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Unripe plantain presents a high content of resistant starch (RS); however, upon cooking the fruit, the RS is transformed into digestible starch. In an attempt to keep the levels of indigestible carbohydrates high in unripe plantain flour (UPF), it was acid-treated (modified unripe plantain flour: MUPF) and used for spaghetti preparation. The semolina typically used in the finished pasta was substituted with equal parts of MUPF and UPF during the preparation. Chemical composition, starch digestibility, antioxidant capacity, and sensory analysis were evaluated in the finished product. When compared to the control sample, total dietary fiber content had a 3–fold increase due to substitution of semolina with MUPF, and it was doubled for the case of substitution with UPF. Spaghetti with MUPF presented lower slowly digestible starch (SDS) than its counterpart with UPF. Spaghetti with MUPF showed the lowest hydrolysis rate and glycemic index. Similar antioxidant capacity was found in spaghetti containing both MUPF and UPF. A slight decrease in the overall acceptability of spaghetti with MUPF compared with the control was observed.

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 in vitro digestibility and molecular and crystalline structures of rice starches (Seilmi, Dasan1, and Segoami) with differing amylose content were investigated. Segoami had the highest amylose content (30.9%), whereas Dasan1 had the lowest amylose content (21.2%). The molecular weight (M w ) of amylose and amylopectin in Segoami was much lower than that of the other two rice starches. Segoami had the highest proportion (8.7%) of amylopectin short branch chains (DP 6-12) and the lowest proportion of B1 chains (DP 13-24). The relative crystallinity, intensity ratio of 1047-1022 cm ?1 (1047/1022) and gelatinization enthalpy followed the order: Segoami>Seilmi~Dasan1. Segoami showed substantially low pasting viscosity. Rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) contents showed the highest value in Seilmi, Dasan1, and Segoami, respectively. The expected glycemic index (eGI) of Segoami was lower than that of the other two rice starches. Overall results suggested that the digestibility of rice starch could be highly influenced by their molecular and crystalline structure.

The in vitro digestibility, molecular structure and crystalline structure of waxy rice starches isolated from six Korean cultivars (Shinsun, Dongjin, Baekok, Whasun, Chungbaek, and Bosuk) were investigated. The molecular weight ( M w ) of waxy rice starches ranged from 1.1 × 10 8 g/mol to 2.2 × 10 8 g/mol. Chungbaek waxy rice starch had the highest average chain length (24.3) and proportion (20.7%) of long branch chains (DP ≥ 37), and the lowest proportion (19.0%) of short branch chains (DP 6–12) among the tested six waxy rice starches. The relative crystallinity and intensity ratio of 1047/1022 ranged from 38.9% to 41.1% and from 0.691 to 0.707, respectively. Chungbaek had the highest gelatinization temperature and enthalpy. Chungbaek had the highest pasting temperature (70.7 °C), setback (324 cP) and final viscosity (943 cP), whereas Baekok showed the highest peak viscosity (1576 cP) and breakdown (1031 cP). Chungbaek had lower rapidly digestible starch (RDS) content and expected glycemic index (eGI), and higher resistant starch (RS) content, whereas Whasun exhibited higher RDS content and eGI. The slowly digestible starch (SDS) content of Shinsun (38.3%) and Bokok (32.0%) was significantly higher than that of other cultivars (11.3–22.0%).

To investigate the digestion mechanisms of EJFSS, the structural characteristics of slowly digestible starch (SDS) and resistant starch (RS) fractions isolated from native and extruded JFSS were studied. The SDS + RS and RS fractions in both native JFSS and that treated by IECT exhibited higher gelatinization temperatures, relative crystallinity and short-range molecular order, but lower gelatinization enthalpy (ΔH), than the control. Compared to the native JFSS, the ΔH, relative crystallinity and molecular order of JFSS subjected to IECT were significantly decreased (P

Chickpea starch was subjected to triple retrogradation cycle with time intervals of 24, 48 and 72 h. The impact on in vitro digestibility, functional, pasting and structural characteristics was investigated. Compared to native chickpea starch, the resistant starch (RS) content of triple retrograded starch was significantly increased with increased retrogradation time whereas slowly digestible starch content was decreased. Water binding capacity and solubility of triple retrograded starch were significantly increased whereas swelling power and pasting properties were decreased. Triple retrograded starches showed B type and B + V type crystalline structure. After triple retrogradation, the organised granular structure was disrupted, irregularly shaped particles were formed showing porous, coarse, filamentous network structure. FT-IR spectra perceived a slight change in percentage intensity of C–H stretch of triple retrograded starches (TRSs). Triple retrogradation was observed to be a promising methods for RS product.

Over the 65–100 °C range and at a water content of 1.6 kg kg−1 db, a comparison was conducted between plantain paste (dispersion made of flour and water) and pulp pieces after cooking to evaluate their respective degree of starch gelatinization (α) and in vitro digestibility. Below 76 °C and at 100 °C, the gelatinization behaviour of starch into pulp pieces and paste was similar, whereas at 85 °C a significant mean relative difference was observed in between. For α in the 0–1 range, pieces of plantain pulp exhibited a lower rapidly digestible starch fraction (30%) and a higher resistant starch fraction (33%) than the flour paste, suggesting some structural effects. Both Weibull and exponential models showed a good fit for α over temperature range and starch digestibility fractions over α. Although no explicit relationship was established between the intact pulp structure and grinded flour state of plantain, the evaluation of the degree of starch gelatinization and digestibility of a plantain flour paste, could be used to predict the gelatinization and digestibility behaviour of plantain starch in entire pieces of pulp.

Summary Shepody potatoes were cooked using three common cooking methods – microwaving, boiling and pressure cooking. Microwaving for 2.5 min retained the highest amounts of slowly digestible starch (SDS, 19.6%) and resistant starch (RS, 48.8%) as compared to the other cooking treatments. Similarly, enthalpy and FTIR results (ratio of 1047/1022 cm−1) were also higher for microwaved samples, again indicating incomplete gelatinisation. Potatoes were also boiled for 15, 30 or 45 min, followed by 1, 3 or 7 days retrogradation at 23 or 4 °C. Retrogradation enthalpy increased significantly (P ≤ 0.05) with increased storage time and decreased storage temperature; FTIR results displayed temperature dependency; at 4 °C, ordered structure increased with increasing storage time, whereas the opposite trend was seen at 23 °C. Lastly, formation of SDS and RS was favoured for longer boiling times (30 – 45 min), extended storage times (3–7 days) and 4 °C.

Summary Four methods were applied to dry yam slices, and then, starches were isolated from dried yam slices. Starch isolated from fresh yam was as the study control, and physicochemical properties and in vitro digestibility of starches were studied. The results showed that the amylose content ranged from 12.62% to 28.25%, water-binding capacity (WBC) from 111.67% to 262.88%, paste clarity from 2.1% to 6.23%, resistant starch (RS) from 66.60% to 88.49% and crystallinity from 11.27% to 25.52%. Compared with the control starch, hot air-drying at 60 °C significantly decreased amylose content, paste clarity, RS and crystallinity, while increasing the WBC. Low levels of rapidly digestible starch and glucose and high RS levels were found in the starch from freeze-drying yam. Digestibility of the starches was significantly correlated with amylose content, WBC, paste clarity and swelling power. The starch samples were divided into three groups by principal component analysis (PCA).

The effects of various buckwheat materials (buckwheat flour [BF], dietary fiber extract [DE], flavonoids extract [FE], and rutin-enhanced flavonoids extract [REFE]) on starch digestibility and noodle-making properties were evaluated. When FE and REFE were incorporated into noodles, the amount of rapidly digestible starch and the predicted glycemic index (pGI) were reduced. However, BF and DE did not significantly decrease the pGI value of noodles. When assessing noodle properties, hardness was increased with increasing content of buckwheat materials, whereas other texture parameters were not significantly affected by buckwheat addition. All noodles were similar in regard to water absorption and swelling index, but cooking loss was slightly increased in FE and REFE noodles. FE and REFE demonstrated higher flavonoid stability during noodle making and, additionally, were more effective at reducing starch digestibility than BF and DE. REFE, specifically, does not generate quercetin (the cause of a bitter tast...

To analyze the effects of the freezing process, frozen storage temperature and frozen storage time on starch digestion characteristics, 3 kinds of foxtail millet-derived products were produced and frozen stored at −18 °C or −40 °C. The in vitro starch digestibility, degree of gelatinization (DG) and estimated glycemic index (eGI) of reheated samples were investigated after frozen for 1, 3, 5, 7, 14, 21 and 28 days respectively. The results showed that the variation trends of DG, eGI and rapidly digestible starch content were basically the same during freezing and frozen storage. Starch digestion characteristics of frozen millet products stored at −40 °C were more stable than those of counterparts stored at −18 °C. The first two weeks, especially the first day of frozen storage, had a greater effect on starch digestibility, as compared to the rest days of frozen storage. Thus fresh prepared foxtail millet-derived products are required for determining the glycemic index of specific food or conducting a short-term dietary intervention while frozen stored products are available for long-term intervention. Moreover, addition of pregelatinized starch into millet pancake may increase its glass transition temperature and thus decrease its degradation rate.

Starch retrogradation in plantain starch was studied by an enzymatic method and X-ray diffraction analysis. The enzymatic method and X-ray diffraction gave comparable results. Retrograded starch (RS3) and physically trapped starch (RS1) contents of plantain foods were subsequently determined by the enzymatic method. RS3 content of 5.0 ± 0.9 to 13.2 ± 3.0 g/100 g dry weight basis was obtained for unripe samples while a value ranging from 0.9 ± 0.4 to 2.5 ± 0.9 g/100 g was obtained for ripe samples. Retrogradation increased slowly digestible starch (SDS) and physically inaccessible starch (RS1) portions in some of the samples but not in others. Retrogradation resulted in an increase in the quantity of SDS for ripe plantain samples. In unripe plantain samples cooked without salt, there was a significant increase (p ≤ 0.05) in the value of RS1 from 4.6 ± 3.6 to 7.7 ± 2.0 g/100 g after 48 h of cold storage but no significant change for samples cooked with salt.

The grain of six standard wheat cultivars and one high-amylose wheat cultivar was ground and milled to produce common white flour used to prepare bread, biscuits and wafers. Changes in rapidly and slowly digestible starch (RDS and SDS), resistant starch (RS) and fibre caused by different milling and by the preparation of bakery products were observed. Depending on the milling process, RDS ranged from 28.3 to 32.4% of dry matter and SDS from 18.3 to 35.2%. The preparation of bakery products increased RDS by 30–80% to the detriment of SDS. RS comprised on average 6.6% of ground grain, 3.9% of wheat flour and 3.5, 5.9 and 1.0% of bread, biscuits and wafers, respectively. Variance amongst standard wheat cultivars was low, with only the high-amylose wheat showing unique technological and nutritional properties. RS and total starch (TS) were measured using two different methods. TS determinations correlated closely, although the linear regression varied amongst the different matrices. The correlation between RS values measured by the two methods was loose, and no significant linear regression was found. The article brings new information on variability in starch digestibility in cereal products depending on wheat cultivar used for production.

RESUMO: Nos últimos anos, a banana verde tem despertado interesse do mercado consumidor, pois, além do aspecto nutricional, destaca-se a presença de compostos funcionais, em especial o amido resistente. Contudo, sua adstringência limita seu consumo e sua comercialização em forma de farinhas é a principal forma de consumo e utilização, como ingrediente funcional. O objetivo do presente trabalho foi avaliar os potenciais usos da farinha de banana verde (FBV) na elaboração de produtos alimentícios e os principais métodos de obtenção, e seus efeitos sobre a qualidade físico-química, sensorial e funcional das farinhas obtidas. Fatores como tipo de cultivar ou variedade da fruta, presença ou ausência de casca, técnica de desidratação e condições de operação do equipamento influenciam as características físico-químicas, tecnológicas e funcionais da FBV. A FBV tem sido utilizada como ingrediente funcional na elaboração de diferentes produtos alimentícios, como pão, biscoito cookie, pré-mistura de bolo, snacks, nuggets e, sobretudo, na elaboração de massas alimentícias. De forma geral, o emprego de FBV e produtos alimentícios promove a melhoria de suas propriedades funcionais, devido ao aumento do teor de amido resistente, compostos fenólicos e da atividade antioxidante. A FBV também reduz o teor e a porcentagem de hidrólise do amido digerível e, consequentemente, do índice glicêmico dos produtos, que apresentaram potencial para compor a dieta, principalmente de indivíduos diabéticos e obesos. A FBV pode ser amplamente utilizada tanto pela indústria de alimentos (pães, biscoitos, macarrão, etc.), como ingrediente na preparação de pratos prontos e na elaboração de produtos cárneos. ABSTRACT: Recently, the market interest in green banana has raised because of its nutritional aspects, mainly due to its functional compounds as resistant starch. However, the adstringency limits green banana consumption hence it has been mostly marketed as flour or starch. The aim of this research was to evaluate the main applications of green banana flour (GBF) in food products and the effects of the main utilized processes on sensorial, physicochemical and functional properties. The cultivar or variety of fruit, presence or absence of peel, type and conditions of dehydration process have influenced on the aforementioned properties of GBF. It was also verified that the GBF has been utilized as a functional ingredient in different types of food products like breads, cookies, cake pre-mixture, snacks, nuggets and, mainly, pastas. Altogether, the use of GBF in food products enhanced their functional properties, because it improves the resistant starch, total phenolics content and antioxidant capacity. The GBF also reduces the content and hydrolysis of digestible starch and, therefore, glycemic index of these products that show a great potential in nutrition therapy of diabetes mellitus and obesity.

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...

Debranched waxy rice starch was subjected to repeated crystallization (RC) treatment, and its physicochemical properties and digestion pattern were investigated. The A-type crystalline pattern of native starch was crystallized to a complex of B- and V-type patterns by debranching and RC treatment. Among the treated starches, the relative crystallinity of debranched starch reached its maximum (29.6%) after eight repetitions of crystallization. Changes in weight-average molar mass among treated starch samples were not significantly different. The repeated-crystallized starches showed higher thermal transition temperatures and melting enthalpy than that of debranched starch. As a result, slowly digestible starch (SDS) content of repeated-crystallized starches reached a very high level (57.8%). Results showed that RC treatment induced structural changes of waxy rice starch result in a great amount of SDS.

This study investigated the effects of extrusion types (collet and cooking) and parameters (moisture content, screw speed and temperature) on the β-glucan content of barley and the impact of β-glucan content on starch digestibility. The results demonstrated that extrusion significantly reduced the total β-glucan (TBG) content of barley as a raw material, but the differences in TBG from extrudates obtained using different extrusion parameters were not significant. Extrusion at high moisture content, as in cooking extrusion, increased SBG, whereas extrusion at low moisture content, as in collet extrusion, lowered SBG. The regression coefficients revealed that the most significant extrusion parameters affecting SBG and IBG content in barley extrudates were feed moisture content for collet extrusion and screw speed for cooking extrusion. The in vitro digestion analysis demonstrated that collet and cooking extrudates containing high amounts of SBG revealed the highest slowly digestible starch (SDS) content. In conclusion, different extrusion types and parameters exhibited more pronounced effects on the SBG and IBG content than on the TBG content, and higher SBG content implies higher SDS content.

This study was performed to investigate the effects of lactic-fermented rice flour on the quality characteristics of pan-fried food (Jeon). Pan-frying flour containing 5∼20% lactic fermentation rice flour mixture was prepared. In rapid visco analyzer examination, peak viscosity, trough, final viscosity, breakdown, and setback of the lactic-fermented rice flour mixture were lower than those of rice flour or wheat flour. The L-value (lightness) of Jeon decreased with increasing the ratio of lactic-fermented rice flour. On the other hand, a-value (redness) and b-value (yellowness) increased with increasing ratio of lactic-fermented rice flour. Texture profiles showed that Jeon prepared with lactic-fermented rice flour mixture had higher springiness and gumminess than 100% rice flour. The oil absorptions of Jeon prepared with 100% rice flour and 20% lactic-fermented rice flour were 7.5% and 6.33%, respectively. For digestive properties, Jeon prepared with lactic-fermented rice mixture showed a greater amount of rapidly digestible starch and lower amount of slowly digestible starch. In the sensory evaluation, Jeon prepared with lactic-fermented rice mixture showed higher scores for appearance, flavor, and taste than others (rice flour and wheat flour). Especially, Jeon prepared with 10% lactic-fermented rice mixture showed the highest overall preference. In conclusion, the results demonstrate that lactic-fermented rice flour may prove quite useful as a pan-frying flour with desirable qualities properties.

The present work aimed to identify the nutritional characteristics that best explain cereal feed preference in pigs. A total of 25 cereals of known preference (at 60% of inclusion in complete feed) from a previous study were evaluated. The cereals were analyzed for DM, OM, crude fiber, ether extract, CP, GE, digestible starch, and glycemic index. Additionally, for 12 of the cereals, complete feeds (the same composition as those previously used to measure preference) were prepared, analyzed for DM, OM, CP, and starch, and fed to pigs (33 ± 5.1 kg BW) fitted with ileal T-cannulae to assess the apparent ileal (AID) and total tract digestibility (ATTD) of these nutrients using titanium dioxide as an indigestible marker. The relationships among the different energy and nutrient contents were studied by principal component (PC) analysis, and the correlations between the generated PC scores and cereal preference were analyzed. A correlation between preference and the second PC obtained with data of the 25 cereals was observed (P < 0.01), which indicated that crude fiber (negatively) and digestible starch, OM, and glycemic index (positively) were correlated with feed preference. Statistically significant linear relationships with preference were confirmed for crude fiber, digestible starch, and glycemic index (R 2 = 0.38, 0.36, and 0.23, respectively; P < 0.02). Similarly, the first PC obtained with data of the 12 feeds also correlated with preference (P < 0.01), indicating that the digestible nutrients (positively) and the nondigestible nutrients (negatively) were correlated with preference. Statistically significant relationships with preference were observed for the contents of starch (total, digestible AID, and digestible ATTD: R 2 = 0.62, 0.66, and 0.63, respectively; P < 0.01), AID DM (digestible and nondigestible: R 2 = 0.41 and 0.44, respectively; P < 0.05), ATTD DM (digestible and nondigestible: R 2 = 0.67 and 0.70, respectively; P < 0.01), AID OM (digestible and nondigestible: R 2 = 0.45 and 0.43, respectively; P < 0.05), and ATTD OM (digestible and nondigestible: R 2 = 0.64 and 0.66, respectively; P < 0.01). It is concluded that cereal preference in pigs is positively related with their content in digestible nutrients, such as starch, and negatively related with their nondigestible nutrients, such as crude fiber.

Long shelf life is important for industrially packaged cooked chestnut kernel. This study aims to investigate the physicochemical and digestive properties of starch in cooked chestnut stored for varying periods of up to 12 months. Apparent amylose content decreases significantly during the initial storage period of 2 months and then increases gradually in the succeeding 10 months. During storage, the degree of gelatinization decreases, whereas the degree of retrogradation (DR) increases. The relative crystallinity of cooked chestnut starch increases during storage and shows a significant positive correlation with DR. The content of rapidly digestible starch (RDS) decreases significantly during shelf life. Starch retrogradation and relative crystallinity exhibit a significant negative correlation with RDS content, and the short‐range molecular order of starch is negatively correlated with the content of slowly digestible starch. The results indicate that the digestibility of cooked chestnut kernel decreases during storage because of an increase in the crystallinity of starch.

A trial was undertaken to evaluate how a low sugar cracker format (GLY-HYP, 45 g) controlled blood glucose. Consumer sensory trials scored the products very highly (9/10). Clinical data were generated in volunteers ‘calibrated’ by consuming 50 g doses of glucose and trialled against a biscuit (45 g) brand that claimed up to four-hour energy release. The products contained a similar amount of carbohydrate - 66% (22% sugar) for the commercial biscuit and 61.5% (1.5% sugar) for the GLY-HYP crackers; which contained also 22.9% slowly digestible starch. After consuming 50 g glucose, blood glucose increased from ~5 mmol/l to a peak of ~9.3 mmol/l at 60 min then preceded to fall until 120 min to below baseline. Thereafter it fell to about 4.1 mmol/l at 180 min and recovered a little to 4.4 mmol/l at 240 min. The commercial biscuits blood glucose profiles rose to a peak at 30 min of ~6.6 mmol/l whereupon the concentration decreased slowly to ~5.2 mmol/l at 240 min. The GLY-HYP crackers reached a broad peak at 30 min too, 6.3 mmol/l, and then decreased slowly to ~5.2 mmol/l at 240 min. The commercial biscuits and GLY-HYP crackers contained 25.8 and 29.1% indigestible starch respectively after 240 min digestion. The GLY-HYP crackers can provide blood glucose control for up to at least four hours.

The study investigated the effect of the pectin (PEC) on structure changes, pasting property and digestibility of the fried potato starch (PS). Frying can cause starch granules disintegrate, and decrease the short-range ordered structures. All of these changes cause the fried starch to digest rapidly. The addition of the PEC can significantly reduce the structural change and lower the gelatinization behavior of the fried starch. Moreover, the fractions of slowly digestible starch (SDS) and resistant starch (RS) increased after addition of the PEC. The hydrolysis kinetic analysis indicated that PEC reduced the digestibility of the fried starch to a lower equilibrium hydrolysis percentage (C∞) and kinetic constant (k). This phenomenon was attributed to the ability of PEC to seclude some of water, thus reducing starch granule structural changes, as well as due to their ability to hinder the enzymes to access the starch granules and interfere with starch digestion process.

The molecular structures of starch in cooked wheat were measured and related to its in vitro digestibility. The structures were characterized by size-exclusion chromatography (SEC) and fluorophore-assisted carbohydrate electrophoresis (FACE) to measure the chain-length distribution (CLD) of amylose and amylopectin chains and the whole-molecule weight distribution. The CLDs were fitted to two biosynthetic models, one for amylopectin and another for amylose, which reduced the data to a small number of biologically significant parameters expressing enzyme activities. The digestibility of starch was greatly influenced by medium amylose chains, and the percentage of total starch digested at a long time ( C ∞ ) was negatively correlated with the amount of medium amylose chains (hAm,ii) and positively correlated with the length of medium amylose chains (βAm,ii). These results suggested that the medium amylose chains reduced the total digestible starch fraction. This study may help in making informed decisions about wheat starches to aid the formulation of wheat-based diets for conditions such as diabetes.

The use of oleogels for replacing solid fats is a hot topic in the food industry. The objective of this work was to partially or totally replace butter by candelilla wax/canola oil oleogel, and evaluate its effect on starch digestibility and texture of wheat sponge cake bread. Candelilla wax/canola oil oleogel/butter blends were made substituting butter in 0, 25, 50, 75 and 100% by the oleogel. Increased substitution levels of oleogel by butter produced batters with significantly reduced the viscoelastic properties (up to ~ 60–70%). Total butter substitution by oleogel decreased cakes hardness from 29.61 to 13.37 N, but increased cake specific volume from 1.91 to 1.98 cm3/g. FTIR analysis indicated the formation of hydrated and short-range crystallized starch structures at the expense of a reduction of amorphous domains, with the short-range ordering increasing by about 120%. Oleogel incorporation had a positive effect on the in vitro starch digestibility, as the digestible starch fraction increased from 70% to about 84%. Overall, the results showed that the use of oleogel for the preparation of sponge cake imposes a trade-off problem between improving the textural properties or increasing starch digestibility.

The impact of replacement of wheat flour with finger millet and pearl millet flours in Belgian waffle was evaluated for quality characteristics and nutritional composition. Control waffles where no millet flours are present have harder texture with a shear force of 35.86N while the same for the experimental waffles ranges from 19.68N to 27.02N. The waffles which have 30% and 40% finger millet respectively showed the highest acceptability in terms of sensory attributes. Replacement of wheat flour with millets did not have any negative impact on the crumb integrity and structure of the waffles. Use of millets in the formulation resulted in increased total dietary fiber, reduced carbohydrate and caloric value of the waffles. All the experimental waffles exhibited higher values of slowly digestible starch (SDS) and resistant starch (RS) fractions as compared to control. The highest amounts of ISDF (6.46%) and SDF (1.29%) were detected in waffles which have 30% finger millet and 20% pearl millet. A significant increase in the mineral content in all the experimental waffles was observed. Use of millets can effectively enhance the nutritional profile of waffles.

A long storage time (>7 days) is generally required for starch retrogradation sufficient to resist enyzmatic breakdown. To accelerate retrogradation in tuber to 3 days, two sets of time-temperature cycle processes were studied: cooked potato tubers were stored between (i) −20 °C and 4 °C, TTC1; and between (ii) 4 °C and 65 °C, TTC2 for 3 days. Relaxation times measured by LF NMR indicated that freeze-chill cycles led to the redistribution of water pools signifying the creation of starch-rich and starch-depleted (once ice) regions in tuber. Consistent with this, the TTC1 samples had higher retrogradation enthalpies than both TTC2 samples and 3-day chill retrograded samples which were never frozen. TTC-processed tubers subsequently exposed to digestive enzymes in vitro showed 60–67% starch hydrolysis, significantly lower than tubers retrograded for 3-days at 4 °C (72%) or freshly cooked tubers (87%). The residual enthalpies of digesta of TTC-processed tubers suggest the formation of slowly digestible starch.

This research reports the effects of gac fruit powder (5–15% w/w) on in vitro starch digestion, the characteristics and sensory acceptability of pasta. Incorporation of unripe (10–15%) and ripe (5–15%) gac fruit powder containing phenolic compounds and carotenoids remarkedly reduced the starch digestibility of pasta. Furthermore, gac fruit powder also decreased the percentage of rapidly digestible starch with a concomitant increase in the percentage of undigested starch in pasta. The dietary fiber content was markedly increased by the addition of gac fruit powder into pasta. The cooking loss, yellowness (b*), hardness and cohesiveness of pasta was increased with higher amount of ripe gac fruit powder. The replacement of wheat flour with unripe (5%) and ripe gac fruit powder (5–10%) had no effect on sensory acceptability of pasta. The findings suggest that gac fruit seems to be a promising functional ingredient to incorporate with pasta for reduction of starch digestibility.

In this study, the impacts of pregelatinized starch (PGS) with different conditions (2-8%, w/w) on the characteristics, microstructures and quality parameters of glutinous rice flour and dumplings were determined. The results indicated PGS favored the formation of elastic gel-like network structure on starch granules. PGS addition, especially at high PGS content, significantly influenced the granular, crystalline and molecular structure of glutinous dumplings, probably due to the structural amorphization of PGS. Accordingly, the dumplings complexation with suitable PGS exhibited a better storage, an increased content of slowly digestible starch (SDS), and integrated quality attributes including transmittance, cracking rate, and textural properties via weakening the water mobility. Pearson's correlation matrix exhibited that the quality of glutinous dumplings could be well predicted by physicochemical properties of rice flour. Thus, it is feasible to improve the textural and nutritional attribute of glutinous rice dumplings via simply complexation with PGS.

In consideration of health benefits, more digestible vinasses were investigated, which are associated with the use of different raw cereals and fermented leavens. In an in vitro digestibility test, milled long-grain glutinous rice vinasse with Taibai rice leaven showed a slow glucose-controlled release potential, which contained 37.08% slowly digestible starch, after complete vinasse consumption. The crystalline structure, thermal properties and morphology of vinasse starches were analysed. The relatively long amylopectin chains, which originated from the starch structure present in raw rice and the higher glucoamylase activity of the fermented leaven, partly explained the slower digestion of vinasse. By the optimization of the type of fermented leaven used and the starch structure of the raw rice in fermentation, the rate of vinasse starch digestion could be controlled, resulting in improved nutritional value. The results of this study are important for designing healthy vinasse products by controlling starch structures and digestion rates.

The role of raw plantain flour (RPF) and its citric acid (CA)-esterified counterpart (EPF) on the carbohydrate nutritional properties of cookies was investigated. Cookies were elaborated with commercial wheat flour (CWF), RPF, EPF, or a CWF-EPF blend, and assessed for composition, starch digestibility, texture and sensory properties. EPF-cookie showed the lowest digestible starch (DS) content and estimated glycemic index (pGI) (25.0% and 59.3, respectively). Cookies made with CWF-EPF exhibited the highest indigestible fraction values attributed to the synergistic presence of the RS from EPF and the protein and non-starch polysaccharides from CWF. All RPF containing cookies exhibited lower hardness than CWF-cookie. Although the use of RPF decreased consumer’s acceptability compared to CWF-cookie, the cookies with EPF showed sensory characteristics of 52–65% compared with the CWF-cookie (100%). This study shows CA esterification of plantain flour as a successful strategy to manufacture cookies with low DS and pGI.

Waxy rice starch slurry (10%, w/w) was treated with high hydrostatic pressure (HHP) (100–600 MPa) for 20 min and morphology, gelatinization property, X-ray diffraction pattern, semi-crystalline structure, and in vitro digestibility was determined. The morphology analysis showed that HHP treatment significantly affected the shape of starch granules. The thermal properties indicated an increase in gelatinization temperature s and decreased enthalpy with increasing pressure. However, compared with lower pressure, a complete gelatinization of starch was induced by 600 MPa. The lamellar repeat distance increased with increased pressure, while scattering peak disappeared at 600 MPa as a result of starch gelatinization. Based on the in vitro digestibility results of slowly digestible starch, HHP treatment at 400 MPa could be beneficial for improving the functionality of the waxy rice starch.

Impact of wheat flour replacement at 34% by ternary blends of 20% teff (T), 7% chestnut (CN) and 7% chickpea flours (CP) used native and submitted to heat moisture treatment (HMT) on in vitro starch digestibility were investigated in breads thereof. During the early stages of hydrolysis (0–60 min), HMT breads were hydrolyzed to a smaller extent than their native counterparts depending on the flour. All samples practically reached the plateau after 120 min and approached the equilibrium percentage of starch hydrolysed C∞ to an extent higher than 99.5% in all cases. Higher and delayed resistance towards the action of digestive enzymes was provided by CP flour on HMT when incorporated to bread formulations. The lowest value for hydrolysis index corresponded to samples with thermally treated T and CP flours that reached the lowest equilibrium percentage of starch hydrolyzed C∞, and hence leading to the lowest expected glycaemic index. Maximum formation of slowly digestible starch was achieved in breads with thermally treated T and native CP flours., The authors acknowledge the Institutions Ministerio de Economía y Competitividad (MINECO) and Federación Europea de Desarrollo Regional (FEDER) for funding the Project AGL2015-63849-C2-1-R

Starch is a staple constituent of foodstuffs and energy source in the human diet. In many cases, its practical use is limited because of its lack of versatility to function adequately in the whole range of food product. Functional starch is designated as chemical, physical, or enzymatical modified starch with specific functional properties such as physiological function, healthy benefits, absorption function, sustained slow energy release, and other functions. Functional starches such as slowly digestible starch, resistant starch, porous starch, starch microemulsions, nano-sized starch, and starch copolymers are the dominating varieties that can be used in the food industry. Nowadays, the preparation of functional starch is an ongoing process as there are numerous possibilities, resulting from an evolution of new processing technologies and market trends. This chapter reviewed the current state of knowledge on functional starch. Particular emphasis was placed on the definition, classification, and characterization of functional starch in the food industry. The preparation and application of functional starches were overviewed, which gave a brief introduction for the following chapters.

The consumption of slowly digestible and resistant starches results in a lower glycemic response compared with rapidly digestible starch due to the slower absorption of glucose in the small intestine. Resistant starch is the portion of starch that passes undigested to the colon, where it is fermented by microbiota. Slowly digestible and resistant starches contribute to the health benefits of whole grains and whole grain products. However, resistant starch differs from traditional fibres in that it is fermented in the large bowel, producing short-chain fatty acids which are known to promote large bowel health. The formation of resistant starch is primarily dependent on the activities of specific starch synthesis enzymes. The alteration of these enzyme activities by genetic mutations has led to the production of high-amylose grain cultivars rich in resistant starch. Commercially available resistant starch can be incorporated into grain-based products. The addition of resistant starch provides an avenue to increase the fibre content of foods, with superior sensory acceptability and nutritional value compared with other fibres. The ease of incorporation of resistant starch into foods combined with the profound influence on health makes resistant starch an excellent ingredient for grain-based functional foods.

Banana starches from diverse varieties (Macho, Morado, Valery and Enano Gigante) were studied in their physicochemical, structural and digestibility features. X-ray diffraction indicated that the banana starches present a B-type crystallinity pattern, with slight difference in the crystallinity level. Macho and Enano Gigante starches showed the highest pasting temperatures (79 and 78 °C, respectively), whilst Valery and Morado varieties presented a slight breakdown and higher setback than the formers. Morado starch presented the highest solubility value and Valery starch the lowest one. The swelling pattern of the banana starches was in agreement with their pasting profile. All banana starches showed a shear-thinning profile. The resistant starch (RS) fraction was the main fraction in the uncooked banana starches. Morado variety showed the highest amount of slowly digestible starch (SDS) and the lowest RS content reported until now in banana starches. Banana starch cooked samples presented an important amount of SDS and RS. Molecular weight and gyration radius of the four banana starches ranged between 2.88–3.14 × 10 8 g/mol and 286–302 nm, respectively. The chain-length distributions of banana amylopectin showed that B1 chains (DP 13–24) is the main fraction, and an important amount of long chains (DP ≥ 37) are present. The information generated from this study can be useful to determine banana varieties for starch isolation with specific functionality.

Physicochemical and digestive properties between wheat starch (WS) and wheat flour (WF) which had been modified by using heat-moisture treatment (HMT) were investigated. Reduced peak viscosity and increased pasting temperature were found in both WS and WF after HMT. Samples treated with a higher moisture treatment (25% and 35%) exhibited biphasic endotherms. HMT significantly changed crystal structure of WS and WF, and patterns transferred from A to A + V with moisture content increase indicating a formation of starch–lipid complex. Besides, HMT caused the clumping of starch granules and the aggregation of denatured protein, observed using confocal laser scanning microscopy (CLSM) and light microscopy. The higher moisture contents produced HMT samples with higher resistant starch content. In addition, HMT wheat flour showed a higher resistant and slowly digestible starch content when compared to the other counterpart of WS.

The effects of continuous retrogradation (CR) and intermittent retrogradation (IR) treatments under 4 °C and 25 °C or temperature-cycled condition of 4/25 °C on the digestibility and structural properties of waxy wheat starch were investigated. The results indicated that IR treatment under temperature cycles of 4/25 °C (IR-4/25) was more beneficial to the formation of slowly digestible starch (SDS, 42.24%). Moreover, the gelatinisation enthalpy of IR-4/25-treated starch sample was lower than that of CR-4/25-treated sample. Variation in infrared absorbance ratio of 1047 cm−1/1022 cm−1 of IR-treated starch samples was consistent with relative crystallinity. Through retrogradation treatment under 4/25 °C or 4 °C, starch samples exhibited X-ray diffraction pattern of B-type, while CR-25 and IR-25-treated samples showed a mixed A + B type pattern. Besides, the swelling power of CR-4/25-treated starch sample was higher than that of IR-4/25-treated sample. The pasting temperatures of IR-treated starch samples were higher than those of the CR-treated samples.

This study investigated whether the crystalline structure of the retrograded starch affects the contents of slowly digestible starch (SDS) and resistant starch (RS). When the relative crystallinities were similar, there was no difference in RS content between the retrograded starches with A- and B-type crystallites. However, the SDS content in A-type crystalline structure was constantly higher than B-type, contradicting the observation that the granular starches with B-type crystallites were more enzyme resistant. Therefore, the primary factor that accounts for the digestibility of granular starch is not the crystalline structure, but the granular properties, including the surface pores and the size.

Waxy rice starch was subjected to annealing (ANN) and heat-moisture treatment (HMT). These starches were also treated by a combination of ANN and HMT. The impact of single and dual modifications (ANN-HMT and HMT-ANN) on the molecular weight (M(w)), crystalline structure, thermal properties, and the digestibility were investigated. The relative crystallinity and short-range order on the granule surface increased on ANN, whereas decreased on HMT. All treated starches showed lower M(w) than that of the native starch. Gelatinization onset temperature, peak temperature and conclusion temperature increased for both single and dual treatments. Increased slowly digestible starch content was found on HMT and ANN-HMT. However, resistant starch levels decreased in all treated starches as compared with native starch. The results would imply that hydrothermal treatment induced structural changes in waxy rice starch significantly affected its digestibility.

Impact of heat-moisture treatment (HMT) on nutritional properties of normal maize starch (NMS) under various reaction conditions was investigated. NMS was adjusted to moisture levels of 20%, 25%, 30% and 35% and heated at 80, 100, 120 and 140°C for 4, 8, 12 and 16h. Response surface methodology (RSM) based on Box-Behnken design (BBD) was employed to obtain the optimal combination of moisture level (X1: 20-30%), length of heating (X2: 4-12h), and temperature (X3: 100-140°C). The optimum reaction condition decreased rapidly digestible starch (RDS) from 87.10% to 82.21%, when NMS was subjected to HMT at 23.6% moisture content and heated at 114.8°C for 9.04h. The ANOVA measurement and confirmation experiments were performed to verify the predictive value and the RSM model, indicating that temperature was the main factor to determine the digestion rate of HMT NMS. The results suggested that RDS was not correlated to heating length but positively correlated to temperature and moisture content. Reaction condition had no correlations with slowly digestible starch (SDS) and resistant starch (RS). This study could provide more information for producing low-glycemic index products.

Unripe banana flour is an important source of indigestible carbohydrates, mainly resistant starch (RS). However, during cooking of the fruit, the indigestible carbohydrates are transformed to digestible. The aim of this study was to test different treatments: cooking (5, 15 and 25 min), cooking plus high-moisture treatment (HMT) and cooking plus HMT plus storage (HMT + S), to increase the slowly digestible starch (SDS) and RS fractions. Polarization light microscopy, leached amylose, X-ray diffraction pattern, thermal and pasting characteristics, and starch digestibility analysis of the flours were evaluated. The longest cooking time decreased the RS content in the non-gelatinized samples; HMT and HMT + S increased the SDS level. These samples could be used in products without heat treatment during their preparation. The gelatinized samples presented a significant fraction of RS in comparison with the non-gelatinized, demonstrated that the samples can be used in products where cooking is necessary, conserving a high amount of indigestible carbohydrates. PRACTICAL APPLICATIONS Unripe bananas are an alternative source of indigestible carbohydrates, mainly resistant starch (RS) and dietary fiber (DF). Unripe banana is also considered the richest natural source of RS; however, this characteristic is lost when the fruit is cooked. The digestion rate of starch present in unripe banana flour can be modified to produce a functional or nutraceutical ingredient. The use of physical treatments on unripe banana flour such as cooking, high-moisture treatment, storage and combinations of these, have shown to increase the slowly digestible starch and RS fractions. The physical treatments on unripe banana flour produce a powder that, because of the high amount of indigestible carbohydrates, can be considered as nutraceutical ingredient and can be used in products such as pasta and bakery products in which cooking is necessary, while maintaining a high amount of indigestible carbohydrates.

Structure-function relationship of rice starch is scarce in the literature. Starch was isolated from diverse Mexican rice varieties and their swelling power (SP), soluble solids (ss), thermal and pasting properties, XRD pattern, in vitro starch digestibility, and AP chain-length distribution were evaluated. Rice starches with low SP at 60°C had higher temperature and enthalpy of gelatinization. The peak viscosity of rice starches ranged between 2426 and 3519 cP, and the samples presented high values for setback due to the AM content. Rice starches presented the typical A-type XRD pattern with crystallinity values between 32.7 and 36.3%. Rice starches presented high amounts of short chains (A and B1), and differences were found among the cultivars. AM content for rice starches ranged between 18.4 and 22.9%, and the main fraction recorded by HPSEC was the Fraction III (short chains) with values around 60%. The uncooked rice starch samples presented high values of slowly digestible starch (SDS) and rapidly digestible starch (RDS), and differences were found among the cultivars. In cooked samples decreased SDS and increased RDS and RS. Onset temperature and enthalpy of gelatinization were correlated with the percentage of A-chains and an opposite pattern was found with the percentage of B1 chains. AP structural characteristics affect the functional, physicochemical, and digestibility properties of rice starches.

Growing and cooking conditions influence the quality and nutritional value of beans. The objective of this research was to determine the effect of cooking on digestibility and physicochemical properties of two varieties of bean grown under different water regimes. Black 8025 and Pinto Durango varieties were grown in irrigated and temporal (rain fed) conditions in two locations of Guanajuato, Mexico. The pasting profiles of the cooked beans showed a significant decrease in viscosity. The enthalpy of the raw and cooked beans ranged from 2.75 to 3.95 and 0.62 to 0.97J/g, respectively. The percentage of rapidly digestible starch and slowly digestible starch increased, while the percentage of resistant starch was lower in cooked samples. Black 8025 beans had lower glycemic index than Pinto Durango, but no significant difference (P

Samples of normal, high-amylose, and waxy barleys (NB, HAB, and WB, respectively) were tempered and then microwaved using three treatment protocols at each of three power levels. Microwave treatment increased starch digestibility, as rapidly digestible starch (RDS) concentrations were markedly higher and resistant starch (RS) and slowly digestible starch (SDS) concentrations were significantly lower, in all microwaved samples compared to corresponding unprocessed samples. Levels of RDS, on a dry sample basis, were similar in corresponding microwaved samples of the three barley types but were higher in WB when expressed on a starch basis. Levels of RS were lowest in microwaved WB samples. Microwave treatment was most effective in increasing starch digestibility at higher microwave power levels and when samples were tempered and then stored for 14 days at 4°C prior to microwaving, although the magnitude of the increase may not justify the cost of the storage step and might be achieved more economically through the use of an even higher power level. Increases in starch digestibility were attributed to gelatinization of starch. This conclusion was supported by degree of starch gelatinization, thermal analysis, and pasting data.

Digestibility of starches in four rice samples with amylose content (AC) from 1.7 to 55.4%, including a newly developed high-amylose rice, was investigated. An in vitro enzymatic starch digestion method and an AOAC method were applied to correlate rapidly digestible starch (RDS), slowly digestible starch (SDS), resistant starch (RS), and total dietary fiber (TDF) content with the AC in the samples. SDS content decreased and RS and TDF content increased with the increase in AC. The low-amylose rice (AC = 16.1%) had starch granules with weak crystalline structure and was lower in RS and TDF content even though it had a higher AC compared to waxy rice. The digestibility of the starches was not correlated with granule size or degree of crystallinity. The newly developed high-amylose rice starch exhibited a predominant B-type X-ray diffraction pattern, a great proportion of long chains in amylopectin, high gelatinization temperature, and semi-compound starch granules which are attributed to its increased resistance to enzyme digestion.

Starch can be classified into rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) according to its resistance to amylolytic enzymes. This study investigated the effects of cultivar and feedstock under varying parboiling conditions on the physicochemical properties and starch fractions of parboiled rice. Rice (rough or brown) was soaked, steamed under pressure, dried immediately or stored at room temperature for 24 hr prior to drying, and then treated with or without a repeated steam cycle prior to milling. The storage treatment significantly increased the retrograded amylopectin enthalpy and amylose-lipid complex melting temperature of parboiled rice. Parboiled rice samples prepared from brown rice feedstock had higher peak melting temperatures but lower enthalpy values of retrograded amylopectin than samples prepared from rough rice after the storage treatment. The pasting viscosity of parboiled rice was most affected by the repeated autoclaving treatment a...

The physicochemical properties, textural properties, and starch digestibility of rice cultivars grown in Mexico were evaluated. Variations existed in grain dimensions, and the rice grains were classified as medium, long, and extra long. Huimanguillo had the highest amylose content (30.4%), and A06, A92, A98, and Champoton presented the lowest amylose content (24.3–25.2%). The protein content was 7.1–11.0% and the lipid level was 0.47–1.22% among these Mexican cultivars. Champoton showed the highest temperature and enthalpy of gelatinization, and this with A98, Culiacan, and Huimanguillo had the highest enthalpy of retrogradation. Cotaxtla had the highest pasting peak, setback, and final viscosity. The texture assessment in cooked rice showed that A06 had the highest hardness, and A96 and A98 had the highest stickiness. There was little difference in the rapidly digestible starch, slowly digestible starch, and resistant starch content of tested Mexican rice cultivars. The differences in the physic...

Banana starch was chemically modified using single (esterification or cross-linking) and dual modification (esterification-cross-linking and cross-linking-esterification), with the objective to increase the slowly digestible starch (SDS) and resistant starch (RS) concentrations. Physicochemical properties and in vitro digestibility were analyzed. The degree of substitution of the esterified samples ranged from 0.006 to 0.020. The X-ray diffraction pattern of the modified samples did not show change; however, an increase in crystallinity level was determined (from 23.79 to 32.76%). The ungelatinized samples had low rapidly digestible starch (RDS) (4.23-9.19%), whereas the modified starches showed an increase in SDS (from 10.79 to 16.79%) and had high RS content (74.07-85.07%). In the cooked samples, the esterified starch increased the SDS content (21.32%), followed by cross-linked starch (15.13%). Dual modified starch (cross-linked-esterified) had the lowest SDS content, but the highest RS amount. The esterified and cross-linked-esterified samples had higher peak viscosity than cross-linked and esterified-cross-linked. This characteristic is due to the fact that in dual modification, the groups introduced in the first modification are replaced by the functional group of the second modification. Temperature and enthalpy of gelatinization decreased in modified starches (from 75.37 to 74.02 °C and from 10.42 to 8.68 J/g, respectively), compared with their unmodified starch (76.15 °C and 11.05 J/g). Cross-linked-esterified starch showed the lowest enthalpy of gelatinization (8.68 J/g). Retrogradation temperature decreased in modified starches compared with unmodified (59.04-57.47 °C), but no significant differences were found among the modified samples.

The influence of dry heat treatment (DHT) of high amylose rice starch was investigated on starch digestibility and physical properties and their characteristics were compared through the PCA analysis. High amylose rice starch was prepared by DHT under different temperatures (110, 130, and 150°C) and times (0, 1, 2, and 4h). The gelatinization temperature and enthalpy decreased as temperature and time increased, revealing the change of semi-crystalline region. There were significant increases in gel strength and pasting viscosity above 130°C, whereas gel strength and pasting viscosity were reduced with increasing heating time. On in vitro starch digestibility of DHT starch gel, the rapidly digestible starch and predicted glycemic index of DHT starches were lower than those of native starch. Both the lowest predicted glycemic index and the highest gel strength was observed at 130°C for 1h. In the results of PCA analysis, the heating temperature was negatively correlated with in vitro starch digestibility as well as pasting viscosity and gel strength. These results demonstrated that DHT could be useful of enhancing the physical and nutritional properties of high amylose rice starch.

Effect of heat-moisture treatment (HMT) of brown rice flour on the quality and digestibility of Korean rice cake (jeolpyeon) was investigated. Brown rice flour with 20% moisture content was heat-moisture treated at 100–110 °C for 1–2 h, and subsequently cooled to 4 °C for 1–2 h. The lightness of HMT rice cake decreased as HMT temperature and time increased, whereas redness and yellowness increased. The hardness, springiness, and cohesiveness of HMT rice cake were much lower than those of brown rice cake. HMT of rice cake caused an increase in the resistant starch content and a decrease in the rapidly digestible starch content. In sensory evaluation, hardness of HMT rice cake was substantially lower than that of rice cake made with untreated brown rice due to retardation of retrogradation. However, the overall acceptability of HMT rice cake was lower than that of white rice cake or brown rice cake.