Production of Resistant Starch by Roasting Retrograded Starch with Glucose.

Starch is a natural plant raw material applicable in many areas of industry. In practice, it is most often used in a modified form, i.e., after various treatments aimed at modifying its properties. Modifications of native starch enable producing resistant starch, which, as a prebiotic with confirmed health-promoting properties, has been increasingly used as a food additive. The present study aimed to determine the effect of roasting retrograded starch with the addition of anhydrous glucose at different temperatures (110, 130 or 150 °C) and different times (5 or 24 h) on the modified starch's properties. The results of high-performance size-exclusion chromatography coupled with refractive index detector (HPSEC/RI) analysis and the changes observed in the solubility of starch roasted with glucose in DMSO, as well as in its other properties, confirm the changes in its molecular structure, including thermolytic degradation and the ongoing polymerization of starch with added glucose.

An Attempt to Replace Pure Citric Acid with Natural Lemon Juice during Potato Starch Esterification.

The application of chemical operations in food processing, in which pure chemical compounds are used to modify food ingredients, often raises social concerns. One of the most frequently modified dietary substances is starch, e.g., E1401-E1404, E1412-E1414, E1420, E1422, E1440, E1442, and E1450-E1452. An alternative solution to chemical treatments seems to be the use of raw materials naturally containing substrates applied for starch modification. Heating starch with a lemon juice concentrate can be considered a novel and effective method for producing starch citrate, which is part of the so-called "green chemistry". The modified preparations obtained as a result of potato starch esterification with natural lemon juice had a comparable degree of esterification to that of the esters produced with pure citric acid. In addition, the use of the juice doubled their resistance to amylolytic enzymes compared to the preparations made with pure acid. Replacing citric acid with lemon juice can facilitate the esterification process, and the analyzed properties of both types of modified preparations indicate that starch esters produced with pure citric acid can be successfully replaced by those produced using natural lemon juice, which may increase the social acceptance of these modified preparations.

Effect of Long-Term Potato Starch Retention with Citric Acid on Its Properties.

The present study aimed to determine changes in the properties of starch triggered by its long-lasting (1, 2, 4, 7, 10, or 14 days) retention with citric acid (5 g/100 g) at a temperature of 40 °C. The starch citrates obtained under laboratory conditions had a low degree of substitution, as confirmed via NMR and HPSEC analyses. The prolonging time of starch retention with citric acid at 40 °C contributed to its increased esterification degree (0.05-0.11 g/100 g), swelling power (30-38 g/g), and solubility in water (19-35%) as well as to decreased viscosity of the starch pastes. Starch heating with citric acid under the applied laboratory conditions did not affect the course of DSC thermal characteristics of starch pasting. The low-substituted starch citrates exhibited approximately 15% resistance to amylolysis.

The Annealing of Acetylated Potato Starch with Various Substitution Degrees.

This study aimed to determine the effect of "annealing" acetylated potato starch with a homogenous granule size and various degrees of substitution on the thermal pasting characteristics (DSC), resistance to amylases, rheology of the prepared pastes, swelling power and dynamics of drug release. A fraction of large granules was separated from native starch with the sedimentation method and acetylated with various doses of acetic anhydride (6.5, 13.0 or 26.0 26 cm3/100 g starch). The starch acetates were then annealed at slightly lower temperatures than their pasting temperatures. The annealing process caused an almost twofold increase in the resistance to amylolysis and a threefold increase in the swelling power of the modified starch preparations. The heat of phase transition decreased almost two times and the range of starch pasting temperatures over two times, but the pasting temperature itself increased by ca. 10 °C. The 40 g/100 g addition of the modified starch preparation decreased the rate of drug release from a hydrogel by ca. one-fourth compared to the control sample.

Assessment of the Content of Glycoalkaloids in Potato Snacks Made from Colored Potatoes, Resulting from the Action of Organic Acids and Thermal Processing.

Glycoalkaloids (TGAs, total glycoalkaloids), toxic secondary metabolites, are found in potatoes (110-335 mg·kg-1 DW), mainly in the peel. Colorful, unpeeled potatoes are an innovative raw material for the production of snacks which are poorly tested in terms of their glycoalkaloid content. Third-generation snacks and French fries made from red-fleshed Mulberry Beauty (MB) and purple-fleshed Double Fun (DF) potatoes were produced with the use of 1% solutions of ascorbic, citric, lactic, malic, and tartaric acids to stabilize the structure of anthocyanins in the raw material and maintain their color in obtained products. The influence of the type of acid and thermal processes, like frying, microwaving, and baking, on the content of glycoalkaloids in ready-made products was examined. Only 0.45-1.26 mg·100 g-1 of TGA was found in pellet snacks and 1.32-1.71 mg·100 g-1 in French fries. Soaking blanched potatoes in organic acid solution reduced the α-chaconine content by 91-97% in snacks and by 57-93% in French fries in relation to the raw material to the greatest extent after the use of malic acid and the DF variety. The effect of lactic and citric acid was also beneficial, especially in the production of baked French fries from MB potatoes.

Effect of resistant starch RS4 added to the high-fat diets on selected biochemical parameters in Wistar rats.

BACKGROUND: Resistant starch (RS) is part of potato starch that is not digested in the gastrointestinal tract. RS4 is a chemically modified starch (for example by oxidation and esterification) and physically (by heating). OBJECTIVE: The study was aimed at determining the effect of resistant starch on lipid metabolism and activity of hepatic enzymes in Wistar strain rats fed high-fat diets containing 15% of lard or 15% of soybean oil. MATERIAL AND METHODS: Four types of diets were administered to the animals (4 groups of males, n = 32): control diet (K1) containing 15% of soybean oil; control diet (K2) containing 15% of lard as well as two groups receiving the same diets with 10% addition of resistant starch RS4 (K1S and K2S). RESULTS: The mean concentration of total cholesterol was lower in the group of animals fed a diet with vegetable oil (39.9 mg/dl) as compared to that reported in the group of rats fed the lard-supplemented diet (55.2 mg/dl). Compared to the control groups in both groups of animals receiving the diet supplemented with resistant starch RS4 the total cholesterol concentration in serum decreased by ca. 25% (differences were statistically significant). In groups of rats receiving oil- or lard-containing diets with the addition of the resistant starch preparation the concentration of triglycerides in serum decreased by ca. 47% and 10%, respectively. CONCLUSIONS: A beneficial effect of the resistant starch RS4 added to Wistar rats diets on the lipid metabolism has been shown. The concentrations of total cholesterol and triglycerides in the serum were lower and concentration of HDL-cholesterol was higher in the rats fed with the diets containing the addition of the RS4 preparation as compared to the control groups. Based on the activity of hepatic enzymes the degree of liver damage was lower in groups of rats fed with diets containing resistant starch RS4 as compared to the control groups.

Physical Properties of Starches Modified by Phosphorylation and High-Voltage Electrical Discharge (HVED).

High-voltage electrical discharge (HVED) is considered as a novel, non-thermal process and is currently being researched regarding its effect on microorganisms (decontamination of food), waste water treatment, and modification of different compounds and food components. In this paper, four native starches (maize, wheat, potato, and tapioca) were treated with HVED, phosphorylated with Na2HPO4 and Na5P3O10, and modified by a combination of HVED with each phosphorylation reaction both prior and after chemical modification. Pasting properties, swelling power, solubility, gel texture, and particle size were analyzed. Although HVED induced lower contents of P in modified starches, it had an effect on analyzed properties. The results revealed that HVED treatment alone had a limited effect on pasting properties of starches, but it had an effect on properties of phosphorylated starches, both when it was conducted prior and after the chemical modification, reducing the influence of Na5P3O10 and Na2HPO4 on the decrease of pasting temperature. With minor exceptions, the gel strength of starches increased, and the rupture strength decreased by all modifications. HVED treatment resulted in a decrease of the particle size after the modification of maize and wheat starches, while potato and tapioca starches were not significantly influenced by the treatment.

Phosphorylation of Maize Starch Enhanced with High-Voltage Electrical Discharge (HVED) Instead of Thermal Treatment.

The aim of this research was to explore the use of a high-voltage electrical treatment (HVED) as a substitute for heating during the phosphorylation of maize starch. Starch was treated with HVED, phosphorylated with Na2HPO4 or Na5P3O10 with and without thermal treatment and phosphorylated in combination with HVED prior to and after the chemical modification. When starch was phosphorylated with Na2HPO4, HVED was more efficient in catalyzing reaction (3.89 mg P/kg for 30 min HVED in relation to 0.43 mg P/kg for thermal treatment), whereas with Na5P3O10 similar P content was achieved as with thermal treatment (0.76 P/kg for 30 min HVED in relation to 0.86 mg P/kg). The order of HVED and chemical reactions did not have a marked effect on phosphorous content. In combination with Na2HPO4, HVED pre-treatment had a more pronounced effect on the solubility and water absorption, whereas post-treatment was favoured with Na5P3O10. Mean diameter was increased by all treatments, where HVED had a marked effect. Enthalpy of gelatinization ranged from 11.76 J/g for starch treated with Na5P3O10 and 10 min-HVED to 13.58 J/g for Na5P3O10 treated sample. G' and G″ increased after both thermally and HVED enhanced phosphorylations, with a slightly more pronounced effect of the HVED.

Physicochemical Properties and Digestion Resistance of Acetylated Starch Obtained from Annealed Starch.

One of the examples of physical starch modifications is the retention of a starch suspension in water having a temperature slightly lower than the pasting temperature (annealing). The aim of this study was to investigate the effect of the annealing process performed at various temperatures as the first stage of starch modification. The annealed starch preparations were then esterified using acetic acid anhydride. Finally, the annealed and acetylated starch preparations were determined for their properties. The annealing of starch before acetylation triggered changes in the properties of the modified preparations. It contributed to a higher degree of starch substitution with acetic acid residues and to the increased swelling power of starch. Both these properties were also affected by the annealing temperature. The highest resistance to amylolysis was found in the case of the starch preparation annealed at 53.5 °C and acetylated. The double modification involving annealing and acetylation processes increased the onset and end pasting temperatures compared to the acetylation alone. Similar observations were made for the consistency coefficient and yield point.

Properties of Potato Starch Roasted with Apple Distillery Wastewater.

This study aimed to produce starch esters by roasting potato starch with apple distillery wastewater at various temperatures and aimed to determine the effects of esterification conditions on selected properties of the modified preparations. Apple distillery wastewater was concentrated, mixed with starch (30 g of dry matter per 100 g of starch), dried, and roasted at temperatures of 110, 130 or 150 °C for 3 h. The resulting preparations were rinsed 30 times with a 60% ethanol solution, dried, and disintegrated. After that, the following analyses were performed: content of substituted acids (after alkaline de-esterification) with high performance liquid chromatography (HPLC); thermal characteristics with differential scanning calorimetry (DSC); swelling power and solubility in water at 80 °C; color changes with a colorimeter; rheology of the pastes based on the plotted flow curves; and the pastes' resistance to amyloglucosidase. Starch treatments with apple distillery wastewater at 130 and 150 °C caused significant changes to its properties when compared to the control samples of native starch and starch roasted without wastewater, including: a lower temperature and heat of pasting, lower swelling power and solubility in water, darker color, higher resistance to amyloglucosidase, and the formation of pastes with a lower viscosity.

Effect of the Botanical Origin on Properties of RS3/4 Type Resistant Starch.

This study aimed to compare properties of retrograded starch acetates with an identical degree of substitution, but produced from raw materials of various botanical origin. Retrograded starch was produced from potato, wheat, corn, and tapioca starch, and afterwards acetylated with an acetic acid anhydride, adjusting reagent doses to achieve an identical degree of esterification of the modified preparation (2.1 g/100 g). Preparations of retrograded starch and acetylated retrograded starch differed significantly in their properties, which was due to the disparate botanical origin of starch. The highest susceptibility to acetylation was demonstrated for potato starch, and the lowest one for wheat starch. Acetylation of retrograded starch of various botanical origin increased its solubility in water, swelling power and viscosity of its pastes, as well as decreased its amylose content. Preparations of acetylated retrograded starches of disparate botanical origins may be deemed preparations of RS3/4 type resistant starch because they exhibit significant (23.5⁻34.0%) resistance to the activity of amylolytic enzymes.

The Influence of Chemically Modified Potato Maltodextrins on Stability and Rheological Properties of Model Oil-in-Water Emulsions.

The aim of this study was to determine the effect of the maltodextrins prepared from chemically modified starches (crosslinked, stabilized, crosslinked and stabilized) on the stability and rheological properties of model oil-in-water (o/w) emulsions. Based on the obtained results, it was concluded that emulsion stability depended on hydrolysates dextrose equivalent (DE) value. Maltodextrin with the lowest degree of depolymerization effectively stabilized the dispersed system, and the effectiveness of this action depended on the maltodextrin type and concentration. Addition of distarch phosphate-based maltodextrin stabilized emulsion at the lowest applied concentration, and the least effective was maltodextrin prepared from acetylated starch. Emulsions stabilized by maltodextrins (DE 6) prepared from distarch phosphate and acetylated distarch adipate showed the predominance of the elastic properties over the viscous ones. Only emulsion stabilized by maltodextrin prepared from distarch phosphate (E1412) revealed the properties of strong gel. Additionally, the decrease in emulsions G' and G″ moduli values, combined with an increase in the value of DE maltodextrins, was observed.