Starch Processing Research Articles

Scaling-up and techno-economics of ethanol production from cassava starch via separate hydrolysis and fermentation

Nowadays bioethanol is being used extensively in fuel production because of its technical feasibility, economically competitive, and environmentally friendly. It is expected that biofuel will contribute to 30% of the global energy demand by 2050. Therefore, it is very important to investigate any cost-effective bioprocessing that can improve the overall production yield. The study aims to produce bioethanol from cassava starch by Kluyveromyces marxianus at a laboratory scale and a 5L fermentation rig. A separate hydrolysis and fermentation (SHF) process of cassava starch was introduced due to high sugar content in starch, using a thermoanaerobe able to reduce the cooling time after hydrolysis. A combination of 0.35% v/w amylase and 0.20% v/w amyloglucosidase used in the hydrolysis of cassava starch produced 19.18 g/L of sugar. A 15 g/L of K. marxianus showed to be the best yeast concentration which could produce the highest bioethanol, 42.85 g/L. When the laboratory scale was scaled up to 5 L fermentation, the result was comparable at 42.33 g/L. The same SHF parameters in laboratory scale had been proven to be effective in a larger scale fermentation based on similar results obtained. Simulation using SuperPro software indicated that 50.13% of starch can be converted into ethanol.

Safety evaluation of a food enzyme with glucan 1,4-α-glucosidase and α-amylase activities from the genetically modified Aspergillus niger strain NZYM-BX.

The food enzyme with glucan 1,4‐α‐glucosidase (EC 3.2.1.3) and α‐amylase (EC 3.2.1.1) activities is produced with the genetically modified strain of Aspergillus niger NZYM‐BX by Novozymes A/S. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. The food enzyme is intended to be used in starch processing for the production of glucose syrups and distilled alcohol. Since residual amounts of total organic solids are removed by distillation and by the purification steps applied during the production of glucose syrups, dietary exposure was not calculated. Genotoxicity tests did not raise a safety concern. The repeated dose 90‐day oral toxicity study in rats made with a substitute enzyme was not considered suitable. However, since no exposure was expected from the intended uses, this study was not considered necessary. Similarity of the amino acid sequence of the food enzyme to those of known allergens was searched and two matches were found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood is considered to be low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Corn starch processing wastewater treated by a full-scale expanded granular sludge bed reactor and comprehensive analysis of microbial community at low and high organic loading rate

In this study, a full-scale expanded granular sludge bed (EGSB) reactor treating corn starch processing wastewater (CSPW) was monitored. The efficacy and microbial diversity of sludge granules were thoroughly investigated. The results demonstrated that 90.7% of the average chemical oxygen demand (COD) removal efficiency was observed to be in the range of an organic load rate (OLR) of 1.3 to 18.7 g COD/L·d. The Illumina MiSeq sequencing revealed that Proteobacteria, Bacteroidetes, Acidobacteria and Euryarchaeota were the dominant phyla. Acetoclastic and hydrogenotrophic methanogens were shown to play functions in methane production and the maintenance of the granular sludge under high and low OLR operation conditions, respectively. Syntrophorhabdus, Syntrophus and Candidatus Cloacimonas had the correlation with the transformation of the proteinaceous subtances into VFAs. The results will guide development of microbial management methods to improve the process stability of EGSB treating CSPW.

The Deconstruction of Character Change on Creative Image in Painting Art Work

Art is a reflection and sensitivity of spiritual experience related to environmental phenomena. It is the values of life which constantly offer anxiety over the changes. Exploration through observation and scrutiny on this phenomenon stimulates imaginative and expressive spirit. Therefore, it is necessary to do a deeper approach on life values through understanding and appreciation. This can be transformed into visual works which present moral messages of lifereality. Life today is full of a challenge that changes the mental attitude. There is a tendency of being materialistic which affects the uncontrolled behavior of life. So, crime is rampant with different motives and forms in society. Abuse of power, authority, law and religion are only a mask to meet the goal of temporary interests. Money and property have been embezzled the soul and the sense of human’s life. These phenomena have stimulated spiritual and emotional feeling to lift up an idea about the meaning of changes. The admirers of changes took pride of this material world. Life is a process of love, sorrow, sadness and starch as the nature of life. All material elements are not eternal. They are being bound by the limitation of the natural law of life cycle; the birth, growth and destruction (pralina). Appreciating these values can create ideas in understanding of the character of the material elements such as aging, decrepitude, distraction and destruction. In the creation process, this idea is very important.

Effect of the addition of cassava fibers on the properties of cassava starch composite films

In this study, cassava bagasse, an agro-industrial waste from the processing of cassava starch, was used in the production of composite cassava starch-based films plasticized with glycerol, using the solvent casting technique. Films were produced with different contents of cassava bagasse and compared concerning their morphology, mechanical properties, contact angle, opacity, water vapor permeability, and water sorption capacity. The cassava bagasse content had a significant effect (p ≤ 0.05) on all the properties investigated when compared to the control film. There was an increase of 543.5% in tensile strength and a reduction of 64.5% in water vapor permeability. These results come from the fibers contained in the cassava bagasse, which reduce the molecular mobility of the starch chains, making the films more resistant and less permeable. The addition of cassava bagasse resulted in less hydrophilic films with contact angles greater than 70° and UV light barrier properties. Furthermore, the obtained films exhibited compact and cohesive structures. Therefore, these results highlighted the appreciation of the use of cassava bagasse waste in the manufacture of sustainable starch-based films with improved properties.

Safety evaluation of the food enzyme α-amylase from the genetically modified Bacillus licheniformis strain DP-Dzb52.

The food enzyme α‐amylase (1,4‐α‐d‐glucan glucanohydrolase; EC 3.2.1.1) is produced with the genetically modified Bacillus licheniformis strain DP‐Dzb52 by Danisco US Inc. The production strain contains multiple copies of an antimicrobial resistance gene. However, based on the absence of viable cells and DNA from the production organism in the food enzyme, this is not considered to be a risk. The α‐amylase is intended to be used in starch processing for the production of glucose syrups, brewing processes and distilled alcohol production. Since residual amounts of the food enzyme are removed by the purification steps applied during the production of glucose syrups and distillation, no dietary exposure was calculated. Based on the maximum use levels recommended for the brewing processes and individual data from the EFSA Comprehensive European Food Consumption Database, dietary exposure to the enzyme–total organic solids (TOS) was estimated to be up to 0.145 TOS/kg body weight per day in European populations. The toxicity studies were carried out with another α‐amylase from B. licheniformis strain DP‐Dzb54, considered by the Panel as a suitable substitute. Toxicological tests indicated that there was no concern with respect to genotoxicity or systemic toxicity. A no observed adverse effect level was identified in rats which, compared with the dietary exposure, results in a margin of exposure of at least 750. A search for similarity of the amino acid sequence to known allergens was made and one match was found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions can be excluded in distilled alcohol production and is considered low when the enzyme is used in starch processing and brewing. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

The effect of size and solid content in hydrolysis of sweet potato starch using endogenous beta-amylase enzyme

Sweet potato contains significant amount of endogenous amylase enzymes. The endogenous enzymes can be used in maltose production from sweet potatoes to carry out pre-hydrolysis of the starch to some extent, follow by complete hydrolysis using external enzymes. The main objective of the current study is to investigate the effect of particle size and solid to liquid ratio in hydrolysis process of sweet potato starch using endogenous enzymes. The extent of hydrolysis process is measured by dextrose equivalent of the crude maltose solution. Hydrolysis process consists of liquefaction and saccharification process. The liquefaction process is carried out at 71.5°C and pH 6 for 25 minutes while saccharification process is carried out at 53°C and pH 5,5 for 72 hours. Dextrose equivalent is measured using Lane-Eynon method. The results show that the access of enzyme to the potato tubers is the key to hydrolysis process. The smaller size of tubers gives bigger surface area while lower solid-to-liquid ratio increases enzyme mobility but decreases sugar concentration. Base on the results, a simulation shows that the pre-hydrolysis of sweet potatoes using endogenous enzymes can save almost a half of enzymes required for traditional hydrolysis process.

Morphological, Structural and Functional Properties of Starches from Different Legume Resources

Background: Legume is well known for its high nutrition and health care values. Considering that starch is the main carbohydrate in legume, its properties directly affect the development and utilization of legume resources. Methods: Starches were extracted from the seeds and root tubers of five legumes. The morphological, structural and functional properties of the starches were investigated and compared using scanning electron microscopy, X-ray diffraction and attenuated total reflectance-Fourier transform infrared spectroscopy.Result: The granules of kudzu, broad bean and pigeon pea starches were kidney-shaped with a large size, while groundnut and white pea starches were small granules with a mixture of irregularly polyhedral and spherical shape. The five legume starches had different apparent amylose contents and exhibited remarkably different crystalline properties. Among the samples, the relative crystallinity of kudzu starch was the highest, while pigeon pea starch had the highest short-range ordered degree. The swelling power and water solubility of the five legume starches were also varied. Furthermore, white pea starch is more susceptible to acid and enzymatic hydrolysis than the four other starches. The results are important for the processing and utilization of legume starches and can provide reference for the development of legume-based functional food.

Aspects and Recent Trends in Microbial α-Amylase: a Review.

α-Amylases are the oldest and versatile starch hydrolysing enzymes which can replace chemical hydrolysis of starch in industries. It cleaves the α-(1,4)-D-glucosidic linkage of starch and other related polysaccharides to yield simple sugars like glucose, maltose and limit dextrin. α-Amylase covers about 30% shares of the total enzyme market. On account of their superior features, α-amylase is the most widely used among all the existing amylases for hydrolysis of polysaccharides. Endo-acting α-amylase of glycoside hydrolase family 13 is an extensively used biocatalyst and has various biotechnological applications like in starch processing, detergent, textile, paper and pharmaceutical industries. Apart from these, it has some novel applications including polymeric material for drug delivery, bioremediating agent, biodemulsifier and biofilm inhibitor. The present review will accomplish the research gap by providing the unexplored aspects of microbial α-amylase. It will allow the readers to know about the works that have already been done and the latest trends in this field. The manuscript has covered the latest immobilization techniques and the site-directed mutagenesis approaches which are readily being performed to confer the desirable property in wild-type α-amylases. Furthermore, it will state the inadequacies and the numerous obstacles coming in the way of its production during upstream and downstream steps and will also suggest some measures to obtain stable and industrial-grade α-amylase.

Esterification reaction in SC-CO2 catalyzed by lipase produced with corn steep liquor and Minas Frescal cheese whey

Corn steep liquor (CSL) from the processing of starch and cheese whey (CW) from the production of Minas Frescal cheese were used to produce the lipase of Geotrichum candidum. This enzyme show activity of 19.87 U/mL and productivity of 0.83 U/mL.h in optimally conditions (5% CSL, 40% CW and a pH 6.0). This lipase was a catalyst in the esterification reaction of oleic acid (OA) with methanol (MeOH) in supercritical medium (SC-CO2), in solvent-free medium and with hexane. The use of SC-CO2 as a solvent increased the reaction yield by 3 times, reaching 37.73% with a molar ratio of OA: MeOH at 1:3, 2.5 U/g, at 30 °C and 30 MPa. The objective of this study was to evaluate the activity of the lipase produced using CSL and CW and to measure the catalytic capacity of the lipase in the esterification reaction in a different medium, that demonstrate the superiority of the esterification reactions using SC-CO2.

Characterizing a thermostable amylopullulanase from Caldisericum exile with wide pH adaptation and broad substrate specificity

To improve starch processing as well as enrich the enzyme resources, an amylopullulanase (CEApu) from Caldisericum exile was heterologously expressed and characterized. CEApu was identified as a glycoside hydrolase from glycoside hydrolase (GH) family 57. The optimal temperature and optimal pH were determined to be 75 °C, and pH 5.5 and 8.5, respectively. CEApu had a wide pH adaptation and activity, retaining >50% activity from pH 4.5–10.0. CEApu also had broad substrate specificity, as it could hydrolyze α-1,4/α-1,6 glycosidic linkages in starch, dextrin, oligosaccharide (degree of polymerization (DP) > 3), pullulan, and even γ-cyclodextrin (γ-CD), but not α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD). The maximum reducing sugar content was 103 mg/g released from gelatinized cassava starch. CEApu was a biocatalyst that may be used for the preparation of starch sugars, resistant starches or linear dextrins. These results confirmed that CEApu was a thermostable amylopullulanase with a strong application potential.

Safety evaluation of the food enzyme α-amylase from the genetically modified Bacillus licheniformis strain NZYM-KE.

The food enzyme α‐amylase (4‐α‐d‐glucan glucanohydrolase; EC 3.2.1.1) is produced with the genetically modified Bacillus licheniformis strain NZYM‐KE by Novozymes A/S. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. The α‐amylase is intended to be used in starch processing for the production of glucose syrups and other starch hydrolysates, and distilled alcohol production. Since residual amounts of the food enzyme are removed by the purification steps applied during the production of glucose syrups and distillation, no dietary exposure was calculated. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level at the highest dose of 1,100 mg TOS/kg body weight (bw) per day. A search for similarity of the amino acid sequence of the food enzyme to known allergens was made and one match was found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood is considered to be low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Physicochemical properties of phosphate butyrate arenga starches from dual modifications

Native arenga starch has infirmity physicochemical properties so that its use is limited to functional food. Dual modification is a starch processing to improve physicochemical properties of starch. The objective is to determine the optimum concentration of sodium trimetaphosphate (STMP) based on the physicochemical properties of the phosphate butyrate arenga starch (PBAS) from dual modification of butyrylation and phosphorylation. The method of making PBAS is using butyric anhydride 5% (w/v) and STMP concentration variation consisting of 2%, 4%, 6%, 8%, 10% and 12% (w/w) of the starch weight repeated three times and native arenga starch as a comparison. Physicochemical properties analyzed were percent butyryl, degree of substitution (DS), phosphate content, binding of butyrate phosphate with fourier transform infrared (FTIR), water, starch, amylopectin, amylose and ash contents. The results showed that the optimal STMP concentration range of 4-6% based on percent butyryl, DS and phosphate content that produce PBAS suitable for functional food ingredients. Binding of the functional group of PBAS formed a new peak in the FTIR spectra at wave number 1365.60 cm-1 which indicates the presence of phosphate (P=O) groups of STMP on starch molecules. The water content of PBAS decreased with increasing STMP concentrations. The amylose, amylopectin and ash contents of PBAS were changed after the process of butyrylation and phosphorylation. PBAS is potential as a functional food ingredient due to its butyrate and phosphate contents.

Removal of Ciprofloxacin from Aqueous Solution Using Prepared Biodegradable Potato Cross-linked Starch Ester

Potato starch was modified chemically to prepare an adsorbent that is efficient for removing the ciprofloxacin antibiotic from its aqueous solution. The chemical modification process of potato starch involved cross-linking and esterification steps. The high-resolution X-ray diffraction characterization shows that the modification processes do not damage the starch crystal but reduces the crystallinity and the crystal size. In addition to that, holes on the surface of the round and oval shapes of the modified starch were noticed via scanning electron microscope. The parameters that could affect ciprofloxacin removal efficiency on cross-linked potato starch ester were investigated in detail, which included initial concentration of ciprofloxacin in aqueous solution, pH and temperature. The removal efficiency of ciprofloxacin increased with the increase in the initial pH value of the aqueous solution and reached the highest value of removal at a pH of 7, after which it was noticed that the removal efficiency decreased. The removal efficiency was decreased with increasing initial concentration of ciprofloxacin (expressed as chemical oxygen demand) from 25 to 125 ppm. Finally, the results showed that the increase in the temperature treatment from 25 to 45 °C negatively affected the removal efficiency.

Isolation Bacteria Producing α-Amylase from Black Soldier Fly larvae (Hermetia illucens) L.

Black Soldier Fly (Hermetia illucens) larvae used as a large-scale organic waste bioreduction agent with ability reduce organic waste up to 200 tons per day. The potency of BSF larvae to process organic waste was related to the function of phisiology, microbial and biochemical processes. The gut extracts had high amylase, lipase and protease activities. α-amylase is one of the important enzyme in development of biotechnology and belongs to the main enzyme class on the world enzyme market. α-amylase used to replace chemical hydrolysis process in starch processing industry. α-amylase from microorganism was more prospective than plant and animal amylase, because it was more easily manipulated to produces targetted enzymes, characteristics and more economical. The purpose of this study was to isolate bacteria producing α-amylase from BSF larvae. The research method was extracted of 200 BSF larvae in phosphate buffer pH 7.4. Homogenate was isolated in Lysogeny Broth (LB) by serial dilution and fourway strick. Each culture was screened based on the activity of α-amylase by Fuwa method. The results of isolation obtained 8 single colonies bacteria. The α-amylase activity assay for Fuwa method obtained the highest α-amylase activity unit was 10.86 units/ml, produced by the 8th colony.

Experimental and Numerical Simulation of Starch Degradation under Sonication Process

Starch processing technology has been developed to enlarge the application of starch in most of food, medical and fermentation industries. Sonication is prominent technology that can alter physical and molecular structure of many material by generating vigorous cavitation which gives radicals and a microjet. Many researches of starch sonication process has been carried out experimentally, but there is only very small number of published works that correlated the experiment data and suitable reaction model. In this study, a reaction model that correlates with experimental results was develop to predict molecular weight, granule size, and conversion of cassava starch. The sonication has simulated with the nth-order reaction model. The result show the reaction was controlled by physical process control. The simulation depict that sonication process can produce a lower molecular weight of starch in very short time. At later time process, the sonication degradation ability was reduced because some part of granule have ability to withstand the cavitation.

Effect of high-temperatures and aqueous ethanol treatment on the formation process and properties of V-type Granular Starch (VGS)

Starch-water-ethanol mixtures were heated between 80 and 160 °C. The formation process of V-type granular starch (VGS) was investigated. DSC analysis showed that starch gelatinization was completely inhibited in 70 % ethanol. Microscopic analysis showed that starch remained granular morphology after modification, but when temperature exceeded 110 °C, Maltese cross and A-type crystalline structure disappeared, a V-type crystalline structure developed with increasing temperature, and short-range order of modified starch was reduced. It was indicated that VGS was formed at temperatures exceeding 110 °C in 70 % ethanol. When temperature was increased from 80 to 140 °C, starch cold-water viscosity increased from 17.00 cP to 1932.00 cP. Further temperature increase resulted in decreased cold-water viscosity because of starch degradation. It was found that cold-water viscosity was positively correlated with the crystallinity of V-type starch structure. Ethanol washing before drying made VGS dispersed better, and strengthened V-type crystalline structure, so that ethanol washed VGS had better paste properties.

Activity-Based Protein Profiling of Retaining α-Amylases in Complex Biological Samples.

Amylases are key enzymes in the processing of starch in many kingdoms of life. They are important catalysts in industrial biotechnology where they are applied in, among others, food processing and the production of detergents. In man amylases are the first enzymes in the digestion of starch to glucose and arguably also the preferred target in therapeutic strategies aimed at the treatment of type 2 diabetes patients through down-tuning glucose assimilation. Efficient and sensitive assays that report selectively on retaining amylase activities irrespective of the nature and complexity of the biomaterial studied are of great value both in finding new and effective human amylase inhibitors and in the discovery of new microbial amylases with potentially advantageous features for biotechnological application. Activity-based protein profiling (ABPP) of retaining glycosidases is inherently suited for the development of such an assay format. We here report on the design and synthesis of 1,6-epi-cyclophellitol-based pseudodisaccharides equipped with a suite of reporter entities and their use in ABPP of retaining amylases from human saliva, murine tissue as well as secretomes from fungi grown on starch. The activity and efficiency of the inhibitors and probes are substantiated by extensive biochemical analysis, and the selectivity for amylases over related retaining endoglycosidases is validated by structural studies.

Kinetics of growth and co-production of amylase and protease in novel marine actinomycete, Streptomyces lopnurensis KaM5.

Amylases and proteases are among the industrially most important enzymes for food processing, animal feed, brewing, starch processing, detergents, healthcare, leather processing, and biofuel production. In this study, we investigated the growth kinetics and statistically optimized the co-production of amylase and protease in a phylogenetically novel haloalkaliphilic actinomycete, Streptomyces lopnurensis KaM5 of seawater. The Plackett-Berman design using Minitab 14.0 software was employed to assess the impact of the nutritional factors, temperature, pH, and incubation time. Further, starch, yeast extract, NaCl concentrations, and incubation time were optimized by Box-Behnken design at their three levels. The Pareto charts, contour, surface plots, and individual factorial analysis expressed the variability and levels for the optimal enzyme production. ANOVA analysis admitted the statistical fitness and significance level among the variables. A two-fold increase in enzyme production was achieved by cost-effective co-production media. The study was further extended to growth kinetics associated with enzyme production. Specific growth rate (μ), maximal cell mass (Xmax), volumetric product formation (Pmax), rate of product formation (Qp), and generation time (g) were computed and analyzed. These parameters significantly improved when compared with the pre-optimized conditions, and the production economics of the enzyme was industrially viable. The initial studies on the characteristics of the enzymes suggested its ability to function under the combination of alkaline pH and high salt concentrations. The co-production of enzymes from extremophiles can be a potentially viable option for large-scale production and applications.

Optimization of Cassava Pulp Pretreatment by Liquid Hot Water for Biomethane Production

Cassava pulp (CP) is considered as a major and low-cost agro-industrial solid byproduct of cassava starch processing, where 48% of starch granules was still entrapped in its complex lignocellulosic matrix of cell wall structure with 21% cellulose and 8% hemicellulose. In this study, the liquid hot water (LHW) pretreatment was aimed to disrupt the cell wall structure of CP and solubilized hemicellulose and starch into saccharides to enhance biomethane production. Reaction conditions of LHW pretreatment, temperature (160–200 °C), and time (0–30 min) were optimized by response surface methodology. LHW pretreatment at 187 °C for 7 min boosted the highest level of starch and hemicellulose solubilization into the liquid phase, resulting in the maximized glucose yield of 444 mg/gCP. Starch and hemicellulose were mostly removed from CP at 99 and 79%, respectively, while 68% cellulose and 10% lignin particularly remained in solid residue. The disrupted cell wall structure and crystalline cellulose after LHW pretreatment were also observed. Microbial inhibitors such as furfural and hydroxymethylfurfural were found in low concentration at 31 and 32 μg/mL, respectively. In addition, there were no lag phase and inhibitory effect during anaerobic digestion of the pretreated CP. Biochemical methane potential of the LHW-pretreated CP showed the methane production rate and methane yield at 1.6 times and 35% higher than that of non-pretreated CP, respectively, by shortening anaerobic digestion time from 22 d to 10 d. It was shown that LHW was an efficient chemical-free method for enhancing biodegradability of CP in conversion to biomethane.