Characterization of proteins from grain of different bread and durum wheat genotypes

The classical Osborne wheat protein fractions (albumins, globulins, gliadins, and glutenins), as well as several proteins from each of the four subunits of gliadin using SDS-PAGE analyses, were determined in the grain of five bread (T. aestivum L.) and five durum wheat (T. durum Desf.) genotypes. In addition, content of tryptophan and wet gluten were analyzed. Gliadins and glutenins comprise from 58.17% to 65.27% and 56.25% to 64.48% of total proteins and as such account for both quantity and quality of the bread and durum wheat grain proteins, respectively. The ratio of gliadin/total glutenin varied from 0.49 to 1.01 and 0.57 to 1.06 among the bread and durum genotypes, respectively. According to SDS-PAGE analysis, bread wheat genotypes had a higher concentration of α + β + γ-subunits of gliadin (on average 61.54% of extractable proteins) than durum wheat (on average 55.32% of extractable proteins). However, low concentration of ω-subunit was found in both bread (0.50% to 2.53% of extractable proteins) and durum (3.65% to 6.99% of extractable proteins) wheat genotypes. On average, durum wheat contained significantly higher amounts of tryptophan and wet gluten (0.163% dry weight (d.w.) and 26.96% d.w., respectively) than bread wheat (0.147% d.w. and 24.18% d.w., respectively).

Acrylamide in Corn-Based Thermally Processed Foods: A Review

Widely consumed thermally processed corn-based foods can have a great contribution to acrylamide dietary intake, thus bearing a high public health risk and requiring attention and application of strategies for its reduction. This paper reviews the literature on the acrylamide content of corn-based food products present in the market around the world. The potential of corn for acrylamide formation due to its content of free asparagine and reducing sugars is described. Human exposure to acrylamide from corn-based foods is also discussed. The content of acrylamide in corn/tortilla chips, popcorn, and corn flakes, as widely consumed products all over the world, is reported in the literature to be between 5 and 6360 μg/kg, between <LOD and 2220 μg/kg and between <LOD and 1186 μg/kg, respectively. Although these products are important acrylamide sources in the common diet of all age populations, higher intake values occurred among younger generations.

Microencapsulation of anthocyanin-rich black soybean coat extract by spray drying using maltodextrin, gum Arabic and skimmed milk powder

Black soybean coat is insufficiently valorised food production waste rich in anthocyanins. The goal of the study was to examine physicochemical properties of spray dried extract of black soybean coat in regard to carrier materials: maltodextrin, gum Arabic, and skimmed milk powder. Maltodextrin and gum Arabic-based microparticles were spherical and non-porous while skimmed milk powder-based were irregularly shaped. Low water activity of microparticles (0.31-0.33), good powders characteristics, high solubility (80.3-94.3%) and encapsulation yields (63.7-77.0%) were determined. All microparticles exhibited significant antioxidant capacity (243-386 μmolTE/g), good colour stability after three months of storage and antimicrobial activity. High content of total anthocyanins, with cyanidin-3-glucoside as predominant, were achieved. In vitro release of anthocyanins from microparticles was sustained, particularly from gum Arabic-based. These findings suggest that proposed simple eco-friendly extraction and microencapsulation procedures could serve as valuable tools for valorisation and conversion of black soybean coat into highly functional and stable food colourant.

Effects of enzyme activities during steeping and sprouting on the solubility and composition of proteins, their bioactivity and relationship with the bread making quality of wheat flour

The aim was to determine the effect of steeping and sprouting on wheat grain proteins and the functional consequences in this regard.

Free asparagine and sugars profile of cereal species: the potential of cereals for acrylamide formation in foods

Cereals-based food is one of the major source of Maillard reaction products in the diet. Free amino acids and reducing sugars are considered to be the main precursors in the formation of these heat-induced compounds. In order to determine genetic resources with reduced potential for acrylamide formation, the content of sugars as well as free asparagine were analysed in a total of 30 cultivars of 10 varieties belonging to eight species (Triticum aestivum var. lutescens, T. aestivum var. alba, T. aestivum var. compactum, T. durum, T. spelta, T. dicoccum, Secale cereale, Hordeum vulgare var. nudum, Avena sativa var. nudum, and Zea mays var. indentata) grown at the same location in the 2015 growing season. Our results provide evidence of differences in the content of sugars and asparagine between and within species of small grain cereals and maize. The highest content of glucose, fructose and asparagine was found in cultivars of rye and hull-less oat. All maize varieties examined contained significantly higher amounts of non-reducing and total sugars (on average 1.25% and 2.36%, respectively) than small cereal grain species. Principal component analysis showed a high positive correlation between monoreducing sugars and asparagine in bread wheat, durum wheat and hull-less barley.

Investigations on the formation of Maillard reaction products in sweet cookies made of different cereals

In this study, the content of Maillard reaction products from its initial, intermediate and final stage (5-hydroxymethylfurfural, α-dicarbonyl compounds, furosine, N-ε-carboxymethyllysine and N-ε-carboxyethyllysine) was measured in sweet cookies made of wholegrain flour of eight genotypes of small-grain cereals (bread wheat, durum wheat, soft wheat, hard wheat, triticale, rye, hulless barley and hulless oat) and four corn genotypes (white-, yellow- and red-colored standard seeded corn and blue-colored popping corn). Furthermore, the effect of the initial content of sugars, total proteins, free and total lysine in flour on the formation of Maillard reaction products was investigated using the principle component analysis. 3-deoxyglucosone was the predominant α-dicarbonyl compound in all cereal cookies and the highest content was measured in those made from flour of different colored corn genotypes (on average, 98.35, 151.28 and 172.85 mg/kg after baking for 7, 10 and 13 min, respectively). Heating dough at 180 °C for 7, 10 and 13 min differently affected the content of 5-hydroxymethylfurfural and α-dicarbonyl compounds in the cereal cookies. The 5-hydroxymethylfurfural content gradually increased, while a reduction in 3-deoxyglucosone content was observed in the cookies baked for 13 min except for those made from soft wheat, hulless oat, red- and blue-colored corn. After 7 min of heating, the content of furosine measured in the cereal cookies reached its maximum (from 320.9 mg/kg in yellow-colored corn-based cookies to 585.7 mg/kg in hulless oat-based cookies), while N-ε-carboxymethyllysine and N-ε-carboxyethyllysine showed the opposite trend. The highest content of advanced glycation end products was detected in cookies also made from hulless oat flour rich in proteins (16.80%) and total lysine (10670.3 mg/kg). The interrelationship analysis showed that the initial content of sugars in flour of cereals affected 5-hydroxymethylfurfural and 3-deoxyglucosone formation in the cookies. In addition, a high correlation between protein-bound Maillard reaction products in the cookies and the total proteins and the total lysine content in the flours was found.

Thermal Inactivation of Soybean Bioactive Proteins

Inactivation of trypsin inhibitor, lipoxygenase 1, and urease during the processes of dry extrusion, wet extrusion, micronisation, microwave roasting and autoclaving were studied. Cultivars Bosa, ZPS 015, Goyou Kurakake and L93-7290 were used in the experiment. Depending on a technological procedure of processing, kernels were exposed to temperatures from 57 to 150 oC for different time: from 25-30 sec in the process of dry and wet extrusion, to 30 min in autoclaving. The process of dry extrusion had the greatest influence on reduction of the trypsin inhibitor content and inactivation of urease and lipoxygenase 1. During the dry extrusion at 100 oC trypsin inhibitor declined by 74.2 % and the residual activity of a lipoxygenase 1 and urease was only 0.76 i.e. 0.55 %, respectively. Lipoxygenase 1 was the most heat labile enzyme, followed by urease and than trypsin inhibitor.

Microencapsulates of Blue Maize Polyphenolics as a Promising Ingredient in the Food and Pharmaceutical Industry: Characterization, Antioxidant Properties, and In Vitro-Simulated Digestion

An anthocyanin-rich blue maize waste product was used for anthocyanin extraction. To preserve bioactive phenolic compounds, a spray-drying technique was employed using conventional wall material maltodextrin (MD), with novel one, hydroxypropyl-β-cyclodextrin (HPBCD). The obtained spray-dried maize extract (SME) and microencapsulates were analyzed based on physicochemical powder properties, chemical analysis, antioxidant activity, and digestibility. The examined microencapsulates demonstrated good powder properties, exhibited a high powder yield (up to 83%), and had a low moisture content (less than 5%). HPBCD and MD + HPBCD combinations demonstrated superior powder properties in the terms of decreasing the time necessary for rehydration (133.25 and 153.8 s, respectively). The mean average particle diameter ranged from 4.72 to 21.33 µm. DSC analyses signified high powder thermal stability, around 200 °C, related to the increasing preservation with biopolymer addition. The total phenolic and anthocyanin compounds ranged from 30,622 to 32,211 mg CE/kg (CE-catechin equivalents) and from 9642 to 12,182 mg CGE/kg (CGE-cyanidin 3-glucoside equivalents), respectively, associated with good bioactive compound protection. Microencapsulates with both carriers (15% MD and 15% HPBCD) had the highest digestibility (73.63%). Our results indicated that the microencapsulates created with the active ingredient and the wall materials (MD and HPBCD) could protect phenolic compounds/anthocyanins against ABTS radicals (63.53 and 62.47 mmol Trolox Eq/kg, respectively).

Black soya bean and black chia seeds as a source of nutrients and bioactive compounds with health benefits

Recent trends in healthy lifestyle and diet made functional foods rich in quality nutrients and bioactive compounds with potential health benefits highly sought after. Some cultivated plants, such as soya and chia can provide a viable source of nutraceuticals with high fibre, protein, and protective antioxidant potential. The whole-grain flours of black soya beans and black chia seeds were used in this study. Potential nutritive and health-benefitting properties of these flours were compared by assessing their chemical composition and antioxidant profile. The content of dietary fibres such as NDF, ADF, ADL and hemicellulose determined in black chia seed sample was higher than in black soya soya beans which had higher fibre content. The total protein content recorded in black soya beans was almost as twice as high (42.26±0.14%) as chia protein content (25.04±0.20%). Black soya beans had the highest content of water soluble proteins (29.00±0.13% d.m.) with NSI (nitrogen solubility index) acounting for as much as 70.96±0.31% of total proteins, while black chia seeds had the highest content of globulins (14.64±0.07% d.m.) and NSI 58.48±0.27% of total proteins. Both black soya bean and black chia contained a high amount of total phenolic compounds (830.66±5.46 and 1201.94±16.29 mg GAE/kg, respectively) and exhibited a considerable total antioxidant capacity, which makes them good contestants for functional food ingredients with potential health benefits.

Properties of different silage maize hybrids

The aim of this study was to observe the properties of ten maize hybrids from Serbia including agronomic traits, lignocellulosic fibre composition and in vitro dry matter digestibility. Five yellow kernel dent hybrids and five analogue red kernel hybrids were used in this study to evaluate the agronomic traits, dry matter content of the whole plant, lignocellulosic fibre composition, ratios between different fibres, in vitro dry matter and NDF digestibility. Correlation coefficients between the investigated traits of the maize hybrids were assessed. Even though the results of our study showed variations regarding nutritional composition of the whole maize plant between the investigated maize hybrids, the hybrid and the differences in kernel colour (yellow or red) did not considerably affect the properties that influence quality of the maize hybrids for silage production. The highest IVDMD was determined in yellow kernel hybrid ZP 388, while the maximum NDFD was detected in the red kernel hybrid ZP 606red which also showed the lowest ADL/NDF and ADF/NDF ratios. The results indicate that all of the hybrids used in this study are good candidates for the production of high-quality silage for ruminant nutrition.

Effect of Ultrasonic and Hydrothermal Treatment on Digestibility and Antioxidant Properties of Whole Wheat Flour with Different Amylose Content§

Research background

The consumption of whole grain cereal flour contributes to increased intake of dietary fibre and phenolic compounds beneficial to human health. However, whole grain flour also has some disadvantages, such as poor baking properties and lower technological quality. Applying ultrasonic and hydrothermal treatments can provide new opportunities to modify and improve the baking and biofunctionality of flour as well as the quality of baked goods.

Experimental approach

The whole grain flour samples of six wheat varieties with different amylose content were studied. The original chemical composition and viscosity profiles of the flour were determined. The flour samples were subjected to ultrasonic treatment at a frequency of 30 kHz and temperature of 40 °C for 10 min and hydrothermal treatment on a magnetic stirrer with heating for 3 min after reaching the boiling point. The treatments were carried out to determine their influence on the studied digestible and antioxidant properties of the flour. A multistep in vitro enzymatic digestibility protocol simulating the digestion process in the human gastrointestinal tract was applied to the untreated and treated whole grain flour samples. Total free phenolic compound content and total antioxidant capacity were also determined.

Results and conclusions

Hydrothermal treatment had a positive effect on the digestibility of the whole grain flour, especially in waxy wheat genotypes compared to those with high amylose content, due to the formation of resistant starch. The hydrothermal treatment had an overall negative effect on the antioxidant capacity of the flour samples, while ultrasonic treatment generally increased the analytical values of total free phenolic compounds by enhancing their extractability. These findings can provide valuable information for the development of new whole wheat foods.

Novelty and scientific contribution

To the best of our knowledge, this type of study of the effects of ultrasound and hydrothermal treatment on the digestibility and antioxidant properties has not yet been performed on whole wheat flour with different amylose content. Waxy and high-amylose wheat varieties are considered novel raw materials because of their unique properties in bread making, such as improved bread texture and increased dietary fibre content.