Authors:Katarzyna Niespodziana, Karolina Jurczyk, and Mieczyslaw Jurczyk
Hydroxyapatite (HA, Ca
shows excellent biocompatibility, so it can be the most suitable ceramic
material for hard tissue replacement implants. On the other hand, due to its
low mechanical properties, HA cannot be used for heavy applications. The combination
of good biocompatibility of hydroxyapatite and excellent mechanical properties
of titanium is a good candidate way to expand the biomedical applications. The
aim of this study was to develop new titanium-hydroxyapatite nanocomposites for
biomedical applications. Bulk nanocomposites with different HA contents were
successfully prepared by the combination of mechanical alloying (MA) and powder
metallurgical process. The structure, mechanical and corrosion properties of
these materials were investigated. The
results show an enhancement of properties due to the nanoscale structures in
bulk consolidated materials. For example, Vickers' hardness of Ti-10 vol% HA
composite is higher than of pure microcrystalline Ti metal (250 HV) and reaches
1300 HV. On the other hand, the Ti-10 vol% HA composite is more corrosion
= -0.48) than the microcrystalline titanium (
= -0.47). Titanium-hydroxyapatite bulk structures are
promising biomaterials for the use as replacement
Authors:X.L. Jiang, G.F. Chen, X.J. Li, G. Li, Z.G. Ru, and J.C. Tian
This study aimed to clarify the genetic mechanisms behind wheat flour color. Flour colorrelated traits (L*, a*, and b*) and polyphenol oxidase (PPO) activity are important parameters that influence the end-use quality of wheat. Dissecting the genetic bases and exploring important chromosomal loci of these traits are extremely important for improving wheat quality. The diverse panel of 205 elite wheat varieties (lines) was genotyped using a highdensity Illumina iSelect 90K single-nucleotide polymorphisms (SNPs) assay to disclose the genetic mechanism of flour color-related traits and PPO activity. In 2 different environments and their mean values (MV), 28, 30, 24, and 12 marker-trait associations (MTAs) were identified for L*, a*, b* traits, and PPO activity, respectively. A single locus could explain from 5.52% to 20.01% of the phenotypic variation for all analyzed traits. Among them, 5 highly significant SNPs (P ≤ 0.0001), 11 stable SNPs (detected in all environments) and 25 multitrait MTAs were identified. Especially, BS00000020_51 showed pleiotropic effects on L*, a*, and b*, and was detected in all environments with the highest phenotypic contribution rates. Furthermore, this SNP was also found to be co-associated with wheat grain hardness, ash content, and pasting temperature of starch in previous studies. The identification of these significantly associated SNPs is helpful in revealing the genetic mechanisms of wheat colorrelated traits, and also provides a reference for follow-up molecular marker-assisted selection in wheat breeding.
Authors:Z. Kohajdová, J. Karovičová, and M. Jurasová
Dietary fibre rich powder obtained from grapefruit by-products was analysed for its chemical composition and functional properties. The results revealed that grapefruit powder contained 50.39% of total dietary fibre, 17.36% of pectin substances, 6.65% of proteins, and 2.77% of fats. Grapefruit powder also exhibited good hydration properties (water holding, water retention, and swelling capacity), whereas its fat absorption capacity and emulsifying activity were very low. The effect of grapefruit powder as partial substitution of wheat flour in biscuit making (substitution levels 5, 10, and 15%) on the farinographic properties of wheat dough, physical characteristics, and sensory parameters of produced biscuits were also investigated. It was observed that increasing the level of grapefruit powder in dough increased water absorption and dough development time, while dough stability and mixing tolerance index decreased. Physical characteristics of biscuits (specific volume, volume index, width, thickness, and spread ratio) significantly decreased with the increasing level of grapefruit powder in biscuits. Biscuits containing 5% of grapefruit powder were the most acceptable for assessors, higher levels of grapefruit powder in biscuits negatively affected overall acceptance presumably due to the high intensity of bitter taste and increased hardness of biscuits.
Physical properties of maize were evaluated as a function of moisture content. The obtained data provide help in the designing of post-harvest handling machinery. In the moisture range of 10–18% wet basis (w.b.), the length of the rewetted grain increased from 10.01 to 10.65 mm, width increased from 8.57 to 8.70 mm, thickness ranged from 4.63 to 4.97 mm, geometric mean diameter (GMD) increased from 7.34 to 7.67 mm, sphericity increased from 0.72 to 0.73, thousand kernel weight (TKW) increased from 258.1 to 287.9 g, bulk density decreased from 591.6 to 554.2 kg m−3, true density increased from 1194.9 to 1267.2 kg m−3, porosity increased from 52.61 to 56.27%, hardness decreased from 293.75 to 228.04 N, initial cracking force decreased from 190.11 to 137.35 N and area ranges from 55.09 to 36.58 Nmm. In the same moisture range the angle of repose varied from 23.36 to 28.55 for grain. Lightness (L) of grain ranges from 62.82 to 59.26, a value (red-green axis) ranges from 13.97 to 8.96, b value (yellow-blue axis) ranges from 31.05 to 26.19 and hue angle (z%) decreased from 14.59 to 14.06 with increase in moisture content of grain from 10 to 18% w.b.
Authors:S. Ferenczi, Zs. Cserhalmi, B. Visnyei, V. Szűcs, and B. Czukor
Microwave vacuum drying is a novel and mild food preserving technology. Beside its basic preserving function, it can be combined with other technologies, like hot-air drying. As a result of this combination, special snack can be produced from apple. The product is characterized by its unique consistency, high nutritional value, and consumer preference. In this work physical (dry mass content, hardness, bulk density, and colour), sensory (appearance, colour, odour, taste, texture) and nutritional (antioxidant activity and total phenolics) properties of dried apple snack were investigated as a function of pre-drying, microwave energy input, and batch weight. For evaluation of data, central composite experimental design was applied. According to the results, the physical properties of products produced by microwave vacuum drying combined with hot-air pre-drying (CMVD) mainly depend on the specific energy input. Higher specific energy input results higher dry mass content, which is associated with harder consistency, lower bulk density, and positive consumer perception as well. Bulk density had an optimum point of batch weight at 336 g. Higher value of pre-dried dry mass content resulted lighter colour but less antioxidant activity and less total phenolics, therefore shorter hot-air drying and prolonged microwave vacuum drying is recommended.
Refined olive oil (ROO) was blended with tristearin (TS) and palm oil (PO) at two different ratios (ROO:TS:PO; 75:15:10 and 85:10:5) and chemical interesterification was performed in order to produce two interesterified fats (IF1 and IF2) with high unsaturated fatty acids and low trans fatty acids contents.
Solid fat content (SFC), slip melting point (SMP), and fatty acid composition were determined in IF1 and IF2; the values were compared to that of partially hydrogenated industrial cookie shortening (ICS). Higher SMP was measured in interesterified fats contaning 75% ROO (IF1) and lower SMP was obtained in interesterified fats containing 85% ROO (IF2). SFC values of interesterified ROO blended oils were lower than ICS. Interesterified fats were used for cookie production, and cookie quality parameters, including oxidation stability, were determined.
Results showed that hardness values of cookies were not affected by fat types and higher spread ratios and lighter colors were obtained. IF1 and IF2 had higher total oxidation values as compared to ICS.
Authors:L. Darnay, A. Tóth, B. Salamon, K. Papik, G. Oros, G. Jónás, K. Horti, K. Koncz, and L. Friedrich
The aim of this study was to show how microbial transglutaminase (mTG) can be used as an effective texture-modifier for two popular Hungarian products: Trappist cheese and frankfurter. In both cases we investigated how components of these products, milkfat in cheese and phosphate in frankfurter, can be substituted by mTG. Therefore, Trappist cheese samples were produced from cow milk of 2.8%, 3.5%, and 5% milk fat. The effect of ripening was evaluated with Texture Profile Analysis (TPA) and sensory evaluation (scoring test, 10 trained panellists). Springiness and cohesiveness values were significantly higher by enzyme-treated semi-hard cheese samples at lower milk fat levels. Sensory evaluation showed that the enzyme-treatment led to higher scores by cheese samples made from cow milk of 3.5% and 5% milk fat. Frankfurter was made with 0.1%, 0.3%, 0.5%, and 0.7% tetrasodium pyrophosphate, and partly enzyme-treated with 0.2% commercial mTG enzyme preparation. Our results showed that mTG is able to significantly improve hardness and crunchiness by frankfurters made with 0.1% phosphate addition. Our sensory evaluation suggests that mTG and phosphate should be applied in combination in order to have a final product with recognisably more homogeneous texture.
Milk and dairy products are high-value foods; however, consumers suffering from lactose intolerance are not able to enjoy the nutritional benefits of these commodities. There are more and more researches and developments focusing on lowering the lactose content of milk and dairy foods in order to make them available for lactose intolerant people. In this study, we examined the coagulation time, product quality, texture profile properties, and syneresis of yoghurts prepared from lactose-free milk. Significant differences were observed between the control and lactose-free milks with respect to coagulation time and texture profile. The first rupture time, the hardness, and the adhesion force of the lactose-free yoghurt were higher compared to the control product. We observed remarkable difference between the whey leakage of control and lactose free yoghurt samples (21.47% and 14.63%). Results coming from instrumental texture profile analyses showed that the preliminary lactose hydrolysis of milk resulted a firmer texture. It was confirmed by the results of sensory evaluation, and considering the texture and taste, there was significant difference between the control and lactose-free yoghurts.
Authors:V. Valenčič, M. Bučar-Miklavčič, and T. Golob
Table olives are prepared from the sound fruits of varieties of the cultivated olive tree (
L.) that are chosen for their production of olives whose volume, shape, flesh-to-stone ratio, fine flesh, taste, firmness and ease of detachment from the stone make them particularly suitable for processing. The world production in the crop year 2006/2007 is estimated at 1.8 million tons of table olives and in the last fifteen years it has constantly increased. Most of the Slovenian Istria table olive production is based on a modification of the Spanish style. Results of qualitative and quantitative sensory assessments of two olive cultivars, ‘Storta’ and ‘Istrska belica’, are presented. Sensory characteristics were determined after four and six months of fermentation. Texture differences between the two production systems were revealed. Significant decrease in hardness was determined after six months of fermentation with initial alkaline treatment. The effect of cultivar type was also evident. After four and six months, the bitterness of table olives produced by the traditional technology decreased and the olives were appropriate for consumption.
An extruded product was made based on oats and dried green pea using central composite rotatable design. Effects of incorporation level of oat flour (OF, 15.86 to 44.14%) and dried green pea flour (DGPF, 7.93 to 22.07%) on the physical and functional characteristics of extruded products based on composite flour were studied using response surface methodology. Second order polynomial equation was used to describe the effect of OF and DGPF on lateral expansion (LE), bulk density (BD), water solubility index (WSI), water absorption index (WAI), and hardness (HD). Results indicated that OF had negative effect on LE, while positive effect on BD, WSI, WAI, and HD. On increasing DGPF, LE and WSI increased, but it had negative effect on BD, WAI, and HD. Numerical optimization resulted in 41.91% OF and 7.93% DGPF to produce acceptable extrudates. The results suggest that oats and dried green pea flour can be extruded with rice flour and corn flour into an acceptable snack food.