Formation Of Resistant Starch Research Articles

Amylosucrase-modified waxy potato starches recrystallized with amylose: The role of amylopectin chain length in formation of low-digestible fractions

This study examined the contribution of amylose to the organization of each starch fraction in recrystallized starch. Amylosucrase (AS)-modified waxy potato starches with different branch chain lengths were completely solubilized with amylose (3:1 ratio) and recrystallized at 4 °C for 48 h. The content of rapidly digestible starch and resistant starch (RS) showed linear change with degree of AS modification, while slowly digestible starch (SDS) did not. The changes in structural characteristics were tracked according to serial removal of each fraction. Results from iodine binding property, branch chain length, X-ray diffraction, and thermal property analysis indicated that branch chain length of amylopectin determined the length of the amylose-amylopectin double helix and the mobility of amylose and that formation of SDS or RS could be induced by controlling the length of amylopectin chains. These findings could be used for production of customized starches with specific digestive properties for health benefits.

Effects of water-deficit and high-nitrogen treatments on wheat resistant starch crystalline structure and physicochemical properties

This work investigated the effects of water-deficit and high-nitrogen (N) treatments on wheat resistant starch (RS) formation, molecular structure, and physicochemical properties. The results of consecutive 2-year field experiments revealed that water deficit significantly reduced starch granule number and diameter, amylose, RS content, RS particle size distribution, and physicochemical properties, including peak and trough viscosities, oil absorption capacity, and freeze-thaw stability. Water deficit also altered the long- and short-range structures of RS. In contrast, high-N fertilizer application significantly improved the RS content, long- and short-range structures, and physicochemical properties. Pearson correlation analysis revealed that RS content was positively correlated with total starch, amylose, rapidly digesting starch, 90th percentile of RS particle size, relative crystallinity, infrared 1047/1022 cm−1 ratio, peak and breakdown viscosities, oil absorption capacity, and freeze-thaw stability, and was negatively correlated with slowly digestible starch content, 1022/995 cm−1 ratio, and final viscosity.

Citrate esterification of debranched waxy maize starch: Structural, physicochemical and amylolysis properties

Considering that the content of resistant starch (RS) in original starch is very low, chemical modification is one of choices to increase RS level for enhancing its application. The current study applied debranched waxy maize starch (DBS) to produce a citrate-esterified debranched starch (CADS) and investigated impact of the modification on RS formation. Native starch was also citrate esterified without debranching treatment as the control (CANS). Physicochemical and digestion properties of each sample were characterized, and the results indicated an absorption at 1724 cm −1 in FTIR spectrum was determined in either CADS or CANS, indicating the occurrence of the esterification. Debranching of starch molecules led to a higher degree of substitution (DS) of 0.793 for CADS than CANS. Furthermore, re-association of debranched starch achieved a B type crystalline pattern rather than an A type from its native starch granules. Esterification greatly destroyed crystalline regions until completely disappeared in CADS. The loss of crystalline region was highly consistent with the absence of endothermic peak both in CADS and CANS as revealed by DSC. Hydrolysis rate and digestibility of each sample followed the order: native starch > DBS > CANS > CADS, which may indicate that the introduction of the citric anhydride onto the starch molecules led to an increased space steric hindrance that delayed the enzyme contacting within glucosidic bonds. It could be the first report to prepare a citrate-esterified debranched starch with a higher resistance to amylolysis, and the current investigation may highlight a potent to produce a starch derivative with a higher RS content.

Physicochemical Properties and Digestibility of Heat Moisture–Treated Potato Starches for Different Treatment Conditions

Potato starch was subjected to heat moisture treatment (HMT) in which the temperature and moisture content were varied. Two different levels of moisture content (30 and 35%) and temperature (100 and 120 °C) were selected. The crystallinity of the starches decreased after HMT, as confirmed by both X-ray diffraction (XRD) and Fourier Transform Infra-Red (FT-IR) analysis, and the XRD pattern of native starch changed from B-type to A+B type after HMT. Swelling, solubility, clarity and freeze-thaw stability of the HMT starches were less than native starch and were found to be dependent on both temperature and moisture content. Pasting viscosities of the modified starches were significantly lower than native starch and were found to be more for the starches treated at 120 °C than the starches at 100 °C. The pasting temperature increased after modification. The firmness of the modified starch pastes increased whereas the consistency decreased. The formation of resistant starch increased after HMT.

Physicochemical properties of starch obtained from Curcuma karnatakensis - A new botanical source for high amylose content

Curcuma karnatakensis, a member of Zingiberaceae, is endemic to the state of Karnataka, India. The structure and physicochemical properties of starch isolated from rhizomatous rootstocks of two samples - A and B were analyzed for the first time. Sample A contains 76.4 ± 0.3% of starch, of which 86.6 ± 0.4% is amylose, while sample B has 75.0 ± 0.4% of starch containing 84.6 ± 0.4% of amylose according to UV-Vis spectrophotometric analysis. The shape of the starch granules in both the samples is polygonal and cuboidal with a smooth surface, as revealed by SEM studies. The X-ray diffractogram indicated A type of polymorphs in contrast to other Curcuma species, where B types are reported. Since its high amylose content leads to an increased tendency to retrogradation and the formation of resistant starch, this taxon could become one of the major dietary sources of starch in the future. In addition, a source rich in amylose specifies its prospective application in the pharmaceutical and biodegradable film industry.

An in-vitro investigation on the effect of chilling and reheating different starchy meals on resistant starch content

AbstractFood processing has been shown to influence starch digestibility, due to the formation of indigestible starches known as resistant starch (RS). RS has been shown to have similar health promoting properties to those of insoluble dietary fibre. These beneficial effects include lower glycaemic response, improved insulin sensitivity, enhanced overall gut health, and better plasma lipid profile. Additionally, the presence of other nutrients such as proteins or lipids may also impact the amount of RS formed.The present work aimed to measure the effect of cooking and /or additional meal ingredients on the RS content of 5 different starchy meals, 3 made with pasta (one of which had cheese added) and 2 made with potato, using the Megazyme RS kit (K-RSTAR). The cooked meals were tested either freshly cooked, chilled overnight, or chilled overnight and reheated. Moreover, different amounts of fat were used in the test meals (10 g fat per 100 g pasta, 30 g fat per 100 g pasta, 5 g fat per 100 g potato and 10 g fat per 100 g potato) in order to examine the effect of the amount of fat on RS formation. The total number of meals tested was 15.The amount of RS in the 2 pasta meals without cheese were 40% and 44% higher in the chilled and reheated meals compared to the same meals freshly cooked for the 10 g and 30 g of fat meals, respectively. The chilled overnight meals were not different from the freshly cooked meals for both fat amounts. Moreover, the potato meals showed a more substantial difference between the meals for the two fat amounts. The chilled and reheated potato meals were 73% and 85% higher in RS content than the freshly cooked identical meal, in the 5 g and 10 g of fat, respectively. Additionally, the chilled potato meals had higher RS contents compared to freshly cooked potato meals (68% and 83%, respectively). Furthermore, the presence of protein reduced the total amount of digested starch and RS in all pasta meals when compared to the meals without cheese. The findings of this in-vitro investigation suggests that chilling and reheating starchy meals significantly increases their content of RS. Future work will determine if these in vitro findings will translate to health benefits in vivo.

Optimization of an Extrusion Cooking Process to Increase Formation of Resistant Starch from Corn Starch with Addition of Citric Acid

AbstractEffects of extrusion cooking process (ECP) with citric acid (CA) addition on the physicochemical changes and resistant starch (RS) formation in native corn starch (NCS) are evaluated. NCS at different feed moisture levels (18–32%) and CA concentrations (0–10.3%), are subject ECP under constant conditions of screw speed (233 rpm) and die temperature (127 °C). The obtained extrudates are stored at 4 °C for 120 h and then at room temperature. The water absorption index (WAI), water solubility index (WSI), RS content, peak temperature (Tp), ∆H, peak viscosity (PV), setback viscosity (SV), FT‐IR, X‐ray analysis and microstructural (SEM) properties are evaluated. RS content and WSI increased with decreasing moisture content (MC), WAI, PV and SV shows that increases in MC caused an increase, while ∆H and Tp decreases with decreasing MC. SEM shows that ECP with CA destroys the granular structure of NCS generated amorphous structures owing to gelatinization and dextrinization. FT‐IR analysis shows that extruded samples with CA cause starch hydrolysis, increasing the intensity of bands 994 and 1016 cm−1 in comparison to NCS. The highest RS yield (1.15 g/100 g) is obtained at 18% moisture content and 5.2% of CA: an increase of 71% with respect to NCS.

Pullulanase activity: A novel indicator of inherent resistant starch in rice (Oryza sativa. L)

Starch quality studies over the decades highlighted the immense health benefits of resistant starch (RS), but still much is needed to elucidate the science behind its inherent formation. Till date, there is no report to establish the relationship between inherent RS content and pullulanase (PUL) activity in any of the crops. In this study, we emphasize the novel role of debranching enzyme, PUL towards inherent RS formation, using rice as a model crop. Biochemical analysis of 51 rice genotypes for amylose content (AC) revealed a good amount of variation ranging from 7.03 to 37.33%. Further, hierarchical clustering which resulted in 11 genotypes of varying RS (0.33–2.7%), highlighted medium dependency towards amylose and low dependency towards amylopectin content. The discrete differences in microstructure, unimodal distribution and tight packing of starch granules observed in higher RS genotype indicated the higher possibility of compact cluster structure of amylopectin, modulated by PUL. Qualitative and quantitative assays performed validated the relevant role of PUL towards inherent RS content with very high dependency score (R2 = 0.98). This is the first report regarding the fact that higher PUL activity contribute to inherent RS using novel hypothetical 'Pullulanase-Amylopectin Trimming Model'.

Effects of Lintnerization, Autoclaving, and Freeze-Thaw Treatments on Resistant Starch Formation and Functional Properties of Pathumthani 80 Rice Starch

The objective of this study was to assess the effects of lintnerization, autoclaving, lintnerization followed by autoclaving, and freeze thawing treatments on the production of resistant starch from Pathumthani 80 (RD 31) rice. The produced resistant starch was further evaluated for some important physicochemical properties including pasting properties, swelling behavior, digestibility, water holding capacity, and functional properties including glycemic index and antioxidant properties. The lintnerization treatment and autoclaving significantly (p ˂ 0.05) increased resistant starch content to 64% (w/w) and gave the lowest glycemic index (46.12%). The lintnerization followed by autoclaving treatment significantly increased the solubility and water holding capacity, reduced the swelling power, and disrupted the crystalline structure of the starch granules. The native rice starch with autoclave treatment exhibited the highest swelling power among the samples, while the acid hydrolyzed starch was followed by autoclave treatment showing the lowest swelling power (1 g/g) at 90 °C. Fourier transform infrared analysis revealed the modified structures and bonding of the starch materials with the shifting of C=O stretch. However, the antioxidant properties and pasting properties were observed to decrease with the lintnerization, autoclaving, and freeze-thawing treatment of the native starch. The highly resistant starch content and low glycemic index value of the autoclaved RD 31 starch indicates the potential of the resistant starch’s application for the formulation of functional foods targeting the diabetic population.

Effects of fractionation and heat-moisture treatment on structural changes and digestibility of debranched waxy maize starch

The effects of fractionation (chain length) and recrystallization (starch solids concentration) combined with heat-moisture treatment (HMT) on the reorganization and resistant starch (RS) formation of debranched waxy maize starch (DWMS) were investigated in this study. Waxy maize starch (WMS) was debranched at 5% and 10% starch concentrations and 24 h, and the parent DWMS was fractionated in different ethanol solutions (ethanol: water 1:1.5 and 1:3.0), and further subjected to HMT to enhance RS content. The fractionated products DWMS1.5 and DWMS3.0 (RS content: 48.0%–62.4%) were more resistant to enzyme digestion than the parent DWMS products (35.1%–39.4%). HMT broadened the endotherms and increased crystallinities and enthalpies of DWMS products. Fractionation combined with HMT led to A-type structure formation of DWMS, with a higher peak melting temperature (115.31 °C) and a higher RS content (86.7%). Moreover, this knowledge can be used for optimization of RS-containing products with different degrees of resistance to enzyme digestion based on recrystallization in combination with HMT.

Nutritional and functional effects of the lactic acid bacteria fermentation on gelatinized legume flours

Aiming at meeting recent consumers requirements in terms of high nutritional value and functional foods, the cereal food industry has proposed the use of legumes as wheat substitutes due to the high contents of proteins with high biological value and dietary fibers. Nevertheless, legumes contain several anti-nutritional factors which may limit the bio-availability of several nutrients. In this study, an integrate biotechnological approach, combining a thermal treatment (“gelatinization”) and fermentation with selected lactic acid bacteria, was set-up in order to improve the functional and nutritional quality of red and yellow lentils, white and black beans, chickpeas and peas flours. Gelatinization carried out at pilot-plant level on legume grains before milling, affected the nutritional properties of the flours by the increase of protein digestibility, resistant starch formation, the decrease of trypsin inhibitors, although negatively affecting the antioxidant activity. Fermentation with Lactobacillus plantarum MRS1 and Lactobacillus brevis MRS4 further enhanced the nutritional properties of processed legume flours through the increase of free amino acids concentration and protein digestibility, the degradation of phytic acid, condensed tannins and raffinose, and the decrease of the trypsin inhibitory activity and starch hydrolysis index. Moreover, fermentation also contributed to the increase of the radical scavenging activity of both raw and processed legumes.

In Vitro Digestibility and Thermal Properties of Native and Modified Sago (Metroxylon Sagu) Starch

In recent years, there is growing interest in the nutritional implications of resistant starch in foods due to its functional properties and health benefits. This has resulted to the development of various modification techniques to induce the formation of resistant starch. This study aimed to elucidate the effect of different modifications on digestibility and thermal properties of sago starch. Sago starch was treated with hydrothermal treatment [heat moisture treatment (HMT) and annealing (ANN)] as well as combined modification of acid methanol treatment (AMT) and hydrothermal treatment (HMT and ANN), respectively. Combined modification (AMT-HMT and AMT-ANN) had more pronounced effect in increasing the resistant starch (RS) content and lowering the glycemic index (GI) of sago starch, especially in gelatinized form. Strong negative correlation was obtained between RS and GI in both raw and gelatinised starch. Combination of acid methanol treatment with annealing caused the highest increment in gelatinization temperatures of sago starch.

Combination of rice varieties and cooking methods resulting in a high content of resistant starch

AbstractBackground and objectivesWith the interest in increasing resistant starch (RS) of cooked rice, lowering its digestibility has been attempted but not established yet. Herein, we aimed to develop a simple cost‐effective method to prepare RS‐enriched cooked rice. Various combinations of rice types, cooking methods, and additives were investigated to increase the RS content.FindingsThe high‐amylose cultivar (~28% amylose), retort‐type cooking (121°C, 30 min, 15 psi), and brown rice resulted in higher RS content than that of normal rice, conventional cooking, and white rice, respectively. The effect of various food additives in soaking water on additional RS formation was marginal except for citric acid or soybean oil.ConclusionsThe method for producing RS‐enriched cooked rice was successfully established using high‐amylose brown rice via soaking in 30–40 mg/ml citric acid solution, retort‐type cooking, and drying. Its high RS content is likely due to collective effects from starch retrogradation, amylose‐lipid complex, restricted starch swelling/gelatinization by bran layer and non‐starch dietary fiber, and chemical cross‐linking.Significance and noveltyA simple cost‐effective method was developed resulting in the highest RS content reported to date for intact cooked rice (7.60%), which can be consumed as‐is or as a rice product ingredient requiring low glycemic index properties.

Effects of debranching and repeated heat-moisture treatments on structure, physicochemical properties and in vitro digestibility of wheat starch

In this study, wheat starch (WS) was firstly debranched with pullulanase (PUL) and then subjected to repeated heat-moisture treatments (RHMT). The effects of PUL and RHMT on the structure, physicochemical properties and in vitro digestibility of WS were investigated. The proton nuclear magnetic resonance spectroscopy confirmed that the ratio of α-1,6 glycosidic linkage decreased. Raman and Fourier transform-infrared spectroscopy demonstrated that more ordered structure of starch was formed. Differential scanning calorimetry and X-ray diffraction analysis revealed that RHMT could enhance thermal stability and degree of crystal perfection of PUL-WS sample. Scanning electron microscopy results showed that more agglomerates appeared on the surfaces of RHMT starch granules. The swelling power and solubility significantly decreased after HMT. Additionally, the resistant starch (RS) content of RHMT samples significantly increased. These results suggest that debranching and RHMT can significantly change the physicochemical properties and digestibility of WS, and it’s beneficial to the RS formation.

Resistant Starch from Isolated White Sorghum Starch: Functional and Physicochemical Properties and Resistant Starch Retention After Cooking. A Comparative Study

In an effort to promote the formation of resistant starch (RS), four different modification methods are applied to isolated white sorghum (WS) starch by subjecting the latter to heat‐moisture treatment (RSa), annealing (RSb), hydrolysis through pullulanase debranching enzyme (RSc), and dual autoclaving‐cooling cycles (RSd). Functional and physicochemical properties, individual RS content, and the behavior after cooking in terms of apparent RS retention (aRSr) of samples (i.e., WS, RSa, RSb, RSc, and RSd) are compared. Differences in thermal and pasting properties, in the ratio of ordered starch to amorphous starch, along with lower solubility and swelling power values, and greater water absorption capacity are measured in the four RS ingredients when compared to native WS starch. All the four modification methods prove to be similarly effective in increasing the amount of RS with respect to native WS starch, with an average 30% increase. However, based on the aRSr values, analyses revealed that the greater heat stability after cooking was obtained for RSb (93.7%) and decreased in the order of RSb>RSc>RSa = RSd>WS. Present results shed light on the properties of modified WS starch as a potential heat‐stable source of RS for food applications.

Resistant starch formation through intrahelical V-complexes between polymeric proanthocyanidins and amylose

Reducing starch digestibility can significantly benefit efforts to combat obesity and associated chronic diseases. Polymeric proanthocyanidins (PA) form complexes with starch via unknown mechanisms, resulting in dramatically decreased starch digestibility. We hypothesized that V-type complexes are involved in these interactions. Sorghum derived PA was complexed with amylose, amylopectin, and granular maize starches in regular and deuterated solvents, and structural properties and in vitro digestibility of the complexes investigated. Based on iodine binding, X-ray diffraction patterns, crystallinity, and thermal properties, we demonstrated, for the first time, that type II semi-crystalline V-complexes are formed between amylose and PA. Furthermore, suppression of H-bonding led to amorphous complexes, suggesting extensive H-bonding facilitate and/or stabilize the V-complexes. We speculate that the complexation involves inclusion of B-rings of the PA units into the amylose helical cavity. The V-complex formation significantly increased resistant starch in gelatinized normal starch and pure amylose (by 35–45%), indicating likely physiological benefits.

Optimisation of heat-moisture treatment conditions for producing high amounts of resistant starches from purple sweet potato and yam starches using response surface methodology

Heat-moisture treatment, a physical modification method of starch, causes changes in the internal structure of starch and thereby produces resistant starch (RS). In this study, the heat-moisture treatment conditions (moisture content, heating temperature, and incubation time) was optimized to maximise the RS contents of the treated sweet potato and yam starches, using the Box-Behnken design and response surface analysis. The predicted maximised RS content of the treated sweet potato starch (43.9%) was obtained under optimal conditions of 34.76% moisture content, heating temperature of 100.11oC, and incubation time of 6.01h; the predicted maximised RS content of the treated yam starch (36.8%) was obtained under optimal conditions of 30.06% moisture content, heating temperature of 109.68oC, and incubation time of 6.59h using a quadratic model within the range of various process variables. The experimental RS contents of the treated sweet potato and yam starches obtained under optimal treatment conditions were 42.4% and 35.4%, respectively; this confirms that the models were valid and adequate because the predicted data and experiment data did not differ significantly. The results also indicate that the RS contents of the treated sweet potato starch were significantly higher than that of the treated yam starch. As a result, both starch structure and treatment conditions were determined to significantly affect the formation of RS in the heat-moisture treated starches.

Modeling the effects of corn and wheat resistant starch on texture properties and quality of resistant starch‐enrichment dough and biscuit

AbstractThis work aimed to develop innovative dietary fiber‐enriched biscuits using resistant starch (RS Type III) from corn (CRS) and wheat (WRS) as wheat‐flour replacers at several ratios (0, 20, 40, 60, 80, and 100%). The effect of replacement on the physicochemical properties of dough and biscuits (moisture content, protein, amylose, resistant starch, specific volume), and their color, textural properties, microstructure, and sensory acceptability was investigated. The potential of multiple linear regression (MLR) to predict dough and biscuit properties was also assessed. Results showed that total resistant starch content was higher in biscuits containing WRS than in CRS samples, and that the chemical properties of flour had an important role in the formation of resistant starch after baking. Moisture content, protein, density, and textural characteristics reduced on increasing the resistant starch levels in both CRS and WRS samples compared with the control, while the sensory acceptability improved. Results also showed that MLR was suitable for modeling the response variables and predicting the effect of moisture and RS (before and after baking) content on texture, color, and overall liking of biscuits.Practical applicationsIndustries and researchers have long investigated the manufacture of dietary biscuits with low sugar content and no unfavorable aftertaste. Replacement of sugar with other sweeteners would lead to a vast effect on the sensory and structural properties of biscuits. Due to high starch content in flour, and starch hydrolysis into glucose in the human body, replacement of sugar with sugar replacers would not lead to a dietary product. Therefore, one of the suitable techniques for making biscuits with the most favorable dietary properties is the replacement of flour with resistant starch. The results of this study will be used to evaluate production methods of dietary fiber‐enriched biscuits using resistant starch.

The influence of acid hydrolysis followed by autoclaving-cooling on physical properties and resistant starch of purple sweet potato (Ipomea batatas L.) flour

In this study influence of acid hydrolysis using HCl 2% followed by autoclaving-cooling at 121°C for 15 minutes and cooled at 5°C for 72 hours with two repetition cycles on resistant starch of purple sweet potato flour were investigated and physical properties were analyzed. This treatment exhibited beneficial impacts of modified flour on resistant starch formation by 14.35%. Significant difference was exhibited between native and modified flour for ΔE value. Rapid visco analyzer was also used to determine pasting properties including peak viscocity, trough viscocity, breakdown, final viscosity, setback, and peak time where all of them except breakdown value were higher than the native one. Moreover, no signs of damage on the surface of native purple sweet potato flour were showed in micrograph of scanning electron microscopy. While autoclaving-cooling sample exhibited a rough structure as a result of the loss of its granular appearance and destroyed shape. This study also indicated a change of X-ray diffraction pattern from C-type to B-type caused by the modification treatment.

Influence of High Pressure or Autoclaving-Cooling Cycles and Pullulanase Treatment on Buckwheat Starch Properties and Resistant Starch Formation

Influence of High Pressure or Autoclaving-Cooling Cycles and Pullulanase Treatment on Buckwheat Starch Properties and Resistant Starch Formation