Nutritional recommendations for the elderly, but also the general public, include incorporation of plant proteins in the diet, an increase in the intake of Ω-3 fatty acids and an increase in intake ...of dietary fibre. Protein structure and structuring behaviour of plant proteins differ from that of milk proteins. Therefore, the aim of the presented study was to characterise the structuring process and resulting structure of yoghurt-style gels containing 10% pea protein with and without addition of nutritionally recommended ingredients like rapeseed-oil and/or commercial oat fibre. Rheological measurements were combined with microscopy for sample characterisation. Generally, all studied formulations were able to form acid induced gels via fermentation. The acidification led to a two-phase gelation process resulting in thick gels that showed mainly weak rheological behaviour. Supplementation with oil and/or fibre resulted in an increase of the relative concentration of pea protein in the aqueous phase and led to a strong increase in the complex shear modulus |G*| as well as the maximum structuring velocity d|G*|/dt. These effects need to be considered when tailoring yoghurt-style gels with high consumer acceptance.
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•Two-step structuring process comprising pre-aggregation and condensation.•An increase in relative protein content accelerates structure formation.•In multi component systems the dominating structure is a weak pea-protein gel.•Only limited direct effects of oil and fibre addition on gel properties.
Hempseed protein concentrate (HPC) was extracted from hempseed press cake with a protein content of 85.7% and co-extruded with oat fibre residue (OFR) to produce high-moisture meat analogues (HMMA) ...at different moisture contents (60, 63, 66%), screw speeds (500, 700, 900) and temperature profiles (40-70-110-130 °C and 40-70-120-150 °C). The effect of extrusion processing parameters such as moisture content, screw speed, and different temperature profiles on the properties of the extrudates was investigated. The produced meat analogues had a fibrous structure and brown colour, which may be due to the derived hempseed protein. The specific mechanical energy (SME) required in this study was low and ranged from 63 to 185 kJ/kg. As moisture content increased, it was discovered that hardness, chewiness, and cutting strength values decreased. Nevertheless, cutting strength values increased when a higher temperature profile was used. By using a higher temperature profile, the protein was completely denatured, leading to the formation of stronger fibres in the meat analogues with a higher quality in terms of texture. The study demonstrated the possibility for both materials from underutilised side-streams to be converted into meat analogues, which would provide variety for the HMMA on the market.
•HME turned side-stream materials from a mixture of hempseed protein concentrate and oat fibre residue into novel meat analogues.•HMMA from hempseed protein concentrate – oat fibre residue mixture cooked at a high temperature offered greater texture quality and consumed less energy.•The technique used in this study could enhance the use of hempseed press cake and oat fibre residue in the food industry.
The aim of the study was to assess the sensory quality of wheat bread rolls with and without the addition of 12% of oat fibre (with high β‐glucan content) from a consumer perspective. A consumer ...group of 383 people rated the acceptability of fresh rolls and rolls after 1 day of storage using 9‐point hedonic scales. A trained panel evaluated fresh rolls and rolls after 1 and 2 days of storage using quantitative descriptive analysis as a sensory profile method. The consumer group assessed the overall acceptability of the fresh bread rolls enriched with fibre as higher than fresh bread rolls without fibre addition. The decrease in the sensory quality of rolls during storage was observed by both groups of evaluators. The trained panel found that increased storage time resulted in a greater reduction of aroma and flavour ratings, as well as in elasticity and overall quality, in the stored rolls with 12% fibre addition compared to those without fibre addition. Nevertheless, consumers’ high sensory acceptability of the fresh bread rolls enriched with fibre should be taken into account in the introduction of the oat fibre source product onto the market.
The biggest challenge in the production of gluten-free baked products is creating a structure without gluten while maintaining physicochemical and sensory properties. The aim of this study was to ...evaluate the possibility of applying oat β-glucan as the thickening and structure-making agent instead of xanthan (control sample), due to its pro-health technological properties, in yeast-leavened gluten-free cake. Thus, high-in-β-glucan oat fibre powder was incorporated into cake formulations as 5, 10, 15 and 20% replacement of rice or corn flour. The complex analysis of physicochemical and sensory properties was conducted, where texture and rheological aspects were the most important. An analysis of the correlation between rheological and physical properties was also conducted. Corn and rice cakes differed, but the results showed the increase of β-glucan, total dietary fibre, springiness, cohesiveness, storage (G′) and loss (G″) modulus and the decrease of firmness and lightness. Improvement of porosity and volume was also noticed. Significant correlation was observed among G′, G″, specific volume and texture components. Accelerated texture changes were noticed after 24 h of storage. To sum up, it is justified to incorporate oat fibre into gluten-free baked products, both to increase nutritional value and improve cake structure.
In response to the growing interest of modern society in functional food products, this study attempts to develop a bakery product with high dietary fibre content added in the form of an oat fibre ...powder. Oat fibre powder with particle sizes of 75 µm (OFP1) and 150 µm (OFP2) was used, substituting 4, 8, 12, 16 and 20% of the flour. The physical properties of the dough and the final bakery products were then measured. Results indicated that dough with added fibre had higher elasticity than the control group. The storage modulus values of dough with OFP1 most closely approximated those of the control group. The addition of OFP1 did not affect significantly the colour compared to the other samples. Increasing the proportion of oat fibre powder resulted in increased firmness, which was most prominent in wheat bread rolls with oat fibre powder of smaller particle sizes. The addition of oat fibre powder with smaller particles resulted in a product with the rheological and colour parameters that more closely resembled control sample.
Bifidobacterial food applications are limited since bifidobacteria are sensitive to e.g. acidic conditions prevalent in many food matrices. The aim of the present study was to investigate whether a ...low pH selection step alone or combined to UV mutagenesis could improve the viability of an acid sensitive
Bifidobacterium strain,
B. breve 99, in low pH food matrices. Furthermore, the potential of carriers and an oat fibre preparation to further improve the stability was studied. The best performing low pH tolerant variants in the present study were generated by UV-mutagenesis with 70–700
μJ/cm
2 followed by incubation in growth medium at pH 4.5. The most promising variants regarding the low pH tolerance showed, in repeated tests with cells grown without pH control, about one Log-value better survival in pH 3.8 fruit juice after one week storage at 4
°C compared to wild-type
B. breve 99. Cells grown with pH control, PDX formulated and then frozen showed poorer viability in low pH fruit juice than cells grown with no pH control. For frozen concentrates pH 3.8 was too stressful and no or small differences between the variants and the wild-type strain were seen. The differences detected at pH 3.8 with the cells grown without pH control were also seen with the frozen concentrates at pH 4.5. Some improvement in the stability could be achieved by using a combination of trehalose, vitamin C and PDX as a freezing carrier material, whereas a significant improvement in the stability was seen when oat fibre was added into the fruit juice together with the frozen cells. Due to the initial very poor fruit juice tolerance of
B. breve 99 the obtained improvement in the stability was not enough for commercial applications. However, the same methods could be applied to initially better performing strains to further improve their stability in the fruit juice.
► We studied low pH selection and UV mutagenesis to improve the viability of B. breve. ► Potential of carriers and oat fibre to improve the stability of B. breve was studied. ► Viability and stability of B. breve cells in low pH fruit juice was improved. ► Methods can be applied to improve the stability of probiotics in fruit juice.
This work was aimed at decreasing the glycaemic index (GI) of white wheat bread. Breads made with wheat flour (WF) or wholemeal flour (WMF) and fermented with baker's yeast had similar values of ...resistant starch (RS; 1·4–1·7 %, starch basis). Sourdough Lactobacillus plantarum P1 and Lactobacillus brevis P2 favoured the highest formation of RS (approximately 5 %) when fermented with WF and WMF. The mixture (1:1) of WF and WMF (WF/WMF) was selected. The effect of dietary fibres, chemical or sourdough acidification on the hydrolysis index (HI) of WF/WMF bread was determined. Among fibres, only the addition of oat fibre (5 %) decreased the HI to 90·84 %. Lactic acid determined the lowest HI, and the effect was related to the decrease of pH. For the same decrease of pH, breads fermented with L. plantarum P1 and L. brevis P2 (sourdough WF/WMF) showed values of HI lower than chemical acidification. The glucose response and GI of WF bread or sourdough WF/WMF bread enriched with oat fibre was determined by using fifteen healthy volunteers. Anhydrous glucose was used as reference. The area under the glucose response curve and the value of GI (72 %) of WF bread were significantly (P < 0·05) higher than sourdough WF/WMF bread enriched with oat fibre (GI = 53·7 %). The decrease of GI of the sourdough WF/WMF bread may be due to both fibre content and decreased pH. Compared to WMF bread, sourdough WF/WMF bread, enriched with oat fibre, had higher specific volume, better cell crumb structure and more appreciated acidulous smell, taste and aroma.
The formation of SCFA in rats fed fermented oat fibre concentrates was compared with that of rats fed native oat fibre concentrate. The cultures used were lactic acid bacteria consisting of ...Lactobacillus bulgaricus and Streptococcus thermophilus (V2), the exopolysaccharide-producing strain Pediococcus damnosus 2.6 (Pd) and L. reuteri (Lr). The materials were incorporated into test diets yielding a concentration of indigestible carbohydrates of 80g/kg (dry weight). Rats fed the V2-fermented fibre-concentrate diet yielded higher caecal and distal concentrations of acetic acid (p<0·01) than rats fed the native fibre concentrate. All the fermented fibre concentrates resulted in a higher propionic acid concentration in the distal colon (p<0·05), while rats fed Pd-fermented fibre concentrate resulted in lower concentration of butyric acid (p<0·05,p <0·01) in all parts of the hindgut as compared with rats fed the native fibre concentrates. Butyrate concentrations ranged between 5–11μmol/g (distal colon) and 6–8;μmol/g (13d faeces). Higher proportions of acetic acid (p<0·05; p<0·01) were observed in the caecum of rats fed the fermented fibre concentrates. Rats fed Pd- and Lr-fermented fibre concentrates produced higher proportions of propionic acid (p<0·05; p<0·01) in the caecum. Changes in SCFA formation in the caecum, distal colon and faeces of rats fed the fermented samples compared with the native sample indicate that these microbes probably survive in the hindgut and that modification of the microflora composition with fermented foods is possible. This may be important for the gastrointestinal flora balance in relation to colonic diseases.
U današnje je doba sve veća potražnja za funkcionalnom hranom, pa je svrha ovoga rada bila razviti nove pekarske proizvode s velikim udjelom zobenih vlakana u prahu. U smjesu je umjesto 4, 8, 12 ili ...20 % pšeničnog brašna dodan zobeni prah veličine čestica od 75 i 150 μm. Ispitana su fizikalna svojstva sirovog tijesta i pečenih peciva. Rezultati pokazuju da je tijesto s dodatkom zobenog praha bilo elastičnije od kontrolne skupine. Tijesto s česticama praha veličine 75 μm imalo je vrijednosti modula čuvanja najsličnije onima kontrolne skupine. Dodatak finijeg praha zobenih vlakana nije bitno utjecao na boju peciva. S povećanjem udjela zobenog praha povećala se tvrdoća peciva, i to osobito nakon dodatka finijeg praha. Reološka svojstva i parametri boje peciva s dodatkom finijeg zobenog praha bili su najsličniji kontrolnom uzorku.
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