Improving the flavour and nutritional value of flour products with encapsulated fermented wheat bran extract

The adequate intake of dietary fibre is linked to several health benefits, for example, reducing the risk of non-communicable diseases, such as cardiovascular disease and diabetes. However, the population’s intake of dietary fibre is below the dosage recommended by the World Health Organisation. The incorporation of fibre ingredients, such as bran, in cereal based products affects the techno-functional and sensory properties, resulting in inferior product quality. To compensate quality loss, wheat bran (WB) and oat bran (OB) were fermented using the lactic acid bacterium strain Leuconostoc citreum TR116 prior to the application in a biscuit system. Two types of fermentation, one without any addition of sugars (FB) and one with the supplementation of 5% fructose and 5% sucrose to trigger the production of mannitol (FB +), were conducted and sugar and acid profiles as well as pH and total titratable acids (TTA) were evaluated. Fermented WB showed a higher TTA (+ 58%) compared to fermented OB. Furthermore, FOB + resulted in higher microbial cell count and higher residual sugars after 48 h of fermentation. The application of fermented brans in a biscuit system showed a decrease in dough stickiness (− 41.7%) and an increase in dough hardness (+ 32%). The type of bran (WB and OB) as well as the type of fermentation (FB or FB +) influenced the results of biscuit dough and biscuit quality (p < 0.005). Fermentation increased biscuit spreading, influenced biscuit snap force, enhanced crunchiness and colour formation, and lowered the predicted glycaemic index. Fermented OB (FOB +) resulted in a sensory profile comparable to the control.

Gluten-Free Diet: Imprudent Dietary Advice for the General Population?

The consumption of fiber-rich foods such as cereal bran is highly recommended due to its beneficial health effects. Pre-fermentation of bran with lactic acid bacteria can be used to improve the otherwise impaired flavor and textural qualities of bran-rich products. These positive effects are attributed to enzymatic modification of bran components and the production of functional metabolites like organic acids and exopolysaccharides such as dextrans. The aim of this study was to investigate dextran production in wheat and rye bran by fermentation with two Weissella confusa strains. Bran raw materials were analyzed for their chemical compositions and mineral content. Microbial growth and acidification kinetics were determined from the fermentations. Both strains produced more dextran in rye bran in which the fermentation-induced acidification was slower and the acidification lag phase longer than in wheat bran. Higher dextran production in rye bran is expected to be due to the longer period of optimal pHfor dextran synthesis during fermentation. The starch content of wheat bran was higher, which may promote isomaltooligosaccharide formation at the expense of dextran production. W. confusa Cab3 produced slightly higher amounts of dextran than W. confusa VTT E-90392 in all raw materials. Fermentation with W. confusa Cab3 also resulted in lower residual fructose content which has technological relevance. The results indicate that wheat and particularly rye bran are promising matrices for producing technologically significant amounts of dextran, which facilitates the use of nutritionally valuable raw bran in food applications.

The purpose of this study was to investigate the value of residue discarded after harvesting sweet potatoes (Ipomoea batatas L.). The study analyzed the physiological activity and cytotoxicity of the fermented extract and the hot water extract gathered from the residue. The pH level of the extracts indicated that all were acidic. The organic content was similar in the fermented extract and the hot water extract, at 0.98% and 0.97%, respectively. The macroelements phosphoric acid, potassium, calcium, and magnesium were all higher in the hot water extract than in the fermented extract. Nitrogen was the only macroelement that was the same in both extracts. The microelements were higher in the hot water extract than the fermented extract, except for zinc. The total polyphenol content was 60.5±2.7 mg/g in the hot water extract. This result was 37.8 mg/g higher than the 22.7±4.2 mg/g of the total polyphenol content of the fermented extract (p<0.05). The total flavonoid content was 50.7±2.7 mg/g in the hot water extract. This result was 36.7 mg/g higher than the fermented extract content of 14.0±2.1 mg/g. This showed that the hot water extract had a higher total level of polyphenol content than the fermented extract (p<0.05). DPPH and ABTS radical scavenging ability showed higher antioxidant activity in the hot water extract than in the fermented extract (p<0.05). A cytotoxicity test was conducted on the extracts using the MTT assay. The cytotoxicity was found to be weak at all concentrations for both extracts. Therefore, the results of the study suggest that the extract of the residue discarded after harvesting sweet potatoes would be suitable for functional feed or agricultural materials.

This study aimed to produce fermented extracts with sugar made from lotus root (LR) and Platycodon grandiflorum (PG), using lactic acid fermentation, and confirmed their physiological and anti-oxidative activities as basic data for manufacturing functional drinks through sensory tests. For the final sugar concentrations, PG showed 48.1 °brix and LR showed 52.0 °brix. Sugar concentrations during lactic acid fermentation following dilution of sugar to 12 °brix, ranged from 11.5∼12.1 °brix for PG and 11.9∼12.4 °brix for LR. During lactic acid fermentation, lactic acid bacteria numbers tended to decrease in both fermented LR and PG extracts with sugar as the fermentation period increased. For DPPH radical scavenging ability, LR was three times higher in control without lactic acid fermentation while PG showed significant increases in L. acidophilus (77%), L. brevis (90%), and L. delbrueckii (177%) during lactic acid fermentation. For total polyphenol content, LR showed a higher concentration than PG, and except for fermented L. delbrueckii extract showing similarity with the control, contents of fermented extracts decreased. In the case of PG, CUPRAC, increased significantly in L. brevis, whereas FRAP, increased significantly in L. delbrueckii with lactic acid fermentation. For reducing power, except for fermentation with L. brevis, all PG showed lower reducing power activities. In the sensory test of fermented LR and PG extracts with sugar, both fermented extracts showed better results with L. brevis or L. delbrueckii than control or those with L. acidophilus in every item. Based on these results, it is highly possible to develop fermented extract drinks with sugar using LR or PG. In particular, lactic acid bacteria such as L. delbrueckii and L. brevis showed generally higher activities with potential as a functional drink.

Feruloylated arabinoxylan (AX) is a potential health-promoting fiber ingredient that can enhance nutritional properties of bread but is also known to affect dough rheology. To determine the role of feruloylation and hydrolysis of wheat bran AX on dough quality and microstructure, hydrolyzed and unhydrolyzed AX fractions with low and high ferulic acid content were produced, and their chemical composition and properties were evaluated. These fractions were then incorporated into wheat dough, and farinograph measurements, large and small deformation measurements and dough microstructure were assessed. AX was found to greatly affect both fraction properties and dough quality, and this effect was modulated by hydrolysis of AX. These results demonstrated how especially unhydrolyzed fiber fractions produced stiff doughs with poor extensibility due to weak gluten network, while hydrolyzed fractions maintained a dough quality closer to control. This suggests that hydrolysis can further improve the baking properties of feruloylated wheat bran AX. However, no clear effects from AX feruloylation on dough properties or microstructure could be detected. Based on this study, feruloylation does not appear to affect dough rheology or microstructure, and feruloylated wheat bran arabinoxylan can be used as a bakery ingredient to potentially enhance the nutritional quality of bread.

Cadmium accumulation from diets with and without wheat bran in rats with different iron status

Exploring the chemical composition, antioxidant potential, and bread quality effects of the nutritional powerhouse: Wheat bran – A mini-review

One of the most important biological substances consumed in insufficient quantity is fibre that is often deficient in the diet. In general, dietary fibre is edible part of plants, or similar carbohydrates, that are resistant to digestion and absorption in the small intestine. Nowadays, there are many sources of fibre available for bakery industry, whether through addition of non-traditional bread cereals or through isolated form as additives. Except to supposed increase the nutritional value of bakery products with added fiber and raw materials containing fiber is necessary to think about their technological quality and rheological properties of dough. The aim of this experimental work was to investigate the effect of the addition of selected polysaccharides (inulin, Potex - potato fiber) and non-bakery crops (naked barley, malt) containing significant polysaccharides used in the mixture with wheat flour type T-650 in different ratios on the basis of farinographic evaluations. Based on the results of rheological measurements we found out that quality of dough was deteriorating proportionally to the amount of used additives. On the other hand, positively could be considered the increase of water absorption with addition of Potex and naked barley.

The flavour quality of biscuits could be lost during baking and storage. Therefor, the impact of using cinnamon essential oil (EO) encapsulated in maltodextrin (CO-MD), as exogenous flavour, on the flavour quality and stability of biscuits was evaluated. The results were compared with those of using cinnamon oil dissolved in propylene glycol (CO-PG), as a delivery solvent. The main volatile compounds in cinnamon oil were used as markers to monitor its stability in biscuits flavoured with CO-MD and CO-PG during baking and storage. The volatile components generated in flavoured biscuits and nonflavoured biscuits (control) were analyzed by headspace solid phase microextraction and gas chromatography-mass spectrometry. The retention of cinnamaldehyde, eugenol and β-caryophyllene in biscuits flavoured with CO-MD was significantly (P < 0.05) higher, over the shelf life test, than in biscuits flavoured with CO-PG. The Maillard reaction products showed the highest retention in biscuits flavoured with CO-MD compared with those flavoured with CO-PG and control sample. However, all of them showed a gradual decrease during storage. The lipid degradation products showed an opposite trend. Storage for 90days revealed a gradual decrease in the overall acceptability for both samples. The results of aroma sensory analysis confirmed those of instrumental analysis. This study demonstrated that microencapsulated cinnamon EO affects positively the overall qualities of biscuits.

Traditional rooibos iced teas prepared using fermented rooibos extract contain a low concentration of the unique antioxidant, aspalathin, which also has anti-diabetic properties. In order to increase the aspalathin content an array of rooibos iced tea formulations containing aspalathin-enriched green rooibos extract or the same extract solubilised in nanomicelles in the presence of ascorbic acid (solubilisate), as well as a mixture of the solubilisate and fermented extract, were formulated with or without lemon flavour. Since sensory attributes are important from a consumer viewpoint, the broad-based sensory attributes of these formulations were compared with those of traditional fermented rooibos iced tea. The iced tea formulations containing green rooibos extract exhibited a “plant-like” character, which was reduced with the addition of a commercial lemon flavour. The formulations containing the solubilisate had a prominent “hay-like” flavour, which was reduced by the addition of both lemon flavour and fermented rooibos extract. The formulations containing fermented rooibos extract exhibited a prominent “rooibos-woody” flavour characteristic of fermented rooibos tea. The perceived intensity of this characteristic attribute decreased with addition of commercial lemon flavour and solubilisate. All the iced teas exhibited a measure of astringency, but the astringency of iced teas containing fermented extract was the greatest and was reduced by addition of lemon flavour. In order to gauge consumer acceptance, the four lemon flavoured variants of rooibos iced tea were evaluated by a consumer panel. Consumers preferred the iced teas with fermented rooibos extract and disliked those with green rooibos extract. Preference mapping showed that the presence of the “rooibos-woody” flavour and the absence of a “plant-like” flavour most likely drive the preference of rooibos iced teas amongst South African consumers. The presence of a slight “hay-like” character did not reduce the preference of rooibos iced teas. Despite the functional benefits associated with a higher aspalathin content of green rooibos iced tea compared to the traditional fermented rooibos iced tea, consumers disliked the product, because of its overt “plant-like” note. However, a green rooibos extract solubilised in nanomicelles in combination with the fermented extract can be used to produce an iced tea with enhanced aspalathin content that is still acceptable to consumers from a taste point of view.

The fermentation characteristics of diets containing acid-treated beech-sawdust in an artificial rumen

This research was conducted to find out the effect of wheat bran, rice bran, corboxy methyl cellulose (CMC) and guar gum supplementation on the quality of whole wheat flour biscuits. The proximate composition of whole wheat flour (WWF), wheat bran (WB) and rice bran (RB) were 9.0, 11.30, and 7.00% moisture, 7.19, 12.61 and 14.80% crude protein, 1.92, 3.79, and 2.29% crude fat, 0.36, 4.78 and 9.96% ash, 1.97, 12.7 and 14.2% crude fiber and 75.95, 67.52 and 65.95% NFE respectively. Biscuits were prepared by adding this bran’s @ 4 to 8% and CMC and guar gum @ 0.14% in WWF. The samples were prepared as Bo (control), B1 96%WWF+4%WB, B2 92%WWF+8%WB, B3 96%WWF+4%RB, B4 92%WWF+8%RB, B5 96%WWF+4% WB + 0.14% CMC, B6 96%WWF+4% WB +0.14 % guar gum, B7 96%WWF+4% RB + 0.14 CMC and B8 96%WWF+4%RB +0.14% guar gum. The moisture content (%) increased in WB (from 2.71 to 2.87) and RB (from 2.69 to 2.78) supplemented biscuits, while decrease was recorded in CMC (from 2.82 to 2.62) and guar gum (from 2.69 to 2.58) respectively. Protein content (%) increased in WB (from 5.09 to 5.51) and RB (from 5.17 to 5.61) supplemented biscuits, while decrease was recorded in CMC (from 5.44 to 5.35) and guar gum (from 5.33 to 5.08) respectively. The NFE content (%) decreased in WB (from 65.39 to 59.0) and RB (66.74 to 66.09) supplemented biscuits, while it is increased in CMC (from 64.05 to 64.69) and guar gum (from 64.42 to 65.17) respectively. The moisture, crude protein, crude fat, crude fiber, ash content and NFE were significantly (p<0.05) influenced by the level of supplementation. The physical analysis i.e. width and spread factor decreased by increasing the levels of bran, CMC and guar gum, while thickness increased by increasing levels of bran and decreased in CMC and guar gum supplementation. There was significant difference in the mean scores for sensory evaluation of the biscuit (p<0.05).

Wheat bran are widely used as a source of dietary fiber with enhanced health benefits. However, its hight application level in bakery products caused lower quality of these products (eg. reduced volume and increased hardness of product). Different mechanical, physical or chemical methods are used for modification of wheat bran physicochemical properties. Wheat bran obtained from two wheat variety was used to evaluate the effect of bran stabilization process on qualitative properties of baked goods. Stabilization was performed using hot air and microwave heating. Threated and unthreated wheat bran were blended with wheat flour at 5, 10 and 15% substitution level. Influence of bran addition on rheological properties was evaluated using Mixolab 2. Stabilized wheat bran increased water absorption up to 11.7% (hot air stabilization) and 11.9% (microwave stabilization), respectively. Hot air stabilization of wheat bran improved heat resistance of dough proteins during mixing and the stability of hot gel during heating. Stabilization process of wheat bran using both methods also increased the volume and spread ratio values of enriched cookies. Cookies incorporated with hot air treated bran were significantly softer than cookies contained raw bran. Sensory evaluation showed that addition of stabilized bran improved the shape and taste of cookies. Additionally, it was concluded that the most acceptable cookies were obtained at 5% addition level of bran stabilized using microwave heating.

To address the poor functionality and quality of wheat bran-added cookies the present research explores raw wheat bran (RWB), NaOH treated wheat bran (NaOH-WB), and wet-refined wheat bran (WR-WB) to supplement traditional cookies (CL). The microscopic (SEM), crystallographic (XRD) and functional group analysis (FTIR) of bran samples showed a significant effect of modification. The cookies (with 5%, 10%, and 15% of each bran) quality evaluation based on spread factor, hardness, and sensory, further judged by PCA, showed that upto 10% addition of the wheat bran produced acceptable cookies. Further evaluation of the 10% bran-added cookies showed increased baking weight loss, degraded color properties except for the NaOH-WB cookies, increased moisture, and no change in water activity. The maximum protein observed for RWB cookies, fat for RWB and WR-WB cookies, ash for WR-WB cookies, total dietary fiber for NaOH-WB and WR-WB cookies, available carbohydrate for CL cookies, energy content for CL and RWB cookies, total phenolic content and DPPH activity for WR-WB cookies. The in vitro digestion showed a slowed glucose release rate for NaOH-WB and WR-WB cookies. It was concluded that WR-WB has good scope for use in cookie preparation (maximum at 10% level) with improved physiological, nutritional, and antioxidant properties. Graphical abstract