Pullulanase Debranching Research Articles

Preparation of rutin-loaded microparticles by debranched lentil starch-based wall materials: Structure, morphology and in vitro release behavior

Different treatments of autoclaving, pullulanase debranching and/or ultrasound were applied to prepare debranched lentil starch (DBLS). Their fine structures can affect the retrogradation patterns of DBLSs, which consequently could affect their potential use as delivery carrier of sensitive bioactive compounds. An attempt was made to use these DBLSs as wall materials to encapsulate rutin, aiming to improve the bioaccessibility, meanwhile to enhance the aqueous solubility and stability of rutin molecules. Their encapsulation efficiency, structural characteristics, thermal stability, morphological features, antioxidant activity and in vitro release behavior under simulated upper gastrointestinal tract environment were evaluated. The results suggested that rutin was dispersed in the DBLS polymer matrix, showing the amorphous nature that further authenticates the encapsulation and entrapment of rutin. The structural analyses of microparticles revealed that rutin could interacted with DBLS biopolymer chains by hydrogen bonds, making the starch molecular chains less susceptible to interact with themselves for reordering. The encapsulation efficiency was found to be in an opposite trend with those values obtained for relative crystallinity, melting enthalpy, degree of order/double helices of DBLS wall materials before encapsulation. The release rate results indicated that DBLS carrier with lower Mw, DPn and higher molecular order was beneficial for the slower release of rutin encapsulated in the microparticles.

Effect of Pullulanase Debranching and Retrogradation on Resistant Starch Yield and Glycemic Index of Garri

Aims: This research is aimed at developing a method of processing to increase the quantity of resistant starch in garri and reduce its glycemic index using pullulanase-producing Bacillus subtilis organism.
 Place and Duration of Study: Department of applied microbiology and brewing, Nnnamdi Azikiwe University, Awka between January, 2018 and February, 2019.
 Methodology: The organism was isolated from different cassava processing sites in Anambra metropolis, Nigeria. It was then identified based on phenotypic, biochemical and molecular characteristics After which the pullulanase assay, the fermentation studies, resistant starch analysis and glycemic index was analysed.
 Results: Pullulanase assay result showed Bacillus subtilis as a very good pullulanase producing organism with a pullulanase quantity of. The resistant starch content was found to be higher for the samples fermented with the choice organism and retrograded at 10oC at 14.29%, than the control garri sample fermented without any organism and not retrograded at 4.73%. The glycemic index was relatively high in all the garri samples, however, the lowest glycemic index, 62% was observed in the garri sample produced with the choice organism.
 Conclusion: This research has been able to show that pullulanase enzyme from Bacillus subtilis is a very useful industrial raw material in production of functional foods with low glycemic index.

Effect of pullulanase debranching on complexation, structure, digestibility, and release of starch‐ascorbyl palmitate inclusion complexes

Effect of pullulanase debranching on complexation, structure, digestibility, and release of starch‐ascorbyl palmitate inclusion complexes

Effects of Dual Pullulanase‐Debranching and Temperature‐Cycling Treatments on Physicochemical Properties and In Vitro Digestibility of Sago Starch and Its Application in Chinese Steamed Buns

AbstractEffects of dual pullulanase‐debranching (PD) and temperature‐cycling (TC) treatments on the physicochemical properties and in vitro digestibility of sago starch as well as its potential application in Chinese steamed buns (Mantou) is investigated. Sago starch are debranched using PD (30 pullulanase unit per g) for 0, 2, 4, 8, 16, and 24 h before subjecting to TC (4/30 °C, for 24 h each) for 3 cycles. The modified sago starch (MSS) obtained at the optimum conditions is used to replace wheat flour at 20%, 30%, and 40% for production of Mantou. All the MSS samples exhibit B‐type crystalline pattern and have lower relative crystallinity than the native starch. The PD results in an increase in the relative crystallinity of the MSS. The 8 h PD followed by TC storage are the optimum conditions for producing MSS with the highest slowly digestible starch (10.76%) and the lowest rapidly digestible starch (81.61%) contents. The physical, textural, and sensorial properties of Mantou decrease with increasing substitution level of the MSS due to a reduction of gluten network and a detrimental effect of retrograded starch. However, the Mantou containing 20% MSS substitution is found to be acceptable based on the sensory evaluation.

Effects of pullulanase pretreatment on the structural properties and digestibility of lotus seed starch-glycerin monostearin complexes

The effects of pullulanase pretreatment, combined with ultrasound-microwave synergistic processing, on the structural properties and digestibility of lotus seed starch-glycerin monostearin complexes was investigated. The pullulanase pretreatment improved the complex index of the inclusion complexes. The structural properties analysis indicated the debranching of starch by pullulanase facilitated an increase in microcrystalline regions and ordering of starch. However, extensive debranching resulted in a blend of B- and V-type crystalline structures and a high degree of freedom of amylose chains. The microstructural morphology revealed that pullulanase debranching inhibited the gelatinization of starch by promotion of V-complex formation, while excessive enzymolysis did not. The stability of starch complex structure determined its digestibility, and the digestion analysis revealed that 100 min of pullulanase debranching contributed to the high content of V-type resistant starch. After that, starch helix conformations was more inclined to imperfect amylose double helices, reflecting an increase in slowly digestible starch content.

Effects of pullulanase debranching on the properties of potato starch-lauric acid complex and potato starch-based film

The effects of different debranching time on the properties of potato starch and its films were evaluated. Potato starch granules were debranched with pullulanase for 0, 0.5, 1.0, 1.5 or 2.0 h. The effects of pullulanase debranching treatment on the chain-length distributions of amylopectin were analysed by high performance anion exchange chromatography (HPAEC), which proved that the shorter debranching treatment generated more linear chains with favourable lengths to facilitate the formation of potato starch-lauric acid complexes. The debranched starch-lipid complexes showed higher lauric acid content than that of the untreated sample. X-ray diffraction showed that the diffraction intensity of the debranched sample was stronger than that of the undebranched sample, and when the debranching time was >1.5 h, the diffraction intensity and relative crystallinity of the complexes decreased. The sample exhibited a high melting enthalpy (ΔH) under the pullulanase debranching treatment for 1.5 h. Scanning electron microscope data indicated that the surface of the composite film was flatter after the debranching treatment and that the films exhibited the lowest water vapour permeability and highest tensile strength after the treatment time for 1.5 h.

Effects of amylose content and enzymatic debranching on the properties of maize starch-glycerol monolaurate complexes

The effects of pullulanase debranching on the properties of maize starch (waxy, normal and high amylose)-glycerol monolaurate (GML) complexes were studied. Pullulanase pretreatment produced more starch chains with favourable lengths (DP ≥ 25) to encourage inclusion complex formation. The debranched starch showed higher amylose content (from 11.2 to 58.6%) than the native starch (from 0.68 to 53.4%). The V-type characteristic diffraction peaks (7.5°, 13.1° and 20.2° 2θ) became more obvious after the starch received the debranching treatment. Thermal properties indicated that the melting enthalpy of the debranched starch-GML complexes (from 6.45 to 10.13 J/g) was higher than those of the untreated complexes (from 0 to 8.91 J/g). The swelling power values and degree of hydrolysis of the starches decreased with the increase in amylose content. In vitro digestibility analysis suggested that the hydrolysis of the starch-GML samples was further restricted by applying the debranching treatment to the starch.

Structural characteristics and physicochemical properties of field pea starch modified by physical, enzymatic, and acid treatments

In order to meet industrial demands, field pea starch was modified by autoclaving (ACP), microwave cooking (MCP), and combined treatments of autoclaving with ultrasonication (UP), acid hydrolysis (AHP), or pullulanase debranching (PDP). The influence of different processing treatments on the structural and physicochemical characteristics of pea starch was investigated by X-ray diffraction (XRD), solid-state 13C nuclear magnetic resonance (13CNMR), Fourier transform infrared spectroscopy (FT-IR), small angle X-ray scattering (SAXS), differential scanning calorimeter (DSC), and scanning electron microscope. Processing of pea starch tended to decrease the long-range structural order with relatively lower values of crystallinity observed from XRD, whereas the double helical structure which is arranged at short range scale was enhanced to certain extents after different treatments. Microwave cooking was shown to be less effective than other treatments in promoting the formation of stabilized double helical structure, with the lowest values of crystallinity, degree of order (DO), double helix content, and gelatinization enthalpy obtained for MCP based on XRD, FT-IR, 13CNMR, and DSC observations. The experimental results also suggested that autoclaving had a less pronounced effect than the combined treatments of autoclaving-debranching, acid hydrolysis-autoclaving, and ultrasound-autoclaving on facilitating the formation of short-range ordered structure, with significantly lower values of DO, and double helix content obtained for ACP compared with AHP, PDP, and UP. This study was expected to provide a theoretical basis for the better understanding of the structure-processing-functionality relationship of starch polymers and to help the food industry to design novel starch materials with desirable functional properties.

Effects of different treatment methods on properties of potato starch-lauric acid complex and potato starch-based films

The effects of different treatment methods on the physicochemical properties of potato starch (PS) and PS-based films were studied. The complexing indices of PS-lauric acid (LA) complexes followed the order: pullulanase debranching (PD) > ultrasound treatment (UT) > dimethyl sulfoxide heating (DSH) > Control. Light microscopy showed that PS-LA complexes exhibited irregularly shaped fragments. X-ray diffraction indicated that the diffraction intensity of the PD sample was stronger than that of the other samples. The melting enthalpies (△H) of the DSH, UT and PD samples were higher than that of the Control. PD sample had the lowest enzymatic-hydrolysis rate among all of the tested samples. PS-LA composite films showed higher tensile strength, lower elongation at break, and lower moisture permeability than native starch-based film, and the films prepared by PD method had the highest tensile strength and lowest water vapour permeability among all of the tested films.

Long- and short-range structural characteristics of pea starch modified by autoclaving, α-amylolysis, and pullulanase debranching

Pea starch (S) was modified by autoclaving (A), α-amylolysis (E), and pullulanase debranching (P), the effect of pretreatments including autoclaving and α-amylolysis on the structural modifications to the pullulanase debranched starch was investigated. All processed pea starch was transformed from a C– to a B-type crystalline structure. The power law exponent (α) ranging from 1.85 to 2.64 suggested the existence of mass fractal structure. Compared with native starch, all treatments applied caused an enhanced short-range order which was reflected by the increased values of α, degree of double helix (DD), degree of order (DO), and double helix content based on SAXS, FTIR, and 13CNMR observations. The processed starch sample of AS, and APS exhibited the highest DO, and α values, as well as the stronger absorption peak between 3000 and 3695 cm−1on FT-IR spectrum. AEPS exhibited the significantly highest double helix content, indicating that the higher extent of degradation induced by the combined treatments of autoclaving, α-amylolysis, and pullulanase debranching would give the molecular chains a higher alignment opportunity for the evolution towards coil-to-helix transition. The results would be helpful for better understanding the structure-processing relationship and to provide theoretical foundation for the development of food ingredients with targeted functional properties.

Modelling the Effects of Debranching and Microwave Irradiation Treatments on the Properties of High Amylose Corn Starch by Using Response Surface Methodology

Response surface methodology was applied to determine the effects of pullulanase debranching, microwave irradiation time (2–4 min) and power (20–100%) on resistant starch (RS) formation and in-vitro glycemic index (GI) values in high amylose corn starch, Hylon VII. Starch:water (1:10) suspensions were cooked and autoclaved, debranched with pullulanase (1000 PUN/g; 1500 U/kg starch) at 60 °C and then different microwave-storing cycles and drying (oven or freeze drying) processes were applied. In order to describe the relationship between the dependent and independent variables (microwave power and irradiation time), the response values were fitted by first order polynomial regression models. Significance analysis showed that microwave irradiation time had significant effect on RS content and GI value of the samples treated with one cycle of microwave-storing prior to freeze-drying. Microwave power had significant factor on the GI value of the samples that were oven-dried after one cycle of microwave-storing. Solubility and water binding capacity values of all heat treated samples were higher than those of native starch. On the other hand, RVA viscosity values were lower than native starch for oven-dried samples. Water binding capacity, solubility and final viscosity values of the freeze-dried samples were higher than those of oven-dried ones.

Pullulanase Debranching of Various Starches Upgrades the Crystalline Structure and Thermostability of Starch‐Lauric Acid Complexes

Cassava, rice, and chickpea starches with different amylose contents and amylopectin structure are used to prepare helical inclusion complexes with lauric acid (LA) and to investigate the effect of pullulanase debranching on complex formation, crystalline structure, thermostability, and morphology compared to their non‐debranched counterparts. The quantity of inclusion complexes in debranched starches increased 2–9 times compared to non‐debranched starches, due to the release of debranched, linear amylopectin chains. The amount of complexes after debranching increased with amylopectin content, and with the proportion of amylopectin short chains. Retrogradation occurred under the same conditions as and in competition with complexation; however, carefully adjusting the conditions enabled minimization of retrogradation and maximization of complex formation.

A study on the optimization and characteristics of enzymatic preparation of Artocarpus heterophyllus Lam (Jackfruit) seed resistant starch

Objective: With the development of the Artocarpus heterophyllus Lam (A. heterophyllus) processing industry, A. heterophyllus Lam seed as by-products, usually are cooked to eat or discarded, and no industrial application has yet been discovered in china. It is especially important to study the nutrients of A. heterophyllus Lam seed and to develop and utilize them. A. heterophyllus Lam seeds are rich in starch. At present, there are few reports on the processing of native starch of A. heterophyllus Lam seed and its modification as well as the application. To find the best way to prepare the resistant starch of A. heterophyllus Lam seed and to witness the changes in starch properties before and after the treated starch molecules. Methods: A. heterophyllus Lam seed starch was used as raw material in this paper and was treated by autoclaving and pullulanase debranching to produce resistant starch. Resistant starch content was confirmed by a resistant starch assay kit from Megazyme, Ireland, according to the AOAC 2002.02 standard method recommended by the American Society of Analytical Chemists. Taking resistant starch content as an indicator, the single factor and L9 (34) orthogonal experiment were used to optimize the processing parameters. Electronic scanning microscopy, X-diffraction and Differential scanning calorimetry were used to characterize native starch and treated starch molecules. Results: The optimal preparation process for preparing the resistant starch of A. heterophyllus Lam seed was starch milk concentration with the ratio of 15%, with enzyme15 ASPU/g, and with enzyme treatment time in 24 h, and starch retrograde time in 24 h. The resistant starch content was 25.82%. After being treated, A. heterophyllus Lam seed starch became a sheet with a large number of micropore. Crystal of starch changed from A type to B+V type, and the gelatinization temperature range became wider and gelatinization enthalpy value became decreaser. Conclusions: Resistant starch content of A. heterophyllus Lam seed starch was greatly improved after being treated. High resistant starch content of the treated starch indicates that it can be used as one of the carbohydrate components in diabetic foods to control blood sugar. The porous structure of the treated A. heterophyllus Lam seed starch indicates that it can be used for advanced controlled release of bioactive extracts.

Comparison of structural features and in vitro digestibility of purple yam (Dioscorea alata L.) resistant starches by autoclaving and multi-enzyme hydrolysis.

Resistant starches (RS) were prepared from purple yam by dual autoclaving-retrogradation (DAS), and pullulanase debranching treatment (PDS). DAS and PDS were then hydrolyzed by α-amylase and amyloglucosidase to obtain DAS.H and PDS.H. Differences in structural characteristics and in vitro digestibility among the four samples were investigated. The results showed that granules of RS had a rough surface and irregular shape. DAS had the lowest amylose content (29.52%), whereas PDS.H had the highest amylose content (41.96%). The order of crystallinity of the RS was: PDS.H (31.23%)>DAS.H (30.16%)>PDS (21.23%)>DAS (15.30%). Analysis by in vitro digestibility indicated a decreased hydrolysis index and glycemic index due to lower swelling power and water-binding capacity, and a well-ordered double helix structure and more crystallization in PDS.H than in the other RS samples. These results suggest that pullulanase debranching combined with α-amylase and amyloglucosidase hydrolysis may produce better RS with improved crystalline structure and higher digestion resistibility.

In structure and in-vitro digestibility of waxy corn starch debranched by pullulanase

Waxy corn starch (WCS) debranched by pullulanase was used to prepare starches with different debranching degrees. The effects of debranching degree on in vitro digestibility and structural properties of WCS were investigated. Pullulanase debranching of WCS decreased rapidly digestible starch (RDS), and increased slowly digestible starch (SDS; from 2% to 23%) and resistant starch (RS; from 13% to 19%) contents, with increase in debranching degrees. Weight-average molecular weights of debranched starches (determined using gel permeation chromatography) decreased from 450 kDa to 100 kDa, which were considerably smaller than WCS. X-ray diffraction patterns of debranched and B-type starches were almost similar, confirming that debranched starches contain partially ordered crystalline structures. SDS contents of debranched starches can be increased by increasing debranching degrees and provides useful information for the application of debranched starches in food industries.

Structural and functional characterization of RS III produced from gelatinized, enzyme-hydrolyzed and retrograded sweet potato starch

The demand for the application of resistant starch as a functional ingredient is growing, thus, the analysis of its structural, thermal and digestibility properties can help food producers in optimizing industrial applications. The effect of autoclaving (120 °C/30 min)-debranching (2% pullulanase/50 °C) time (1 or 11 or 21 h) and retrogradation temperature (4 or 32 or 60 °C/24 h) on sweet potato starch fractions were studied. Further, the functional, pasting, thermal and structural properties of gelatinized, enzyme-hydrolyzed and retrograded (GEHRS) were also investigated. All the treated starches exhibited a dextrose equivalent value ranging between 3.70 and 5.30%. Debranching of starch at 50 °C for 21 h and retrogradation at 4 °C yielded 63% of RS. Results showed that most of the functional properties had been enhanced in GEHRS. GEHRS registered a lower pasting profile, higher gelatinization temperatures and displayed the B + V diffraction pattern with an increased crystallinity. The SEM of debranched starches showed rough plate-like surfaces with irregularly shaped structures. The study concludes that pullulanase debranching of sweet potato starch at 50 °C for 21 h and subsequent retrogradation at 4 °C produce a higher amount of resistant starch in sweet potato starch.

Effect of pullulanase debranching and storage temperatures on structural characteristics and digestibility of sweet potato starch

The effect of autoclaving (120°C/30min), debranching (2% pullulanase/1h) and storage at 4°C (DS4) or 32°C (DS32) or 60°C (DS60) for 24h on starch fractions, functional, pasting, thermal and structural properties of sweet potato starch was investigated. Results showed that DS4 sample displayed the lower functional properties than other modified starches. Debranching showed a significant increase in the apparent amylose content of native starch from 18.56% to 25%. A higher yield of RS (28.76%) was observed in debranched starch stored at 4°C (DS4) due to the higher degree of retrogradation. All debranched starches showed a substantial decrease in pasting profile and higher gelatinization temperatures than in native starch. B+V X-ray diffraction pattern was observed in debranched starches with increased crystallinity value. The scanning electron micrographs of debranched starches showed rough plate-like surfaces with irregularly shaped structures were observed due to debranching and retrogradation during storage. The study concludes that a combination of autoclaving, debranching and subsequent storage at 4°C is best technique to produce a higher amount of resistant starch in the sweet potato starch.

Physicochemical characteristics and in vitro digestibility ofindica,japonica, and waxy type rice flours and their derived resistant starch type III products

Physicochemical and in vitro digestibility of three types of rice flours with different amylose contents, namely, indica (IR), japonica (JR) and japonica waxy (WR), and their derived resistant starch (RS) products prepared with treatments involving pullulanase debranching followed by a one cycle of freeze–thaw process were assessed. The native rice flours displayed a typical A-type polymorph with different crystallinity levels closely related to the amylopectin content and the enthalpy change. The nonwaxy rice flours, especially IR, showed a more restricted-swelling pasting behavior, a higher gelatinization temperature, and a lower glycemic response than WR. Significant differences in glycemic response between the rice flours were associated with amylose and RS contents and breakdown viscosity. The RS products had a substantial increase in amylose and RS contents. The process for obtaining RS changed the crystallinity pattern to a mixture of B- and V-type polymorphs and increased the crystallinity. The RS products showed less pronounced changes in pasting behavior and enhanced thermostability. The rate and extent of starch digestion were significantly decreased in the RS products, and the highest RS and the lowest estimated glycemic index was seen for the RS product produced from WR.

Preparation and structure characterization of linear long‐chain dextrin obtained from pullulanase debranching of cassava starch

A relatively simple and economical method to prepare linear long‐chain dextrin (LLD) was created, with a resulting product that could act as a high‐amylose starch for a variety of downstream applications. Native cassava starch was chosen as the starting material due to its inexpensive price and low‐gelatinization temperature. A pretreatment with NaOH solution was applied to increase the susceptibility of cassava starch to pullulanase attack. The apparent amylose content of the final LLD product was extremely high (above 90%), as determined by the iodine binding colorimetric method. Using HPLC, the optimum amount of enzyme was determined to be 25 U pullulanase per gram of starch. The structure of the LLD was found to be a V6I crystalline type, and this was confirmed by multiple physical techniques, including X‐ray powder diffraction, solid‐state nuclear magnetic resonance, and Fourier transform infrared. Overall, this study could promote further investigations into the efficient preparation and characterization of amylose products.

Preparation and properties of RS III from waxy maize starch with pullulanase

Waxy maize starch was treated by pullulanase debranching and retrogradation at room temperature to produce resistant starch (RS). Physicochemical properties, crystalline structure and in-vitro digestibility of starch samples with different RS content were investigated. Compared with native starch, apparent amylose content of RS products increased. Based on Gel Permeation Chromatography (GPC) the Molecular Weight Distribution (MWD) of resistant starches significantly changed. Scanning Electron Microscopy (SEM) showed that upon pullulanase debranching and retrogradation treatment the granular structure of native starch was destroyed and all RS samples exhibited irregular shaped fragments. Crystal structure of samples changed from A–type to a mixture of B and V–type. The crystallinity of resistant starch also improved as compared with native starch. Moreover, samples with higher resistant starch showed higher relative crystallinity. Differential Scanning Calorimetry (DSC) determination showed that To、Tp、Tc and ΔH all increased which was in agreement with RS content. The resistance of waxy maize starch with Pullulanase treatment to α-amylase digestibility also increased, while the in-vitro digestibility of products decreased.