Banana starch and molecular shear fragmentation dramatically increase structurally driven slowly digestible starch in fully gelatinized bread crumb

Assessing the impact of plasma-activated water-assisted heat-moisture treatment on the extrusion-recrystallization process of hausa potato starch

The study explored the plasma-activated water (PAW)-assisted heat-moisture treatment (HMT) on the structural, physico-chemical properties, and in vitro digestibility of extrusion-recrystallized starch. Native starch of hausa potatoes underwent modification through a dual process involving PAW-assisted HMT (PHMT) followed by extrusion-recrystallization (PERH) using a twin-screw extruder. The PHMT sample showed surface roughness and etching with a significantly greater (p ≤ 0.05) RC (20.12 %) and ΔH (5.86 J/g) compared to DHMT. In contrast, PERH-induced structural damage, resulting in an irregular block structure, and altered the crystalline pattern from A to B + V-type characterized by peaks at 17.04°, 19.74°, 22°, and 23.94°. DSC analysis showed two endothermic peaks in all the extrusion-recrystallized samples, having the initial peak attributed to the melting of structured amylopectin chains and the second one linked to the melting of complexes formed during retrogradation. Dual-modified samples displayed notably increased transition temperatures (To1 74.54 and 74.17 °C, To2 122.65 and 121.49 °C), along with increased RS content (43.76 %-45.30 %). This study envisages a novel approach for RS preparation and broadens the utilization of PAW in starch modification synergistically with environmentally friendly techniques.

In vitro gastric digestion of polysaccharides in mixed dispersions: Evaluating the contribution of human salivary α-amylase on starch molecular breakdown

The aim of this work was to investigate the impact of the addition of salivary α-amylase on starch hydrolysis in protein-containing dispersions during an in vitro digestion process. In vitro digestion provides useful insights on the fate of nutrients during gastro-intestinal transit in complex food matrices, an important aspect to consider when developing highly nutritious foods. Many foods contain polysaccharides, and as their disruption in the gastric stage is limited, salivary α-amylase is often neglected in in vitro studies. A reference study on the effect of salivary α-amylase using one of the most advanced and complex in vitro digestion models (INFOGEST) is, however, not available. Hence, this work reports the gastrointestinal breakdown of three mixed dispersions containing whey protein isolate with different polysaccharides: potato starch, pectin from citrus peel and maize starch. The latter was also studied after heating. No polysaccharide or salivary α-amylase-dependent effect on protein digestion was found, based on the free NH2 and SDS-PAGE. However, in the heat-treated samples, the addition of salivary α-amylase showed a significantly higher starch hydrolysis compared to the sample without α-amylase, due to the gelatinization of the starch granules, which improved the accessibility of the starch molecules to the enzyme. This work demonstrated that the presence of different types of polysaccharides does not affect protein digestion, but also it emphasizes the importance of considering the influence of processing on food structure and its digestibility, even in the simplest model systems.

Inhibition of starch digestion by phenolic acids with a cinnamic acid backbone: Structural requirements for the inhibition of α-amylase and α-glucosidase

This study investigated the inhibition mechanism of cinnamic acid-based phenolic acids (cinnamic acid: CIA, 3,4-dimethoxy cinnamic acid: 3,4-mCIA, caffeic acid: CA, ferulic acid: FA) on starch digestion. CA, FA, and 3,4-mCIA contributed to reducing the rapidly digested starch content and increasing the resistant starch content. The enzyme activity inhibition results responded that the four phenolic acids inhibited α-amylase activity better than α-glucosidase. The order of IC50 against α-amylase and α-glucosidase was CA > FA > 3,4-mCIA > CIA. Phenolic acid's benzene ring formed conjugated Pi-systems with the amino acid residues of α-amylase. Salt-bridge interactions were the main driving forces for the binding of phenolic acids to α-glucosidase. The binding was stabilized by the hydroxyl (OH) group and the methoxy on the benzene ring, where the OH exerted a better effect. These results illuminate the inhibition mechanism of starch digestion with cinnamic acid-based phenolic acids from an interaction perspective.

Factors influencing the starch digestibility of starchy foods: A review

Starchy foods are a major energy source of the human diet, their digestion is closely related to human health. Most foods require lots of processing before eating, therefore, many factors can influence starch digestibility. The factors that affect the digestibility of starches have been widely discussed previously, but the extracted starches in those studies were different from those present within the actual food matrix. This review summarizes the factors influencing the starch digestibility in starchy foods. Endogenous non-starch components hinder the starch digestive process. Food ingredients and additives decrease starch digestibility by inhibiting the activity of digestive enzymes or hindering the contact between starch and enzymes. Storage induce the retrogradation of starch, decreasing the digestibility of foods. Therefore, preparing starchy foods with whole grains, processing them as little as possible, using food additives reasonably, and storage conditions may all be beneficial measures for the production of low GI foods.

Effects of high-speed shear and double-enzymatic hydrolysis on the structural and physicochemical properties of rice porous starch

This study aimed to investigate the physicochemical properties of the rice porous starch (HSS-ES) prepared by high-speed shear combined with double-enzymatic (α-amylase and glucoamylase) hydrolysis, and to reveal their mechanism. The analyses of ¹H NMR and amylose content showed that high-speed shear changed the molecular structure of starch and increased the amylose content (up to 20.42 ± 0.04 %). FTIR, XRD and SAXS spectra indicated that high-speed shear did not change the starch crystal configuration but caused a decrease in short-range molecular order and relative crystallinity (24.42 ± 0.06 %), and a loose semi-crystalline lamellar, which were beneficial to the followed double-enzymatic hydrolysis. Therefore, the HSS-ES displayed a superior porous structure and larger specific surface area (2.962 ± 0.002 m²/g) compared with double-enzymatic hydrolyzed porous starch (ES), resulting in the increase of water and oil absorption from 130.79 ± 0.50 % and 109.63 ± 0.71 % to 154.79 ± 1.14 % and 138.40 ± 1.18 %, respectively. In vitro digestion analysis showed that the HSS-ES had good digestive resistance derived from the higher content of slowly digestible and resistant starch. The present study suggested that high-speed shear as an enzymatic hydrolysis pretreatment significantly enhanced the pore formation of rice starch.

Effects of primary, secondary and tertiary structures on functional properties of thermoplastic starch biopolymer blend films

To better understand the correlation between structure and properties in thermoplastic starch biopolymer blend films, the effects of amylose content, chain length distribution of amylopectin and molecular orientation of thermoplastic sweet potato starch (TSPS) and thermoplastic pea starch (TPES) on microstructure and functional properties of thermoplastic starch biopolymer blend films were studied. After thermoplastic extrusion, the amylose contents of TSPS and TPES decreased by 16.10 % and 13.13 %, respectively. The proportion of the chains with the degree of polymerization between 9 and 24 of amylopectin in TSPS and TPES increased from 67.61 % to 69.50 %, and from 69.51 % to 71.06 %, respectively. As a result, the degree of crystallinity and molecular orientation of TSPS and TPES films increased as compared to sweet potato starch and pea starch films. The thermoplastic starch biopolymer blend films possessed a more homogeneous and compacter network. The tensile strength and water resistance of thermoplastic starch biopolymer blend films increased significantly, whereas thickness and elongation at break of thermoplastic starch biopolymer blend films decreased significantly.

Effects of Extrusion on Starch Molecular Degradation, Order-Disorder Structural Transition and Digestibility-A Review

Extrusion is a thermomechanical technology that has been widely used in the production of various starch-based foods and can transform raw materials into edible products with unique nutritional characteristics. Starch digestibility is a crucial nutritional factor that can largely determine the human postprandial glycemic response, and frequent consumption of foods with rapid starch digestibility is related to the occurrence of type 2 diabetes. The extrusion process involves starch degradation and order-disorder structural transition, which could result in large variance in starch digestibility in these foods depending on the raw material properties and processing conditions. It provides opportunities to modify starch digestibility by selecting a desirable combination of raw food materials and extrusion settings. This review firstly introduces the application of extrusion techniques in starch-based food production, while, more importantly, it discusses the effects of extrusion on the alteration of starch structures and consequentially starch digestibility in various foods. This review contains important information to generate a new generation of foods with slow starch digestibility by the extrusion technique.

Preparation of Slowly Digested Corn Starch Using Branching Enzyme and Immobilized α-Amylase

The aim of this study was to modify the digestibility and structure of corn starch by treatment with compound enzymes. Corn starch was treated with two enzymes (α-amylase, which catalyzes hydrolysis, and branching enzyme, a transglycosidase that catalyzes branch formation), and the reaction was monitored by determining the content of slowly digestible starch in the reaction product. The fine structure and physical and chemical properties of enzyme-modified starch samples were analyzed using scanning electron microscopy, gel chromatography, and X-ray diffraction methods; modified starch has a high degree of branching, a high proportion of short-chain branched structures, and greatly improved solubility. The results show that the slow digestion performance of corn starch was significantly improved after hydrolysis by α-amylase for 4 h and treatment with branching enzyme for 6 h. These results show that enzymatic modification of corn starch can improve its slow digestibility properties.

Gluten-free bakery products: Ingredients and processes

There is an increasing demand for gluten-free products around the world because certain groups of people, which have increased in the last decades, need to eliminate gluten from their diet. A growing number of people consider gluten-free products to be healthier. However, making gluten-free products such as bread is a technological challenge due to the important role of the gluten network in their development. However, other products, such as cakes and cookies usually made with wheat flour, can easily be made with gluten-free starches or flours since gluten does not play an essential role in their production. To replace wheat flour in these elaborations it is necessary to resort to gluten-free starches and/or flours and to gluten substitutes. Additionally, it can be convenient to incorporate other ingredients such as proteins, fibers, sugars or oils, as well as to modify their quantities in wheat flour formulations. Regarding gluten-free flours, it will also be necessary to know the parameters that influence their functionality in order to obtain regular products. These problems have originated a lower availability of gluten-free products which have a worse texture and are less tasty and more expensive than their homologues with gluten. These problems have been partially solved thanks to research on these types of products, their ingredients and their production methods. In recent years, studies about the nutritional improvement of these products have increased. This chapter delves into the main ingredients used in the production of gluten-free products, the processes for making gluten-free breads, cakes and cookies, and the nutritional quality of these products.

The temperature induced disruption process of amylopectin under ultrasonic treatments

In this study, amylopectin was ultrasonicated at different temperatures to explore its disruption process. Results showed a significant decrease in amylopectin M_w after ultrasonic treatments and a retarded effect was detected with the increase of temperatures. The amylopectin disruption process fitted to the second order kinetic model (1/M_wt - 1/M_w0 = kt) and its disruption rate coefficient decreased from 2.203 × 10^-8 to 0.986 × 10^-8 mol/g min as the temperatures increased from 20 to 80 °C. This was ascribed to the higher vapour pressure and the lower viscosity of the solution at higher temperatures. Ultrasound induced break points preferentially occurred to B3 chains of amylopectin at higher temperatures which contributed to an increase of A chains, which because that amylopectin would be more extended at higher temperatures. The activation energy of amylopectin disruption was negative (-11.6 KJ/mol), which indicated that its scission process by ultrasound was essentially a mechanical action.

Cassava and banana starch modified with maleic anhydride-poly (ethylene glycol) methyl ether (Ma-mPEG): A comparative study of their physicochemical properties as coatings

This study proposes a simple route to obtain starch grafted copolymers from cassava and banana starches chemically modified with amphiphilic maleic anhydride-poly (ethylene glycol) methyl ether (Ma-mPEG). The starches were extracted from cassava (StC) and banana (StB) pulp and characterized by FTIR spectroscopy, amylose content, scanning electron microscope (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and average molecular weight. Starches were chemically modified with amphiphilic Ma-mPEG in three mass ratios 1:1, 1:2 and 1:3. Thermal behavior and interactions of Ma-mPEG/starch in the St-g-(Ma-mPEG) copolymers were studied by DSC and TGA. The T_g values showed a higher plasticizer effect in the copolymers obtained from StC. Films were formed from StC-g-(Ma-mPEG) and StB-g-(Ma-mPEG) copolymers, thermal and morphological properties were studied. An increase in the mass ratios of Ma-mPEG and the absence of the glycerol in the formulations formed homogeneous films. StC-g-(Ma-mPEG) 1:3 with 2% concentration showed a potential use as coating in strawberries, presenting a lower weight loss (15.5 ± 5.7%) than the control sample (18.6 ± 3.3%).

Pre-Gelatinisation of Rice Flour and Its Effect on the Properties of Gluten Free Rice Bread and Its Batter

In order to improve the quality of the gluten free rice bread (GFRB), pre-gelatinised rice flour (PGRF) was made and used to partially replace natural rice flour in the production of GFRB. The pre-gelatinisation parameters were optimised and the effects of PGRF on the quality of the GFRB and its batter were studied. The results showed that optimal PGRF was obtained when 50% total water was mixed with 1.0% rice flour and the mixture heated at 80 °C for 2 min. Supplementation with PGRF significantly improved the properties of GFRB by affecting its baking properties, textural properties, colour, and crumb grain features. Effects of PGRF on GFRB were mainly caused by the more closely packed gel structure of rice starch in the bread batter, the higher onset temperature during gelatinisation and the complex effect of PGRF on water-binding capacity in bread batter during the baking process. As the pre-gelatinisation parameters of flours and their effect on gluten-free baked products varied with grain variety, processing properties should be studied before using them, and emphasis should be placed on new techniques such as flour pre-gelatinisation to obtain gluten-free foods with improved quality.

A Systematic Review on Gluten-Free Bread Formulations Using Specific Volume as a Quality Indicator

This study aimed to perform a systematic review on gluten-free bread formulations using specific volumes as a quality indicator. In this systematic review, we identified 259 studies that met inclusion criteria. From these studies, 43 met the requirements of having gluten-free bread with a specific volume greater than or equal to 3.5 cm³/g. Other parameters such as the texture profile, color (crumb and crust), and sensory analysis examined in these studies were presented. The formulations that best compensated the lack of the gluten-network were based on the combination of rice flour, rice flour with low amylose content, maize flour, rice starch, corn starch, potato starch, starch with proteins and added with transglutaminase (TGase), and hydrocolloids like hydroxypropylmethylcellulose (HPMC). Of the 43 studies, three did not present risk of bias, and the only parameter evaluated in common in the studies was the specific volume. However, it is necessary to jointly analyze other parameters that contribute to the quality, such as texture profile, external and internal characteristics, acceptability, and useful life of the bread, especially since it is a product obtained through raw materials and unconventional ingredients.

Causal relations among starch fine molecular structure, lamellar/crystalline structure and in vitro digestion kinetics of native rice starch

Causal relations among starch fine molecular structures, lamellar/crystalline structures, and the in vitro digestion kinetics of native rice starches.

On the role of the internal chain length distribution of amylopectins during retrogradation: Double helix lateral aggregation and slow digestibility

A structure-digestion model is proposed to explain the formation of α-amylase-slowly digestible structures during amylopectin retrogradation. Maize and potato (normal and waxy) and banana starch (normal and purified amylopectin through alcohol precipitation), were analyzed for amylose ratio and size (HPSEC) and amylopectin unit- and internal-chain length distribution (HPAEC). Banana amylopectin (BA), like waxy potato (WP), exhibited a larger number of B3-chains, fewer BS- and B_fp-chains and lower S:L and BS:BL ratios than maize, categorizing BA structurally as type-4. WP exhibited a significantly greater tendency to form double helices (DSC and ¹³C-NMR) than BA, which was attributed to its higher internal chain length (ICL) and fewer DP6-12-chains. However, retrograded BA was remarkably more resistant to digestion than WP. Lower number of phosphorylated B-chains, more S- and B_fp-chains and shorter ICL, were suggested to result in α-amylase-slowly digestible structures through further lateral packing of double helices (suggested by thermo-rheology) in type-4 amylopectins.

The Effect of Bread Fortification with Whole Green Banana Flour on Its Physicochemical, Nutritional and In Vitro Digestibility

The use of Whole Green Banana Flour (WGBF) in bread production may be a strategy to improve the nutritional profile of bread, but the extent of improvement may depend on the processing conditions of the flour. Therefore, WGBF was produced using two methods (freeze-drying and air-oven drying) and was used in bread-making. This study investigated the effect of flour type-FDF (WGBF produced by freeze-drying) and ODF (prepared by air-oven drying at 50 °C)-at fortification levels of 0% (control), 10%, 20%, and 30% on the fortified bread. A significant decrease in energy caloric value and an increase in moisture and fibre at >20% fortification level (p < 0.05) was noted. The ODF bread samples had a higher browning index compared to the control and the FDF samples. Addition of WGBF improved macro minerals (Mg, Ca, Na, K, and P) with a no significant change in micro minerals (Fe, Zn, and Mn). The use of FDF in bread resulted in a marked increase in resistant and slow digestible starch levels in F30 compared to ODF samples and their comparable fortification levels. The digestibility of the bread samples showed that WGBF can be used as an alternative functional ingredient to prepare bread with better nutritional value.

The Compositional and Functional Attributes of Commercial Flours from Tropical Fruits (Breadfruit and Banana)

The objective of this study was to compare the compositional and functional properties of tropical flour sources (two breadfruit flours (type A and type B) and a banana flour) with a more traditional flour source (wheat flour). Macro-nutrient composition, pH, water and oil holding capacity, bulk density, particle size, solubility, swelling power, pasting properties, and thermodynamics (gelatinization and retrogradation) were determined. All flours evaluated were similar in their composition with high levels of carbohydrates (greater than 82.52 g/100 g on a dry-matter basis), with most of the carbohydrate content comprised of starch (greater than 67.02 g/100 g). The tropical fruit flours had greater (p < 0.05) water holding capacity than wheat flour. Breadfruit flour B had the lowest (p < 0.05) bulk density, while banana flour had the greatest (p < 0.05) bulk density. The swelling power of the tropical flours was greater (p < 0.05) than the wheat flour. The viscosity of the tropical flours was higher than wheat flour but decreased significantly when temperature was held at 130 °C. These results indicated that the two breadfruit flours and banana flour have great potential for application in processed food products, and have similar compositional attributes to a more traditional flour.

Evaluation of the behaviour of unripe banana flour with non-conventional flours in the production of gluten-free bread

Gluten-free breads were developed by incorporating unripe banana flour in a blend of alternative flour/cassava starch, 45/50. A factorial design was applied to determine the simultaneous effect of percentage of unripe banana flour (2, 8, 15%) and the type of alternative flour (quinoa, oyster mushroom, yellow pea and lentil flour) on structural and colour properties of bread. Principal component analysis was used to evaluate the behaviour of the formulations from a comprehensive perspective. Three formulations, denoted as P8 (pea + 8% unripe banana flour), Q15 (quinoa + 15% unripe banana flour) and L15 (lentil + 15% unripe banana flour) exhibited the closest profiles to reference (wheat bread). Breads with oyster mushroom flour showed a profile significantly different from the rest of formulations. The interactions among the factors were significant for all studied properties and showed that the unripe banana flour fortification did not lead to proportional responses on the bread properties, but the behaviour of unripe banana flour in breadmaking relied on the percentage and the type of alternative flour used. The P8, Q15 and L15 exhibited high fibre content and carbohydrate content lower than the reference. In addition, P8 formulation can be classified as intermediate glycaemic index.

Structural Basis of Resistant Starch (RS) in Bread: Natural and Commercial Alternatives

Bread is categorized as having a high amount of rapidly digested starch that may result in a rapid increase in postprandial blood glucose and, therefore, poor health outcomes. This is mostly the result of the complete gelatinization that starch undergoes during baking. The inclusion of resistant starch (RS) ingredients in bread formulas is gaining prominence, especially with the current positive health outcomes attributed to RS and the apparition of novel RS ingredients in the market. However, many RS ingredients contain RS structures that do not resist baking and, therefore, are not suitable to result in a meaningful RS increase in the final product. In this review, the structural factors for the resistance to digestion and hydrothermal processing of RS ingredients are reviewed, and the definition of each RS subtype is expanded to account for novel non-digestible structures recently reported. Moreover, the current in vitro digestion methods used to measure RS content are critically discussed with a view of highlighting the importance of having a harmonized method to determine the optimum RS type and inclusion levels for bread-making.

Esterified plantain flour for the production of cookies rich in indigestible carbohydrates

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.

Nutritional and physical characterization of sugar-snap cookies: effect of banana starch in native and molten states

Starch digestion and consumer's acceptance of gluten-free sugar-snap cookies can be simultaneously improved by using banana starch as starchy replacer.

Banana flour phenolics inhibit trans-epithelial glucose transport from wheat cakes in a coupledin vitrodigestion/Caco-2 cell intestinal model

A 10% replacement of wheat flour with banana flour subjected to different processing conditions resulted in from 45.0 to 54.5% higher glucose transport inhibition.

Gluten-Free Products for Celiac Susceptible People

The gluten protein of wheat triggers an immunological reaction in some gluten-sensitive people with HLA-DQ2/8 genotypes, which leads to Celiac disease (CD) with symptomatic damage in the small intestinal villi. Glutenin and gliadin are two major components of gluten that are essentially required for developing a strong protein network for providing desired viscoelasticity of dough. Many non-gluten cereals and starches (rice, corn, sorghum, millets, and potato/pea starch) and various gluten replacers (xanthan and guar gum) have been used for retaining the physical-sensorial properties of gluten-free, cereal-based products. This paper reviews the recent advances in the formulation of cereal-based, gluten-free products by utilizing alternate flours, starches, gums, hydrocolloids, enzymes, novel ingredients, and processing techniques. The pseudo cereals amaranth, quinoa, and buckwheat, are promising in gluten-free diet formulation. Genetically-modified wheat is another promising area of research, where successful attempts have been made to silence the gliadin gene of wheat using RNAi techniques. The requirement of quantity and quality for gluten-free packaged foods is increasing consistently at a faster rate than lactose-free and diabetic-friendly foods. More research needs to be focused on cereal-based, gluten-free beverages to provide additional options for CD sufferers.