The Influence of Hydroponic Potato Plant Cultivation on Selected Properties of Starch Isolated from Its Tubers.

Starch is a natural polysaccharide for which the technological quality depends on the genetic basis of the plant and the environmental conditions of the cultivation. Growing plants under cover without soil has many advantages for controlling the above-mentioned conditions. The present research focuses on determining the effect of under cover hydroponic potato cultivation on the physicochemical properties of accumulated potato starch (PS). The plants were grown in the hydroponic system, with (greenhouse, GH) and without recirculation nutrient solution (foil tunnel, FT). The reference sample was PS isolated from plants grown in a tunnel in containers filled with mineral soil (SO). The influence of the cultivation method on the elemental composition of the starch molecules was noted. The cultivation method also influenced the protein and amylose content of the PS. Considering the chromatic parameters, PS-GH and PS-FT were brighter and whiter, with a tinge of blue, than PS-SO. PS-SO was also characterized by the largest average diameters of granules, while PS-GH had the lowest crystallinity. PS-SO showed a better resistance to the combined action of elevated temperature and shear force. There was a slight variation in the gelatinization temperature values. Additionally, significant differences for enthalpy and the retrogradation ratio were observed. The cultivation method did not influence the glass transition and melting.

Methodologies for producing amylose: A review.

Three main in vitro approaches can be distinguished for obtaining amylose (AM): enzymatic synthesis, AM leaching, and AM complexation following starch dispersion. The first uses α-d-glucose-1-phosphate (G1P), a glucosyl primer with a degree of polymerization (DP) of at least 4 and phosphorylase (EC 2.4.1.1), commonly from potatoes. Such approach provides AM chains with low polydispersity, the average DP of which can be manipulated by varying the reaction time and the ratio between G1P, primer, and enzyme dose. AM leaching is the result of heating a starch suspension above the gelatinization temperature. This approach allows isolating AM on large scale. The AM DP, yield, and purity depend on the heating rate, leaching temperature, shear forces and botanical origin. High leaching temperatures (80-85°C) result in mostly pure AM of DP >1000. At higher temperatures, lower purity AM is obtained due to amylopectin leaching. Annealing as pretreatment and ultracentrifugation or repetitive organic solvent-based precipitations after leaching are strategies, which improve the purity of AM extracts. When AM is separated by complex formation, complete dispersion of starch is followed by bringing AM into contact with, e.g., n-butanol or thymol. The resultant complex is separated from amylopectin as a precipitate. Complete starch dispersion without degradation is critical for obtaining AM of high purity. Finally, higher DP AM can be converted enzymatically into AM fractions of lower DP.

Preparation and evaluation of regioselectively substituted amylose derivatives for chiral separations.

Six novel regioselectively substituted amylose derivatives with a benzoate at 2-position and two different phenylcarbamates at 3- and 6-positions were synthesized and their structures were characterized by 1 H nuclear magnetic resonance (NMR) spectroscopy. Their enantioseparation abilities were then examined as chiral stationary phases (CSPs) for high-performance liquid chromatography (HPLC) after they were coated on 3-aminopropyl silica gels. Investigations indicated that the substituents at the 3- and 6-positions played an important role in chiral recognition of these amylose 2-benzoate serial derivatives. The derivatives demonstrated characteristic enantioseparation and some racemates were better resolved on these derivatives than on Chiralpak AD, which is one of the most efficient CSPs, utilizing coated amylose tris(3,5-dimethylphenylcarbamate) as the chiral selector. Among the derivatives prepared, amylose 2-benzoate-3-(phenylcarbamate/4-methylphenylcarbamate)-6-(3,5-dimethylphenylcarbamate) exhibited chiral recognition abilities comparable to that of Chiralpak AD and may be useful CSPs in the future. The effect of mobile phase on chiral recognition was also studied. In general, with the decreased concentration of 2-propanol, better resolutions were obtained with longer retention times. Moreover, when ethanol was used instead of 2-propanol, poorer resolutions were often achieved. However, in some cases, improved enantioselectivity was achieved with ethanol rather than 2-propanol as the mobile phase modifier.

Molecular characteristics and physicochemical properties of very small granule starch isolated from Agriophyllum squarrosum seeds.

Novel starch resources isolated from accessible botanical origins are of special interest to food scientists in the context of food security. In this study, Agriophyllum squarrosum starches (AS-1, AS-2, and AS-3) were isolated from three ecotypes of A. squarrosum seeds and compared with quinoa starch (QS). The mean particle diameter of AS granules ranged from 1.12 to 1.15 µm, and AS amylopectin had a significantly higher Mw than QS (p < 0.05). Compared with QS, AS samples had more branching and substitution of amylopectin structures. The peak viscosity, breakdown viscosity, and swelling degree of the AS samples were significantly lower than those of QS (p < 0.05). AS showed a lower crystalline degree and higher gelatinization temperatures, and the freshly cooked AS showed a slower digestibility rate than QS. The physicochemical properties and chain profiles of AS facilitate the application of AS and the domestication of A. squarrosum crops.

Amylose/cellulose nanofiber composites for all-natural, fully biodegradable and flexible bioplastics.

Thermoplastic, polysaccharide-based plastics are environmentally friendly. However, typical shortcomings include lack of water resistance and poor mechanical properties. Nanocomposite manufacturing using pure, highly linear, polysaccharides can overcome such limitations. Cast nanocomposites were fabricated with plant engineered pure amylose (AM), produced in bulk quantity in transgenic barley grain, and cellulose nanofibers (CNF), extracted from agrowaste sugar beet pulp. Morphology, crystallinity, chemical heterogeneity, mechanics, dynamic mechanical, gas and water permeability, and contact angle of the films were investigated. Blending CNF into the AM matrix significantly enhanced the crystallinity, mechanical properties and permeability, whereas glycerol increased elongation at break, mainly by plasticizing the AM. There was significant phase separation between AM and CNF. Dynamic plasticizing and anti-plasticizing effects of both CNF and glycerol were demonstrated by NMR demonstrating high molecular order, but also non-crystalline, and evenly distributed 20 nm-sized glycerol domains. This study demonstrates a new lead in functional polysaccharide-based bioplastic systems.

Structural changes of rice starch and activity inhibition of starch digestive enzymes by anthocyanins retarded starch digestibility.

The effects of anthocyanins on in vitro and in vivo digestibility of rice starch were evaluated in this study. Then, the effects of anthocyanins on physicochemical properties of rice starch and on starch digestive enzymes (α-amylase and α-glucosidase) were investigated to understand the mechanism of the effects of anthocyanins on starch digestibility. Characterization of physicochemical properties of rice starch indicates a structural change due to the presence of anthocyanins, hindering its access to starch digestive enzymes. Besides, anthocyanins inhibited the activities of starch digestive enzymes by binding to their active sites, competing with the substrates and changing the secondary structure of the enzymes. The above stated changes of rice starch and starch digestive enzymes due to the presence of anthocyanins both contributed to retarding the digestibility of rice starch. This study could offer some theoretical guidance to the development of new type rice-based food with low glycemic index.

Annealing treatment of amylose and amylopectin extracted from rice starch.

Annealing behavior of amylose and amylopectin was unclear. In this work, high purity amylose and amylopectin were extracted from rice starch, and structural properties of the retrograded rice starch, amylose, and amylopectin before and after annealing treatment were explored. It was found that the purity of the amylose and amylopectin was 95.64% ±â€¯2.69% and 94.98% ±â€¯0.97%, respectively. Their molecular weight was (2.93 ±â€¯0.21) × 106 Da and (5.90 ±â€¯0.13) × 107 Da, respectively. Besides, the relative crystallinities and ratios of 1047 cm-1/1022 cm-1 of the retrograded rice starch and amylose were significantly increased by annealing treatment, while that of retrograded amylopectin did not change. These results clarified that amylose was more sensitive to annealing treatment than amylopectin, and amylose was more responsible for annealing of starch than amylopectin. The findings contributed to a better understanding of the annealing behavior of starch.

Autoclaving and extrusion improve the functional properties and chemical composition of black bean carbohydrate extracts.

Common beans (Phaseolus vulgaris L.) are rich in starch with a high content of amylose, which is associated with the production of retrograded and pregelatinized starch through thermal treatments. The purpose of this study was to evaluate the composition, morphology, thermal, functional, and physicochemical properties of carbohydrate extracts (CE) obtained from autoclaved (100 and 121 °C) and extruded (90, 105, and 120 °C) black beans. After evaluation of the functional properties, the CE from autoclaved beans at 100 °C for 30 min and 121 °C for 15 min 2×, and extruded beans at 120 °C and 10 rpm, were selected to continue the remaining analysis. Autoclaving treatments at 100 °C for 30 min and 121 °C for 15 min 2× showed a reduction of resistant starch by 14.4% and 26.6%, respectively, compared to dehulled raw bean CE. Meanwhile, extrusion showed a reduction in resistant starch of 54.2%. Autoclaving and extrusion treatments also decreased the dietary fiber content. Extrusion reduced almost entirely the content of α-galactooligosaccharides, in comparison to dehulled raw bean CE. The results showed differences in color and granule morphology. The onset, peak, and conclusion temperatures, transition temperature range, and enthalpy of autoclaved and extruded bean CE were lower than dehulled raw bean CE. The CE from autoclaved and extruded beans contain retrograded and pregelatinized starch, which could be incorporated in food products as a thickening agent for puddings, sauces, creams, or dairy products. PRACTICAL APPLICATION: Thermally treated black bean carbohydrate extracts are rich in starch, fiber, and protein. Because these extracts are already cooked, they can be added to products that do not require a thermal process such as puddings, sauces, creams, or dairy products, acting as a thickening agent.

Resistant starch from five Himalayan rice cultivars and Horse chestnut: Extraction method optimization and characterization.

In this study resistant starch (RS) was extracted from five Himalayan rice cultivars and Indian Horse chestnut (HCN) using porcine pancreatin enzyme following which it was subsequently characterized for its physicochemical, structural and functional properties. In vitro digestibility test showed that RS content of the rice cultivars and HCN was in the range of 85.5 to 99.5%. The RS extracted from the rice cultivars and HCN showed significant difference in the apparent amylose content (AAC), ranging between 31.83 to 40.68% for rice and 45.79% for HCN. Water absorption capacity (WAC), swelling and solubility index of RS ranged from 112-133.9%, 5.28-7.25 g/g and 0.033-0.044 g/g, respectively. The rice RS granules were polyhedral and irregular shaped with granular length in the range of 4.8-5.9 µm. The HCN RS granule morphology showed smooth surfaced, round, elliptical, irregular and oval shapes with average granular length of 21 µm. Pasting behavior also varied significantly between rice RS and HCN RS with later showing the lower values of pasting properties. Thermal properties (T0, Tp, Tc) and ΔH gel also varied considerably between the rice RS and HCN RS, wherein the highest values for peak gelatinization temperature and gelatinization enthalpy were seen for CH-1039. X-ray diffraction pattern of rice RS and HCN RS showed the characteristic A type of pattern in consonance with cereal starches.

Physicochemical, structural, and thermal properties of "batata-de-teiú" starch.

Jatropha elliptica (Pohl) Muell Arg is a sub-shrub herbaceous plant native to the Brazilian Cerrado, and popularly known as "batata-de-teiú". There is lack of scientific knowledge about the structural characterization, physicochemical and technological aspects of the carbohydrate content present in Jatropha elliptica roots. Thus, this work aim contributes with new data about the evaluation of chemical-structural, thermal and technological properties of starch extracted from "batata-de-teiú". The starch presented low levels of ash, protein and total fiber and amylose content of 32.82%. The initial gelatinization temperature of "batata-de-teiú" starch was 70.1 °C, peak temperature was 73.84 °C and final 85.52 °C, and starch had low trend to retrogradation. The results of x-ray and 13C cpmass show a A-type structure with high crystallinity degree. Finally, this results suggested that the "batata-de-teiú" starch is a macromolecular structure with high branching degree, favoring intermolecular Coulomb, Van der Waals forces and hydrophobic interactions, which directly corroborated with the low solubility observed (maximum of 6.44 g·100 g-1 at 80 °C). The extraction of "batata-de-teiú" starch can be viable, and it has technological characteristics suitable for use in the food industry or pharmaceuticals, since "batata-de-teiú" starch has good thermal stability and low trend to retrogradation.

Effects of high temperature during two growth stages on caryopsis development and physicochemical properties of starch in rice.

Global warming may affect the development of rice at different growth stages, thereby decreasing rice yield and deteriorating grain quality. The difference in rice responses to high temperature during primordial differentiation (PD) and pollen filling (PF) stages has been rarely studied. In this paper, two temperature treatments (40 °C and 30 °C) at the two stages (PD and PF) were imposed to four rice groups under the controlled temperature chambers. Compared with rice under normal temperature, high temperature-stressed rice showed accelerated growth rate, smaller caryopsis and decreased yield. Moreover, high temperature affected the starch physicochemical properties, resulting in lower apparent amylose content and higher order degree, gelatinization temperatures, and thereby increased peak, trough and final viscosities in starch. High temperature during PD stage inhibited cell development and starch deposition, thus leading to small starch granule and low retrogradation. However, temperature-stressed rice during PF stage showed increased starch accumulation and larger granule size. Therefore, effects of high temperature during the two stages on caryopsis development and starch properties were partly similar but also notably different. These results enriched and deepened the study of high temperature-stressed rice and served as an important reference for the processing and utilization of rice starch in food industry.

High performance liquid chromatographic enantioseparation of chiral bridged polycyclic compounds on chiralcel OD-H and chiralpak OT(+).

The HPLC enantiomeric separation of 29 racemic bridged polycyclic compounds was examined on commercially available Chiralcel OD-H and Chiralpak OT(+) columns. The separations were evaluated under normal-phase mode (hexane containing mobile phase) for Chiralcel OD-H and under normal-phase as well as under reversed-phase mode (pure MeOH, temperature 5 degrees C) for Chiralpak OT(+). Almost all compounds were resolved either on Chiralcel OD-H or on Chiralpak OT(+), in some cases on both. The use of trifluoroacetic acid (TFA), as modifier of the hexanic mobile phase, had a beneficial effect on the enantioseparation of some polar and acidic compounds on Chiralcel OD-H. The influence of small chemical structural modifications of the analytes on the enantioseparation behavior is discussed. A structure-retention relationship has been observed on both stationary phases. This chromatographic evaluation may provide some information about the chiral recognition mechanism: in the case of Chiralcel OD-H, hydrogen bonding, pi-pi and distereoselective repulsive are supposed to be the major analyte-CSP interactions. In the case of Chiralpak OT(+), a reversed-phase enantioseparation could take place through hydrophobic interactions between the aromatic moiety of the analytes and the chiral propeller structure of the CSP. The synthesis of some unknown racemic bromobenzobicyclo[2.2.1] analytes is also described.

Effect of degree of polymerization of amylopectin on the gelatinization properties of jackfruit seed starch.

Five gelatinized jackfruit starches (GJFSS: M1', M5', M6', M11', and BD') were prepared using amylose mixed with five types of amylopectin. M1' had the lowest degree of polymerization while BD' had the highest. The five GJFSS samples showed significant variations in microstructures, varying from a compact structure (M1') to a loose structure (BD'). The freeze-thaw stability was consistent with results of the microstructure. High syneresis formed compact structure (M1'), and low syneresis formed a loose structure (BD'). As the degree of polymerization of amylopectin increased, the gelatinization enthalpy, peak viscosity, breakdown, final viscosity, setback, and absorbance ratio decreased, while the transition temperature and pasting temperature increased. The thermal, pasting properties, and the short-range molecular order, were consistent with the results of the microstructure and syneresis. All the results indicated that the degree of polymerization of amylopectin is an important structural factor that can significantly affect the gelatinization properties of starch.

Characterization of amylose and amylopectin fractions separated from potato, banana, corn, and cassava starches.

Analytical techniques such HPSEC, DSC, and TGA have been employed for amylose determination in starch samples, though spectrophotometry by iodine binding is most commonly used. The vast majority of these techniques require an analytical curve, using amylose and amylopectin standards with physicochemical properties similar to those found in the original starch. The current study aimed to obtain the amylose and amylopectin fractions from potato, banana, corn, and cassava starches, characterize them, and evaluate their behavior via thermogravimetric curves. Blue amylose iodine complex and HPSEC-DRI methods have obtained high purity amylose and amylopectin fractions. All molecular weights of the obtained amylose and amylopectin fractions were similar to those presented in other reports. Different results were obtained by deconvolution of the amylopectin polymodal distribution. All amyloses presented as semi-crystalline V-type polymorphs, while all amylopectin fractions were amorphous. The Tg of all Vamyloses presented were directly proportional to their respective crystalline index. TGA evaluations have shown that selective precipitation of amylose with 1-butanol strongly changes its thermal behavior. Therefore, the separation procedure used was an ineffective pathway for obtaining standards for thermal studies.

Extraction and characterization of starch granule-associated proteins from rice that affect in vitro starch digestibility.

Starch granule-associated proteins (SGAPs) including granule-surface proteins and granule-channel proteins in waxy, low- and high-amylose rice starch were extracted and identified. The in vitro digestibility of starch was investigated before and after the extraction of granule-channel proteins or total SGAPs. The results showed that 10 types of major differentially expressed proteins (DEPs) including 14-3-3-like protein and ribosomal protein were found among starches. In addition, the lack of only granule-channel proteins or total SGAPs led to significant and different changes in the levels of rapidly digestible starch, slowly digestible starch and resistant starch. Possible mechanisms are related to the accessibility of amylase into starch granules and structural properties of SGAPs. This study provides more information about DEPs in rice starch with different amylose content and supports further study on the relationship between SGAPs and in vitro starch digestibility.

Structural and thermodynamic properties of starches extracted from GBSS and GWD suppressed potato lines.

A combined DSC-SAXS approach was employed to study the effects of amylose and phosphate esters on the assembly structures of amylopectin in B-type polymorphic potato tuber starches. Amylose and phosphate levels in the starches were specifically engineered by antisense suppression of the granule bound starch synthase (GBSS) and the glucan water dikinase (GWD), respectively. Joint analysis of the SAXS and DSC data for the engineered starches revealed that the sizes of amylopectin clusters, thickness of crystalline lamellae and the polymorphous structure type remained unchanged. However, differences were found in the structural organization of amylopectin clusters reflected in localization of amylose within these supramolecular structures. Additionally, data for annealed starches shows that investigated potato starches possess different types of amylopectin defects. The relationship between structure of investigated potato starches and their thermodynamic properties was recognized.

Effect of drying conditions on crystallinity of amylose nanoparticles prepared by nanoprecipitation.

In this study, amylose nanoparticles prepared by nanoprecipitation were dried at different conditions. The crystalline structure, crystallinity, re-dispersibility and morphological characteristic of the amylose nanoparticles after drying were investigated. X-ray diffraction analysis revealed that the V-type crystalline structure of the amylose nanoparticles formed in the drying process instead of the precipitation process, and drying condition significantly affects the crystallinity. The temperature cycles drying at 4°C and 40°C considerably increased crystallinity of the amylose nanoparticles, 24h (4/40°C, 12h/12h) drying under 11% relative humidity could give rise to a crystallinity up to 50.05%. The applied drying procedures had no obvious effect on the appearance of the amylose nanoparticles. The Z average-size (d. nm) and polydispersity index (PDI) obtained from dynamic light scattering analysis suggested that the drying processes caused some aggregates, but the dried amylose nanoparticles could be well dispersed in water.

Composition, Granular Structure, and Pasting Properties of Native Starch Extracted from Plectranthus edulis (Oromo dinich) Tubers.

Chemical composition, granular morphology and pasting properties of native starch extracted from tubers of Plectranthus edulis were analyzed. Starch was extracted from tubers of 6 accessions collected from 4 different areas in Ethiopia. Particle size analysis (PSA) and cryo-scanning electron microscope (cryo-SEM) imaging were used to examine the granular morphology and visualize the starch paste, respectively. Pasting properties, water absorption, and gelation capacity were compared. A wide range was found for the amylose (14.2% to 23.9%), calcium (216 to 599), potassium (131 to 878), and phosphorus (1337 to 2090) contents (parts per million per dry matter). PSA showed a bimodal distribution containing small spherical (14.6 µm) and large ellipse-shaped (190.4 µm) granules. Major differences were found for the pasting with peak viscosities differing from 3184 to 7312 mPa⋅s. Starch from accessions Chencha and Inuka showed a difference in packing density as clearly seen through cryo-SEM image at 75% of the peak viscosity (PV), and the granular integrity was mainly responsible for the significant difference in their PV and breakdown. Principal component analysis revealed 2 distinct groups: native starch extracted from accessions at the Wolayta zone (Inuka, Lofua, and Chenqoua) and other accessions (Jarmet, Arjo white, and Chencha). The study revealed the potential of P. edulis starch for its application in food industries. However, the inherent variation due to environmental conditions on physicochemical properties of the starch needs further investigation. PRACTICAL APPLICATION: Plectranthus edulis is cultivated in considerable amounts throughout Ethiopia, which makes it a valuable starch source. Due to its low tendency to retrograde, it could be applied in food industry as an equivalent for the current starch sources. Moreover, the low amylose content makes it preferable for an application in refrigerated foods as this unique quality trait prevents syneresis in end products during storage. Based on the significantly higher pasting temperature of the studied P. edulis starch extracts, it can form an alternative for potato starch, which is less suitable for its use in pasteurized foods.

Damaged starch characterisation by ultracentrifugation.

The relative molecular size distributions of a selection of starches (waxy maize, pea and maize) that had received differing amounts of damage from ball milling (as quantified by susceptibility to alpha-amylase) were compared using analytical ultracentrifugation. Starch samples were solubilised in 90% dimethyl sulfoxide, and relative size distributions were determined in terms of the apparent distribution of sedimentation coefficients g*(s) versus s(20,w). For comparison purposes, the sedimentation coefficients were normalised to standard conditions of density and viscosity of water at 20 degrees C, and measurements were made with a standard starch loading concentration of 8 mg/mL. The modal molecular size of the native unmilled alpha-glucans were found to be approximately 50S, 51S and 79S for the waxy maize, pea and maize amylopectin molecules, respectively, whilst the pea and maize amylose modal molecular sizes were approximately 14S and approximately 12S, respectively. As the amount of damaged starch increased, the amylopectin molecules were eventually fragmented, and several components appeared, with the smallest fractions approaching the sedimentation coefficient values of amylose. For the waxy maize starch, the 50S material (amylopectin) was gradually converted to 14S, and the degradation process included the appearance of 24S material. For the pea starch, the situation was more complicated than the waxy maize due to the presence of amylose. As the amylopectin molecules (51S) were depolymerised by damage within this starch, low-molecular-weight fragments added to the proportion of the amylose fraction (14S)--although tending towards the high-molecular-weight region of this fraction. As normal maize starch was progressively damaged, a greater number of fragments appeared to be generated compared to the other two starches. Here, the 79S amylopectin peak (native starch) was gradually converted into 61 and 46S material and eventually to 11S material with a molecular size comparable to amylose. Amylose did not appear to be degraded, implying that all the damage was focused on the amylopectin fraction in all three cases. Specific differences in the damage profiles for the pea and maize starches may reflect the effect of lipid-complexed amylose in the maize starch.

[Screening of glucosidase inhibitors from various fractions of Mulberry leaves].

OBJECTIVE: To search for glucosidase inhibitors of various fractions extracted from mulberry leaves. METHOD: The constituents of mulberry leaves water fraction were prepared by the process of boiling, condensing, precipitating, exchanging with resins and rinsing. In vitro glucosidase inhibitory activities were examined by photometric bioassay derived from rats. To investigate in vivo effect of lowering blood glucose, the mouse blood glucose level was assayed by glucose tolerance experiments. RESULT: The glucosidase inhibitory activities were found in all the constituents of alkaloids, flavones and amyloses, the alkaloid constituent being the strongest. CONCLUSION: The effect of reducing blood glucose of mulberry leaves is related to the inhibitory activities against glucosidase of different constituents.