Cooked Potato Starch Research Articles

Mechanistic insights into the influence of flavonoids from dandelion on physicochemical properties and in vitro digestibility of cooked potato starch

Flavonoids extracted from a potential edible dandelion were found to exhibit a high level of pancreatic α-amylase inhibitory activity. However, the effects of dandelion flavonoids on starch physicochemical properties and in vitro digestibility have not yet been examined. This study investigated the crystalline characteristics, infrared spectrum, rheology, thermal behavior and microstructure, and enzymatic hydrolysis of cooked potato starch in the presence of dandelion flavonoids, aiming to quantify the interactions between starch and dandelion flavonoids. The textural parameters and moduli of cooked starch pastes decreased significantly with the addition of flavonoids. Compared with the pure starch paste, the starch-flavonoids complex pastes exhibited a looser gel network structure. The digestion rate coefficient ( k ) and terminal digestibility ( C ∞ ) were significantly decreased from 0.119 to 0.083 1/min and 94.6% – 75.8%, respectively, resulting in a significant increase in resistant starch (RS) content in the presence of 10% dandelion flavonoids. The decline in the rate and extent of starch hydrolysis was mainly attributed to the interaction between starch and dandelion flavonoids through non-covalent bonding, as evidenced by XRD and FT-IR data. The interaction might hinder starch digestion by limiting the availability of starch substrate to amylase, as well as restricting gelatinization of starch granules during cooking, which were supported by the increased crystallinity, higher gelatinization temperatures and enthalpy change with flavonoids addition. The present study demonstrates that dandelion flavonoids can potentially be used as a functional additive for making low glycemic index (GI) diets for managing human health. • Interactions between cooked potato starch and dandelion flavonoids were studied. • Hardness and modulus decreased in the starch pastes with the flavonoids added. • Starch hydrolysis decreased with increasing flavonoids addition. • Dandelion flavonoids protected starch from gelatinization during cooking. • The decreased starch hydrolysis mainly due to the formation of flavonoids-starch complex.

Analysis of kinetic parameters and mechanisms of nanocrystalline cellulose inhibition of α-amylase and α-glucosidase in simulated digestion of starch.

This study evaluated the in vitro inhibitory influence of particle size of nanocrystalline cellulose (NCC) fractions against α-amylase and α-glucosidase using cooked potato starch-protein food model system. The kinetics of the resulting inhibitions in the presence of NCC of the two tested enzymes were examined and characterised. Both the size and dose of NCC significantly (p < 0.05) inhibited α-amylase and α-glucosidase by modulating the rate of hydrolysis of starch in the food model system lower than that of the control (no added fibre). At equal concentrations of each NCC fraction, the smallest particle size (≤125 nm) exhibited the highest potency as an inhibitor (median inhibitory concentration (IC50) = 2.98 mg mL-1 and 4.57 mg mL-1 for α-amylase and α-glucosidase, respectively). Increasing concentrations of each NCC fraction caused an apparent significant decrease in Vmax values (p < 0.05) with insignificant change in the Km values for both the tested enzymes. Furthermore, binding assays demonstrated that NCC particles may bind to the two tested enzymes in a non-specific manner. Analysis of the kinetics of the enzymes suggested that the mechanism of inhibition showed that the two tested enzymes mainly exhibited non-competitive mode of inhibition. The observed inhibition of the two tested enzymes suggests that reducing the cellulose size ≤125 nm may enhance its inhibition potency and potentially attenuate starch hydrolysis when added to diet.

Inhibition of starch digestion by gallic acid and alkyl gallates

As phenolic compounds, alkyl gallates may inhibit the activity of digestive enzymes for starch. Furthermore, their alkyl chains may facilitate starch inclusion complexation and results in an increased resistant starch (RS) content or slowly digestible starch (SDS) content, which may further retard starch digestion. The significance of such inhibition is that the rate of starch hydrolysis into glucose is reduced, thereby preventing hyperglycemia and related metabolic diseases. This study examined the inhibitory effects on in vitro enzymatic digestion of starch by gallic acid and five alkyl gallates of varying alkyl chain lengths, i.e., butyl gallate, octyl gallate, dodecyl gallate, hexadecyl gallate, and octadecyl gallate. Raw and cooked potato starch (PS) and high-amylose maize starch (HAMS) were tested. For both types of raw starch, gallic acid and all the alkyl gallates significantly (p < 0.05) increased RS content except for octadecyl gallate. In the case of cooked starch, the RS contents were markedly decreased (p < 0.05) as compared to those in raw starch, because gelatinization caused an overall greater susceptibility to enzymatic digestion. The reduction in RS content was less in cooked HAMS than that in cooked PS, due to a higher gelatinization temperature range of HAMS. The aforementioned effect of gallates on RS content was also found for cooked PS, while cooked HAMS experienced increased RS only with gallic acid and butyl gallate. Overall, for the digestion of both starches, regardless of raw or cooked, gallic acid and alkyl gallates with shorter chains demonstrated the strongest inhibitory effects. Our findings indicate that shorter alkyl gallates are effective in inhibiting enzymatic digestion of starch and therefore may have potential in modulating glycemic response.

Effect of different sources and forms of dietary carbohydrates on growth performance, body indices and lipogenesis activity of striped catfish Pangasianodon hypophthalmus fingerlings

A 12‐week feeding trial was conducted to determine a suitable carbohydrate source and form for Pangasianodon hypophthalmus. Ten isoenergetic, isonitrogenous and isolipidic diets, including five carbohydrate sources (dextrin, potato starch, wheat starch, corn starch and sago starch) and two carbohydrate forms (raw and cooked), were formulated. Results showed that specific growth rate, weight gain percentage, whole‐body lipid and 6‐phosphogluconate dehydrogenase enzyme activity of fish fed with cooked carbohydrates were significantly lower (p < .05) than those fed with raw carbohydrates (p < .05). Similarly, the fatty acid synthase enzyme activity of fish fed with the cooked form of carbohydrates was significantly lower (p < .05) than that fed with the raw form of carbohydrates except fish fed with cooked potato starch. The blood glucose level and malic enzyme activity of fish fed with cooked carbohydrate were significantly (p < .05) higher than those fed with raw carbohydrate. In summary, this study showed that cooked starch is an unsuitable dietary carbohydrate form for Pangasianodon hypophthalmus fingerlings. The raw forms of dextrin starch and potato are suitable dietary carbohydrate sources for further scientific studies on the carbohydrate utilization of P. hypophthalmus.

Purification and characterization of extracellular amylase from the marine yeast Aureobasidium pullulans N13d and its raw potato starch digestion

The extracellular glucoamylase in the supernatant of the cell culture of the marine yeast Aureobasidium pullulans N13d was purified to homogeneity with a 7.3-fold increase in specific activity as compared to the concentrated supernatant by ammonium sulfate fractionation and gel filtration chromatography (Sephadex™ G-75). According to the data on native polyacrylamide gel electrophoresis, the molecular weight of the purified enzyme was 98 kDa. However, the data on SDS polyacrylamide gel electrophoresis show that the purified enzyme consisted of two subunits whose molecular weights were 65 and 33 kDa, respectively. The optimal pH and temperature of the purified enzyme were 4.5 and 60 °C, respectively. The enzyme was activated by Ca 2+, Ba 2+, Na +, Cu 2+, Mg 2+ and Co 2+ and stabilized by CaCl 2. On the other hand, Hg 2+ and Ag + inhibited the enzyme. The enzyme was inhibited by EDTA, EGTA and SDS, but was not inhibited by iodoacetic acid and PMSF. K m and V max values of the purified enzyme for soluble starch were 5.75 ± 0.3 mg/ml and 0.25 ± 0.02 mg/ml/min, respectively. Among raw potato starch, corn starch and sweet potato starch tested, all of them were absorbed by the purified enzyme, but only raw potato starch was digested by the purified enzyme. 15.8% of raw potato starch (1.0%, w/v) and 21.1% of cooked potato starch (1.0%, w/v) were hydrolyzed within 30 min by 0.5 U/mg starch of the purified enzyme and only glucose was detected in the hydrolysate, indicating that the enzyme was glucoamylase with debranching activity.

Potato-lactulose breath hydrogen testing as a function of gastric motility in diabetes mellitus.

Scintigraphic determination of gastric emptying is the current standard for the assessment of gastric motility and the diagnosis of diabetic gastroparesis. However, such studies are expensive, inconvenient, and involve exposure to radiation. Because the time course of breath hydrogen (H2) excretion after ingestion of lactulose correlates with upper gastrointestinal transit time, we hypothesized that patients with diabetic gastroparesis would exhibit prolonged breath H2 excretion after ingestion of a test meal containing complex carbohydrate and lactulose compared to subjects without diabetes and subjects with diabetes but without gastroparesis. Ten healthy subjects without diabetes, 10 subjects with diabetes but without gastroparesis (gastric emptying T1/2,T1/2 < 90 minutes), and 10 subjects with diabetes and previously diagnosed gastroparesis (T1/2 > 90 minutes) were admitted for a single 24-hour study. Gastric motility agents were withheld 24 hours prior to the study. Euglycemia was established and maintained overnight in subjects with diabetes with continuous intravenous insulin infusion. At 6:00 AM, all subjects ingested a breakfast containing 100 g of cooked potato starch and 20 g lactulose. Breath H2 excretion was monitored at baseline and every 30 minutes for 12 hours after ingestion of the test meal. Twelve hours after ingestion of the test meal, raw and baseline adjusted breath H2 excretion was significantly elevated in the gastroparesis group compared to the unaffected group with diabetes and the group without diabetes (p < 0.001). The baseline and 12-hour data points were adequate to discriminate between normal and delayed gastric emptying. We conclude that patients with previously diagnosed gastroparesis exhibit prolonged breath H2 excretion after ingestion of a test meal. This test may prove to be a safe, reliable, and affordable outpatient screening test for diabetic gastroparesis.

Consumption of Raw Potato Starch Alters Intestinal Function and Colonic Cell Proliferation in the Rat

Raw potato starch (RPS) may escape complete digestion to enter the colon and produce alterations in colonic function, while cooked potato starch (CPS) is nearly completely digested in the rat small intestine. Effects of RPS and CPS on colonic function [fecal weight, transmit time and thymidine kinase (TK) activity (a marker for cell proliferation)] were contrasted in a 6-wk feeding study. Male F344 rats consumed either dextrose/sucrose (DS; control), 30% CPS or 30% RPS diet. RPS feeding resulted in a 3-fold increase in fecal weight and a 30% prolongation in transit time, as well as elevated levels of colonic mucosal total protein (50%) and TK activity (4- to 7-fold) compared to DS-fed rats. A second study revealed normal large intestinal histology in rats fed CPS or RPS, with elongated colonic crypts (33% increased over CPS) in group RPS. Large intestinal contents were heavier in group RPS than in group CPS. These studies demonstrate that RPS feeding significantly enhances fecal weight yet prolongs total gastrointestinal transit time. Enhanced colonic TK and elongated colonic crypts suggest that RPS stimulates colonic mucosal growth.

Effect of thermal treatment of potato products on nutrient decomposition in the digestive tract of swine. 1. Passage and digestibility of nutrients in the various portions of the intestine

In addition to a basic ration (barley, dried green fodder, fishmeal) pigs (castrated males, 100 ... 130 kg live weight) received a supplement of raw potato starch, raw ensiled potatoes, cooked potato starch or steamed ensiled potatoes; nutrient and amino acid passage and digestibility (absorption) were measured in the small intestine, the upper large intestine and the total digestive tract with the help of simple cannulae at the distal ileum and the middle of the hind gut and the estimation of the HCl insoluble ash as an indicator. In addition, the amounts of bacteria in faeces were determined and the influence of raw and cooked potato starch on N retention was ascertained. When raw potato products were fed, distinctly higher amounts of dry matter, organic matter and starch pass the ileum, which get into the colon undigested, i.e. the digestibility of these substances is low at the end of the ileum (raw potato starch 24%, starch of raw ensiled potatoes 36%). Up to the middle of the colon there is intensive bacterial starch degradation so that in this place the difference between raw and thermically treated potatoes is only small. No matter what the previous treatment of the potatoes was, there is hardly any starch in faeces, i.e. it was nearly 100% digested up to the end of the digestive tract. The passage and digestibility resp. of ash and crude cellulose from the basic ration is not influenced by the supplement of raw or thermically treated potato products in the individual sections of the digestive tract. At the end of the ileum there are no differences between the apparent digestibility of the crude protein and absorption of amino acids of supplemented raw or cooked potato starch or steamed ensiled potatoes; after the use of raw ensiled potatoes they are, however, significantly more reduced than the comparison of analyses of faeces shows. In the large intestine the high amount of potato starch stimulates the metabolism and the reproduction of faecal bacteria as is shown by an increase by 20-30% in bacteria N excretion in faeces. Apparent crude protein digestibility and amino acid absorption are diminished by that. The increased N excretion in faeces after the supplement of raw potato starch to the basic ration is-in comparison with the supplement of heated starch-compensated by a commensurately lower N excretion in urine so that N retention practically remains uninfluenced by the supplement of variously treated potato starch.(ABSTRACT TRUNCATED AT 400 WORDS)

Dietary fiber and cholesterol metabolism in rabbits and rats ,

Rabbits fed semipurified diets have elevated plasma cholesterol levels, and they oxidize [26-14C]cholesterol to expired 14CO2 more slowly than rabbits on a natural ingredient diet. Addition of several different types of fibrous material to a semipurified diet failed to prevent the hypercholesterolemic response. Rats on semipurified diets also oxidized [26-14C]cholesterol more slowly and tended to have somewhat higher plasma cholesterol levels than rats on commercial feed. Cholesterol oxidation was not stimulated by addition of fibrous materials to the semipurified diet, but rats fed a semipurified diet containing raw potato starch oxidized cholesterol at a rate comparable to that of rats on commercial diet. Raw potato starch was poorly digested by the rats. Cooked potato starch was well digested and failed to stimulate the rate of oxidation of cholesterol. A semipurified diet containing raw potato starch did not produce a hypercholesterolemic response in rabbits, even though the raw starch was well digested.

The potato ( Solanum tuberosum) as a source of nutrients for pigs, calves and fowl — A review

Potatoes outyield cereals in terms of nutrients produced per hectare, but the nutritive worth of the potato as an animal feed has long been disputed. Conventional descriptions of nutritive content, such as are satisfactory for cereals, are inadequate for the potato. The potential of the potato as an alternative to cereals as a source of nutrients can only be realised if predictable animal responses are obtained to potato feeding. The review attempts to quantify those factors which influence the nutritive value of potatoes and thereby to enable appropriate dietary inclusion levels of potato and potato products to be made. Potato products are diverse because of the many different processing methods. Potatoes may contain alkaloid toxins and trypsin inhibitor activity, while the concentration of starch and the quality of potato protein appear to be second to none amongst vegetable sources. Potato dry matter (DM) contains 17 MJ gross energy (GE)/kg and 13–17 g N/kg, the protein fraction being of biological value about 70. Cooked potato has a digestible energy (DE) content in the region of 16.0 MJ DE/kg DM for pigs, and a metabolizable energy (ME) content of 13.6–15.0 MJ ME/kg DM for fowl. Digestibility coefficients for energy and N in cooked potato are about 0.95 and 0.85 respectively for pigs, and 0.95 and 0.80 for fowl, while the digestibility of cooked potato starch for calves increases from 0.50 at 10 days of age to 0.74 at 24 days. The digestibility of raw potato is lower and more variable, particularly for N; digestibility coefficients for pigs range from 0.76 to 0.92 for energy and from 0.23 to 0.76 for N. In the case of fowl, digestibility coefficients as low as 0.22 and 0.36 have been determined for raw potato organic matter and N respectively. Cooked potato is of approximately equivalent nutritive value to maize, whereas raw potato is usually associated with a reduction in animal performance. Cooked potato products are particularly appropriate for inclusion in pig diets. With calves, potato has been associated in some instances with digestive disturbances, while the inclusion of potato in diets for poultry tends to increase the moisture content of the excreta.

Paper electrophoresis of serum in rats fed various carbohydrate diets.

SummaryThe effect of various carbohydrates on the serum protein and serum protein fractions in rats have been investigated. Without L-lysine supplementation, rats fed raw or cooked potato starch showed the lowest serum protein and serum albumin concentration; whereas rats fed glucose showed the highest serum albumin concentration. Lysine supplementation increased serum protein and serum albumin concentration in rats regardless of the sources of carbohydrates. The type of carbohydrate in the diet influences the serum protein pattern in rats,