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The link between carbohydrate intake and health is becoming increasingly important for consumers, particularly in the areas of glycemic index (GI) and extended energy-releasing starches. From a physiological point of view, slowly digestible starch (SDS) delivers a slow and sustained release of blood glucose along with the benefits resulting from low glycemic and insulinemic response. SDS has been implicated in several health problems, including diabetes, obesity, and cardiovascular diseases (metabolic syndromes). It may also have commercial potential as a novel functional ingredient in a variety of fields, such as nutrition, medicine, and agriculture. The present review assesses this form of digestion by analyzing methods to prepare and evaluate SDS, and factors affecting its transformation, its health benefits, and its applications.

Composite biscuits made of heat-moisture-treated banana flour and wheat flour with ratio ranging from 25 to 75% were characterized for its postprandial glucose response in mice, diffraction pattern by X-ray diffraction, organoleptic and texture properties. Biscuit made of 100% wheat flour was used as a control. Composite biscuits resulted in lower blood glucose response, lower glycemic index and load due to its resistant starch and slowly digestible starch content as well as lipid-starch complex. Composite biscuit made of 75% banana flour is potential to use as a source for long lasting energy product as it displayed stable blood glucose response for 4 hours. Among sensory attributes, color and taste of biscuits were the most sensitive to the addition of the banana flour. The difference in the hardness of biscuits using instrumental analysis did not significantly affect the acceptability of texture perceived by consumers except at 75% of the banana flour.

The biofunctionality of native and nanostructured starch obtained from blue corn was evaluated on prediabetic Wistar rats. The surface of both types of starch was analyzed by atomic force microscopy (AFM). Total polyphenols content, antioxidant activity and digestibility were also evaluated. Prediabetes was induced by feeding a diet high in fat, carbohydrates and the administration of streptozotocin. Experimental design included a control group, prediabetic group and two prediabetic groups, one supplemented with native starch and the other with nanostructured starch. AFM analysis showed nano-cavities

The effect of lintnerization on the banana starch of the Roatan cultivar from acid hydrolysis at 3, 5, and 7 days on the starch digestibility and morphological and thermal features was evaluated. Acid treatment produced an increase in the rapidly digestible starch (RDS) (20.2%) and slowly digestible starch (29.7%), but a decrease in the resistant starch (36.3%) content, as compared with its native counterpart. However, over the longest acid-treatment time, a decrease in the RDS over 5 days was observed. The lintnerized banana starch can be used in food products without additional cooking. The temperature (77–80°C) and enthalpy (11.6–14.1 J/g) of gelatinization increased significantly when the acid-treatment time increased, indicating an arrangement of the crystalline lamella by the double helices of the amylopectin chains. The acid treatment increased the retrogradation rate of the lintnerized banana starch gels. The lintnerization of banana starch for different lengths of time modified its morphology, st...

Pulses such as the chickpea are generally considered to be valuable dietary sources of slowly digestible starch, a form of starch that is considered beneficial to health since it results in relatively low post-meal blood glucose levels compared with more rapidly digested starch. The development of novel chickpea-based foods is necessary to help expand the worldwide consumption of the chickpea. However, the effect of different processing methods on the starch digestibility of chickpea-based foods has not been widely investigated. This study used an in vitro method simulating human carbohydrate digestion to determine levels of slowly digestible starch, rapidly digestible starch (RDS), resistant starch, total starch and rapidly available glucose (RAG) of: (i) whole-chickpea products (domestically boiled, commercially canned and commercially precooked/vacuum-packaged); and (ii) standard white bread, chickpea flour bread (25% replacement of wheat flour by chickpea flour) and extruded chickpea flour bread (25% replacement of wheat flour by extruded chickpea flour). The RAG levels were then used to predict the relative in vivo glycaemic indices of the products. The commercially precooked/vacuum-packaged whole chick peas demonstrated higher levels of RDS than the commercially canned and domestically boiled products (P0.05). In addition, the domestically boiled product had lower levels of RAG (g/100 g available carbohydrate) compared with the canned and precooked/vacuum-packaged products (P0.05). There were no significant differences between any of the carbohydrate digestibility measures of the white bread, chickpea flour bread and extruded chickpea flour bread (P0.05) and all bread products demonstrated far higher RAG (g/100 g available carbohydrate) values than the whole-chickpea products. The findings suggest that the commercially precooked/vacuum-packaged whole chick peas and the canned product may have higher and less beneficial glycaemic indices than the domestically boiled chick peas. It appears unlikely that the use of chickpea flour or extruded chickpea flour, at the incorporation rate investigated in this study, would modify the glycaemic index of bread. It is probable, however, that the chickpea bread products investigated would demonstrate higher and potentially less beneficial glycaemic indices than the whole-chickpea products.

Bread has become a widely consumed staple food in South-east Asia. However, there is very little data on the glycaemic potential of local commercial breads. The objective of this study was to comparatively assess the glycaemic potential of some commonly consumed commercial breads using a validated in vitro model. Sixteen types of breads representing the most popular brands and types were evaluated. The results showed that white and enriched white breads had a greater glycaemic potential than wholemeal breads (rapidly digestible starch (RDS) content450 mg of glucose/g of sample). The lowest glycaemic potential was observed for wholegrain breads (RDS content375 mg of glucose/g of sample). The glycaemic impact of some specialty breads such as pandan bread, milk bread and corn loaf was also examined. Whist the data show that South-east Asian breads have notably differential effects on glycaemia, it highlights the need to formulate Asian dietary guidelines for bread which will enable better food choice and glycaemic control.

The structure-properties relationships of native and debranched starch (DBS) were investigated by analyzing the results of DSC, XRD, NMR, HPAEC, FT-IR, SEM, hydrolysis, and digestibility properties. After debranching of starch in waxy rice, japonica rice, and indica rice, the linear short-chain molecules formed were easier to alignment and aggregation, and associate into a double helix. The crystalline structure of the rice starch after the pullulanase treatment was transformed from the type A to the type V crystalline by XRD measurement. Based on FT-IR and 13C NMR observations, molecular rearrangement and degree of order in starch granules increased. The DSC curve showed an increase in gelatinization temperature of debranched starch compared to native starch. Meanwhile, Solubility, water holding capacity and resistant starch content of DBS also raised. The study of structure- properties relationship provides a theoretical foundation for the development of foods or drugs with targeted functional properties. Abbreviations: WS: waxy rice starch; JS: Japonica rice starch; IS: Indica rice starch; DBWS: debranched waxy rice starch; DBJS: debranched Japonica rice starch; DBIS: debranched Indica rice starch; RDS: rapidly digestible starch; SDS: slowly digestible starch; RS: resistant starch; DP: degree of polymerization; DSC: differential scanning calorimertry; Gelatinization temperature at onset (To), peak (Tp), and end (Tc); ∆H: transition enthalpy; HPSEC: high-performance size-exclusion chromatography; ATR-FTIR: Attenuated total reflectance Fourier transform infrared spectroscopy; NMR: nuclear magnetic resonance; XRD: X-ray diffraction; SEM: Scanning electron microscopy; WHC: Water holding capacity.

Starch/amylose-guest inclusion complexes, a class of supramolecular host-guest assemblies, are of critical importance in the processing, preservation, digestion, nutrients/energy uptake, and health outcomes of starch-containing foods. Particularly, the formation of inclusion complex has been suggested to lower the rate and extent of enzymatic digestion of starch and starch-containing foods. Compared with rapidly digestible starch, starch inclusion complex may fall into the category of slowly digestible starch, providing sustained glucose release and maintaining glucose homeostasis. Therefore, the ability of starch-guest inclusion complex to alter the digestive behavior of energy-dense starchy foods has been of interest to many researchers and has the potential to be developed and formulated into functional foods. In this article, we provide a comprehensive and critical review on the current knowledge of the

Mung bean starch slurries (75% moisture) were respectively treated by repeated annealing (RANN) at 50°C for eight repetitions (every repetition was treated for 12 h) and continuous annealing (CANN) at the same temperature for 24, 48, 72 and 96 h. After RANN and CANN modifications, variations in the physicochemical properties, structures as well as digestive characteristics of mung bean starch were investigated. Scanning electron microscopy observed the grooves on the surfaces of starch granules became deeper after RANN and CANN modifications, and the cracks in the granule centers were monitored by light microscopy. However, there was no distinct change detected by confocal laser scanning microscopy. RANN and CANN modifications increased the crystallinity and degree of crystalline order, but the crystalline patterns were not changed. Under the same annealing time, RANN samples presented higher crystallinity, gelatinization temperature, enthalpy, peak time, pasting temperature, resistant starch (RS), slowly digestible starch (SDS) and SDS+RS values, but lower solubility, swelling power, peak viscosity, breakdown and rapidly digestible starch (RDS) values than CANN samples. Therefore, RANN could exert conspicuous impacts compared to CANN, which illustrates the annealing impact on starch modification and it could be applied in food processing as an innovative approach.

Allelic variation at the Wx locus plays a vital role in regulating apparent amylose content (AAC) as well as other important starch properties in rice grain. However, the extent of Wx allelic variation affecting amylopectin fine structure and enzymatic hydrolysis properties of rice starch remains unknown. In this paper, a series of rice single-segment substitution lines with five different Wx alleles (wx, Wxt, Wxg1, Wxg2 and Wxg3) were used for comparative studies. The results showed that the five Wx alleles exhibited a wide variation in amylopectin molecular structure, hydrolysis and in vitro digestion properties of rice starch. Amylopectin chain length distribution as evaluated by fluorophore-assisted capillary electrophoresis was significantly different for the five Wx alleles, which might result in different functional properties. The hydrolysis degree of the five Wx genotype starches by α-amylase or amyloglucocidase was in the order wx > Wxt > Wxg1 > Wxg3 > Wxg2. The rapidly digestible starch (RDS) content of the tested rice starches followed the order wx = Wxg3 > Wxt = Wxg1 > Wxg2. The extent decrease of slowly digestible starch (SDS) content was wx = Wxt > Wxg1 > Wxg2 > Wxg3, while the trend in resistant starch (RS) content was Wxg2 > Wxg3 > Wxg1 > Wxt > wx. Correlation analysis indicated that AAC was significantly positively correlated with RS but significantly negatively correlated with SDS and hydrolysis. The RDS showed a significant positive correlation with amylopectin short chains (DP 6–12) but no significant correlations with other structural properties. The present results could provide important information for the application of rice starches with different Wx genotypes.

Wheat breads prepared from frozen partially baked breads were characterized by their content of rapidly digestible starch (RDS) and slowly digestible starch (SDS) by the in vitro starch digestibility method developed by Englyst. Breads with different contents and types of fibre and breads prepared with different fermentation processes were studied. Bread with inulin and with a double fermentation had the lowest RDS content of 58.8 ^ 1.7 and 60.0 ^ 1.9 (% dry matter), respectively. Wheat bran bread, seeded bread, triple fermentation white bread and baguette-type bread showed values of RDS between 63.1 ^ 1.7 and 65.7 ^ 1.7 with no significant differences between them (p , 0.05). The fraction of SDS was higher in wheat breads than in breads with added fibre. The highest values of the starch digestive rate index (SDRI) were obtained by the three types of breads with added fibre, which ranged from 91.8 ^ 3.5 to 95.8 ^ 3.5 versus 80.2 ^ 3.5 to 87.5 ^ 3.5 for white wheat breads. A significant (p , 0.01) positive linear correlation between the insoluble fibre content and SDRI was obtained (R 2 ¼ 0.96). Insoluble fibre dilutes and disrupts gluten network and probably weakens the interaction between gluten and starch, which protects starch from digestive enzymes action. Scanning electronic microscopy microstructure of bread crumbs corroborated this statement.

This study investigated how process conditions affect the digestibility of pea starch from pea starch powder (PSP). The factors considered were resistant starch (RS), slow digestible starch (SDS) and rapidly digestible starch (RDS) content. The examined five process factors were: material/water ratio, cooking temperature, cooking time, soaking time, and heat dehydration time. Changes in process conditions mainly altered the content of RS and SDS. Analysis with Sephadex G-200 chromatography and differential scanning calorimetry revealed that RS was mainly from retrograded amylose and amylopectin, while SDS and RDS were mainly derived from amylopectin.

With emerging knowledge of the impact of the metabolic quality of glycemic carbohydrates on human health, there is a need for novel carbohydrate ingredients that can be custom-made to deliver controlled amounts of glucose to the body and to test hypotheses on the postprandial metabolic consequences of carbohydrates.The goal of the present study was to demonstrate the applicability and action of starch-entrapped biopolymer microspheres as customized, novel, slowly digestible carbohydrates to obtain desired glycemic responses.Starch-entrapped microspheres were developed; and starch digestion and glucose release, subsequent to their cooking (100 degrees C, 20 min) in water, were initially monitored by measuring the rapidly digestible, slowly digestible, and resistant starch fractions using the in vitro Englyst assay. Glycemic and insulinemic responses after consumption of glucose and two different slowly digestible starch microsphere diets were compared using a crossover study in 10 healthy individuals. The mechanism of starch digestion in the microspheres was elucidated from scanning electron microscopic images of the in vitro digested microspheres.Factors such as biopolymer type and concentration, microsphere size, and starch type were manipulated to obtain starch materials with defined amounts of slowly digestible starch based on in vitro studies. Scanning electron microscopy showed that cooked starch entrapped in the dense biopolymer matrix is digested layer by layer from the outside to the inside of the microsphere. Glycemic and insulinemic responses to microsphere test diets were moderate as compared to a glucose diet, but more important, they showed extended glucose release.Starch-entrapped microspheres provide a useful tool to study the postprandial metabolic consequences of slowly digestible carbohydrates.

We sought to determine whether design of carbohydrate-based microspheres to have different digestion rates, while retaining the same material properties, could modulate gastric emptying through the ileal brake. Microspheres made to have three slow digestion rates and a rapidly digested starch analogue (maltodextrin) were administrated to rats by gavage and starch contents in the stomach, proximal and distal small intestine, and caecum were measured 2 h post-gavage. A stepwise increase in the amount of starch retained in the stomach was found for microspheres with incrementally slower rates of digestion. Postprandial glycaemic and insulinaemic responses were incrementally lower for the different microspheres than for the rapidly digestible control. A second-meal effect was observed for slowly digestible starch (SDS) microspheres compared to glucose. Thus, dietary slowly digestible carbohydrates were designed to elicit incremental significant changes in gastric emptying, glycaemic and insulinaemic responses, and they may be a means to trigger the ileal brake.

Producing food products from sweet potato flour are very feasible in worldwide due to wide availability, natural color, high-energy, low-protein, good biological activity in the human diet and low cost, as a result, become a key ingredient for the production of new products in the current global habitation. Sweet potato flours can be used for imparting desired properties, nutritional value, antioxidants, and natural color to processed foods and also used as thickeners and gelling agents. However, the paucity of information regarding the functional properties of the sweet potato flour greatly limits its exploitation. This review attempts at gathering data available on the functional properties of sweet potato flour, highlighting their unique properties and potential field of applications. A significant variation was observed in functional properties upon the variety and some processing methods. Also, the differences in the size of the granules and the various contents of starch, protein and amylose influenced functional characteristics such as viscosity, pasting temperature, gelatinization temperature, swelling power and solubility. The modified flours using steam and blanching are useful in food preparations to reduce paste thickness in food products such as confectioneries, as well as in pharmaceuticals industry as a drug binder and disintegrant as they exhibited high bulk density. Low-paste viscosity of the acetylated flour makes these flour to be used in formulations that require a high volume of solids. As thickening agents, enzymes modified that have high viscosity paste are good. The use of modified flours in food products would guarantee a suitable amount of digestible starch. This information can also be used to design protocols for the food processing industry, aiming at consumer’s needs, such as diabetics and obese people who may benefit from low digestibility of starch. The range of characters and food developments observed makes the sweet potato flour amenable to different applications in food industries based on their properties. An awareness of their potential uses can help in large-scale cultivation of these crops and the production of flour from them.

"Diabesity" is the term to illustrate the interdependent relationship between obesity and diabetes. About 80% of the diabetic patients are diagnosed with obesity. Diabesity can be prevented by dietary interventions, especially by incorporating sufficient amount of resistant starch (RS). In the past few decades, RS has inspired the researchers due to its various health benefits. Differing from digestible starch, RS remains undigested in the small intestine, but in the large intestine, it is subjected to fermentation. This review intends to encapsulate the current information related to the dietary RS on diabetes and obesity. RS attenuate hyperglycemic, hyperinsulinemic and hyperlipidemic response in various subjects by restricting gluconeogenesis, bolstering glycogenesis, maintaining glucose and lipid homeostasis and ameliorating pancreatic dysfunction. Various food products were fortified with RS to enhance its dietary intake and were found to exhibit positive impact on human and animal models. This review identified and summarized the research gaps in the available literature.

Starches isolated from seven different cereals were evaluated for their composition, physicochemical, in vitro digestibility, structural, morphological, and pasting properties. The in vitro starch digestion rate and estimated glycemic index (GI) of cereal starches were evaluated along with the impact of cooking on starch digestion. The cooking of starch slurries increased the rapidly digestible starch content from a range of 34.7–54.4% to a range of 60.5–78.5%. On the basis of hydrolysis index, the GI ranged from 83.6 to 91.8 and after cooking it increased from 95.1 to 98.6 for different cereal starches. Both the swelling power and solubility showed an increasing trend with rising temperature. Paste clarity of starches negatively correlated with fat content. The amylose content of various starches ranged from 17.7 to 24.7% and was negatively correlated to crystalline index (r = -0.975, p ≤ 0.05). XRD pattern revealed A-type pattern of crystalline starch, where crystallinity index ranging between 28.2 to 44.9%. FTIR revealed slight differences among chemical bonding of starches from different cereals. From scanning electron micrograph observations, wheat and barley starch granules proved smoother as compared to other cereal granules. Barley contained the highest (27.5 µm) and rice had the lowest (10.2 µm) size starch granules. The pasting properties were significantly (p ≤ 0.05) different for different cereal starches. Peak, breakdown, and final viscosities were the highest for maize starch (1725, 384, and 2112 mPa.s, respectively), whereas rice and oats exhibited the highest trough and setback viscosities (1420 and 954 mPa.s, respectively).

Low glycemic index (GI) rice flour was prepared through enzymatic hydrolysis. Slowly digestible and resistant starch contents increased significantly (p ≤ 0.05) by 195.82% and 204.03%, respectively, while as total, rapidly digestible and digestible starch contents decreased significantly (p ≤ 0.05) by 55.40%, 51.67%, and 18.74%, respectively, after enzymatic hydrolysis. Glycemic load of low GI rice flour was significantly (p ≤ 0.05) lower than untreated rice flour. The degradation temperature of low GI rice flour (~275°C) was lower compared to untreated rice flour (~298°C). Particle size distribution analysis indicated that both surface mean- D [3, 2] and volume mean diameter – D[4, 3] of low GI rice flour were higher than untreated rice flour. SEM results revealed numerous cracks in low GI rice flour whereas the surfaces of starch granules of untreated rice flour were smooth without scratches. Low GI rice flour presented A- and V-type polymorphs while as untreated rice flour showed only A-type crystallinity pattern.

Acid hydrolysis is an important chemical modification that can significantly change the structural and functional properties of starch without disrupting its granular morphology. A deep understanding of the effect of acid hydrolysis on starch structure and functionality is of great importance for starch scientific research and its industrial applications. During acid hydrolysis, amorphous regions are hydrolyzed preferentially, which enhances the crystallinity and double helical content of acid hydrolyzed starch. This review discusses current understanding of the effect of acid hydrolysis on starch structure and functionality. The effects of acid hydrolysis on amylose content, chain length distribution of amylopectin molecules, molecular and crystalline organization (including lamellar structure) and granular morphology are considered. Functional properties discussed include swelling power, gelatinization, retrogradation, pasting, gel texture, and in vitro enzyme digestibility. The paper also highlights some promising applications of acid hydrolyzed starch (starch nanocrystals) in the preparation of biodegradable nanocomposites, bio-hydrogen, and slowly digestible starch-based healthy foods.

The aim was to estimate the energetic cost of fat deposition from fermentable non-starch polysaccharides (fNSP), starch, and unsaturated fatty acids. A slaughter trial was conducted with a total of 58 individually housed pigs (48–106 kg). The energetic efficiency was monitored at two energy levels; the lysine supply of the pigs was limiting for protein deposition. Control diets were fed either at two or three times of maintenance energy requirement, and the treatments were achieved by isoenergetic addition of the daily nutrient intake (0.2 MJ DE/kg0.75) derived either from fNSP, or digestible starch (dSt), or digestible fat (dFat) above the nutrients from the control diets. Chemical composition of the pigs was determined at 48±4 kg (10 pigs) or 106±3 kg body weight (BW) (48 pigs). In conclusion, under protein limiting conditions, the energetic transformation of fNSP, dSt, and dFat for fat retention (NEfat/DE) was 62%, 80%, and 57%, respectively. The efficiency of fat deposition from a specific en...

Dietary starch varies greatly in digestibility and its effects on the utilization of other nutrients. The variation appears to be due to differences in starch components and their crystallinity. Processing treatments, storage conditions, chemical modification, and genetic breeding influence the digestibility of starch. Cereal starches are generally more digestible than root/tuber and legume starches. Although cooking often significantly improves the digestibility of poor and intermediately digestible starches, some foods such as bananas with starches of these types are consumed uncooked. The efficient digestion of starch is especially important to specific groups of people such as infants under 6 months of age. Ruminants must also be provided with highly digestible starch to assure maximum production efficiency. Poor digestibility of starch may have negative effects on the utilization of protein and minerals but is likely to have positive effects on the availability of certain vitamins. Decreases in the rate of starch digestion may have therapeutic application. Most clinical studies have reported that starch blockers do not elicit a significant decrease in the digestion of starch in humans. Much remains to be learned, clarified, and understood about starch digestion and its effects on diabetes and weight control.