Characterization of Oil-in-Water Emulsions Prepared with Triblock Copolymer Poloxamer 407 and Low-Molecular-Mass Surfactant Mixtures as Carriers of Grape Pomace Waste Polyphenols.

BACKGROUND: Natural antioxidants, such as grape pomace polyphenols, can be extracted by a surfactant-based green technology and incorporated into various emulsions. Therefore, this work aimed to investigate the physical stability and rheological characteristics of oil-in-water emulsions stabilized with poloxamer 407 (P407) and its mixtures with the low-molecular-mass surfactants Brij S20 (BS20) and Tween 60 (T60). Also, the influence of polyphenolic grape pomace extracts on the physical stability and rheological characteristics of the emulsions was examined. METHODS: Grape pomace polyphenols were extracted by aqueous solutions of P407 and BS20/P407 and T60/P407 mixtures. Two different types of oil-in-water emulsions were examined: emulsions prepared with pure surfactants and emulsions prepared with surfactant-based polyphenol extracts of grape pomace. Both types contained 20% sunflower oil. Characterization of the emulsions comprised droplet size evaluation, rheology characteristics and creaming stability. RESULTS: All the emulsions showed shear-thinning flow, while the rheological characteristics and creaming instability depended on the proportion of P407 in the emulsifier mixtures. Incorporation of grape pomace extracts had no effect on the investigated properties of the emulsions. CONCLUSION: The presence of extracted polyphenols in emulsifier mixtures had no significant effects on the emulsions' physico-chemical characteristics and stability. Therefore, the investigated emulsions can be considered suitable carriers for polyphenol-rich extracts.

Fortification of chocolate with microencapsulated fish oil: Effect of protein wall material on physicochemical properties of microcapsules and chocolate matrix.

Protein stabilized fish oil microcapsules were incorporated into chocolates in order to design fortified product which could bear the nutritional claim "source of or high omega-3 fatty acids". Protein wall material (soy, whey and potato) influenced microcapsules and chocolate performance. Soy protein resulted in the smallest microcapsules with the lowest content of surface oil. Peroxide values were low even after 14 days of microcapsules storage. Incorporation of microcapsules into chocolate led to increase in Casson viscosity and breaking force as well as decrease in melting enthalpy, due to prevalence of particle-particle over fat-fat interactions. Increase in microcapsules concentration resulted in chocolate with poorer snap and higher tendency to fat bloom formation. Whey protein microcapsules, having the largest diameter, resulted in chocolate with the lowest breaking force and melting enthalpy and the highest whitening index. In general, microcapsules addition did not require chocolate production modification and led to sensory acceptable product.

Techno-Functional Performance of Emmer, Spelt and Khorasan in Spontaneously Fermented Sourdough Bread.

The aim of this study was to test the suitability of three different ancient wheat varieties (emmer, spelt and khorasan) to produce spontaneously fermented sourdough bread and to evaluate the impact on the dough rheological properties, ultrastructure and baking quality. Modern wheat sourdough bread and bakery yeast fermented bread were used as controls. Sourdoughs produced from modern and ancient wheats exerted different effects on dough viscoelastic properties, bread specific volume, texture, firming rate, colour and sensory properties, while there was no influence on bread water activity. Both khorasan sourdough, being characterised with the highest dough strength and dense gluten protein matrix, and emmer sourdough, with loose and thin gluten strands of low strength, yielded breads characterised by low specific volume and hard crumb texture. Spelt and modern wheat sourdough were characterised by foam-like dough structures with entrapped gas cells leading to breads of similar specific volume and texture. Although the yeast-fermented wheat flour exerted a higher specific volume and the lowest firmness, the sourdough wheat flour bread had a lower firming rate. A comparison of sourdough bread prepared with modern and ancient wheats revealed that breads based on ancient varieties possess a less noticeable sour taste, odour and flavour, thus contributing to more sensory-appealing sourdough bread.

Ancient Wheat Varieties and Sourdough Fermentation as a Tool to Increase Bioaccessibility of Phenolics and Antioxidant Capacity of Bread.

This study aimed to determine the impact of ancient wheat varieties (emmer, spelt and khorasan) and spontaneous sourdough fermentation on the bioaccessibility of total phenolic content (TPC) and the DPPH antioxidant capacity evolution during breadmaking and in vitro digestion. Sourdough and yeast-fermented modern wheat breads were used as controls. After 6 h of fermentation, the total titrable acidity of the sourdough increased from 139 to 167%. The wheat variety, type of fermentation and processing affected TPC, antioxidant activity and bioaccessibility. Antioxidant activity and TPC were reduced by dough mixing, increased after sourdough fermentation and slightly decreased or remained the same after baking. Although wheat flour had the highest TPC, the modeling of TPC kinetic revealed that emmer and spelt sourdough exhibited a higher bound phenolics release rate due to the higher acidity, which contributed to increased phenolics solubility. Although wheat bread, both before and after digestion, had the lowest TPC, especially the one prepared with yeast, high TPC bioaccessibilities and antioxidant activities after the digestion suggested that, except phenolics, digestion process improved the release of additional compounds with different bioaccessibility and biological activity. The results of this study proved that the application of sourdough fermentation can increase the potential of ancient wheats in the developing of functional bakery products.

Chia Seed Hydrogel as a Solid Fat Replacer and Structure Forming Agent in Gluten-Free Cookies.

Gluten-free cookies based on rice and chickpea flour with reduced-fat and increased protein content compared with conventional commercial gluten-free cookies were developed and used as a base for further vegetable fat replacement with chia seed hydrogel. Rheological properties of chia seed hydrogel revealed that 8% gels exhibited the optimal properties as a fat substitute. Designed cookie samples were characterized for their chemical composition, fatty acid profile, mineral content, physical, textural and color parameters, and sensory properties. All gluten-free cookies developed in this study could be labeled as "a source of iron and potassium", while those with chia seed hydrogel and cocoa powder could bear the additional claim "high in zinc and magnesium". Fat replacement with chia seed hydrogel resulted in a more favorable fatty acid composition with a PUFA/SFA ratio over 0.40 and nonsignificant changes in the cookies' hardness, weight, eccentricity, and specific volume, indicating that the chia seed hydrogel addition did not disturb the cookie structure and texture. The results of the sensory analysis confirmed that it is possible to apply chia seed hydrogel to produce reduced-fat cookies with sensory properties comparable to their full-fat counterpart and available commercial samples, and they are more appealing than commercial reduced-fat gluten-free cookies.

Physicochemical Changes of Heat-Treated Corn Grain Used in Ruminant Nutrition.

Cereal grain is processed using different combinations of heat, moisture, time, and mechanical action in order to improve its digestibility. The objective of the present research was to quantitatively represent the physicochemical properties of raw and processed starch using an in vitro methodology, as well as to describe the changes that occurred after heat treatment, such as pelleting, steam flaking, micronization, and extrusion of corn. Based on the obtained results, pelleting, steam flaking, and micronization can be considered as mild heat treatment methods, whereas extrusion proved to be a severe heat treatment method. Analysis of functional and pasting properties implied a possible interaction between the degraded components in the steam-flaked sample, as well as in the micronized sample, through to a lesser extent. Additionally, the occurrence of dextrins was noted after extrusion. The obtained results indicate the existence of significant differences in the physicochemical properties of corn starch depending on the heat treatment applied, which could possibly affect rumen starch degradation traits.

Effect of Sourdough and Whey Protein Addition on the Technological and Nutritive Characteristics of Sponge Cake.

Whey protein and sourdough ferment were used in different combinations to prepare functional sponge cakes, and their mutual influence on batter rheological behaviour as well as product physico-chemical, textural, colour and sensory properties were evaluated. All samples containing whey protein concentrate could bear the nutrition claim 'a source of protein'. The substitution of wheat flour with whey protein significantly influenced batter viscoelastic behaviour, lowered cake-specific volume, increased product hardness, chewiness, gumminess, and browning index and modified its sensory characteristics. The incorporation of sourdough in protein-enriched sponge cakes improved product-specific volume and appearance compared to a protein-containing sample without sourdough. Although sourdough addition has less of a deteriorating effect on sponge cake rheological and textural properties, when combined with whey protein, it led to a significant reduction in batter elasticity and an increase in product hardness. It was also shown that spontaneously fermented sourdough cannot act as the only leavening agent in sponge cake production. In general, the results of this study have shown that sourdough addition can contribute to improvement in protein-enriched sponge cake quality and that further investigations are necessary in terms of different sourdough and flour type incorporation to minimize the negative effects of protein addition.

Gluten-Free Crackers Based on Chickpea and Pumpkin Seed Press Cake Flour: Nutritional, Functional and Sensory Properties.

Research background: Despite the growing trend of the gluten-free market and the presence of a wide range of gluten-free products, there are still some shortcomings in nutritional and sensory quality of these products. The commercially available gluten-free products are characterised as products of inferior nutritional quality, particularly in terms of protein and dietary fibre content and with high glycaemic index. On the other hand, from a sensory point of view, gluten-free products usually have inappropriate textural and mechanical properties, poor mouthfeel and flavour. This is a consequence of the limiting choice of raw materials that mainly possess large amount of carbohydrate components. Experimental approach: Chickpea flour and two types of pumpkin seed press cake flour (virgin and cold pressed), at two substitution mass fractions (20 and 35%), were blended to produce gluten-free crackers without the presence of conventional gluten-free starch-rich ingredients. This study aims to investigate the effect of these non-conventional flours on nutritional and physicochemical properties, sensory acceptability, antioxidant activity and glycaemic index of crackers. Results and conclusions: All produced crackers can bear nutritional claims 'high fibre', 'source of protein' and 'source of minerals'. Replacing chickpea flour with pumpkin seed press cake flour increased protein and total phenolic content and enhanced antioxidant activity. The selected combination of raw materials allows the production of gluten-free crackers with a moderate glycaemic index. Besides nutrient content, the addition of cold-pressed flour increased overall sensory acceptability, noticeably improving taste and flavour scores compared to the control and crackers with virgin pumpkin seed flour. Novelty and scientific contribution: To the best of our knowledge, there is no study investigating the use of chickpea and pumpkin seed press cake flour blend without using conventional gluten-free flour and starch. The used non-conventional flour represents complementary raw materials in terms of protein quality and valuable alternatives to produce nutrient-rich, health-promoting gluten-free crackers with reduced glycaemic response and acceptable sensory properties.

High-Protein Bar as a Meal Replacement in Elite Sports Nutrition: A Pilot Study.

This study was focused on the creation of high-protein bars formulated using whey protein isolate (24%) and soy protein isolate (6%) as the sources of proteins; oat flakes and inulin, both abundant in dietary fibres, and creatine monohydrate and other minor ingredients (vitamin and mineral mixture, potassium sorbate) to achieve the requirements for a meal replacement formula for physically active people. The nutritional profile of the high-protein bar was examined (energy 1215 kJ/288 kcal; protein 34.1 ± 0.20 g, fat 6.01 ± 0.13 g of which was saturated 3.12 ± 0.08 g, fibre 3.10 ± 0.17 g carbohydrate 23.0 ± 0.16 g of which sugars 1.50 ± 0.19 g and starch 21.5 ± 0.11 g in 100 g), and sensory properties with instrumental parameters (texture and colour) were determined and compared with bars commercially available on the market. The created high-protein bar was sensorily acceptable in comparison to other commercially available bars. The dietary intervention study was conducted on elite athletes (professional handball players) to evaluate effects of created versus control bar consumption on their metabolic parameters. The baseline characteristics (mean age, body mass index (BMI), fat mass, muscle mass, lean mass and fat percentage) of the athletes (8) were determined at the start of the study. The cross-over intervention study was organized in two successive phases (5 days each) with a seven-day long washout period between phases. Bars were consumed after the afternoon training unit. Blood samples were collected at the start and the end of the intervention study to analyse the metabolic profiles of the athletes. Serum levels of high-density cholesterol (HDL), low-density cholesterol (LDL) and total cholesterol (HOL), glucose, triacylglycerides (TAG), total and direct bilirubin, creatine kinase (CK), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were measured. The results showed that bar consumption significantly decreased serum aspartate transaminase (AST) and lactate dehydrogenase (LDH) and increased total and direct bilirubin levels, suggesting lower exercise-induced muscle damage and increased antioxidative response, respectively. Therefore, it can be concluded that the consumption of the created high-protein bar was able to improve physiological adaptation after training.

A comprehensive study of parameters correlated with honey health benefits.

One hundred honey samples of different floral origin (acacia, sunflower, meadow, and forest) collected from nine European countries (Serbia, Albania, Croatia, Montenegro, Romania, Bulgaria, Bosnia and Herzegovina, North Macedonia and Hungary) were analysed for various physicochemical, sensory, antioxidant and antibacterial parameters. The relative antioxidant capacity index and relative antibacterial index were calculated, integrated and expressed as a new property - Power of Honey, intended to be used to predict the health potential of a honey based on its antioxidant and antibacterial activities. Free acidity and colour coordinates L* and a* were chosen for building an artificial neural network model for the prediction of honey health potential. These were chosen based on the obtained correlations between the investigated parameters and in light of the simplicity of the analysis. This model successfully predicted the Power of Honey with a gained coefficient of determination of 0.856. Forest honey samples exhibited the highest Power of Honey. This novel approach should make it possible for honey producers to predict the honey health potential of a particular honey based on a quick and simple analysis.

Fiber concentrates from raspberry and blueberry pomace in gluten-free cookie formulation: Effect on dough rheology and cookie baking properties.

Raspberry and blueberry pomace, by-products from fruit juice industry, were dehydrated to obtain fruit fiber concentrates and valorized as ingredients in gluten-free (GF) cookies formulation. The aim was to evaluate the effect of substituting 30% (w/w) of GF flour mixture with different ratios of blueberry/raspberry fiber concentrates (0/30, 15/15, and 30/0) on rheological properties of cookie dough and cookie baking quality. Generally, the incorporation of the fiber concentrates increased the elastic and the viscous moduli thus producing harder doughs and consequently firmer cookies in comparison to the control. Although having similar total, soluble and insoluble fiber content, blueberry fiber concentrates were characterized with higher water absorption capacity and consequently yielded cookies with more rigid dough structure, higher water loss during baking, lower cookie thickness, higher spread ratio, more dense inner structure, and increased cookie hardness than those containing raspberry fiber concentrates. Enrichment of GF cookies with raspberry and blueberry fiber concentrates resulted in products with dietary fiber content higher than 6 g per 100 g, thus making them candidates for bearing "high fiber" nutrition claim. PRACTICAL APPLICATIONS: Currently available GF bakery products mostly lack dietary fibers (DFs) and other important nutrients, because they are usually manufactured from refined flour and/or starches. As the products with long shelf-life, very popular in daily diet of almost all consumer profiles, cookies could represent good matrices for the addition of functional ingredients, such as DFs. In this paper, GF cookies were enriched with the fiber concentrates recovered from blueberry and raspberry pomace. Application of these fiber sources enabled recycling of fruit processing industry by-products into novel, "high fiber" GF product with improved nutritive profile.

Predicting rheological behavior and baking quality of wheat flour using a GlutoPeak test.

The purpose of this research was to gain an insight into the ability of the GlutoPeak instrument to predict flour functionality for bread making, as well as to determine which of the GlutoPeak parameters show the best potential in predicting dough rheological behavior and baking performance. Obtained results showed that GlutoPeak parameters correlated better with the indices of extensional rheological tests which consider constant dough hydration than with those which were performed at constant dough consistency. The GlutoPeak test showed that it is suitable for discriminating wheat varieties of good quality from those of poor quality, while the most discriminating index was maximum torque (MT). Moreover, MT value of 50 BU and aggregation energy value of 1,300 GPU were set as limits of wheat flour quality. The backward stepwise regression analysis revealed that a high-level prediction of indices which are highly affected by protein content (gluten content, flour water absorption, and dough tenacity) was achieved by using the GlutoPeak indices. Concerning bread quality, a moderate prediction of specific loaf volume and an intense level prediction of breadcrumb textural properties were accomplished by using the GlutoPeak parameters. The presented results indicated that the application of this quick test in wheat transformation chain for the assessment of baking quality would be useful. PRACTICAL APPLICATIONS: Baking test is considered as the most reliable method for assessing wheat-baking quality. However, baking test requires trained stuff, time, and large sample amount. These disadvantages have led to a growing demand to develop new rapid tests which would enable prediction of baked product quality with a limited flour size. Therefore, we tested the possibility of using a GlutoPeak tester to predict loaf volume and breadcrumb textural properties. Discrimination of wheat varieties according to quality with a restricted flour amount was also examined. Furthermore, we proposed the limit values of GlutoPeak parameters which would be highly beneficial for millers and bakers when determine suitability of flour for end-use.

Optimization of additive content and their combination to improve the quality of pure barley bread.

The objective of this study was to model the influence of pregelatinized OSA starch (OSA), wheat gluten (Gl) and xylanase (Xyl) on breadmaking potential of barley flour by using response surface methodology. Addition of these ingredients had significant effect on specific bread volume, crust and crumb lightness, crumb texture, average cell size and crumb density. OSA showed the most pronounced effect on specific bread volume, average cell size, crumb density and hardness. Interaction between OSA and Gl, as well as Gl and Xyl, respectively, increased and decreased the specific bread volume and crumb chewiness, while the interaction between OSA and Xyl decreased the specific volume decrease and increased crumb chewiness. An optimal barley bread formulation appeared to be the one containing 9.68% OSA, 2.0% Gl and 4.51 g/100 kg Xyl. This optimal barley bread formulation predicted an increment of 14-28% in volume and a decrease of 105-217% in crumb chewiness in comparison to formulations containing medium amounts of improvers (1% Gl, 5% OSA, 2.5 g/100 kg Xyl).

Antioxidant Capacity, Mineral Content and Sensory Properties of Gluten-Free Rice and Buckwheat Cookies.

Light buckwheat flour was used to substitute rice flour at the level of 10, 20 and 30% to produce gluten-free cookies. The substitution of gluten-free cookie formulation with light buckwheat flour contributed to the significantly higher mineral content, especially magnesium, potassium, iron and copper, in comparison with the control rice cookies (p<0.05). Gluten-free cookies made with rice flour and buckwheat flour exhibited significantly higher total phenolic and rutin content, scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH•), antioxidant activity and reducing power than the control cookies (p<0.05). Comparing all evaluated sensory properties, cookies containing 20% of light buckwheat flour had the most acceptable sensory properties. The obtained results of principal component analysis showed that the cookies with 20 and 30% buckwheat flour had better antioxidant and sensory properties in comparison with other two cookie samples.

Changes in the rheological properties of wheat dough during short-term storage of wheat.

BACKGROUND: The aim of the present study was to investigate the ability of the small- and large-deformation fundamental rheological tests to monitor the changes during short-term post-harvest storage of wheat. RESULTS: At the end of wheat storage period, wet gluten quantity decreased, while gluten index increased in comparison to those of freshly harvested samples. The rheological properties of dough changed over the pre-defined period of storage in terms of becoming more elastic and less extensible in comparison to that of freshly harvested wheat. Visco-elastic properties of weaker flour samples changed more markedly during storage than those of stronger flours, indicating that the intensity of dough rheological changes during wheat storage might be dependent on gluten quality and were the characteristic of wheat variety. CONCLUSION: It was shown that small deformation dynamic oscillation and large deformation creep-recovery tests can be successfully employed to monitor the changes in flour quality during wheat storage and that required storage period after wheat harvesting has to be defined according to wheat variety initial rheological properties and its gluten quality.

Characterization of byproducts originating from hemp oil processing.

Valorization of hemp seed meal, a byproduct of hemp oil processing, was performed by measuring the distribution of nutritional and antinutritional compounds in different hemp seed meal fractions. According to chemical composition, two cotyledon-containing fractions (>180 and <180 µm) were significantly richer in protein (p < 0.05) (41.2% ± 0.04% and 44.4% ± 0.02%, respectively), lipid (15.1% ± 0.02% and 18.6% ± 0.04%, respectively), and sugar content (4.96% ± 0.11% and 3.46% ± 0.08%, respectively) in comparison to the hull-containing fractions (>350 and >250 µm), which were significantly richer in crude fiber content (29.5% ± 0.04% and 21.3% ± 0.03%, respectively). The free radical scavenging capacity (IC50) of fraction extracts increased (p < 0.05) with increasing mean particle size (from 17.18 ± 0.59 to 5.29 ± 0.30 mg/mL). Cannabisin B and N-trans-caffeoyltyramine were the most abundant phenolic compounds in the hull fractions (from 267 ± 15.9 to 287 ± 23.1 mg/kg), while cotyledon fractions had higher content of catechin (from 313 ± 12.4 to 744 ± 22.2 mg/kg) and p-hydroxybenzoic acid (from 124 ± 6.47 to 129 ± 8.56 mg/kg (P < 0.05). Well-balanced ω-6 to ω-3 fatty acid ratio (3:1) was determined in all fractions. Antinutrients (trypsin inhibitors, phytic acid, glucosinolates, and condensed tannins) were mostly located in the cotyledon fractions. These findings indicate that the separation of hemp seed meal into different fractions could be used to concentrate valuable target compounds and consequently facilitate their recovery.

Content of free amino groups during postharvest wheat and flour maturation in relation to gluten quality.

The objective of this study was to monitor the changes in the content of free amino groups during postharvest wheat and flour maturation. The content of free amino groups of wheat flour was analysed immediately after wheat harvest, after 50 days of wheat storage and after 14 days of flour storage varying by wet gluten samples incubation temperatures and incubation times (0, 90 or 135 min at 30°C and after that 180 min at 37°C). The results were observed in relation to wheat-bug damaged kernels content, gluten index values, proteolytic activity and electrophoretic properties of gliadins and glutenins. The content of free amino groups increased during postharvest wheat and flour maturation periods. Proteolytic activity values were the highest 50 days after the wheat storage. The electrophoretic determination indicated a macromolecular redistribution of the gluten proteins from the moment of the wheat harvest until the moment of flour stabilisation.