly approach to improve process feasibility

The production of green coffee oil by mechanical pressing of green coffee beans has been precluded by low extraction yields, which generates a protein-rich byproduct (cake) containing variable amounts of lipids. Subsequent utilization of the cake requires the removal of the residual cake oil by solvent extraction. An eco-friendly extraction strategy, using water, enzymes, and mechanical treatments, was evaluated to concurrently extract lipids and proteins from green coffee flour, without the use of harsh solvents. Among the enzymatic treatments evaluated, the use of 0.5% alkaline protease led to higher protein (62.2%) and oil (47.7%) extractability in a shorter time (30 min). This enzymatic treatment was optimized with respect to solids-to-liquid ratio (SLR) (1:17.5–1:7) and concentration of enzyme (0.1–0.9% w/w). Although optimum extraction conditions (1:17.5 SLR and 0.1% enzyme) achieved high protein (70%) and oil (48%) extractability and reduced enzyme use by 80%, a higher water usage was required. Therefore, a two-stage countercurrent extraction was developed to reduce water usage in the process. The countercurrent extraction strategy not only reduced the amount of water used in the process by 60% but promoted higher protein (72%) and oil (58%) extractability, compared with the single-stage process (62.2 and 47.7%, respectively).

The untapped industrial crop, Cucumeropsis mannii: dry oil extraction, characterization and potential use as biodiesel feedstock and heavy metal sink

Due to the quest to meet a basic need – food, vast potentials of numerous African crops have remained unexplored. Cucumeropsis mannii, an invaluable West African melon, is cultivated for its edible proteinous oil-rich seeds. Here, we report for the first time, its potential use for biodiesel production over an uncommon heterogeneous nanocatalyst, and for wastewater treatment. An identification of the untapped species’ seed was made, for disambiguation. Oil (CMO) was expressed from the C. mannii seeds (CMS) and characterized. The CMS was found composed of 53.5% lipids, while 46.1% of the full-fat CMS flour was recovered as vegetable oil. Transesterification experiments were performed using a specially-prepared heterogeneous nanocatalyst derived from Eobania vermiculata shells, by varying successively: methanol/oil ratio, temperature, and reaction time. Maximum biodiesel (CMOME) yield of 86.2% was achieved at catalyst concentration of 5.4%, methanol to oil molar ratio of 9:1, reaction temperature of 60 °C, after 3 h of reaction. Furthermore, part of the polyunsaturated CMO was sulphur-functionalized and utilized at different dosage levels for extraction of Ag+ from 600 to 1500 ppm simulated water. The modified CMO exhibited desirable sorption properties – sinking 100% of Ag+ from 900 ppm water, after 7-h-phase-contact at 6.9 g (20 mL)− 1 dosage. Stagewise operation (multi-staging) was found capable of improving the extraction efficiency in highly concentrated wastewater. Although CMOME conformed to EN-14214 and ASTM D-6751 standards, it had low oxidation stability; making wastewater treatment a more faithful application. Regarding the crop’s food value, residual CMS cake remained edible, even with longer shelf-life (relative to the full-fat flour) – encouraging commercial flour-defattening and consequent availability of CMO for industrial applications. Lastly, it was concluded (with some relevant recommendations) that CMO has great potentials for use as biodiesel feedstock and as heavy metal removal agent.

Evaluation of Postharvest Processing of Hazelnut Kernel Oil Extraction Using Uniaxial Pressure and Organic Solvent

Uniaxial loading and organic solvent are small-scale oil expression methods used to evaluate the mechanical behavior, oil content, and oil efficiency of oil-bearing materials aimed at designing a low-cost mechanical pressing system. Bulk kernels of pressing height 40 mm were heated from 40 to 60 °C and compressed at maximum force of 60 kN and speeds from 4 to 8 mm/min. Relaxation times between 3 and 12 min were applied to assess the kernel oil efficiency. The kernel oil point was identified at deformation levels between 15 and 25 mm at a speed of 4 mm/min using a litmus test. The kernel oil was analyzed for peroxide value and free fatty acid. Kernel oil content was determined by Soxhlet extraction. Increased speed caused a serration effect on the force–deformation curve leading to lower oil yield. Lower and upper oil point forces at 6.21 ± 0.58 and 10.61 ± 0.71 kN were observed to be useful for predicting the pressure for maximum output oil. The peroxide value and free fatty acid content of kernel oil decreased with increasing temperature, indicating its quality usage. The relaxation time of 12 min after compression increased kernel oil efficiency of 15.6%. In designing new presses, there is a need to consider compression and relaxation processes to reduce the residual kernel cake oil.

Microencapsulation of hydrosoluble extract of babassu nut press cake

Orbignya phalerata Mart. has great socio-economic value, originating various products and by-products; however, there are few studies about obtaining food products from of this raw material. In face of that reality, this study aimed to obtain powder extract from press cake of the babassu nut kernel, and to verify the influence of varying concentrations of Maltogill®10 and drying temperature on process yield through a factorial design, as well as to characterize the final product. Babassu nut used for pressing and acquisition of residual press cake and extract. Spray dryer was used to obtain the powder extract, which adopted a rotating central composite design (RCCD with 11 trials). The final product was characterized by analyses of moisture, solubility, hygroscopicity, water activity and bulk density. The experimental design showed significant influence (p ? 0.05) for the variables inlet temperature in the linear and quadratic models, focusing only on the linear term and the interaction between them, the model adjusted in planning was considered predictive; the best productivity obtained (80.37%), was for the temperature of 95°C with encapsulating agent of 18%. With respect to the powder product analysis, low moisture values, hygroscopicity, and density were observed, as solubility and water activity within the recommended parameters.

Sesame (Sesamum indicum) oil cake—industrial waste biomass for sequestration of Basic Blue 26 from aqueous media

In the present investigation, the adsorption performance of sesame (Sesamum indicum) oil cake, a waste biomass from the oil extraction industry for remediation of Basic Blue 26 (BB 26) from aqueous media was examined. Effects of pH, adsorbent dosage, BB 26 concentration, shaking time temperature, and ionic strength on BB 26 adsorption have been studied in detail. The residual cake was characterized based on FTIR, zeta potential, SEM-EDAX, and BET techniques. Isotherm and kinetic data have been well-exemplified by Freundlich and pseudo second-order equations, respectively. Maximum uptake capacity was reported to increase significantly from 54.52 mg/g for unmodified cake powder to 91.24 mg/g for ZnCl2-modified cake powder, establishing the importance of ZnCl2 activation. The mechanism of BB 26 adsorption on cake powder was reported to involve different steps as predicted from the fitting of kinetic data to Weber-Morris equation. Thermodynamic studies showed that the process of BB 26 adsorption onto cake powder was accompanied by an increase in entropy and reported to be endothermic and spontaneous. Significant recovery and uptake capacity values were reported from the first to the last cycle of reusability. Due to ease of recovery and regenerability, ZnCl2-modified cake powder has been established as a promising remedy for the successful elimination of BB 26 from aqueous media.

Sensory and physical-chemical evaluation of cookies made with extract powders of babassu coconut pie

The demand for products made from food waste has been growing in recent years. In this sense, this study aimed to develop and evaluate cookies made with powdered extract from the residual babassu almond cake. Three biscuit formulations were prepared with different concentrations of powdered extract (F1-5%, F2-15%, F3-25%). It was found that the protein content of cookies varied between 2.75% - 2.99% and that of lipids between 26.12% -26.89%, in addition, they are within the microbiological standards established by the legislation. Among the sensorially tested formulations, F3 was characterized as the sweetest by the trained panel. On the other hand, the affective test pointed out the formulation F2 as being the most accepted by the tasters, with an acceptance rate of 80.86%. Therefore, the preparation of biscuits from a powdered extract from the residual babassu coconut almonds pie is an alternative to add value to this co-product with commercial potential.

Sequencing of unit operations for integral and sustainable peanut processing

The most used biomass are wood, sugar cane, paper, rice husk, and peanut. Based on the concept of sustainability and waste reduction, the full utilization of biomass is an alternative capable of providing people with a better nutritional intake, improving the economy related to biomass and the ecological relationship between man and the environment. So, the aim of this work was the sustainable use the biomass, the peanut, through multiple unit operations. Thus, the material went through several processes as the grinding process, where it was possible to obtain immediate analysis data (moisture content, ash content, volatile content and fixed carbon) and particle size. Then, drying was performed employing solar energy and the drying efficiency was obtained. Infrared and greenhouse tests were performed in the laboratory to determine the drying and humidity curves. After drying, it was also carried out the oil extraction using ethanol as solvent heated by solar energy. After that, the residual cake was used as the adsorbent material in the dye removal by adsorption in a fixed bed. So, the dye-impregnated adsorbent has undergone a process of pyrolysis in order to form fine coal, bio-oil, and gases. With products and by-products of each process, it was possible to generate the infrared spectrum of each. Therefore, it is shown how the integral use of peanut as biomass is possible, using chemical engineering sustainable processes, and how it may contribute to the reduction of the pollution and to the reduction of waste production.

Impact of ionizing radiation on cake from Brazilian macadamia nut (Macadamia integrifolia) after oil extraction

Macadamia oil extraction is commonly performed by cold pressing. This process presents low extraction yields, generating partially defatted meal as a byproduct. To take advantage of their important nutritious components, we propose to use the cake after lipid extraction as a food ingredient following the elimination of potentially hazardous microbiological contamination. Food irradiation is a mature, effective, broad spectrum and residue-free technology that can play an important role in food safety and food security. This study presents the impact of gamma irradiation on the residual cake from Brazilian macadamia pressing. An absorbed dose of 5 kGy reduced yeasts, molds and aerobic mesophilic bacteria below admissible maxima. The concentration of important elements like Ca, Se, Mg or Mn appeared higher in the cake than in the nut itself as measured by instrumental neutron activation analysis (INAA).