Effect of fibers on starch structural changes during hydrothermal treatment: multiscale analyses, and evaluation of dilution effects on starch digestibility

BACKGROUND

Dietary fibers (DFs) may influence the structural, nutritional and techno-functional properties of starch within food systems. Moreover, DFs have favorable effects on the digestive system and potentially a lower glycemic index. These potential benefits may change depending on DF type. Starch processed in the presence of soluble and insoluble fibers can undergo different structural and functional changes, and the present study investigated the effects of short-chain and long-chain inulin and cellulose on the structural and digestive properties of wheat starch.

RESULTS

The combined use of differential scanning calorimetry, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) provided insights into the structural changes in starch and inulin at different levels. Short-chain and long-chain inulin had higher water retention capacity and a potential to limit starch gelatinization. The FTIR results revealed an interaction between starch and inulin. Scanning electron microscopy analysis showed morphological changes in starch and inulin after the hydrothermal treatment. Cellulose fiber was not affected by the hydrothermal treatment and had no influence on starch behavior. The structural differences observed through XRD, FTIR and scanning electron microscopy analyses between starch with and without inulin fibers did not significantly impact starch digestibility, except for the dilution effect caused by adding DFs.

CONCLUSION

The present study highlights the importance of utilizing different analytical tools to assess changes in food samples at different scales. Although short-chain and long-chain inulin could potentially limit starch gelatinization, the duration of the heat treatment (90 °C for 10 min) was sufficient to ensure complete starch gelatinization. The dilution effect caused by adding fibers was the primary reason for the effect on starch digestibility. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Strategic exploration of whole grain cereals in modulating the glycaemic response

In the current context, diabetes presents itself as a widespread and complex global health issue. This study explores the significant influence of food microstructure and food matrix components interaction (protein, lipid, polyphenols, etc.) on the starch digestibility and the glycaemic response of post-prandial glycemia, focusing on the potential effectiveness of incorporating bioactive components from whole grain cereals into dietary strategies for the management and potential prevention of diabetes. This study aims to integrate the regulation of postprandial glycaemic homeostasis, including the complexities of starch digestion, the significant potential of bioactive whole grain components and the impact of food processing, to develop a comprehensive framework that combines these elements into a strategic approach to diabetes nutrition. The convergence of these nutritional strategies is analyzed in the context of various prevalent dietary patterns, with the objective of creating an accessible approach to mitigate and prevent diabetes. The objective remains to coalesce these nutritional paradigms into a coherent strategy that not only addresses the current public health crisis but also threads a preventative approach to mitigate future prevalence and impact.

Acute effect of Melon Manis Terengganu peel powder on glycemic response, perceived satiety, and food intake: a randomized, placebo-controlled crossover trial in adults at risk of type 2 diabetes

BACKGROUND

Melon Manis Terengganu (MMT) peel has a high dietary fiber content, but there is no data examining its health benefits in adults at risk of type 2 diabetes. The objective of the study was to evaluate whether consumption of MMT peel powder improves glycemic response, satiety, and food intake in adults at risk of type 2 diabetes.

METHODS

An open-label, randomized, placebo-controlled, crossover design trial was conducted among adults (n = 30, ages 18-59 y) at risk of type 2 diabetes. They consumed Formulation 3 (formulated MMT peel powder) [A] and control (glucose) [B] with study breakfast based on randomly assigned treatment sequences (AB, BA) established by Research Randomizer ( www.randomizer.org ). Capillary blood glucose and perceived satiety were determined at baseline (0 min), 30, 60, 90 and 120 min, followed by a post-intervention food intake measurement.

RESULTS

The repeated measures analysis of variance (ANOVA) revealed significant time (F = 84.37, p <  0.001, η_p² = 0.744), condition (F = 22.89, p <  0.001, η_p² = 0.441), and time*condition effects (F = 24.40, p <  0.001, η_p² = 0.457) in blood glucose levels. Respondents (n = 30) who consumed Formulation 3 also had a significantly lower blood glucose 2-hour incremental area under the curve (iAUC) of 134.65 ± 44.51 mmol/L*min and maximum concentration (CMax) of 7.20 (7.10, 8.20) mmol/L with relative reduction of 26.8 and 13.3% respectively, when compared with control (p <  0.001). Besides, significantly greater perceived satiety, lower energy and fat intake as well as higher dietary fiber intake were also observed in the intervention group compared with the placebo group (p <  0.05). There were no marked side effects associated with the ingestion of the test products.

CONCLUSIONS

Short-term consumption of formulated MMT peel powder may improve glycemic response, increase perceived satiety and reduce food intake in adults at risk of type 2 diabetes with the potential to be utilized as a functional beverage. Medium-to long-term clinical trial is warranted to determine whether taking this formulated MMT peel powder on a daily basis has an influence on health outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05298111. Registered 28/03/2022.

Effect of Chia Seed as Egg Replacer on Quality, Nutritional Value, and Sensory Acceptability of Sponge Cake

This study aimed to make a cake by incorporating chia seed flour (CSF) at 0, 3, 5, and 7% with egg replacement at 0, 25, 50, and 100%, respectively. The addition of CSF increased the total proteins, fats, and mineral contents. However, cake volume, uniformity, and symmetry were lowered significantly ( $p>0.05$ ) at an elevated level (5% and 7%) of CSF. Similarly, the cake depicted relatively higher textural hardness, springiness, cohesiveness, and chewiness upon addition of CSF. The higher substitution of CSF resulted in darker crust and crumb with lower sensory acceptability by the panelists, though the 3% CSF addition did not compromise the cake acceptance. Nonetheless, there were a significant rise in total phenolics and better antioxidant activity with CSF, measured as free radical scavenging activity. Most importantly, a massive rise in unsaturated fatty acids (ω-3, ω-6) and the simultaneous decline in total cholesterol were detected with increasing substitution of CSF.

In vitro digestion of protein and starch in sponge cakes formulated with pea (Pisum sativum L.) ingredients

This study investigated the in vitro digestion of purified pea fractions (protein isolate and starch) in sponge cakes when compared to unrefined pea flour and to the whole wheat flour and purified maize starch commonly used in the food industry. Proteins in the wheat cake were hydrolysed more rapidly than those in cakes made with either pea flour or a combination of pea proteins and purified starch. In absolute terms, however, more readily bioaccessible protein was released from these pea cakes (by around 40%). By contrast, cakes containing wheat flour or maize starch were more susceptible to amylolysis compared to those based on pea starch in the form of the purified ingredient or whole flour. This could be attributed to a higher proportion of amylose and resistant starch in the pea cakes as well as structural characteristics that might have decelerated enzyme-substrate interactions. Interestingly, similar digestion patterns were observed regarding the purified pea ingredients and unrefined whole pea flour. It was therefore concluded that pea ingredients, and particularly the less purified and thus more sustainable whole pea flour, are promising plant-based alternatives for use in gluten-free baked products.

Sensory and process optimization of a mango bagasse-based beverage with high fiber content and low glycemic index

This research aimed to develop and optimize a mango bagasse (MB) powdered beverage with high fiber content and low glycemic index, acceptable by their potential consumers. The powdered beverage contained 40 g of mango bagasse (Manguifera indica L., var. Manila), xanthan gum (XG), carboxymethyl cellulose (CMC), and silicon dioxide (SDO). The amount of MB remained constant and, 0.5.%, 1.0%, and 2.0% of CMC, XG and SDO were added according to a factorial design 3³. The independent variables evaluated were relative viscosity, sedimentation index, solids (ºBx), and color. Statistical optimization was carried out, looking for low values of viscosity and sedimentation index, obtaining the formulation, 0.5% XG, 0.5% CMC, and 0.5% SDO. A preference test was performed with this formulation using a commercial powdered beverage as a reference, 60 consumers participated. Data showed a preference similar to that of the commercial powered beverage, moreover, the MB beverage had a content of 40.90% of total fiber, from which 15.03% was soluble fiber. The beverage had a low glycemic index (45.99) and its postprandial glycemic curve was stable for 120 min, indicating that the beverage shows potential as a functional food.

Glycemic index values of traditional Kenyan foods: the missing link in the effectiveness of dietary approach in the prevention and management of diabetes mellitus in Kenya

BACKGROUND

Glycemic index (GI) measures postprandial blood sugar after consumption of carbohydrate-rich foodstuff. Kenya is yet to fully embrace this concept in prevention and management of diabetes mellitus.

OBJECTIVE

To review and tabulate GIs of locally consumed foods in order to improve dietary management of diabetes mellitus.

METHODOLOGY

A literature search was conducted using Google scholar and PubMed databases which identified 7 articles on glycemic index values of Kenyan foods published between 2002 and 2020. Two articles failed to meet the inclusion criteria and five proceeded for review. Key search words used included GI, glycemic load and glycemic response combined with Kenya. The data was reported depending on whether the testing involved healthy individuals or patients suffering from diabetes mellitus.

RESULTS

Nine individual foods and 7 mixed meals were identified. Low GI foods included beans and whole maize ugali consumed alongside cowpea leaves. High GI foods included whole maize ugali eaten with beef, boiled rice, boiled cassava and cassava-sorghum ugali eaten with silver fish.

CONCLUSION

Proper meal mixing is important in diabetes management. Cowpea leaves and beans possess GI lowering potential. This information can be used to improve guidance on food choices for diabetes patients.

Combined Effect of Chia, Quinoa and Amaranth Incorporation on the Physico-Chemical, Nutritional and Functional Quality of Fresh Bread

With regard to constant technological innovations in the bakery sector in order to increase bread nutritional value without affecting its technological and sensory characteristics, we applied pseudocereals/oilseeds to obtain an optimal formulation. A factorial design 3³ was used and the independent factors were chia flour (levels: 0, 10, 20% flour basis), quinoa flour (levels: 0, 20, 40% flour basis), and amaranth flour (levels: 0, 20, 40% flour basis). Their effects and interactions were studied through the response surface methodology to optimise the bread formulation from a holistic viewpoint, which included the nutritional, technological and sensory characteristics. The optimum formulation with the highest quality was the blend made with 10, 4, and 20% of chia, quinoa, and amaranth, respectively. The results showed a significant increase in protein amount, ash, lipids, and crumb firmness compared to wheat bread. The calorie value of the control sample and the optimised formula were significantly similar, bearing in mind the high lipid amounts present in raw materials. Loaf-specific volume slightly decreased in comparison to control bread, as expected in formulations with gluten-free raw materials and a large amount of fibre. The optimised formula presented nutritionally/functionally higher indexes and similar overall acceptability to the control bread (p < 0.05).

Comparison of structural, functional and in vitro digestion properties of bread incorporated with grapefruit peel soluble dietary fibers prepared by three microwave-assisted modifications

In our previous study, three kinds of grapefruit peel soluble dietary fibers (SDFs) were prepared by microwave-assisted modifications, including microwave-sodium hydroxide treatment SDF (MST-SDF), microwave-enzymatic treatment SDF (MET-SDF) and microwave-ultrasonic treatment SDF (MUT-SDF). The present study aimed to investigate the structural, functional and in vitro digestion properties of three kinds of bread incorporated with SDFs, named MST-SDF bread (SB), MET-SDF bread (EB), and MUT-SDF bread (UB). Scanning electron microscopy, X-ray diffraction, differential scanning calorimetry and texture profile analysis were used to determine the structural properties. In comparison with the SB and EB, the UB showed an ideal hardness and internal structure, and also significant improvement of the thermal stability. Meanwhile, the UB exhibited the highest overall acceptability in the sensory evaluation. In addition, the water holding capacity (WHC), cholesterol adsorption capacity (CAC) and nitrite ion adsorption capacity (NIAC) of UB were superior to those of the other two samples. Moreover, the in vitro digestive glucose release rates of breads were all significantly reduced by the addition of SDFs, especially that of UB. In summary, the present study showed that UB presented the best performance in terms of structural, functional and in vitro digestion properties, implying that MUT-SDF could be utilized in bread with high quality and low glucose release rate, and developed as a potential ingredient of functional food.

Effect of Chia as Breadmaking Ingredient on Nutritional Quality, Mineral Availability, and Glycemic Index of Bread

Chia seeds and chia flour could be used as ingredients to enrich foods owing to their high amount of nutrients. The goal of this investigation was to provide further information about how replacing wheat flour with chia ingredients (seeds, whole flour, semi-defatted, and low-fat flours) affects the nutritional and functional value of bread. The higher levels of proteins, lipids and minerals determined in raw chia flours directly affected the increase of these nutrients. High levels of phytates were found in chia ingredients (5.1-6.6 μmol/g d.b.), which affect Zn and Fe bioavailability, as predicted by phytate/mineral molar ratios. Bread with chia had a high amount of linoleic acid, especially in bread with chia seeds, owing to protection of seed integrity during baking. Chia ingredients did not show limiting essential amino acids such as lysine, which is deficient in cereals. Glycemic index was lower in bread with chia ingredients compared to control. The beneficial effects on glucose metabolism together with the nutritional and functional characteristics could be clinically important for prevention of metabolic diseases.

Digestibility, textural and sensory characteristics of cookies made from residues of enzyme-assisted aqueous extraction of soybeans

Enzyme-assisted aqueous extraction residue (REAE) has a lower utilization rate as it is the "waste" produced after the enzyme-assisted aqueous extraction (EAE), but its nutritional value is high. To improve the development and utilization of REAE, in this study, cookies were made by adding REAE (0%, 10%, 20%, 30%, 40%, 50%) as a food additive to a small amount of flour. The AOAC method was used to identify the basic components of REAE, analyze its physical and chemical properties, and characterize the cookie structure change in terms of texture, disulfide bond, and thiol content. An in vitro simulation system and sensory evaluation mechanism were established to analyze the bioavailability and impact of quality. The results show that REAE is a potential food additive. With an increase in the REAE content, the cookies become lighter in color, the sweetness and fat content are reduced, the hardness is increased, and the digestibility and glycerin index are reduced. The change in texture is caused by the reduction of disulfide bonds in the dough. The cookies were 'well accepted' with up to 30% REAE. Therefore, the use of the appropriate amount of REAE as a new food additive will reduce the amount of starch added.

Release and metabolism of bound polyphenols from carrot dietary fiber and their potential activity in in vitro digestion and colonic fermentation

Dietary fiber is a carrier of abundant polyphenols and the potential benefits have attracted increasing attention.

Effect of the Addition of Soluble Dietary Fiber and Green Tea Polyphenols on Acrylamide Formation and In Vitro Starch Digestibility in Baked Starchy Matrices

Starch digestibility may be affected by food microstructural changes, as well as by specific interactions with some biomolecules, such as soluble dietary fibers (SDFs). It is well-known that acrylamide (AA) is a toxic and potentially carcinogenic compound formed in starchy food products processed at temperatures above 120 °C. This study aimed to investigate the effect of the addition of SDF and green tea polyphenols (GTP) on AA formation and in vitro starch digestibility in baked starchy matrices. The formulations were prepared using gluten and wheat starch, ensuring ~40 ± 2% (wet basis, w.b.) moisture in the doughs. In some samples, 7.5% (dry basis, d.b.) of starch was replaced with inulin (IN), polydextrose (PD) or partially hydrolyzed guar gum (PHGG), and/or with GTP at 1% (d.b). Acrylamide was determined by gas chromatography–mass spectrometry, and the in vitro starch digestibility using the Englyst method. The GTP was able to reduce AA content by ~48%, and a combination of IN-GTP allowed it to be reduced by up to ~64%, revealing the lowest rapidly available glucose content (~17 mg/g glucose). While a PD-GTP mixture reduced the AA content by around ~57% and gave the highest unavailable glucose fraction (~74 mg/g glucose) compared to the control. This study showed how functional ingredients could be used to develop successfully healthier starchy bakery foods.

Effect of formulation and baking conditions on the structure and development of non-enzymatic browning in biscuit models using images

The aim of this research was to determine the effect of composition (dietary fiber = DF, fat = F, and gluten = G) and baking time on the target microstructural parameters that were observed using images of potato and wheat starch biscuits. Microstructures were studied Scanning Electron Microscope (SEM). Non-enzymatic browning (NEB) was assessed using color image analysis. Texture and moisture analysis was performed to have a better understanding of the baking process. Analysis of images revealed that the starch granules retained their native form at the end of baking, suggesting their in complete gelatinization. Granules size was similar at several different baking times, with an average equivalent diameter of 9 and 27 µm for wheat and potato starch, respectively. However, samples with different levels of DF and G increased circularity during baking to more than 30%, and also increasing hardness. NEB developed during baking, with the maximum increase observed between 13 and 19 min. This was reflected in decreased luminosity (L*) values due to a decrease in moisture levels. After 19 min, luminosity did not vary significantly. The ingredients that are used, as well as their quantities, can affect sample L* values. Therefore, choosing the correct ingredients and quantities can lead to different microstructures in the biscuits, with varying amounts of NEB products.

Incorporation of dietary fibre-rich oyster mushroom (Pleurotus sajor-caju) powder improves postprandial glycaemic response by interfering with starch granule structure and starch digestibility of biscuit

The purpose of this study was to determine the effects of Pleurotus sajor-caju (PSC) powder addition at 0, 4, 8 and 12% levels on the nutritional values, pasting properties, thermal characteristics, microstructure, in vitro starch digestibility, in vivo glycaemic index (GI) and sensorial properties of biscuits. Elevated incorporation levels of PSC powder increased the dietary fibre (DF) content and reduced the pasting viscosities and starch gelatinisation enthalpy value of biscuits. The addition of DF-rich PSC powder also interfered with the integrity of the starch granules by reducing the sizes and inducing the uneven spherical shapes of the starch granules, which, in turn, resulted in reduced starch susceptibility to digestive enzymes. The restriction starch hydrolysis rate markedly reduced the GI of biscuits. The incorporation of 8% PSC powder in biscuits (GI=49) could be an effective way of developing a nutritious and low-GI biscuit without jeopardizing its desirable sensorial properties.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.