Starch Processing Research Articles

The effects of gamma irradiation treatment on starch structure and properties: a review

SummaryGamma irradiation is a new starch processing and modification method. In this paper, the effects of gamma irradiation on starch structure and properties were summarised and discussed. In terms of starch structure, gamma irradiation destroys glycosidic bonds and significantly reduces the average molecular weight of starch, which may be the fundamental reason for the change in starch properties after irradiation. In addition, irradiation has no effects on crystal type but decreases the crystallinity of starch. Meanwhile, gamma irradiation can increase the specific surface area of starch granules but have no significant effects on the granular morphologies, indicating the damage to starch granules caused by irradiation proceeds from inside the granules. In terms of starch properties, gamma irradiation treatment decreases the viscosity, setback, breakdown, To, Tp, Tc, the enthalpy of crystalline melting, storage modulus, loss modulus, consistency coefficient and swelling ability of starches. In addition, gamma irradiation increases the b value, water absorption capacity, oil absorption capacity and solubility of starches. However, the results of the effects of irradiation on starch digestive, retrogradation and texture properties are not consistent in different studies. It may provide a reference for the application of irradiation in starch processing and modification.

Enhanced extracellular production of raw starch-degrading α-amylase in Bacillus subtilis through expression regulatory element modification and fermentation optimization

BackgroundRaw starch-degrading α-amylase (RSDA) can hydrolyze raw starch at moderate temperatures, thus contributing to savings in starch processing costs. However, the low production level of RSDA limits its industrial application. Therefore, improving the extracellular expression of RSDA in Bacillus subtilis, a commonly used industrial expression host, has great value.ResultsIn this study, the extracellular production level of Pontibacillus sp. ZY raw starch-degrading α-amylase (AmyZ1) in B. subtilis was enhanced by expression regulatory element modification and fermentation optimization. As an important regulatory element of gene expression, the promoter, signal peptide, and ribosome binding site (RBS) sequences upstream of the amyZ1 gene were sequentially optimized. Initially, based on five single promoters, the dual-promoter Pveg-PylB was constructed by tandem promoter engineering. Afterward, the optimal signal peptide SPNucB was obtained by screening 173 B. subtilis signal peptides. Then, the RBS sequence was optimized using the RBS Calculator to obtain the optimal RBS1. The resulting recombinant strain WBZ-VY-B-R1 showed an extracellular AmyZ1 activity of 4824.2 and 41251.3 U/mL during shake-flask cultivation and 3-L fermenter fermentation, which were 2.6- and 2.5-fold greater than those of the original strain WBZ-Y, respectively. Finally, the extracellular AmyZ1 activity of WBZ-VY-B-R1 was increased to 5733.5 U/mL in shake flask by optimizing the type and concentration of carbon source, nitrogen source, and metal ions in the fermentation medium. On this basis, its extracellular AmyZ1 activity was increased to 49082.1 U/mL in 3-L fermenter by optimizing the basic medium components as well as the ratio of carbon and nitrogen sources in the feed solution. This is the highest production level reported to date for recombinant RSDA production.ConclusionsThis study represents a report on the extracellular production of AmyZ1 using B. subtilis as a host strain, and achieved the current highest expression level. The results of this study will lay a foundation for the industrial application of RSDA. In addition, the strategies employed here also provide a promising way for improving other protein production in B. subtilis.

Novel Design of an α-Amylase with an N-Terminal CBM20 in Aspergillus niger Improves Binding and Processing of a Broad Range of Starches.

In the starch processing industry including the food and pharmaceutical industries, α-amylase is an important enzyme that hydrolyses the α-1,4 glycosidic bonds in starch, producing shorter maltooligosaccharides. In plants, starch molecules are organised in granules that are very compact and rigid. The level of starch granule rigidity affects resistance towards enzymatic hydrolysis, resulting in inefficient starch degradation by industrially available α-amylases. In an approach to enhance starch hydrolysis, the domain architecture of a Glycoside Hydrolase (GH) family 13 α-amylase from Aspergillus niger was engineered. In all fungal GH13 α-amylases that carry a carbohydrate binding domain (CBM), these modules are of the CBM20 family and are located at the C-terminus of the α-amylase domain. To explore the role of the domain order, a new GH13 gene encoding an N-terminal CBM20 domain was designed and found to be fully functional. The starch binding capacity and enzymatic activity of N-terminal CBM20 α-amylase was found to be superior to that of native GH13 without CBM20. Based on the kinetic parameters, the engineered N-terminal CBM20 variant displayed surpassing activity rates compared to the C-terminal CBM20 version for the degradation on a wide range of starches, including the more resistant raw potato starch for which it exhibits a two-fold higher Vmax underscoring the potential of domain engineering for these carbohydrate active enzymes.

Recovery of Membrane Permeability after Filtration of Sago Starch Suspension by Tangential Flow Filtration

Sago starch is extracted from the stems of the sago palm, Metroxylon sagu, in south-east Asia. Sago starch processing generates approximately 20 tons of starch containing effluents that can be recovered and marketed to sustain a small-scale industry. Tangential flow filtration (TFF) using microfiltration membranes (MFM) has been demonstrated as an effective method for separating suspended solids in biological effluents. When TFF was applied to concentrate sago starch suspensions (SSS), membrane permeability and lifecycle were impacted due to frequent fouling. This study evaluated cleaning methods to recover the permeability and extend the lifecycle of MFM following TFF application. Polysulfone membrane filter cassettes of pore size 0.45 µm and surface area 0.1 m2 were each used to separate starch in 100 L of SSS. Following separation, six chemical and physical cleaning methods were tested at laboratory-scale and the degree of cleaning was measured by normalized permeate flux (NPF) and normalized water permeability (NWP). The results showed that soaking the membranes in a 0.2 M NaOH solution (up to 91%, (p<0.05) within the shortest time of 72 h, (p<0.05) was the best cleaning method. The procedure has been utilized to maintain and extend the lifecycle of the MFM for streams containing starch suspensions.

Maximization of Energy Recovery from Starch Processing Wastewater by Thermophilic Dark Fermentation Coupled with Microbial fuel Cell Technology

Utilization of organic wastewater for hydrogen production has dual advantages of clean energy generation and bioremediation, which is sustainable for a longer period. To maximize the energy recovery from starch rich wastewater, a two stage system comprising of thermophilic dark fermentation coupled with microbial fuel cell was employed. A single parameter optimization strategy was implemented for the operation of the batch system. The maximum cumulative hydrogen production obtained was 2.56 L L−1 with a 48% reduction in COD under the optimal conditions of 35 g L−1 initial substrate concentration (COD), temperature 60 °C, and pH 6.5. The H2 yield and H2 production rate were 6.8 mol H2/kg CODreduced and 731.3 mL L−1 h−1, respectively. The effect of the organic loading rate (OLR) on H2 production rate was studied in a continuous stirred tank reactor (CSTR). A maximum hydrogen production rate of 913 mL L−1 h−1 was observed at an OLR of 5.6 g L−1 h−1. Effluent recycle played an important role in the improvement of H2 production. A maximum H2 production rate of 1224 mL L−1 h−1 was observed at a recycle ratio of 0.6. Power density of 4.2 W m−3 was observed with MFC using the dark fermentative spent media neutralized with carbonate buffer at an optimal pH of 7. A total COD reduction of 86% was observed.

Updated safety evaluation of the food enzyme α-amylase from the non-genetically modified Cellulosimicrobium funkei strain AE-AMT.

The food enzyme α-amylase (4-α-d-glucan glucanohydrolase; EC 3.2.1.1) is produced with the non-genetically modified Cellulosimicrobium funkei strain AE-AMT by Amano Enzyme Inc. In a previous opinion, a safety evaluation of this food enzyme was completed, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in starch processing for maltodextrin production. The applicant has now provided new data to extend the use of this food enzyme to six additional food manufacturing processes: baking processes, cereal-based processes, plant processing for the production of dairy analogues, processing of tea, herbal and fruit infusions, brewing processes and the production of non-wine vinegar. For its use in a total of seven food manufacturing processes, the dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.012 mg TOS/kg body weight (bw) per day in European populations. Using the toxicological data provided in the previous opinion, with a NOAEL of 230 mg TOS/kg bw per day (the highest dose tested), the Panel derived a margin of exposure of at least 19,167. Based on the revised exposure calculation and the outcome of the previous evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use.

FUNCTIONAL PROPERTIES AND POTENTIAL UTILIZATION OF STARCH ISOLATED FROM CHAYOTE FRUIT

Chayote, Sechium edule (Jacq.) Sw., is anoverlooked food‎ plant despite its various ‎potentialities. This study investigated the characteristics of starch isolated from ‎chayote fruit cultivated in Algiers which is known for its Mediterranean ‎climate. The granules morphology, functional properties and amylose content of Algerian chayote fruit starch were examined. Spherical, oval and polygonal shapes and smooth surface were observed using three imaging techniques: a normal and polarized light microscopy with Lucia ‎software and Scanning Electron Microscopy (SEM).‎ Starch granules size was in the rang 3.56-‎‎37.24 μm, and for the chayote tubers, it‎ was 7-50 μm. The amylose content (‎20.36%‎) ‎‎is different from that of the chayote tubers (12.81%), but ‎close‎‎‎ to those of ‎conventional sources. The Algerian chayote fruit starch showed higher swelling strength and lower ‎melting ‎index.‎ The Rapid Visco Analyzer pasting profile revealed a lower peak ‎viscosity (2158.3 cP) than that from chayote tubers (14746 cP).‎ However, Differential Scanning Calorimetry analysis showed higher gelatinisation temperatures (66.89 °‎C) and ‎transition enthalpy (‎15.79‎ J/g)‎. X-ray diffraction profile showed B-type.‎ The digestibility (D∞), hydrolysis index, HI, and average glycemic index, (GI), were estimated at 50.66 %, 52.16% and 70.16 ‎%‎ respectively.‎ The results showed that starch has an ‎acceptable nutritional value with significant in vitro digestion properties and it is suitable for human health and nutrition.‎ The starch of Algerian chayote fruit showed interesting ‎functional characteristics which makes it suitable for relevant applications in both the field food and cosmetics industries. It can, also, be a raw material for starch processing.

Enhancing chemical phosphorus precipitation from tapioca starch anaerobic digestion effluent in a modified pilot-scale fluidized bed reactor

This study aimed to evaluate the possibility of P precipitation as struvite from real anaerobic digestion (AD) effluent of tapioca starch processing. The results showed that at a pH of 9, and without Mg:P molar adjustment, P recovery was at 85%. The percentage of P recovery was increased to 90% and P contained in precipitates was at 11.80–14.70 wt% P, which is higher than commercial single superphosphate fertilizer (SSP, 18–22 wt% P2O5). This was achieved by controlling mixing at 200–400 rpm and upflow velocity at 50–200 cm min−1 inside a fluidized bed reactor (FBR). Based on SEM-EDX, powder XRD, phase identification by profile matching, and FT-IR analysis, the results demonstrated that recovered precipitates formed struvite predominantly. In addition, results of the woodchip ash additions and the one-way ANOVA based-RSM analysis revealed that mixing, the solution pH, and the woodchip ash intensely affected P recovery with the optimum condition found at 400 rpm, pH9, 4 g L−1, respectively. Ash addition enhanced P recovery efficiency but decreased the product's purity. Total costs of P recovery varied considerably from 0.28 to 7.82 USD∙(kg P)−1 depending on chemical consumption and %P content in recovered products. Moreover, the total cost was reduced by 57% from 7.82 USD∙(kg P)−1 (profit margin: −4.30 to −2.82) by a single mixing operation to 3.35 USD∙(kg P)−1 (profit margin: +0.17 to +1.65) employing coupling effect of mixing and Vup. The results indicate that P recovery from tapioca starch AD effluent not only provides a good-quality alternative slow-release P fertilizer, but also helps to curtail environmental problems due to excessive P and nitrogen discharge. These findings also demonstrate the ways of recovering nutrients from an abundant renewable resource that are relevant to simultaneous waste utilization during pollution controls.

Preparation, structure characterization and functional properties of pea dregs resistant dextrin

BackgroundPeas (Pisum sativum L.), the second largest edible bean in the world, have comprehensive and balanced nutrition. In China, peas are mainly used in the processing of starch and related products, during which a large amount of processing by-products—pea dregs—is produced. Because of its large particle size, coarse texture, and difficulty in storage, it is mostly discarded or used as feed, resulting in unnecessary waste.Materials and methodsThe preparation and simulated moving bed chromatographic purification process conditions of pea-resistant dextrin were optimized using pea production waste-pea residue as raw material, and structural characterization and functional properties of pea residue-resistant dextrin were analyzed.ResultsThe results showed that the optimal preparation process conditions for pea-resistant dextrin were as follows: acid concentration 1.0%, acid addition 7.3%, treatment temperature 178.8°C, and treatment time 92.5 min. Subsequently, the pea-resistant dextrin content of 42.15 ± 0.16% was obtained. The optimal SSMB purification conditions were as follows: feed volume 455 g/h, feed volume 682 g/h, circulation volume 346 mL, outlet concentration 24.8 ± 0.2%, purity 99.35 ± 0.17%, and yield 91.08 ± 0.42%. The structural characterization revealed that pea-resistant dextrin had large and variable particle size and amorphous structure; the chemical bond or functional group differences between pea-resistant dextrin and pea starch were not significant; pea-resistant dextrin was a glucose-based dextran with a monosaccharide composition of 2.6% arabinose, 1.5% xylose, and 95.9% glucose, and its molecular weight was (601.1 ± 8.5) × 103 u. Functional characterization revealed that the RS content of pea-resistant dextrin was 92.35%, which had significantly slow digestive properties as well as hypoglycemic and hypolipidemic effects.ConclusionsUsing pea dregs to produce pea dregs resistant dextrin has low production cost and significant functional characteristics, which can be widely applied in the food industry.

Co-Fermentation of Chlorella vulgaris with Oleaginous Yeast in Starch Processing Effluent as a Carbon-Reducing Strategy for Wastewater Treatment and Biofuel Feedstock Production

Low biomass yield and nutrient removal efficiency are problems challenging the employment of microorganisms for wastewater remediation. Starch processing effluent (SPE) was used as a fermentation substrate to co-culture Chlorella vulgaris and Rhodotorula glutinis for biofuel feedstock production. Co-culture options were compared, and the optimal conditions were identified. The result shows that microalgae and yeast should be inoculated simultaneously at the beginning of SPE-based fermentation to achieve high biomass yield and the optimal inoculation ratio, light intensity, and temperature should be 2:1, 150 μmol/m2/s, and 25 °C, respectively. Under the optimal conditions, the lipid yield of microorganisms was 1.81 g/L and the carbon–conversion ratio reached 82.53% while lipid yield and the carbon–conversion ratio in a monoculture fell in the range of 0.79–0.81 g/L and 55.93–62.61%, respectively. Therefore, compared to the monoculture model, the co-fermentation of Chlorella vulgaris and Rhodotorula glutinis in starch processing effluent could convert nutrients to single-cell oil in a more efficient way. It should be noted that with the reduced concentration of residual organic carbon in effluent and the increased carbon–conversion ratio, co-fermentation of microalgae and yeast can be regarded as a promising and applicable strategy for starch processing effluent remediation and low-cost biofuel feedstock production.

Insights into the capability of the lignocellulolytic enzymes of Penicilliumparvum 4-14 to saccharify corn bran after alkaline hydrogen peroxide pretreatment

BackgroundCorn bran is a major agro-industrial byproduct from corn starch processing. It contains abundant arabinoxylan that can be converted into value-added chemicals via biotechnology. Corn bran arabinoxylan (CBAX) is one of the most recalcitrant xylans for enzymatic degradation due to its particular heterogeneous nature. The present study aimed to investigate the capability of the filamentous fungus Penicilliumparvum 4-14 to enzymatically saccharify CBAX and reveal the fungal carbohydrate-active enzyme (CAZyme) repertoire by genome sequencing and secretome analysis.ResultsCBAX1 and CBAX2 with different branching degrees, together with corn bran residue (CBR) were generated from corn bran after alkaline hydrogen peroxide (AHP) pretreatment and graded ethanol precipitation. The protein blends E_CBAX1, E_CBAX2, and E_CBR were produced by the fungus grown on CBAX1, CBAX2, or CBR, respectively. Under the optimal conditions, E_CBAX1 released more than 80% xylose and arabinose from CBAX1 and CBAX2. Almost complete saccharification of the arabinoxylans was achieved by combining E_CBAX1 and a commercial enzyme cocktail Cellic®CTec3. Approximately 89% glucose, 64% xylose, and 64% arabinose were liberated from CBR by E_CBR. The combination of E_CBR with Cellic®CTec3 enhanced the saccharification of CBR, with conversion ratios of 97% for glucose, 81% for xylose, and 76% for arabinose. A total of 376 CAZymes including plentiful lignocellulolytic enzymes were predicted in P.parvum based on the fungal genomic sequence (25.8 Mb). Proteomic analysis indicated that the expression of CAZymes in P.parvum varied between CBAX1 and CBR, and the fungus produced complete cellulases, numerous hemicellulases, as well as high levels of glycosidases under the culture conditions.ConclusionsThis investigation disclosed the CAZyme repertoire of P.parvum at the genomic and proteomic levels, and elaborated on the promising potential of fungal lignocellulolytic enzymes upon saccharification of corn bran biomass after AHP pretreatment.

Postharvest ripening of newly harvested corn: Structural, rheological, and digestive characteristics of starch

Newly harvested corn was stored at 25 °C and 55% relative humidity, the changes in the structure, rheological and digestive properties of corn starch during postharvest ripening were studied. The postharvest ripening process of corn resulted in a reduction in the content of amylose and an increase in the proportion of double-helical structures, short-range orderliness and relative crystallinity. These structural changes significantly improved the thermal stability of the starch and its ability to form gels. The lowest hydrolysis rate constant was demonstrated for corn starch at 30 days, indicating that proper post-ripening could help corn starch to form a stronger gel network structure and slow down the digestibility. The results of the study will contribute to a better understanding of the changes in the structure and properties of corn starch during the postharvest ripening, which provided a pathway for the rational processing and utilization of corn starch and even corn food at different postharvest ripening stages.

The Mechanism Underlying the Amylose-Zein Complexation Process and the Stability of the Molecular Conformation of Amylose-Zein Complexes in Water Based on Molecular Dynamics Simulation

The aim of this study was to employ molecular dynamics simulations to elucidate the mechanism involved in amylose-zein complexation and the stability of the molecular conformation of amylose-zein complexes in water at the atomic and molecular levels. The average root mean square deviation and radius of gyration were lower for amylose-zein complexes (1.11 nm and 1 nm, respectively) than for amylose (2.13 nm and 1.2 nm, respectively), suggesting a significantly higher conformational stability for amylose-zein complexes than for amylose in water. The results of radial distribution function, solvent-accessible surface area, and intramolecular and intermolecular hydrogen bonds revealed that the amylose-zein interaction inhibited water permeation into the amylose cavity, leading to enhanced conformational stabilities of the V-type helical structure of amylose and the amylose-zein complexes. Furthermore, the amylose in amylose-zein complexes displayed the thermodynamically stable 4C1 conformation. These findings can provide theoretical guidance in terms of the application of protein on starch processing aiming to improve the physicochemical and functional properties of starch (such as swelling capacity, pasting properties, and digestibility) for developing novel low-digestibility starch-protein products.

Importance of Inactivation Methodology in Enzymatic Processing of Raw Potato Starch: NaOCl as Efficient α-Amylase Inactivation Agent

Efficient inactivation of microbial α-amylases (EC 3.2.1.1) can be a challenge in starch systems as the presence of starch has been shown to enhance the stability of the enzymes. In this study, commonly used inactivation methods, including multistep washing and pH adjustment, were assessed for their efficiency in inactivating different α-amylases in presence of raw potato starch. Furthermore, an effective approach for irreversible α-amylase inactivation using sodium hypochlorite (NaOCl) is demonstrated. Regarding inactivation by extreme pH, the activity of five different α-amylases was either eliminated or significantly reduced at pH 1.5 and 12. However, treatment at extreme pH for 5 min, followed by incubation at pH 6.5, resulted in hydrolysis yields of 42-816% relative to controls that had not been subjected to extreme pH. "Inactivation" by multistep washing with water, ethanol, and acetone followed by gelatinization as preparation for analysis gave significant starch hydrolysis compared to samples inactivated with NaOCl before the wash. This indicates that the further starch degradation observed in samples subjected to washing only took place during the subsequent gelatinization. The current study demonstrates the importance of inactivation methodology in α-amylase-mediated raw starch depolymerization and provides a method for efficient α-amylase inactivation in starch systems.

Production, partial purification, and characterization of a glucoamylase from Epicoccum nigrum

Starch processing industries use amylases, accounting for approximately 30% of the world’s enzyme market. Previously, an amylase-producing strain of Epicoccum nigrum was isolated from maize grains. Although E. nigrum amylase production is already reported in the literature, no published data on production optimization or characterization of the produced enzyme exists. The objectives of this work were to improve the amylase production by the E. nigrum PG 16 strain and to purify and characterize the produced enzyme. The E. nigrum PG 16 amylase production best conditions in submerged culture were: inoculum of 4% (v v-1) of a five-days-old stationary culture homogenate, agitation at 100 rpm, 25°C, natural light, 72 hours of incubation, starch as the carbon source, and an initial medium pH of 7.0. A molecular exclusion chromatography profile has shown the production of only one amylase, which was partially purified with ammonium precipitation and dialysis. The enzyme optima pH and temperature are 6.0 and 50°C, respectively. The partially purified enzyme lost its activity when incubated for 30 min in temperatures above 40°C, presenting a T50 of 46.25°C. The KM and Vmax of the partially purified enzyme are 1.72 mg mL-1 of starch and 0.15 mg min-1 of degraded starch, respectively. The ion Ca2+ slightly activated the studied enzyme. The ions Cu2+, Zn2+, and Fe3+ and the detergents SDS and Tween 80 acted as inhibitors of the studied enzyme. The partially purified enzyme released glucose from p-nitrophenyl α-D-glucopyranoside (p-NPG). Glucose was the enzyme’s main product from starch hydrolysis, as evidenced by thin-layer chromatography. The E. nigrum PG 16 studied enzyme is a glucoamylase and represents an alternative for enzymatic starch hydrolysis.

Breadfruit (Artocarpus altilis): Processing, nutritional quality, and food applications.

Breadfruit is an underutilized but highly nutritive crop containing complex carbohydrates while being low in fat. It is also a good source of essential amino acids (leucine, isoleucine, and valine). With a better understanding of breadfruit's morphology, its potential as a global solution to food security has been gaining popularity. Breadfruit has been forecasted to have a larger amount of suitable cultivable land area compared to major crops such as rice and wheat, making its cultivation more desirable. Due to its highly perishable nature, good post-harvesting and post-processing practices are essential to extend the shelf life of breadfruit for global transportation and consumption. This paper aims to provide a comprehensive review on various processing methods of flour and starch, nutritional significance and new food applications of this novel food staple. In this review, the effects of the different processing and post-processing methods of breadfruit flour and starch have been described, and the nutritional composition and application of breadfruit flour as an ingredient replacer in various food applications have been discussed. It is vital to understand the processing and post-processing methods of breadfruit flour to enhance its shelf-life, physicochemical and functional properties. Furthermore, a compilation of novel food applications has been done to promote its use in the food industry. In conclusion, breadfruit flour and starch are highly versatile for use in numerous food products with added health benefits.

Ultrasound-assisted activation amylase in the presence of calcium ion and effect on liquefaction process of dual frequency ultrasonicated potato starch

Ultrasound-assisted activation amylase in the presence of calcium ion and effect on liquefaction process of dual frequency ultrasonicated potato starch

The effects of high‐pressure treatment on starch pasting, retrogradation, thermal, crystalline, rheological and digestive properties – A review

SummaryIn this paper, the effects of pressure on starch properties were summarised and discussed. Firstly, high pressure can decrease the relative crystallinity of starch. After a 600 MPa treatment for 10–30 min, the relative crystallinity is reduced by about 37.1% on average. Meanwhile, high pressure can transform the A‐type or C‐type crystal into B‐type crystal. The destruction of high‐pressure treatment to starch crystalline structure is mainly achieved by disturbing the regular arrangement of double‐helixes, instead of directly destroying the double‐helix structure. Secondly, high pressure showed different effect trends on pasting and thermal properties of different starches. In most cases, the enthalpy of starch would become 0 after a 600 MPa treatment for 10–30 min. Thirdly, high pressure can increase retrogradation rate by 1.12–1.81 times. Fourthly, high‐pressure treatment increases the G′, G′′, apparent viscosity and yield stress of starch gel, and has different effect trends on flow behaviour index and consistency coefficient of different starches. Fifthly, high pressure can increase the RS content, up to 466.7%. This paper can provide reference for the application of high‐pressure technology in starch processing and modification.

For efficient treatment of starch using aqueous ionic liquid at room temperature

Considering the renewability and chemical versatility of natural biopolymers, innovative solvation processes to efficiently disrupt the native supramolecular structures of (namely dissolve/gelate) natural polymers for their modification, derivation, and materials fabrication are highly demanded. This work compares the structural disorganization behavior at room temperature among waxy maize, high-amylose maize, cassava and potato starches with the 6:4 (wt/wt) 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc])/water mixture using rapid visco analysis (RVA), scanning electron microscopy (SEM), X-ray diffraction (XRD), small-angle X-ray scattering, Fourier-transform infrared (FTIR), and Raman spectroscopy. All the viscosity, morphological and structural changes show the greater susceptibility of the two A-type (cassava and waxy maize) starches to structural disruption with the aqueous IL than the two B-type (potato and high-amylose maize) ones, while cassava starch is most susceptible. The four starches, once ball-milled (for up to 5 min), display an immediate increase in viscosity with time in RVA, while a lag in viscosity increase for native waxy maize and cassava starches without ball-milling and barely any viscosity change for high-amylose maize and potato starches can be observed. This indicates that the easiness of starch gelation by the aqueous IL is not directly linked to amylose content but is controlled by the granule surface compactness (namely, how easily the aqueous IL can reach and disrupt the most vulnerable parts inside the starch granule and subsequently cause the destruction of the rest parts and the breakdown of the whole granule). The findings can provide insights into developing low-energy processes for starch processing with aqueous ILs.

Safety evaluation of the food enzyme glucan 1,4-α-glucosidase from the non-genetically modified Aspergillus niger strain NZYM-BO.

The food enzyme glucan 1,4-α-glucosidase (4-α-d-glucan α-glucohydrolase; EC 3.2.1.3) is produced with the non-genetically modified Aspergillus niger strain NZYM-BO by Novozymes A/S. It was considered free from viable cells of the production organism. It is intended to be used in seven food manufacturing processes: baking processes, brewing processes, cereal-based processes, distilled alcohol production, fruit and vegetable processing for juice production, production of dairy analogues and starch processing for the production of glucose syrups and other starch hydrolysates. Since residual amounts of total organic solids (TOS) are removed by distillation and during starch processing, dietary exposure was not calculated for these two food manufacturing processes. For the remaining five food manufacturing processes, dietary exposure to the food enzyme-TOS was estimated to be up to 2.97 mg TOS/kg body weight (bw) per day in European populations. 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 of 1,920 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 646. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and one match with a respiratory allergen was found. The Panel considered that, under the intended conditions of use, the risk of allergic reactions by dietary exposure to this food enzyme cannot be excluded (except for distilled alcohol production), but the likelihood is 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.