Extrusion conditions and zea mays endosperm hardness affecting gluten‐free spaghetti quality

The effects of extrusion temperature (80, 90 and 100 °C) and flour moisture content (27%, 31% and 35%) on corn spaghetti quality were evaluated according to a factorial experimental design. Flours obtained from a soft and hard endosperm were processed in a Brabender single screw extruder. Corn spaghettis with good cooking characteristics and resistance to overcooking were obtained by extrusion at 27% flour moisture content for the three temperatures used. They have higher resistance to hydration, long cooking time (around 11 vs. 7 min for poor quality) and low cooking loss (lower than 9% for a 10‐min overcooking). Softer endosperm allowed obtaining better spaghetti quality. Among different physicochemical properties, enzyme susceptibility could be used as an indicator of mechanical energy dissipated by friction. During extrusion cooking, the native structure is partially destroyed, and new crystalline ones, corresponding to the amylose–lipid complex, are formed.     

From wheat sourdough to gluten‐free sourdough: a non‐conventional process for producing gluten‐free bread

Gluten‐free (GF) sourdough was prepared from wheat sourdough and analysed both in fresh (GFS) and dried forms (DGFS). The gluten content in each GF sourdough sample was <20 mg kg^?1. The dough leavening capacity and the properties of the bread samples were investigated and compared to those of bread prepared using bakery yeast (Saccharomyces cerevisiae). Two commercial rice‐based mixtures (different for the presence/absence of buckwheat flour) were used to prepare bread samples. In GFS, lactic acid bacteria (LAB) and yeasts were found in amounts corresponding to 10⁸ and 10⁷ CFU g^?1, respectively, whereas both LAB and yeasts were detected in lower amounts (about 10⁶ CFU g^?1) in DGFS. When used in bread‐making, both GFS types produced significant dough acidification and exhibited good dough development during proofing, resulting in loaves with specific volume values between 3.00 and 4.12 mL g^?1, values similar to those obtained for reference bread (3.05÷4.15 mL g^?1). The use of GFS was effective in lowering the bread staling rate during storage for up to 7 days.     

Antioxidative and reducing capacity,macroelements content and sensorial properties of buckwheat‐enhanced gluten‐free bread

Common buckwheat flour (BF) was used to substitute 10%, 20%, 30% and 40% of corn starch, the main component of a gluten‐free bread formula, to make buckwheat‐enhanced gluten‐free breads. The 40% BF‐enhanced gluten‐free bread showed the highest antioxidant capacity against ABTS⁺˙ and DPPH˙ radicals (4.1 and 2.5 μmol Trolox g^?1 DM, respectively) and reducing capacity measured by cyclic voltammetry (1.5 μmol Trolox g^?1 DM). The antioxidant and reducing capacity of buckwheat‐enhanced gluten‐free breads were positively correlated with their total phenolic contents (r = 0.97). The 40% BF‐enhanced gluten‐free bread showed the highest overall sensory quality (7.1 units) when compared to control gluten‐free bread (1.8 units). The linear relationship between applied increasing BF doses in gluten‐free bread formula and magnesium, phosphorus and potassium content in breads was noted. It was concluded that 40% BF‐enhanced gluten‐free bread could be developed and dedicated to those people suffering from coeliac disease.     

Nutritional aspects of gluten‐free products

In recent years, gluten‐free (GF) goods have become popular, fuelling a growing market, as they not only cater to individuals with medical needs but also to consumers who seek a GF diet. In their development, it is pivotal to pay attention to nutritional quality. This review aims to provide some insights on the nutritional quality of GF products, focusing on major concerns and the strategies to overcome them. In order to mimic the viscoelastic properties of gluten, a large number of flours and starches and other ingredients have been used. Therefore the different mixtures of these ingredients bring a wide difference in the nutritional composition of GF foods with respect to gluten‐containing counterparts. Several GF foodstuffs contain more fat, including saturated, and salt but fewer minerals and vitamins than their equivalents with gluten. The increased fibre content and improved technological processes have positively affected the glycaemic responses from these goods. However, in order to improve their nutritional quality, wholemeal GF cereals and pseudocereals with high nutritive value should replace the low‐nutritional GF flours and consequently the technological processes would be optimized. The improvement of the nutritional quality of GF products, and in turn that of the GF diet, should also be aimed at lowering the risk of later chronic degenerative disorders, especially for infants and young children. © 2015 Society of Chemical Industry     

Physical properties and sensory acceptability of cookies made from chickpea addition to white wheat or whole wheat flour compared to gluten‐free amaranth or buckwheat flour

The effects of chickpea addition (0–100%) on the physical properties and sensory attributes of cookies based on white or whole wheat compared to gluten‐free amaranth or buckwheat flour were studied. The physical properties determined were spread factor, colour and hardness. Sensory evaluation was conducted for colour, taste, texture and overall impression. Chickpea addition decreased the lightness in white wheat cookies while increasing it in whole wheat and amaranth cookies and it significantly increased yellowness in all cookies. Spread factor of the gluten‐free cookies was reduced by chickpea addition and hardness was increased in white wheat and buckwheat cookies, and decreased in whole wheat and amaranth cookies. Sensory evaluation demonstrated that chickpea addition increased the acceptability of all cookies, in particular of the gluten‐free cookies. Optimal levels of chickpea addition were 20–40% in wheat cookies and 60–80% for amaranth and buckwheat cookies.     

Characterisation of chickpea flour‐based gluten‐free batters and muffins with added biopolymers: rheological,physical and sensory properties

Chickpea flour (CF)‐based muffin formulations were made with CF alone and with added biopolymers [whey protein (WP), xanthan gum (XG) and inulin (INL)] to evaluate their suitability to be a wheat flour (WF) substitute in muffins. Structural characteristics of the batters and muffins were studied by means of rheometry, microscopy, physicochemical properties, and texture and sensory analysis. Partial replacement of CF with XG, alone (at 0.5 and 1%) or blended with either WP or INL, significantly increased the batter viscoelasticity as denser matrices developed; moreover, the muffins with XG added at 1% had similar hardness to wheat gluten muffins. The replacement of WF decreased the springiness, cohesiveness, chewiness, resilience and specific volume of the muffin. However, baked muffins with added XG also showed higher sensory sponginess and moisture associated with numerous air bubbles in the batter and were perceived to be easier to swallow and to have better general appearance.     

Production of gluten‐free bread using soybean flour

The effect of soybean flour on gluten‐free bread quality was studied. Full‐fat enzyme‐active, semiactive and inactive soybean flours were evaluated. Active soybean flour improved the volume and structure of gluten‐free bread, while semiactive and inactive soybean flours did not have positive effects on bread quality. The particle size and concentration of the soybean flours also affected bread quality. Levels of addition between 125 and 150 g kg^?1 and particle sizes between 90 and 120 µm of active soybean flour yielded the best results. Heating the active soybean flour destroyed its improving effect. The analysis of proteins by sodium dodecyl sulphate polyacrylamide gel electrophoresis and size exclusion chromatography showed that heating soybean flour at 60–200°C caused protein aggregation. The overall results indicated that the addition of active soybean flour improved gluten‐free bread quality, and this effect seemed to be due to both the structural proteins and the enzymatic activities of the soybean flour. Copyright © 2004 Society of Chemical Industry     

Influence of quinoa roasting on sensory and physicochemical properties of allergen‐free,gluten‐free cakes

The objectives of this study were to determine pasting properties of non‐roasted (NR) and roasted quinoa (RQ) and to investigate the effect of RQ on consumer acceptance and physicochemical properties of an allergen‐free, gluten‐free cake formulation. Quinoa seeds were roasted at 177 °C for 15 (R15), 30 (R30) and 45 min (R45), and flours were analysed for pasting properties. Five cakes including a commercial chocolate cake (CCC) and cakes made with NR and RQ flours were evaluated for preference by fifty panelists. Quality parameters included colour, water activity, moisture content, firmness, weight and height. Peak and final viscosity increased with roasting time. The NR cake had the highest sensory scores for appearance, colour and texture. On flavour and overall acceptability, CCC was the highest. Regarding quality data, CCC, NR and R15 cakes had similar L* values, while CCC had the lowest a*, b*, a_w, moisture content and firmness values.     

Processing of bottom‐fermented gluten‐free beer‐like beverages based on buckwheat and quinoa malt with chemical and sensory characterization

Typical beer contains significant amount of gluten, and being the third most popular beverage worldwide, the commercial production of its gluten‐free form is of rising interest. This research aimed to prepare bottom‐fermented beverages from buckwheat and quinoa and to explore their physical, chemical and sensory properties. Compared with barley, the analysis of brewing attributes of buckwheat and quinoa showed a lower malt extracts, longer saccharification times, higher total protein and fermentable amino nitrogen content and higher values of the iodine test and colour. Fermentability values, the wort pH and the soluble protein content were similar for barley and buckwheat, but different for quinoa, whereas only values of viscosity and beverage pH were similar between barley and quinoa. Both beverages, especially the quinoa beverage, contained a superior level of metal cations. The fermentable carbohydrate content in the buckwheat wort was comparable to barley but lower in quinoa; however, worts derived from both pseudocereals contained predominantly glucose. The amino acid content of the buckwheat wort was similar to barley, whereas the content in the quinoa beverage was almost twice as high. The content of volatile compounds commonly associated with beer aroma was comparable between the barley and buckwheat beverage but significantly lower in the quinoa; however, the latter contained some distinctive volatile substances not found in the other beverages. The organoleptic perception of the buckwheat beverage was better than that of the quinoa, although both showed a good general acceptance. In general, buckwheat appears quite similar to barley, whereas quinoa shows many unique properties. Copyright © 2014 The Institute of Brewing & Distilling     

Effect of hydrocolloids on gluten‐free batter properties and bread quality

The objectives of this study were to assess the effect of the addition of different hydrocolloids on gluten‐free batter properties and bread quality and to obtain information about the relationship between dough consistency and bread quality. Breads were made of rice, corn and soy flours and 158% water. Following hydrocolloids were added: carrageenan (C), alginate (Al), xanthan gum (XG), carboxymethylcellulose (CMC) and gelatine (Gel). Batter consistency, bread specific volume (SV), crumb analysis, crust colour, crumb hardness and staling rate were determined. Hydrocolloids increased batter consistencies: the highest value was obtained with XG, which doubled that of control batter, followed by CMC. Breads with hydrocolloid presented higher SV than control, especially with XG whose SV was 18.3% higher than that of control bread. A positive correlation was found between SV and batter consistency (r = 0.94; P < 0.05). Crumbs with Gel, XG and CMC presented higher cell average size. XG and CMC crumbs looked spongier. Breads containing hydrocolloid evidenced lighter crusts. Crumb firmness was decreased by XG and CMC addition, and staling rate was slower. Overall, XG was the hydrocolloid that most improved gluten‐free bread quality. These results show that, in formulations with high water content, batter consistency is strongly associated with bread volume.     

Influence of phosphorylated rice flour on the quality of gluten‐free bread

The chemical modification of rice flour by phosphorylation is an alternative to improve the technological quality of bakery products. The aim of this study was to investigate the effect of phosphorylation process of rice flour on technological properties (specific volume, crumb and crust colour) of gluten‐free breads and the hardening of these breads during two storage temperatures (21 °C and ?24 °C). Breads were made with native rice flour, with phosphorylated rice flour and with wheat flour, used as control. The phosphorylation causes significant reduction in the synaeresis of pastes and in retrogradation tendency of rice flours, varying from 258.7 cP (native rice flour) to 122 cP (phosphorylated rice flour). The breads prepared with phosphorylated rice flour showed reduction in the hardness in both storage temperatures studied and effect on rice bread volume, crumb appearance and colour, demonstrating the possibility of use of the phosphorylated rice flour in gluten‐free breads.     

Influence of maize flour particle size on gluten‐free breadmaking

BACKGROUND: Maize, one of the suitable grains for coeliac consumption, is, together with rice, the most cultivated cereal in the world. However, the inclusion of maize flour in gluten‐free bread is a minority and studies are scarce. This paper analyses the influence of different maize flour types and their particle sizes on the quality of two types of bread without gluten (80% and 110% water in the formulation) obtained from them. We also analysed the microstructure of the dough and its behaviour during the fermentation. RESULTS: Finer flours had a lower dough development during fermentation in all cases. Among the different types of flour, those whose microstructure revealed compact particles were those which had higher specific bread volume, especially when the particle size was greater. Among the formulations, the dough with more water gave breads with higher specific volume, an effect that was more important in more compact flours. The higher volume breads had lower values of hardness and resilience. CONCLUSION: The type of corn flour and mainly its particle size influence significantly the dough development of gluten‐free bread during fermentation and therefore the final volume and texture of the breads obtained. The flours having coarser particle size are the most suitable for making gluten‐free maize bread. © 2012 Society of Chemical Industry     

Effect of adding fresh and freeze‐dried buckwheat sourdough on gluten‐free bread quality

This study demonstrates new possibilities in using freeze‐dried buckwheat sourdoughs in the processing of gluten‐free bread (GFB). Fresh and freeze‐dried (at temperatures of 20, 40 and 60 °C) sourdoughs were added in the amounts of 10, 20, 30 and 40% of the total flour content. Significant and beneficial changes in the quality of bread under the influence of different quantities of fresh and freeze‐dried sourdoughs additive were observed. Freeze‐dried buckwheat sourdoughs at the level of 20 and 30% gave the best baking results for GFB. pH of bread significantly changed, which had a positive effect on increasing its suitability for the storage. Buckwheat sourdough dried at 40 °C is the most highly recommended for GFB processing. Higher temperatures (60 °C) caused the least change in bread volume; however, a bitter aftertaste from burning was slightly detectable. Freeze‐dried buckwheat sourdoughs can be used directly in processing, thus eliminating the long fermentation of sourdough.     

Effect of different iron compounds on wheat and gluten‐free breads

BACKGROUND: Iron fortification of bread often results in sub‐optimal quality of the final product due to undesirable changes in the physical characteristics and sensory properties of the bread. In this study both the form of iron (soluble, insoluble or encapsulated) and the type of bread (wheat or gluten‐free) were varied in order to investigate the effect of iron and gluten on the product characteristics. RESULTS: The effect of iron on the quality characteristics of the breads investigated depended on iron type, but not on iron solubility. Colour, crust firmness, specific volume, cell number and uniformity as well as aroma were the attributes that were mainly affected in iron‐enriched wheat bread. In some cases, specific volume was 30% lower than that of the control sample, while cell uniformity was significantly lower, as low as 50% of the control sample in some fortified samples. In gluten‐free breads, differences between unfortified and fortified samples included colour, crust firmness, cell number, ‘moisture’ odour, metallic taste and stickiness. In some cases, the sensory scores were better for fortified samples. CONCLUSIONS: Differences due to iron fortification were less pronounced in gluten‐free compared to wheat breads. The choice of the appropriate iron compound which will not cause adverse quality changes is still a challenge. Copyright © 2010 Society of Chemical Industry     

Pomegranate seed powder as a functional component of gluten‐free bread (Physical,sensorial and antioxidant evaluation)

The purpose of this study was to evaluate the effect of the addition of pomegranate seed powder (PSP) on physical, sensorial and antioxidant properties of gluten‐free bread. The PSP was incorporated at different levels (2.5%, 5.0%, 7.5% and 10%) into formula of gluten‐free bread. Control gluten‐free bread made without any addition of PSP was used for comparison. The results showed that the specific volume and springiness of gluten‐free breads increased, whereas hardness and chewiness decreased significantly with increasing PSP addition. The addition of PSP into gluten‐free bread decreased the lightness and yellowness of crumb and crust colour, while redness increased. Total phenolics content (TPC) increased from 46% to 181% with PSP addition (2.5%–10%). Moreover, antioxidant activity was significantly higher for bread with PSP. For bread with the highest percentage of PSP, the highest antioxidant activity was obtained. For sensorial and antioxidant activity, the optimum level of PSP addition was found to be 7.5%.     

Effect of butter content and baking condition on characteristics of the gluten‐free dough and bread

This study aimed to investigate effect of butter content (0–30 g/100 g flour) and baking conditions hot air baking (HA), microwave baking (MW) and hot air‐microwave baking (HA‐MW) on quality of the rice flour dough and bread. The increased butter (up to 15 g butter/100 g flour) enhanced elastic modulus (G′) and viscous modulus (G″) of dough and specific volume of bread. Additionally, the increased butter improved crust colour and reduced hardness of the bread. The HA‐MW and MW conditions were useful for the gluten‐free bread by reducing baking time and predicted glycemic index (GI), regardless of butter content. However, enthalpy of retrogradation and crystallinity in the HA‐MW and MW bread stored at 4 °C for 7 days were increased and higher than those of the HA bread, indicating a faster staling. The predicted GI of both MW and HA‐MW bread remained at a medium level during storage.