Effects of fatty acids and glycerides on the structure, cooking quality, and in vitro starch digestibility of extruded buckwheat noodles.

This study aimed to explore the effects of various lipids on the structure, cooking quality, and in vitro starch digestibility of extruded buckwheat noodles (EBNs) with and without 20% high-amylose corn starch (HACS). Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction revealed that lauric acid bound more strongly to starch than did stearic acid and oleic acid, and the binding capacity of fatty acids with starch was stronger than that of glycerides. The presence of HACS during extrusion facilitated increased formation of starch-lipid complexes. Evaluations of cooking quality and digestion characteristics showed that EBNs containing 20% HACS and 0.5% glycerol monooleate demonstrated the lowest cooking loss (7.28%), and that with 20% HACS and 0.5% oleic acid displayed the lowest predicted glycemic index (pGI) (63.54) and highest resistant starch (RS) content (51.64%). However, excessive starch-lipid complexes were detrimental to EBNs cooking quality and the resistance of starch to digestive enzymes because of the damage to the continuity of the starch gel network. This study establishes a fundamental basis for the development of EBNs with superior cooking quality and a relatively lower GI.

Exploring modified rice flour and supplementation approach to enhance resistant starch content: Visco thermal and structural characterization.

Supplementation of rice flour with Apple Pomace Powder (APP) and Synthetic Vinegar (SV) was investigated to reduce the glycemic potential of ready-to-eat snacks using extrusion cooking. The aim of the study was to compare the increase in resistant starch and decrease in glycemic index of modified rice flour based extrudates after supplementing the Modified rice flour with synthetic vinegar and apple pomace. The effects of independent variables-SV (3-6.5 %) and APP (2-23 %) were evaluated on resistant starch, predicted glycemic index, glycemic load, L*, a*, b*, ΔE and overall acceptability of supplemented extrudates. Design expert predicted 6 % SV and 10 % APP as desirable conditions for enhancement of resistant starch and reduction of glycemic index. Resistant Starch (RS) of supplemented extrudates increased by 88 % while as pGI and GL was decreased by 12 % and 66 % respectively as compared to un-supplemented extrudates. L* value increased from 39.11 to 46.78, a* value increased from 11.85 to 22.55, b* value increased from 10.10 to 26.22 and Δ E increased from 7.24 to 17.93 respectively in supplemented extrudates. The results suggested that apple pomace and vinegar can act in synergy to reduce the in-vitro digestibility of rice based snacks, while maintaining the sensory acceptance of the developed product. The significant (p < 0.001) decrease in the glycemic index was achieved as the supplementation level increased. The increase in RS correlates with the decrease in glycemic index and glycemic load.

Assessment of sensory and nutritional attributes of foxtail millet-based food products.

Millets are a rich source of many health-promoting nutrients as well as bioactive compounds such as dietary fibers, antioxidants, macro and micronutrients etc., compared to other staple cereals such as rice, wheat and maize. These nutrients play a central role in the world nutritional security. Despite the inbuilt nutritional benefits, the production of millets has witnessed sharp decline owing to taste preferences, keeping quality and challenges associated with food preparation from millets. To sensitize the consumers about the nutritional benefits of foxtail millet, the present study was planned to formulate and nutritionally evaluate eight diversified foxtail millet-based food products namely rusk, kheer, pinni, sattu, vegetable dalia, cookies, bar and papad by replacing commonly used cereals such as wheat and rice. The products prepared from Foxtail millet were found to have high acceptability with mean score of more than 8.00. These diversified food products showed higher protein content ranging from 10.98 to 16.10 g/100 g, with the highest protein found in Foxtail millet kheer (16.01 g/100 g). The resistant starch content and predicted glycemic index (PGI) of these products ranged between 13.67 to 22.61 g/100 g and 46.12 to 57.55, respectively, with the highest resistant starch (22.61 ± 0.69 g/100 g) and lowest PGI (48.42 ± 0.20) found in millet bar. The high resistant starch and low PGI in foxtail millet products suggest that they could serve as an excellent food source suitable for diabetics. The obtained results suggest that all the Foxtail millet-based value-added products have superior nutrient profile and are highly acceptable than the traditional products. Inclusion of these foods in the diets of the population may help in the prevention of malnutrition and type 2 diabetes.

In Vitro Starch Digestibility, Rheological, and Physicochemical Properties of Water Caltrop Starch Modified with Cycled Heat-Moisture Treatment.

This study focused on the effect of cycled heat-moisture treatment (cHMT) on the in vitro digestibility, rheological, and physicochemical properties of water caltrop starch. The amylose content increased significantly by cHMT, whereas damaged starch content decreased only in the groups with more than two cycles applications. cHMT generally increased the weight-average molecular weight, except for single cycle treatment which showed the reverse result. In thermal properties, the onset temperature (T0), peak temperature (Tp), and conclusion temperature (Tc) increased, while the enthalpy needed to complete the gelatinization was lowered by cHMT. Water caltrop starch paste showed less shear-thinning behavior with cHMT. Meanwhile, the viscosity and tendency to form strong gel were enfeebled with modification. cHMT significantly changed predicted glycemic index (pGI) value, especially in samples that underwent the most cycles of treatment, which showed the lowest pGI compared to native and other treatment. These results suggested that cHMT water caltrop starch was effectively modified and showed diversified properties.

Effect of processing and variety on starch digestibility and glycemic index of popular foods made from cassava (Manihot esculenta).

In Sub-Saharan Africa (SSA), the prevalence of diabetes mellitus (DM) is rapidly increasing even in populations with significant undernutrition. The role of energy dense staple crops such as cassava is under query and not yet well understood. In this study, varieties of cassava, made into popular SSA products (fufu and gari dough) were studied for their resistant starch (RS), rapidly digestible starch (RDS) and glycemic index (GI). While the glycemic properties of the varieties studied did not differ significantly, processing any variety into either fufu or gari distinctly impacted RS, RDS and predicted GI (pGI) differently. Specifically, fufu had highest range of RS (1.1-2.1 g/100 g) while gari dough had highest RDS (1.1-1.4 g/100 g) and pGI (54-67). The results from this probe imply that fufu, when consumed, will release glucose in a slower manner than gari, therefore may be better suited in the dietary prevention and management of DM.

Sensory Characteristics and Nutritional Quality of Food Products Made with a Biofortified and Lectin Free Common Bean (Phaseolus vulgaris L.) Flour.

Common beans (Phaseolus vulgaris L.) are an important source of nutrients with beneficial effects on human health. However, they contain lectins, that limit the direct use of flour in food preparations without thermal treatment, and phytic acid, that reduces mineral cation bioavailability. The objectives of this research were: to obtain biofortified snacks and a cream using an untreated common bean flour devoid of active lectins (lec-) and with reduced content of phytic acid (lpa) and to evaluate the sensorial appreciation for these products. The main results of the present work were: the products with the lpa lec- flour did not retain residual hemagglutinating activity due to lectins; they showed higher residual α-amylase inhibitor activity (from 2.2 to 135 times), reduced in vitro predicted glycemic index (about 5 units reduction) and increased iron bioavailability compared to the products with wild type flour; products with common bean flour were less appreciated than the reference ones without this flour, but the presence of an intense umami taste can be a positive attribute. Results confirmed that the use of the lpa lec- flour has important advantages in the preparation of safe and nutritionally improved products, and provide useful information to identify target consumers, such as children and elderly people.

Manipulation of the internal structure of starch by propionyl treatment and its diverse influence on digestion and in vitro fermentation characteristics.

High amylose maize starch (HAMS) and waxy maize starch (WMS) were modified by propionylation and their corresponding physicochemical characteristics, digestion and fermentation properties were studied. The results indicated that two new peaks related to methylene (2.20 ppm) and methyl (0.97 ppm) in the NMR spectrum were formed, indicating the occurrence of propionylation, and this was further confirmed by the formation of a characteristic absorption at 1747 cm-1 in the FTIR spectrum. The propionylation led the modified starch having a lower electron density contrast between the crystalline and amorphous flakes, resulting in the formation of a more compact structure following the increased degrees of substitution (DS). The propionylated starch also had a higher thermal stability and hydrophobicity. These structural changes increased the content of resistant starch (RS) and reduced the predicted glycemic index. More importantly, the gut microbiota fermentation properties indicated that the propionylation of the starch can not only increase the yield of propionate, but also increase the concentration of total short-chain fatty acids (SCFAs). This study highlights a new approach to significantly enhance the RS content in starch, together with an increased SCFA generation capacity.

Comparative studies on physicochemical properties, starch hydrolysis, predicted glycemic index of Hom Mali rice and Riceberry rice flour and their applications in bread.

Physicochemical properties, predicted glycemic index (pGI) and bread qualities of a non-pigmented white rice flour (Hom Mali, HM) and a pigmented rice flour (Riceberry rice flour, RB) were investigated. In the present study, RB (15.3% amylose) contained higher total polyphenolics, anthocyanins, and ferric reduction activity power than HM (21.3% amylose). RB had lower swelling power and higher gelatinization temperatures. In addition, RB contained higher levels of beneficial resistant starch (RS) and lower levels of slowly digestible starch (SDS) with medium pGI. RB provided slower glucose release than HM. The pasting characteristics showed that peak and final viscosity, trough and setback value, and breakdown of RB was lower than HM. RB bread had lower cohesiveness, gumminess, chewiness and adhesiveness than HM bread. Furthermore, RB bread demonstrated lower starch hydrolysis and pGI than HM bread. These findings suggest that anthocyanin-rich RB could be used as an alternative food ingredient for gluten-free bread.

Influence of Clitoria ternatea Flower Extract on the In Vitro Enzymatic Digestibility of Starch and Its Application in Bread.

This study aimed to assess the effect of the Clitoria ternatea L. flower extract (CTE), on the inhibition of pancreatic α-amylase, in vitro starch hydrolysis, and predicted the glycemic index of different type of flours including potato, cassava, rice, corn, wheat, and glutinous rice flour. The application in a bakery product prepared from flour and CTE was also determined. The results demonstrated that the 1% and 2% (w/v) CTE inhibited the pancreatic α-amylase activity by using all flours as a substrate. Moreover, 0.5%, 1%, and 2% (w/v) CTE showed a significant reduction in the glucose release, hydrolysis index (HI), and predicted glycemic index (pGI) of flour. In glutinous rice flour, 1% and 2% (w/v) CTE had a significantly lower level of rapidly digestible starch (RDS) and slowly digestible starch (SDS) with a concomitant higher level of undigested starch. The statistical analysis demonstrated strong positive significant correlations between the percentage of CTE and the undigested starch of wheat and cassava. The addition of 5%, 10%, and 20% (w/w) CTE significantly reduced the rate of starch digestion of the wheat bread. The pGI of bread incorporated with 5% CTE (w/w) was significantly lower than that of the control bread. Our findings suggest that CTE could reduce the starch digestibility, the HI, and pGI of flour through the inhibition of carbohydrate digestive enzymes. Taken together, CTE may be a potent ingredient for the reduced glycemic index of flours.

Optimized preparation of anthocyanin-rich extract from black rice and its effects on in vitro digestibility.

The procedure for obtaining anthocyanin-enriched extracts from black rice was optimized by response surface methodology, and the effects of the optimized extract on in vitro starch digestibility were investigated in a wheat flour gel model. The experimental results were well-described by a polynomial multiple regression model (R2 = 0.8812, p = 0.0546) with regard to anthocyanin content in anthocyanin-enriched extracts from black rice. The optimal conditions for obtaining anthocyanin-enriched extracts from black rice were 50.78% ethanol and 1 N HCl (0.60 mL), yielding a predicted anthocyanin content of 624.27 mg cyanidin 3 glucoside extract. The optimized anthocyanin-enriched extract was a stronger inhibitor of α-glucosidase than acarbose. Furthermore, the predicted glycemic index values of gels prepared with the optimized extract were significantly lower than that of wheat flour gel. These results indicate that the optimized extract suppressed starch hydrolysis by inhibiting digestive enzymes.

Exploitation of Common Bean Flours with Low Antinutrient Content for Making Nutritionally Enhanced Biscuits.

Consumption of legumes is associated with a number of physiological and health benefits. Legume proteins complement very well those of cereals and are often used to produce gluten-free products. However, legume seeds often contain antinutritional compounds, such as phytate, galactooligosaccharides, phenolic compounds, lectins, enzyme inhibitors, whose presence could affect their nutritional value. Screening natural and induced biodiversity for useful traits, followed by breeding, is a way to remove undesirable components. We used the common bean cv. Lady Joy and the lpa1 mutant line, having different seed composition for absence/presence of lectins,α-amylase inhibitor, (α-AI) and phytic acid, to verify the advantage of their use to make biscuits with improved nutritional properties. We showed that use of unprocessed flour from normal beans (Taylor's Horticulture and Billò) must be avoided, since lectin activity is still present after baking, and demonstrated the advantage of using the cv. Lady Joy, lacking active lectins and having active α-AI. To assess the contribution of bean flour to biscuit quality traits, different formulations of composite flours (B12, B14, B22, B24, B29) were used in combinations with wheat (B14), maize (gluten-free B22 and B29), or with both (B12 and B24). These biscuits were nutritionally better than the control, having a better amino acid score, higher fiber amount, lower predicted glycemic index (pGI) and starch content. Replacement of cv. Lady Joy bean flour with that of lpa1, having a 90% reduction of phytic acid and devoid of α-AI, contributed to about a 50% reduction of phytic acid content. We also showed that baking did not fully inactivate α-AI, further contributing to lowering the pGI of the biscuits. Finally, data from a blind taste test using consumers indicated that the B14 biscuit was accepted by consumers and comparable in terms of liking to the control biscuit, although the acceptability of these products decreased with the increase of bean content. The B22 gluten-free biscuits, although received liking scores that were just above the middle point of the hedonic scale, might represent a good compromise between health benefits (absence of gluten and lower pGI), expectations of celiac consumers and likeness.

Cooking quality and starch digestibility of gluten free pasta using new bean flour.

The use of rice/leguminous blend may be nutritionally convenient in gluten free product manufacturing. Gluten free spaghetti was prepared with rice flour and different concentrations of bean flour (included at levels of 0%, 20% and 40%, w/w) derived from a new developed white-seeded low phytic acid and lectin free (ws+lpa+lf) bean cultivar. Protein, ash and dietary fibre contents increased linearly (P<0.05) while total starch decreased quadratically (P<0.05) with the inclusion of ws+lpa+lf bean flour. The colour of spaghetti was influenced (P<0.05) by ws+lpa+lf bean inclusion. With respect to 0% spaghetti, the inclusion of ws+lpa+lf bean increased linearly (P<0.05) the optimal cooking time and the water absorption capacity, without affecting cooking loss and texture properties. The ws+lpa+lf bean inclusion increases quadratically (P<0.05) the resistant starch content, while decreasing quadratically (P<0.05) the in vitro glycemic index. The partial replacement of rice flour with bean flour can favourably be used in gluten free spaghetti formulation.