Unmodified Potato Starch Research Articles

Revisiting the Formation of Starch-Monoglyceride-Protein Complexes: Effects of Octenyl Succinic Anhydride Modification.

Starch-lipid-protein complexes are attracting increasing attention due to their unique structure and low enzymatic digestibility. However, the mechanisms underlying the formation of these ternary complexes, especially those with monoglycerides as the lipid component, remain unclear. In the present study, potato starch or octenyl succinic anhydride (OSA)-modified potato starch (OSAPS), various monoglycerides (MGs), and beta-lactoglobulin (βLG) were used in model systems to characterize the formation, structure, and in vitro digestibility of the respective ternary complexes. Colorimetry and live/dead staining assays demonstrated that the OSAPS had good biocompatibility. Experimental data and molecular dynamics simulations showed that both unmodified potato starch and OSAPS formed starch-lipid-protein complexes with MGs and βLG. Of the two types of starch, OSA formed a greater amount of the more stable type II V-crystallites in complexes, which had greater resistance to in vitro enzymic digestion. This study demonstrated for the first time that starch can interact with MGs and βLG to form ternary complexes and that OSA esterification of starch promoted the formation of more complexes than unmodified starch.

Starch-g-PCHMA copolymers: preparation and properties

The chemical modification of potato starch by cyclohexyl methacrylate monomer in the presence of potassium persulfate as an initiator and some of physico–chemical properties of the resulted copolymers have been presented. On a basis of the received results, the maximum of the grafting (45.3% ± 0.2) was found using the following conditions: potato starch to cyclohexyl methacrylate ratio 1:3, an initiator concentration 1.5 mass%, the reaction temperature 70 °C and the reaction time 90 min. The obtained copolymers showed ca. 1.9–5.5 times lower polar solvent swelling, ca. 2.2–9.6 times higher non-polar swelling, ca. 1.6–3.6 times higher moisture resistance and ca. 1.9–6.3 times higher chemical resistance as compared to these properties of unmodified potato starch. Moreover, as it was stated based on the TG/DTG analyses, the novel materials were thermally stable up to the temperature of ca. 180 °C. Their pyrolysis process has included at least four stages where the emission of different structure volatiles was detected by a FTIR analysis.

Effects of Atypical Antipsychotic Treatment and Resistant Starch Supplementation on Gut Microbiome Composition in a Cohort of Patients with Bipolar Disorder or Schizophrenia.

Previous studies identified shifts in gut microbiota associated with atypical antipsychotic (AAP) treatment that may link AAPs to metabolic burden. Dietary prebiotics such as resistant starch may be beneficial in obesity and glucose regulation, but little is known mechanistically about their ability to modify gut microbiota in AAP-treated individuals. This investigation was undertaken to delineate mechanistically the effects of AAP treatment and resistant starch supplementation on gut microbiota in a psychiatric population. Cross-sectional cohort study. The study was performed in an outpatient setting. A total of 37 adults with a diagnosis of bipolar disorder or schizophrenia who were treated with an AAP (clozapine, olanzapine, risperidone, quetiapine, or ziprasidone [21 patients]) or lithium and/or lamotrigine (16 patients) for at least 6 months. Patients in the AAP group received raw unmodified potato starch (resistant starch) daily for 14 days. Of the 37 patients, the mean ± SD age was 52.2 ± 12.5 years, and 57% were male. The primary outcome was gut microbiome DNA composition. Microbiome DNA obtained from stool samples from all patients was subject to 16S ribosomal RNA (rRNA) gene sequencing before and during resistant starch supplementation. Inter- and intragroup microbial diversity measures were performed by permutational multivariate analysis of variance and the Inverse Simpson Diversity Index, respectively. Differentially abundant organisms were detected by using linear discriminant analysis effect size. Although no significant difference in overall microbiota composition was detected at baseline between AAP users and nonusers, non-AAP users showed increased fractional representation of Alistipes. AAP-treated women exhibited decreased diversity compared with non-AAP-treated women. Although the microbiome of AAP-treated patients varied with resistant starch administration, an increased abundance of the Actinobacteria phylum was observed. These data suggest that AAP treatment is associated with measurable differences in gut microbiota, particularly in female AAP-treated patients in whom reduced species richness was observed. Additionally, variable microbiome responses to resistant starch supplementation were seen, with a significant increase in starch degraders.

Effect of Addition of Resistant Starch on Oxidative Stability of Fried Fish Crackers as Influenced by Storage Temperatures and Packaging Materials

The aim of the present work was to investigate the effect of the addition of resistant starch (unmodified potato starch) on physicochemical properties and lipid stability of fried fish crackers packed in two types of packaging. Fish crackers added with one part of resistant starch were prepared, packed into two types of packaging with four different layers of packaging material; (i) polyethylene terephthalate-polyethylene-aluminium-linear low density polyethylene and (ii) oriented polypropylene-polyethylene-metallized polyethylene terephthalate-linear low density polyethylene and stored at 25, 40 and 60°C for 12 weeks. The linear expansion and oil absorption of the fried fish cracker were 58.00 ± 3.46% and 12.60 ± 1.34% respectively. Physical analyses showed an increase in moisture contents (from 2.75-3.47% to 4.08-4.54%), water activities (0.297 to 0.436aw) and a* and b* values (5.27 to 9.14% and 21.09 to 25.27%, respectively), while a decrease in L* value (from 63 to 58%), hardness (from 2.110 to 1.117 kg) and crispiness (from 12.46 to 8.18 kg/sec) throughout 12 weeks of storage at all temperatures tested. The lipid yield of the crackers increased during the storage time and the concentrations of conjugated dienes and thiobarbituric acid reactive substances showed a gradual increase and decrease, respectively. These results showed that the fried fish crackers in the storage study had undergone lipid oxidation where physical and chemical deterioration were observed and measured. In conclusion, the addition of one part of resistant starch in crackers has given positive effect on the stability of the resulting fried fish crackers.

Thermal behavior, decomposition mechanism and some physicochemical properties of starch-g-poly(benzyl acrylate) copolymers

TG/FTIR/QMS-coupled method to study the thermal behavior along with the evolution of volatile decomposition products and thus the decomposition mechanism under inert conditions of some starch-g-poly(benzyl acrylate) copolymers was applied. Starch-g-poly(benzyl acrylate) copolymers under K2S2O8-initiated copolymerization process of benzyl acrylate monomer with gelatinized potato starch were prepared. The ATR-FTIR and 13C CP/MAS NMR confirmed the successful formation of grafted polymers with different grafting parameters such as grafting percent (%G) and grafting efficiency (%GE). The evolution of some physicochemical properties such as swelling, moisture resistance and chemical resistance allowed certifying that the copolymers obtained were more resistant toward polar solvents, moisture and acidic medium due to the incorporation of more hydrophobic chains into starch backbone as compared to unmodified potato starch. The TG/FTIR/QMS studies confirmed their similar thermal stability, two stage decomposition process but different and more complex decomposition mechanism under the second decomposition stage as compared to the previously presented starch-g-poly(benzyl methacrylate) copolymers.

Natural food-grade solid particles for emulsion stabilization

The aim of the present study was to examine the emulsifying properties of natural food powders that are used in medicine and gastronomy. Natural insoluble powders (mustard powder, ground ginger, ground cinnamon, nutmeg powder, potato starch, and talc) were used as solid emulsifiers. O/W emulsions were formed from aqueous dispersions of the food powders (all except talc) and olive oil. Mustard and cinnamon demonstrated the best emulsifying properties. Emulsions stabilized using mustard or cinnamon remained stable in test tubes for one month. The critical concentrations of mustard and cinnamon powder emulsifiers required to prevent coalescence were 0.3 and 2% (mass), respectively. The critical concentration needed to prevent sedimentation was 15% (mass) for both powders. The emulsion from unmodified potato starch was not stable. Stable W/O emulsions were formed from aqueous dispersions of talc and olive oil. These results suggest that cinnamon powder is a more promising solid emulsifier, reflecting the emulsifying capacity and antioxidant and antimicrobial properties of this compound.

Mechanical and barrier properties of starch-based films plasticized with two- or three component deep eutectic solvents

The aim of this work was to prepare two- and three-components deep eutectic solvents (DES) and investigate their potential as starch plasticizers. Starch/DES films were prepared via casting method. Mechanical properties, water vapor- and oxygen transmission rates were measured; additionally contact angle and moisture sorption were determined and FTIR analysis was applied on the films. Native potato starch and hydroxypropylated and oxidized starch (HOPS) with common plasticizers (e.g. polyols, urea) and DES were studied. Moreover, influence of three methods of DES introduction and concentration of plasticizer on the films properties were compared. HOPS films were prepared by two methods: as non-cured and cured samples. Some of DESs containing citrate anion exhibited crosslinking ability of polysaccharide matrix. Non-cured HOPS/DES films exhibited more favourable mechanical and barrier properties than cured analogue films. Samples prepared with unmodified potato starch had higher mechanical and barrier properties than films made with HOPS. Starch-based films plasticized with novel DESs with parallel crosslinking activity exhibited satisfactory mechanical and barrier properties.

Starch-g-poly(benzyl methacrylate) copolymers

The physicochemical properties such as swelling in polar and non-polar solvents, moisture resistance, chemical resistance, ability for gelatinization and the thermal properties along with the evolution of volatile decomposition products of some starch-g-copolymers obtained through the grafting of benzyl methacrylate monomer onto potato starch have been studied. The chemical structure of copolymers was confirmed using ATR–FTIR analysis. The prepared materials were characterized by completely different properties than unmodified potato starch due to the covalent bonding of poly(benzyl methacrylate) chains onto starch backbone. The copolymers were not able to gelate; however, they exhibited higher swelling in non-polar solvents, lower swelling in polar solvents and higher resistance toward moisture, acid and base conditions than unmodified potato starch. In addition, DSC analysis showed that T g of copolymers was shifted to a little higher values as compared to T g of poly(benzyl methacrylate). The thermal stabilities of copolymers and potato starch were comparable. Their decomposition took place in two main stages connected with the emission of various volatile decomposition products (CO2, CO, H2O, CH4, aldehydes, alcohols, furan derivatives, acids, benzyl methacrylate) in inert atmosphere as it was confirmed based on the simultaneous TG/DSC/FTIR analysis.

Kinetics of the oxidative decomposition of potato-starch-g-poly(phenyl methacrylate) copolymers

The simultaneous TG-DSC-FTIR techniques were applied to study the thermo-oxidation of starch-g-poly(phenyl methacrylate) copolymers, using unmodified potato starch in order to compare the results. The study shows that the degradation of copolymers takes place in three large stages, between 150 and 600 °C. The main evolved volatile compounds were: H2O, CO2 and CO, in addition to a mixture of organic products. The kinetic analysis suggests that the initial degradation from all copolymers (between 245 and 250 °C) starts through a kinetic scheme of a reversible reaction, followed by an irreversible one, where the progressive decreasing of E(α) values, from ∼200 kJ mol−1 up to ∼150 kJ mol−1, reveals the auto-catalytic influence of an intermediary on the overall reaction rate. Subsequently, for α > 0.4 and temperatures higher than 300 °C, with E(α) values between 55 and 150 kJ mol−1, a complex set of competitive reactions linked to the secondary degradation of the graft suggests that both, the reaction mechanism and kinetic parameters are highly dependent on the conversion. For temperatures higher than 400 °C and α > 0.7, the direct gasification of carbonaceous residues occurs in at least two different energetic stages, with significant changes in the conversion dependence of the E(α) values, whose magnitudes and extents are highly dependent on the copolymer samples.

Acetylation of or beta-cyclodextrin addition to potato beneficial effect on glucose metabolism and appetite sensations

Functional foods are gaining more and more interest from health scientists. One way to improve the nutritional properties of foods may be to modify the starch component, often included to stabilize the food product. In this study two chemically modified starches-a 1-2% acetylated potato starch and a starch enriched with 2% beta-cyclodextrin-and a native, unmodified potato starch (control) were investigated with regard to 6-h energy expenditure, substrate metabolism, hormone concentrations, and subjective appetite sensations. Subjects were 11 healthy, normal-weight, young men. The starch (50 g) was prepared as a pudding with fruit sauce and whipped cream (3180 kJ, 49% of energy from carbohydrate, and 40% of energy from fat). The meal was given in the morning after a 2-d carbohydrate-rich, weight-maintenance diet. After the modified-starch meals, response patterns for plasma glucose (P < 0.01), insulin (P < 0.05); gastric inhibitory polypeptide (P < 0.05), subjective satiety (P < 0.05), and fullness (P = 0.06) were significantly different from response patterns after the meal with the control starch. Thus, a flattening of the glucose curve, a lower insulin and gastric inhibitory polypeptide response, and higher fullness ratings were observed after the meal with the beta-cyclodextrin starch. Satiety ratings were higher after both meals with modified starch than after the meal with the control starch. In conclusion, a minor modification insulinemic (1-2%) of native potato starch improved the glycemia, insulinemic, and satiating properties of a meal. This was especially true for the beta-cyclodextrin-enriched starch. Slower gastric-emptying rate or delayed intestinal absorption of the modified starch may explain the observed differences.

A Study of Native and Chemically Modified Potato Starch. Part II: Digestibility in the Rat Intestinal Tract

AbstractThe in vivo digestibility of the following chemically modified potato starch derivatives was evaluated in rats; distarch phosphate (DSP), acetyl di‐starch phosphate (ADSP) and hydroxypropyl di‐starch phosphate (HPDSP). Unmodified potato starch was used as reference. The starches were studied raw and after gelatinization by drum‐drying. The extent of in vivo digestion was evaluated through balance experiments in normal rats (apparent digestibility) and in rats treated with an antibiotic drug to suppress hind‐gut fermentation (true digestibility). Starch digestibility was calculated from direct measurement of starch in feed and faeces. Three different methods for starch analysis were compared.The apparent digestibility of raw potato starches was low, ranging from 50 (HPDSP) to 84% (ADSP). The true digestibility of gelatinized unmodified potato starch was essentially complete and was not affected to any appreciable extent as a result of cross‐linking or acetylation. In contrast, etherification with hydroxypropyl significantly reduced the extent of digestion and absorption to a low level, about 50%, which was not significantly different from that with the corresponding raw material. Thus, the digestibility of the HPDSP derivative was not improved by gelatinization. The maldigested hydroxypropylated starch fraction was only metabolized to a limited degree by the hind‐gut microorganisms.

Studies on the Utilization of Various Starches and Sugars in the Rat

Various types of dietary carbohydrates were fed to growing rats for 28 days with either casein or wheat gluten as the source of dietary protein. Unmodified potato starch and potato amylose resulted in increases in body weight gains and enlarged ceca when casein supplied a dietary protein level of 6%. The same effect was shown when wheat gluten was the dietary protein at either a 9 or 15% protein level. These 2 sources of carbohydrate gave relatively poor weight gains and protein efficiency values when the casein level of the diet was increased to 15% protein. Unmodified corn, wheat, rice, tapioca, and amioca starches, as well as maltose, corn amylopectin, and potato amylopectin gave normal body weight gain values, protein efficiency ratios and ceca weights at both the high and low dietary protein levels. Lactose, unmodified arrowroot starch, fructose, and dextrose gave inferior body weight gains and protein efficiency values. The prevalance of diarrhea and an enlargement of the ceca gave evidence that commercial samples of corn dextrin and pregelatinized amioca starch were not as well utilized as unmodified corn starch or unmodified amioca starch.

The influence of dietary carbohydrate on levels of amino acids in the feces of the white rat.

The effect of various carbohydrates on the levels of amino acids excreted in the feces of rats has been studied. Potato starch, autoclaved potato starch, or dextrin each induced much greater levels of amino acids in the feces than either sucrose or glucose. The amino acids appear to be derived mainly from endogenous nitrogen. However, when rats were fed rations containing unmodified potato starch, undigested dietary protein apparently contributed a significant amount of the amino acids found in the feces. The inclusion of 10% lactose in a ration containing sucrose as the source of carbohydrate caused a statistically significant increase in the levels of lysine and histidine in the feces. The influence of lactose may be related to changes in the intestinal flora. The incorporation of ammonium salts into 9% casein diets had no significant effect on the amounts of amino acids in the feces.

The inadequacy of unmodified potato starch as dietary carbohydrate for the albino rat.

Unmodified (raw) potato starch was poorly utilized, whereas unmodified corn starch and wheat starch were almost completely digested by the rat. The ingestion of unmodified potato starch caused a distention of the caecum and intestines. This enlargement resulted from the accumulation of food residue in the caecum and the consequent formation of gas from fermentation. The utilization of unmodified potato starch was not appreciably improved by the inclusion of either lactose or sucrose in the ration. However, the utilization of potato starch by the rat was improved when the starch was heated in an autoclave at 120° C, in a dry oven at 145° C, or was finely ground. During digestion studies performed in vitro with pancreatin pronounced hydrolysis of both corn starch and wheat starch occurred, but hydrolysis of unmodified potato starch was very slight. Ground potato starch was hydrolyzed very rapidly. The low digestibility of unmodified potato starch was attributed to the resistance of the outermost layer or layers of the granules to attack by alpha-amylase.