In vitro starch hydrolysis and estimated glycaemic index of bread substituted with different percentage of chempedak (Artocarpus integer) seed flour

Chempedak (Artocarpus integer) seed flour (CSF) was substituted for wheat flour at different levels (0%, 10%, 20%, 30% w/w) in bread. Assessment on the in vitro starch hydrolysis was carried out to evaluate the hydrolysis index (HI) and estimated glycaemic index (EGI) of bread substituted with different levels of CSF. Kinetics of in vitro starch hydrolysis in all bread samples (with the exception for white bread) indicated a gradual increase with respect to time intervals. Bread of 30% CSF exhibited significantly lower (p < 0.05) in vitro starch hydrolysis, as compared with the other samples. Results showed that HI value decreased significantly (p < 0.05) as the levels of CSF substitution increased. Resistant starch (RS) content in bread samples was inversely related with HI value as CSF substitution levels increased, thus lowering the EGI value.     

Effect of mechanically damaged starch on wheat flour,noodle and steamed bread making quality

Wheat flour was ground in an ultrafine pulveriser to obtain different levels of damaged starch (DS). The effect of DS content on physicochemical properties of flour and quality attributes of Chinese noodles and northern‐style Chinese steamed bread were investigated. Results showed that the degree of starch damage raised from 6.54% to 12.06% as grinding intensity increased from 0 to 130 Hz (P < 0.05). The falling number, sedimentation value, starch pastes' viscosity, dough proofing stability were negatively, while water absorption, pastes thermal stability, the degree of starch pastes and dough level were positively correlated with DS content, respectively (P < 0.05). The increase in DS content from 6.54% to 8.86% did not lead to a deterioration of texture characteristic, which might be attributed to the slight declining in hardness while enhancing in springiness and cohesiveness. The flour with DS content of 6.54–9.66% was suitable for steamed bread making.     

Physicochemical and functional properties of Caryota urens flour as compared to wheat flour

Starch digestibility, thermal, pasting and gelling properties of Caryota urens (CU) flour were investigated using wheat flour as reference. Amylose content of CU and wheat flour was 32.1% and 28.3%, respectively. CU flour had very low content of protein and lipid but had a high content of total starch (98.2%) and resistant starch (RS) [42.5%]. Gelatinisation temperature (78.5 °C) of CU flour was higher than wheat flour. Pasting behaviour of CU flour was similar to that of high swelling tuber and root and waxy starches. CU flour retrograded to a greater extent than wheat flour. Very specific gelling behaviour was noticed for CU flour where it produced significantly harder gel with high paste clarity, fracture ability, adhesiveness, gumminess and chewiness. Expected glycaemic index (eGI) of CU and wheat flour was 92.4 and 100.4, respectively. CU flour had high eGI despite high content of resistant starch.     

Effect of green plantain flour addition to gluten‐free bread on functional bread properties and resistant starch content

Green plantain flour (GPF) was used as a functional ingredient to produce gluten‐free (GF) bread based on a flour blend of rice flour and GF wheat starch (50:50) to improve their functional properties and to increase their resistant starch (RS) content. In pretrials, an addition of up to 30% GPF provided acceptable bread quality with maximum RS content. Based on these trials, two 2³ factorial screening experimental designs were applied, where water content, baking temperature and baking time of GF bread containing 30% GPF addition were optimised. The best baking conditions to achieve satisfying GF bread quality – higher loaf volume, softer crumb firmness and regular porosity structure at the highest RS content could be defined to a maximum addition of water at 160%, baking temperature of 180 °C and baking time of 90 min. The incorporation of GPF showed good potential to improve the quality of GF bread.     

Impact of the addition of resistant starch from modified pea starch on dough and bread performance

The interest in the use of resistant starch (RS) for the development of new bakery products has significantly increased due to its ascribed physiological effects with proven health benefits. The objective of the present work was to analyse the effects of the wheat flour substitution by modified pea starch with high level of RS (PeaP) on breadmaking performance. The effects of PeaP on wheat dough functionality were evaluated by mixing/overmixing properties, texture profile analysis, viscometric profile and thermal properties. Bread quality was evaluated by physico-chemical parameters, crumb texture profile, digital image analysis, nutritional parameters and sensory evaluation. Flour substitution by PeaP up to 20% allowed keeping mechanical, extensional and viscometric parameters without significant hindering of dough machinability. Overdose of modified pea starch (30%) negatively affects dough mixing and overmixing behaviour. As a functional/prebiotic fibre, PeaP addition up to 10–20% of flour replacement entitles the formulation of wheat bread allowing a significant increase in the RS level (from 0.70 to 5.10%), delay/decrease in amylopectin retrogradation, with acceptable changes in bread quality up to 10–20% of flour replacement.     

Effects of pineapple pomace fibre on physicochemical properties of composite flour and dough,and consumer acceptance of fibre‐enriched wheat bread

Pineapple pomace fibre (PF, containing 70.2% total dietary fibre) can be added to increase dietary fibre of wheat bread. This study was performed to evaluate effects of PF added at 0, 5 or 10% (wheat flour‐basis) on physicochemical properties of the composite flour (wheat flour as the control, CPF‐5 and CPF‐10, respectively) and its dough, to evaluate consumer acceptance of CPF breads and to identify factors affecting willingness to purchase of CPF breads. Incorporating PF affected rheological and pasting properties of CPF. Water‐ and oil‐holding capacity of CPF increased (P < 0.05) as PF levels increased. Bread made with CPF‐5 was more acceptable than that with CPF‐10; however, it was not significantly different from the control, having similar specific volume and texture, but having about three times higher total dietary fibre than the control (4.4% vs. 1.5%). Product label and health benefit information potentially affected consumers' willingness to purchase of fibre‐enriched bread.     

Exploitation of lettuce waste flour to increase bread functionality: effect on physical,nutritional, sensory properties and on consumer response

Phenol and fibre‐rich flour obtained by air‐drying and grinding of lettuce waste was partially substituted (26, 53, 170 and 575 g kg^?1) to wheat flour to produce functional bread. The addition of flour progressively decreased dough leavening capacity while increased bread moisture and firmness. Lettuce waste flour significantly increased the polyphenolic content (up to 3.4 g GAE kg^?1) of bread samples and enhanced their antioxidant activity by 200%. Bread containing 170 and 575 g kg^?1 of lettuce waste flour presented sensory properties and consumer acceptability comparable to those of commercial wholemeal bread with similar rye bran content. Bread containing at least 170 g kg^?1 of lettuce waste flour could be associated to nutritional claims related to its enhanced fibre content (>30 g kg^?1). Data obtained by conjoint analysis demonstrate the possibility of increasing consumer preference for lettuce waste flour bread by proper nutritional (fibre content) and sustainability (lettuce waste valorisation) claims.     

Substitution of wheat starch with non-wheat starches and cross-linked waxy barley starch affects sensory properties and staling of Arabic bread

Substitution of starch from barley, corn, oat, potato, rice or sorghum for prime wheat starch in the formulation of Arabic bread resulted in breads with significantly (P < 0.05) different textural attributes from regular wheat bread except for barley starch. Substitution of waxy barley starch (957 g kg⁻¹ amylopectin) for wheat starch (279 g kg⁻¹ amylopectin) resulted in bread that was not significantly different from regular wheat bread when assessed in the fresh state. However, upon aging, the waxy barley starch-containing bread staled at a significantly (P < 0.05) faster rate than regular wheat bread. Breads made with waxy barley starch cross-linked with 50, 200 or 500 ppm phosphorus oxychloride showed higher enthalpy of melting (ΔH) upon aging and staled faster than the bread formulated with waxy barley starch. These findings suggest that amylopectin retrogradation is one of the determinants of Arabic bread staling and that cross-linking promotes recrystallisation of amylopectin, possibly by keeping the polymer chains in close proximity. The rate of staling in breads formulated with cross-linked waxy barley starch decreased with increasing levels of cross-linking, possibly owing to restrictions in the degree of starch swelling. © 1999 Society of Chemical Industry     

Bread Making Potential of Composite Flour of Wheat-Acha (Digitaria exilis staph) Enriched with Cowpea (Vigna unguiculata L. walp) Flour

Bread-making potentials of composite flours containing 90% wheat and 10% acha enriched with 0-15% cowpea flour were investigated. Proximate composition and functional properties of the blends were studied using AOAC standard methods. Bread loaves were prepared from the blends using the straight dough method and evaluated for loaf height, loaf volume, loaf weight and sensory characteristics. Crude protein, crude fat, crude fibre and ash contents increased significantly (p < 0.05) with increase in level of cowpea flour addition, but moisture content was not significantly (p > 0.05) different among the blends. Functional properties, with exception of bulk density and swelling capacity, were significantly (p < 0.05) different among the blends. Average loaf height and loaf volume decreased significantly (p < 0.05) with increased cowpea flour but loaf weight showed opposite trend with significant (p < 0.05) differences as cowpea flour increased. However, the addition of cowpea flour significantly (p < 0.05) decreased the loaf specific volume but all enriched samples were not significantly (p > 0.05) different. Bread samples from composited blends were rated lower than bread from all wheat bread. Bread loaves from enriched composite flour with up to 10% cowpea flour were acceptable to the panelists.     

The impacts of germinating organic wheat: effects on phytic acid,resistant starch,and functional properties of flour,and sensory attributes of sourdough bread

This study assessed the impact of germination duration on two varieties of wheat grown organically (Expresso and Syngenta SY Basalt (Basalt)). In Expresso, d -glucose content increased from 0.06 g/100 g in the control to 0.55 g/100 g after a 24-h germination period (P < 0.05). In both varieties, similar increases were observed for sucrose and maltose, and no pattern emerged for resistant starch or phytate. In Basalt, baseline phytate (0 h 1.07 g/100 g) did not differ from treatment groups (6 h 0.97 g/100 g; 12 h 0.98 g/100 g; 24 h 1.09 g/100 g; 36 h 0.98 g/100 g). Functional properties of flour decreased with germination duration and resulted in bread which panellists perceived to have inferior crumb (24 h Expresso; 36 h Basalt; P < 0.05). However, there was no difference in the overall acceptability of breads across treatments and inclusion of germinated wheat improved bread sweetness.     

Replacement of buckwheat by black sorghum flour on soba-type noodles

Incorporation of black sorghum flour containing high levels of polyphenols and slowly digestible starch could provide opportunity to enhance nutritional functionality of noodles. Soba-type noodles were prepared based on a typical wheat-buckwheat (65:35) formulation by replacement of buckwheat flour with black sorghum flour at 0%, 25%, 50%, 75% and 100%. Noodle colour, texture, total phenolics, antioxidant capacity, in vitro starch digestibility and sensory acceptability were evaluated. Increasing the addition of black sorghum flour significantly (P < 0.05) decreased the firmness (g) in noodles and imparted a darker colour but increased total polyphenolics and antioxidant capacity. Significantly (P < 0.05) lower rapidly digestible starch and higher resistant starch was found in noodles with >50% replacement with black sorghum flour. Overall acceptability of noodles showed preference for noodles containing 25%–75% black sorghum flour. This study demonstrates the potential of using black sorghum as a novel functional food ingredient in noodle manufacturing.     

Effects of different types of potato resistant starches on intestinal microbiota and short-chain fatty acids under in vitro fermentation

The prebiotic effects of potato resistant starches RS1, RS2, RS3a, RS3b and RS4 were studied using simulated gut fermentation in vitro. The intestinal microbial composition was significantly changed by resistant starch (RS) after 24-h fermentation. All RSs (P < 0.05) decreased the ratio of Firmicutes/Bacteroidetes (F/B), and RS2 exhibited the lowest value of 0.95 ± 0.07. The relative abundance of Bifidobacterium was significantly increased by RS4, whereas Megamonas and Prevotella were promoted by RS2. Further, RS4 produced the highest levels of acetate (138.34 µM), whereas RS2 produced the highest levels of propionate (41.45 µM) and butyrate (21.65 µM). However, Bifidobacterium did not promote the production of propionate or butyrate, even though it was proficient in fermenting RS. Megamonas and Prevotella were positively associated with the higher production of propionate and butyrate. Here, different RSs played key roles in promoting intestinal health, and RS2 especially showed more abundant probiotic functions.     

Effect of acetylation,oxidation and annealing on physicochemical properties of bean starch

Black and Pinto bean starches were physically and chemically modified to investigate the effect of modification on digestibility and physicochemical properties of bean starch. The impact of acetylation, oxidation (ozonation) and annealing on the chemical composition, syneresis, swelling volume, pasting, thermal properties and digestibility of starches was evaluated. The physicochemical and estimated glycemic index (eGI) of the Black and Pinto bean starches treated with ozone were not significantly (P > 0.05) different than that of their respective control starches. Annealed starches had improved thermal and pasting properties compared to native starches. Acetylated starches presented reduced syneresis, good pasting properties and lower eGI. Also, all modified starches had increased levels of resistant starch (RS). Therefore, the digestibility and physicochemical properties of bean starch were affected by the type of modification but there were no significant (P > 0.05) differences between the Black and Pinto bean starches.     

Bread fortified with dietary fibre extracted from culinary banana bract: its quality attributes and in vitro starch digestibility

The effect of fortification of dietary fibre (DF) on dough rheology, quality characteristics and in vitro starch digestibility of bread was studied. Bread was prepared incorporating DF (2–4 g per 100 g of flour mixture). Rheological study of dough showed an increase in dough stiffness and elasticity with higher incorporation of the DF. The results of chemical composition revealed that addition of DF increased total DF (19.65 g per 100 g) content of bread. However, incorporation of 2 g per 100 g DF of flour mixture with 66 g per 100 g moisture showed higher water retention and specific volume of 86.76% and 5.83 cm³ g⁻¹, respectively, which was close to control bread. Improved textural property with acceptable sensory attributes was observed for bread fortified with 2 g per 100 g DF of flour mixture and 66 g per 100 g moisture content. Incorporation of DF (2–4 g per 100 g of flour mixture) showed a decrease in rapidly digestible starch (RDS) and an increase in slowly digestible starch (SDS) content with lower predicted glycaemic index (pGI) than control bread.     

Physicochemical and sensory properties of soy bread made with germinated,steamed, and roasted soy flour

For the development of healthful gluten-free soy bread acceptable to consumers, we evaluated the effects of various processing procedures for soy flour on bread quality, in terms of beany flavour and texture. We pretreated soy flour by both non-heating (raw:NS and germinated:GS) and heating (steamed:SS and roasted:RS) methods. In addition, to improve the loaf volume, we added 1% hydroxypropyl-methylcellulose (HPMC) to RS flour. Lipoxygenase activity was retained in the non-heat-treated flours (279 U/g for NS and 255 U/g for GS), but was significantly reduced in the heat-treated flours (106 U/g for SS and 69 U/g for RS). Moreover, heat-treated flour had higher isoflavone and ferric reducing antioxidant power than had non-heat-treated flour. However, RS flour had the lowest moisture content and lowest L^∗ value. The GS bread had the highest specific loaf volume (3.53 cm³/g), followed by NS (2.96 cm³/g), RS (2.25 cm³/g), and SS (1.81 cm³/g) bread. GS bread had the lowest hardness (1.53 N), followed by NS (1.65 N), RS (2.00 N), and SS (3.75 N) bread. The addition of 1% HPMC to RS increased the loaf volume (2.44 cm³/g), but decreased the bread’s hardness (1.80 N). As to the sensory properties, the bread with heat-treated flour was perceived to have a less beany odour and taste than was the bread with non-heat-treated flour. However, the latter had a better appearance than the former. These results indicated that soy flour pretreatment could enhance the loaf volume and reduce the beany flavour of whole soy bread.     

A study of the effect of the drying process on the composition and physicochemical properties of flours obtained from durian fruits of two ripening stages

Durian cv. Monthong with two ripening stages (unripe and fully ripe) was subjected to microwave vacuum drying (MWD) at 5.49 W g^?1 and hot air drying (HAD) at 60 °C. With an increase in ripening degree, the starch content was significantly (P ≤ 0.05) decreased from 40.08–40.42% to 9.44–11.76%. X‐ray diffraction indicated that the crystalline pattern was changed from starch to sucrose. The starch granule morphology of durian flour was conserved for both drying conditions. Peak gelatinisation temperatures of MWD and HAD flours were increased significantly (P ≤ 0.05) from 56.71–57.32 to 60.71–61.23 °C. Using different drying methods, MWD flour had less a*‐value (P ≤ 0.05) than HAD flour. The peak viscosity and trough of the HAD unripe durian flour (5.92 RVU and 3.45 RVU, respectively) were significantly (P ≤ 0.05) lower than those of the MWD unripe durian flour (34.32 RVU and 11.57 RVU, respectively).     

Techno‐functional properties of wheat flour‐resistant starch mixtures applied to breadmaking

Resistant starch can be used to reduce the availability of carbohydrates in baked products. In this study, the effect of type 4 resistant wheat starch (RS₄) on wheat flour dough and breads was evaluated. Wheat flour was substituted by RS₄ at 10%, 20% and 30% w/w (RS10, RS20 and RS30, respectively). Rheological and thermal behaviours of dough were evaluated. Besides, bread quality, starch digestibility and bread staling were analysed. All substituted dough exhibited viscoelastic behaviour but lower elastic and viscous moduli. Regarding to bread quality, specific volume and crumb texture were negatively affected in samples with RS₄. However, all samples were technologically acceptable. During storage, crumb hardening was observed in breads without and with RS₄ but amylopectin retrogradation was not particularly affected. The in vitro digestibility of bread with RS showed a lower release of reducing sugars and a lower estimated glycaemic index, suggesting a healthier profile for these breads.     

Physicochemical and digestion characteristics of flour and starch from eight Canadian red and green lentils

Physicochemical and nutritional properties of flour and isolated starch from eight Canadian lentil cultivars were assessed to identify unique samples and key factors affecting starch digestion. The results showed that nearly half of apparent amylose in lentil flours was underestimated because it was complexed and embedded within the flour matrix, which led to slower starch digestion of cooked flour. Cooked red lentil flours showed significantly higher resistant starch content (11.0%) than flours from green lentils (6.8%) (P < 0.05). Among green lentils, Asterix and Greenland were unique for their high slowly digestible starch content after cooking, possibly owing to their high phenolic content and α‐glucosidase inhibitory activity. Long‐ and short‐range ordering in starch was more indicative of low starch digestion for raw or cooked lentil flour rather than for isolated starch. The results suggest the flour matrix protects the starch ordered structure from enzyme hydrolysis.     

Effect of hydroxypropyl methylcellulose,whey protein concentrate and soy protein isolate enrichment on characteristics of gluten‐free rice dough and bread

Due to a lack of gluten, rice dough needed some additives to improve its properties. This study aimed to investigate effect of hydroxypropyl methylcellulose (HPMC), whey protein concentrate (WPC) and soy protein isolate (SPI) on rice dough and bread. HPMC increased water absorption of the rice dough (P ≤ 0.05). Adding SPI (2–4 g per 100 g flour) together with HPMC tended to increase stability time and reduce tolerance index. During fermentation, HPMC increased maximum dough height, while SPI increased final dough height (P ≤ 0.05). All addition improved tan δ (G″/G′) to be comparable to the wheat dough, but it could not improve gas production and retention. Therefore, specific volume, springiness, cohesiveness and chewiness of rice bread were lower than those of wheat bread (P ≤ 0.05). Percentage of small pores in rice bread was reduced to be comparable to wheat bread, by adding WPC. All addition could improve porosity of the rice bread.     

Effect of pre-gelatinised high-amylose maize starch combined with Ca2+ -induced setting of alginate on the physicochemical and sensory properties of rice flour noodles

This study explored the effect of pre-gelatinised high-amylose maize starch combined with Ca²⁺ -induced setting of alginate on the physicochemical and sensory properties of rice flour noodles. Rice flour noodles were prepared by partially substituting rice flour with pre-gelatinised high-amylose maize starch in ratios of 5, 10 and 15% (wt/wt), combined with sodium alginate at 1% (wt/wt). The noodles were then immersed in a calcium chloride solution to set the alginate. Results indicated that the hydrocolloids significantly (P < 0.05) increased noodle tensile strength, hardness, water absorption and optimum cooking time while cooking loss was significantly (P < 0.05) reduced. SEM micrographs showed a denser, compact noodle structure with an increase in the matrix's continuity as a result of hydrocolloids addition. Formulated noodles also scored above average (5.91) sensory acceptability on the 7 points hedonic scale. Overall, results proved promising for the preparation of rice flour noodles with enhanced properties.