Rheological and fermentation properties of doughs and quality of breads from colored wheat varieties.

The objective of this study was to examine the rheological and fermentation behavior of doughs prepared from five different colored wheat varieties (black AF Zora, yellow KM 111-18, purple AF Jumiko, blue AF Oxana and red Vanessa - chosen as a standard), which contain polyphenolics in the outer layers of grains. Three wholemeal flour fractions (fine, semi-coarse and coarse) were used for each variety. The flour fractions differed in the particle size of the bran, the ash content and thus the phenolic compound content. The baking trials, texture and sensory analyses of breads were performed, to assess their overall acceptability. The coarser granulation of flour fractions, average hardness (8.5<12.6<20.2 N) and chewiness (584<796<1053 N) of breads increased, while other parameters: springiness (90>87>77%), cohesiveness (78>75>70%) and resilience (35>32>27%) decreased. Moreover, the increase in off-flavors was detected with higher bran content. Regarding the flour granulation, the fine fraction seemed to be the most suitable due to its high gas-retention capacity. The best products in terms of both dough and bread quality reached blue AF Oxana and yellow KM 111-18. Utilization of colored wheat in bakery industry may present a good strategy of providing value-added products to the consumers.

Nanoparticles and Plant By-Products for Edible Coatings Production: A Case Study with Zinc, Titanium, and Silver.

For the development of functional edible packaging that will not lead to rejection by the consumer, it is needed to analyze the interactions between ingredients in the packaging matrix. The aim of this study was to develop edible chitosan-based coatings that have been enriched with red grape extracts, zinc, silver, and titanium nanoparticles. The organoleptic properties of the produced edible packaging were described by quantitative descriptive analysis and consumer acceptability was verified by hedonic analysis. By image analysis, color parameters in the CIELab system, opacity, Whiteness and Yellowness Index were described. The microstructure was described by scanning electron microscopy. The hedonic evaluation revealed that the addition of nanometals and their increasing concentration caused a deterioration in sample acceptability. The overall evaluation was higher than 5 in 50% of the samples containing nanometals. The addition of nanometals also caused statistically significant changes in L*, a*, and b* values. The sample transparency generally decreased with the increasing concentration of nanoparticle addition. Scanning electron microscopy showed, that the addition of nanometals does not disrupt the protective function of the packaging. From a sensory point of view, the addition of ZnO nanoparticles in concentrations of 0.05 and 0.2% appeared to be the most favorable of all nanometals.

Effect of Concentration of Flaxseed (Linum usitatissimum) and Duration of Administration on Fatty Acid Profile, and Oxidative Stability of Pork Meat.

Flaxseed is a common ingredient used for livestock feed. The aim of this work was to study the effect of a diet supplemented with flaxseed at 5% and 10% concentrations in the intervals of 3 and 6 weeks prior slaughter on fatty acid profile and oxidative stability of pork meat. Meat samples were collected after slaughter from each animal (five groups, n = 6). Samples of the musculus longissimus dorsi (MLD) and the musculus gluteobiceps (MGB) were selected. Chemical composition, fatty acid profile and oxidative stability during the storage of meat under chilling conditions (4 °C, 7 days) was analyzed. The addition of flaxseed significantly affected the composition of fatty acid profile and the shelf life of the produced meat. The fat content was changed in the experimental groups with 10% flaxseed supplementation (10.84% in MGB and 9.56% MLD) versus the control group. Despite the different concentrations of flaxseed, the best EPA/AA ratio was observed in the experimental groups fed with flaxseed supplementation for 3 weeks. The worst oxidative stability of meat samples (p < 0.05) was recorded in the experimental groups with the addition of flaxseed for 6 weeks, which was related to higher PUFA content in samples of the experimental groups and higher susceptibility of PUFAs to lipid oxidation. The oxidative stability of meat in the experimental group fed 5% flaxseed supplementation for 3 weeks was not affected.

Identification of pollen taxa by different microscopy techniques.

Melissopalynology is an important analytical method to identify botanical origin of honey. Pollen grain recognition is commonly performed by visual inspection by a trained person. An alternative method for visual inspection is automated pollen analysis based on the image analysis technique. Image analysis transfers visual information to mathematical descriptions. In this work, the suitability of three microscopic techniques for automatic analysis of pollen grains was studied. 2D and 3D morphological characteristics, textural and colour features, and extended depth of focus characteristics were used for the pollen discrimination. In this study, 7 botanical taxa and a total of 2482 pollen grains were evaluated. The highest correct classification rate of 93.05% was achieved using the phase contrast microscopy, followed by the dark field microscopy reaching 91.02%, and finally by the light field microscopy reaching 88.88%. The most significant discriminant characteristics were morphological (2D and 3D) and colour characteristics. Our results confirm the potential of using automatic pollen analysis to discriminate pollen taxa in honey. This work provides the basis for further research where the taxa dataset will be increased, and new descriptors will be studied.

Plant Byproducts as Part of Edible Coatings: A Case Study with Parsley, Grape and Blueberry Pomace.

Studies dealing with the development of edible/biodegradable packaging have been gaining popularity since these commodities are marked as being ecofriendly, especially when byproducts are incorporated. Consequently, this study aimed at the development of chitosan-based coatings with plant byproducts. Their sensory properties, colour attributes, occurrence of cracks in microstructure and biodegradability were analysed. Coatings containing grape and blueberry pomace had statistically significantly (p < 0.05) higher levels of colour intensity. Coating samples were characterised by lower aroma intensity (3.46-4.77), relatively smooth surface (2.40-5.86), and low stickiness (2.11-3.14). In the overall hedonic evaluation, the samples containing parsley pomace in all concentrations and a sample containing 5% grape pomace achieved a statistically significantly (p < 0.05) better evaluation (5.76-5.93). The lowest values of the parameter ΔE2000 were recorded for the sample containing 5% parsley pomace (3.5); the highest was for the sample with 20% blueberry pomace (39.3). An analysis of the coating surface microstructure showed the presence of surface cracks at an 80 K magnification but the protective function of the edible coating was not disrupted by the added plant pomace. The produced samples can be considered to have a high biodegradability rate. The results of our experimentally produced coatings indicate their possible application on a commercial scale.

Detection of Carrageenan in Meat Products Using Lectin Histochemistry.

Carrageenan is a polysaccharide that is widely used in the food industry. Due to its water holding capacity, there is a higher risk of adulteration for economic reasons related to it. A verifiable method for detecting carrageenan is still missing in the food inspection sector. The detection of carrageenan in meat products is not well described. Our study describes lectin histochemistry as a novel approach for carrageenan detection. Within this study, the detection of carrageenan in meat products by lectin histochemistry is validated. Lectins of Arachis hypogaea (PNA) and Bandeiraea simlicifolia (BSA), specific for galactose units of carrageenan, were used. The samples included model meat products (ground chicken-meat products) and meat products from retail markets (chicken and pork hams, sausages, salami, and dried sausages). The limit of determination (LoD) of this method was set at 0.01 g kg-1. The method sensitivity for lectin PNA reached 1, and, for lectin BSA, it reached 0.96. Method specificity for lectin PNA was 1, and, for lectin BSA, it was 1.33. Cross-reactivity with other hydrocolloids tested was not confirmed. The results confirm that lectin histochemistry is suitable for detecting carrageenan in meat products.

Development of Immunohistochemical Methods for Casein Detection in Meat Products.

To increase production efficiency of meat products, milk protein additives are often used. Despite a number of advantages, use of dairy ingredients involves a certain risk, namely the allergenic potential of milk proteins. A number of methods have been developed to detect milk-origin raw materials in foodstuffs, including immunological reference methods. This study presents newly developed immunohistochemical (IHC) methods for casein detection in meat products. Casein was successfully detected directly in meat products where sensitivity was determined at 1.21 and specificity at 0.28. The results obtained from the IHC were compared with the Enzyme-Linked Immuno Sorbent Assay (ELISA) and there was no statistically significant difference between the IHC and ELISA methods (p > 0.05). The correspondence between the methods was 72% in total. The highest correspondence was reached in frankfurters (90%), the lowest in canned pâté (44%).

Assessment of the Effect of Secondary Fixation on the Structure of Meat Products Prepared for Scanning Electron Microscopy.

The aim of the research was to verify the necessity of secondary fixation with osmium tetroxide in various types of meat products and evaluation of structural changes of products using different fixation procedures. The material for the study consisted of 11 types of meat products that were analyzed using a scanning electron microscope (SEM) with two different methods of chemical fixation. The first method included the usual processing of biological samples: glutaraldehyde primary fixation, the use of a buffer, secondary fixation by osmium tetroxide (OsO4), buffer, and dehydration using ethanol of increasing concentrations. The second method comprised the glutaraldehyde primary fixation and dehydration using the ethanol of increasing concentrations only. The results unambiguously suggest that the main difference between these methods is in fixation and visibility of fat. Our analysis principally suggests that fixation of the product with OsO4 allows the tracking of all components (fat droplets, muscle fibers, connective tissue) in meat products. At the same time, our results also support the possibility that the secondary fixation can be skipped during the analysis, where the main objection is an observation of lipid-free structures of the meat products (e.g., connection between muscle and starches or spices) or meat products with an insignificant amount of fat.

Use of IHF-QD Microscopic Analysis for the Detection of Food Allergenic Components: Peanuts and Wheat Protein.

The aim of the study was to analytically evaluate quantum dots in immunohistofluorescence (IHF-QD) microscopic imaging as detectors of food allergens-peanut and wheat. The experiment was designed as two in silico experiments or simulations: (a) models of pastry samples were prepared with the addition of allergenic components (peanut and wheat protein components) and without the addition of allergenic components, and (b) positive and negative commercial samples underwent food allergen detection. The samples from both simulations were tested by the ELISA and IHF-QD microscopic methods. The primary antibodies (secondary antibodies to a rabbit Fc fragment with labeled CdSe/ZnS QD) were labelled at 525, 585, and 655 nm emissions. The use of quantum dots (QDs) has expanded to many science areas and they are also finding use in food allergen detection, as shown in the study. The study indicated that differences between the ELISA and IHF-QD microscopic methods were not observable among experimentally produced pastry samples with and without allergenic components, although differences were observed among commercial samples. The important value of the study is certainly the differences found in the application of different QD conjugates (525, 585, and 655). The highest contrast was found in the application of 585 QD conjugates that can serve for the possible quantification of present food allergens-peanuts and wheat. The study clearly emphasized that QD can be used for the qualitative detection of food allergens and can represent a reliable analytical method for food allergen detection in different food matrixes.

Pork protein addition effect on structural and qualitative parameters of frankfurter-type sausage.

BACKGROUND: Several raw materials and additives are used in meat production. In terms of origin, proteins which are the closest related to meat are derived from slaughtered carcasses. The aim of the work was to assess the effect of their addition on the microstructure, texture and colour of frankfurter-type meat products. RESULTS: Calleja staining, instrumental textural analysis and colour analysis were applied. The microscopic results were evaluated qualitatively. Canonical component and Tukey's HSD were used for textural and RGB evaluation. Microscopically, protein matrix formation in products containing pork haemoglobin (155_16) and pork plasma P (158_16) was found to be different from that in other samples. Texture analysis revealed differences (P < 0.05) in shear force between pork haemoglobin 155_16 and all tested samples, in the hardness between the control (154_16) and pork collagen protein (157_16) and between 157_16 and 160_16. Chewiness showed differences between control 154_16 and collagen proteins 157_16. Colour analysis showed a difference between pork haemoglobin (155_16) and other products (P < 0.05) by component analysis. CONCLUSION: All tested additives were incorporated into the protein matrix. Therefore, they may be used as additives even for unrecommended meat products. Addition of pork haemoglobin has a significant impact on the colour of the final product. © 2018 Society of Chemical Industry.

Substitution of sodium chloride by salt microspheres in dough: Effect on dough rheological properties.

This research aimed to evaluate the impact of different salts on dough rheology parameters and gas cell development during dough preparation. Three types of salts in four concentrations each were used in dough preparation and following analyses were conducted: sodium content, salt structure analysis, dough hardness, dough stickiness and dough image analysis. The research showed how significantly (p < .05) the measured properties of dough can be influenced by the used type of salt, salt concentrations and fermentation time. The emphasis is put on salt substitutes of hollow microsphere salt (Hs) substitutes due to its special physical characteristics. The uniqueness of Hs physical characteristics was confirmed by electron microscope photomicrographs. The gained results are indicating that even low changes in salt concentration (0.40; 0.30; 0.25; and 0.15) make noticeable changes in dough characteristics. The usage of salt substitutes in food industry has been constantly growing and it makes the research a valuable source of information for further application of this salts. PRACTICAL APPLICATIONS: The different salt types (table-Ts, sea-Ss and hollow microsphere-Hs) which were studied in our work differ just slightly. However, an important issue in choosing salt should also be the nutritive perspective, in particular low sodium content as a preventive measure against cardio-vascular diseases. Hs and Ss are therefore suitable alternatives to typical Ts.

Immunofluorescence detection of pea protein in meat products.

In this study we developed an immunofluorescence method to detect pea protein in meat products. Pea protein has a high nutritional value but in sensitive individuals it may be responsible for causing allergic reactions. We produced model meat products with various additions of pea protein and flour; the detection limit (LOD) of the method for pea flour was 0.5% addition, and for pea protein it was 0.001% addition. The repeatabilities and reproducibilities for samples both positive and negative for pea protein were all 100%. In a blind test with model products and commercial samples, there was no statistically significant difference (p > 0.05) between the declared concentrations of pea protein and flour and the immunofluorescence method results. Sensitivity was 1.06 and specificity was 1.00. These results show that the immunofluorescence method is suitable for the detection of pea protein in meat products.

The effect of long-term storage on the quality of sterilized processed cheese.

The aim of this work is to evaluate the effect three different storage temperatures (6, 23 and 40 °C) on the sterilized processed cheese quality during 24-month storage. Sterilized processed cheese (SPC) is a product with extended shelf life (up to 2 years). The samples of SPC were subjected to basic chemical analyses, i.e. pH-values, dry matter, fat, crude protein and ammonia content, and microbiological analyses, i.e. total number of microorganisms, number of coliforms, colony forming units of yeasts and/or moulds and spore-forming microorganisms. Furthermore, amino acid content (ion-exchange chromatography), protein profile (SDS-PAGE) and fat globules size (image analysis of microscopic technique) were monitored and sensory analysis (scale test and pair comparative test) was implemented, too. Increasing storage temperature and length evoked decrease of total amino acid content and protein nutrition value, increase of ammonia amount, protein changes, enlargement of fat globule size and deterioration of sensory properties of SPC. All the changes grew expressive with increasing storage temperature and time.