2018, Vol. 16, Special Issue 2

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/5381

Sirvi

Nüüd näidatakse 1 - 20 27

Study of potential PCR inhibitors in drinking water for Escherichia coli identification
(2018) Dalecka, B.; Mezule, L.
In the last few decades, the polymerase chain reaction (PCR) has become one of the most powerful molecular biological tools. However, the PCR is an enzymatic reaction and therefore sensitive to inhibitors which may occur in drinking water samples. In this work, the possible inhibition effect of chlorine, humic acids, and iron for real - time PCR (qPCR) efficiency was studied and the environmental sample from drinking water treatment system before iron removal was selected and analysed. The results demonstrate d that the highest concentrations of humic acids (5 mg L - 1 and 1 mg L - 1 ) and iron (4 mg L - 1 ) inhibited the PCR reaction while no effect of chlorine was observed. The analysis of the environmental sample with spiked Escherichia coli cells demonstrated reduc tion efficiency of the average threshold cycle (C t ) values compared with control dilution series determining the possible inhibition for qPCR assay.
Shrinkage effect on diffusion coefficient during carrot drying
(2018) Aboltins, A.; Rubina, T.; Palabinskis, J.
Many studies have been previously carried out on the carrot drying and the undergoing processes. The developed mathematical models provide an opportunity to gain an understanding of this complex process and its dynamics. But they are sim plified and based on a number of assumptions, including calculation of diffusion coefficient values. In one of the previous studies, the authors of this study determined that the diffusion coefficient is linearly dependent on the moisture concentration wit h the assumption that the sample's geometric shape does not change. The aim of this study is to determine the dependence of the diffusion coefficient on the moisture concentration taking into account the change in sample thickness during the drying experim ent. The experiments were carried out with carrot slices of three different thicknesses: 5 mm, 10 mm and 15 mm thickness on the film infrared dryer at temperature 40 °C . During the experiments, measurements of the weight and thickness of the slices were pe rformed. Using the experimental data the average thickness and diffusion coefficient of slices was calculated depending on the moisture concentration . Obtained results show that thickness depends linearly on the moisture concentration. Using experimental d ata and obtained average values of samples thickness, the values of diffusion coefficient was calculated. The results indicate that diffusion coefficient value depend linearly on moisture concentration. Their values are close and tend to zero when the conc entration decreases if the thickness changes are taken into account during the experiment.
Meat chemical composition of pasture pure lambs and crossbreeds
(2018) Vecvagars, J.; Bārzdiņa, D.; Kairiša, D.
Increased customer interest of safe, healthy and environmentally friendly food consumption promote development of sheep farming industry in Latvia. Aim of the paper – explain of different pasture - fattened sheep breed and their crosses lamb meat composition traits. A study of pasture fattened lamb meat chemical composition was carried out from year 2013 to 2017. Fattening lambs were kept in breeding rams control station ‘Klimpas’ (57°50’58.8’’N 25°19’39.6’’E) pasture array. Lambs were slaughtered in a certif ied slaughterhouse, but analysis of meat chemical composition were conducted in laboratory of Institute of Food Safety, Animal Health and Environment (BIOR). For the analysis of the meat chemical composition were used up to 1 kg heavy Quadriceps femoris mu scle samples. In meat were analysed following elements of its chemical composition: dry matter, protein, fat, minerals, pH, cholesterol and unsaturated fatty acids. Data analysis shows that the lambs before slaughter ranged in age from 5 to 8 months. Lamb meat obtained from the study groups had a significantly different total amount of dry matter and fat. The lowest total fat, but the highest ash content was obtained in the lamb meat of the extensive breed group. The lowest total fat and the highest ash con tent were obtained in the lamb meat from the extensive breed group. In meat obtained a small (in individual samples < 0.10%) cis - 10 - pentadecenoic acid, cis - 11 - eicosenoic acid and myristoleic acid content. Of unsaturated fatty acids in lamb meat were represented higher amount of oleic acid, linoleic acid and elaidic acid.
Cadmium-induced oxidative damage and protective action of fractioned red beet (Beta vulgaris) root juice in chickens
(2018) Vasiljeva, S.; Smirnova, G.; Basova, N.; Babarykin, D.
Cadmium (Cd) is one of the most dangerous environmental bioaccumulative pollutants that affects many organs in humans and animals. Present investigation was conducted to evaluate the protective effect of fractioned red beetroot juice on Cd - induced oxidative stress in chickens. The named red beetroot juice fraction (BJF) was received by juice ultrafiltration. Per oral administration of BJF for 10 days followed by dietar y Cd exposure (50 mg kg - 1 of diet) was evaluated in the in vivo experiments in chickens. The prominent increase of Cd concentration in blood plasma, liver and kidney provoked the rise of oxidative processes activity in organs. BJF treatment attenuated the Cd - induced oxidative stress. The changes of oxidative stress markers - the reduction of hepatic and kidney malondialdehyde amount, the increase of glutathionperoxidase level in liver and blood catalase activity indicated the possible antioxidative influenc e of BJF. Chickens exposed to Cd showed no evidence of clinical toxicity, but exhibited some features of adverse action of this heavy metal. The increase of uric acid concentration in blood serum is associated with protein catabolic processes intensified b y Cd affect. Suppressive effect of Cd on the immune response in chickens manifested in alteration of cell and humoral immunity parameters. The data of the most investigated oxidative stress markers, biochemical and immunological indices in Cd - exposed chick ens were almost back to the values, when received BJF per os during 10 days. Administration of fractioned red beetroot juice to Cd - treated chickens prevented the oxidative impact of this heavy metal and provided immunomodulating effect.
Bioactive compounds in herbal infusions
(2018) Augšpole, I.; Dūma, M.; Ozola, B.
Herbal teas are very popular and known as important source of biologically active compounds. Some of popular Latvian herbal teas: Calendula (Calendula officinalis L.), Matricaria chamomilla (Matricaria chamomilla), Lady's-mantle (Alchemilla vulgaris L.), Jasmine (Jasminum officinale L.), Yarrow (Achillea millefolium L.) and Linden flowers (Tilia spp.) were selected for analysis. This study was carried out with the aim to investigate the effect of extraction time (10, 15, 20 min) on the content of total flavonoids and total phenols as well as antioxidant activity of herbal tea extracts. The infusions were prepared by usual domestic preparation technique using ground air-dried plant materials and boiling deionized water (0.055 µS cm-1 ) for extraction. Content of total flavonoids, total phenols and antioxidant activity was determined spectrophotometrically. Dry matter content was determined in lyophilized herbal infusions. The obtained results indicated that extraction time did not affected the content of biologically active compounds in the herbal infusions significantly (P > 0.05). The highest level of flavonoids was found in Jasmine and Lady's-mantle infusions (average 104.98 ± 9.21 mg quercetin equivalent 100 g -1 and 115.28 ± 5.25 QE mg 100 g -1 respectivelly), while the lowest was determined in Matricaria chamomilla extract – (average 70.10 ± 4.68 QE mg 100 g -1 ). Lady's-mantle tea contained the largest amount of total phenols (average 4126.62 ± 26.24 mg gallic acid equivalents 100g-1 ), the lowest – Calendula tea 1828.04 ± 10.37 mg GAE 100 g -1 ). Data analysis showed a close linear positive correlation between the content of total flavonoids and total phenols in herbal infusions (R2 = 0.872; r = 0.934) with the probability of 99%. In general, all samples tested in this study, demonstrated high level of antioxidant activity (from 75.04 to 91.54 mmol Trolox equivalents 100 g-1 ). Results of the present experiments demonstrated that content of dry matter in analysed herbal teas was significantly different (P < 0.05).
Comparison of power consumption of a two-roll mill and a disc mill
(2018) Smejtkova, A.; Vaculik, P.
Grinding or milling is often used process, for example in the production of feed, grinding of malt in beer production, grinding of cereals on flour, etc. In order to optimize the energy intensity of the whole production process, it is necessary to know the energy consumption of individual processes. The grinding of malt influences the mashing process, the drawing-off and the boiling yield. Correct grain grinding makes the endosperm available for enzyme and physicochemical reactions during wort production. Husks affect the drawing-off process. Two-, four- or six-roll mills, in some cases a hammer mill or disc mill, are most commonly used for grinding of malt. Power consumption was monitored when light, Munich, caramel and coloring malt were grinding. A two-roll mill and a disc mill with engine speeds of 1,500 rpm and 2,800 rpm were used for grinding. The gap between the mill rollers and the mill disks was set to 0.4 mm. The fineness of the grinding was evaluated for all types of malt on all used equipment. The energy intensity of the grinding was correlated on 1.0 kg of malt and then compared.
A study of dynamics of bitter acids and xanthohumol in hop pellets during storage
(2018) Táborský, J.; Hejtmánková, A.; Hlavatá, E.; Chládek, L.
Eight varieties of hop pellets were analyzed for the contents of α - acids, ß - acids and xanthohumol according to the EBC 7.7 analytical method. The pellets were extracted with acidified mixture methanol - diethylether and analyzed using HPLC with a diode - array detector and a Nova - Pak column C 18 . Four series of analyses were performed: immediately after the unpacking of the pellets and then after five, seven and nine months of storage at 4 °C. According to the first ser i es of analyses, the contents were assayed as following (α - acids, ß - acids, xanthohumol resp., all in weight % in pellets): Galaxy (13.4, 8.0, 0.74), Citra (11.1, 3.0, 0.48), Tradition (8.2, 8.0, 0.58), Cascade (4.5, 5.2, 0.25), Northern Brewer (4.0, 2.9, 0. 37), Sládek (3.5, 4.0, 0.48), Saaz (2.0, 3.4, 0.24), and Triskel (1.7, 3.6, 0.18). According to these results, variety Galaxy was found as the richest in all three parameters. After nine months of storage at 4 °C, the weight loss of α - acids ranged from 4.1 % (Citra and Triskel) to 66.4% (Galaxy). The losses of β - acids and xanthohumol were less distinctive (from zero to 31.3% and 25.7%, resp.) and indicated good long storage possibilities of these compounds at convenient conditions (darkness, low temperature, elimination of direct influence of oxygen).
Flavonoids and total phenolic content in extruded buckwheat products with sweet and salty taste
(2018) Krumina–Zemture, G.; Beitane, I.; Cinkmanis, I.
The aim of research was to evaluate the effect of added ingredients used for taste improvement on flavonoids and total phenolic c ontent in extruded buckwheat products. The added ingredients were – sugar, vanilla sugar, stevia, agave syrup, cinnamon, caraway, garlic powder, sweet pepper powder and salt. Six extruded buckwheat products were analysed, where an extruded buckwheat produc t without added ingredients was a control sample, two extruded buckwheat products were with sweet taste and three products with salty taste. Total phenolic content was determined using the modified Folin – Ciocalteu method but flavonoid content according to LC - TOF - MS method. The highest total phenolic content (p < 0.05) was determined in extruded buckwheat product with vanilla sugar + stevia (91.17 ± 0.67 GAE mg 100g - 1 DW). It was almost three times higher than in the control sample. The significant difference s were observed in extruded buckwheat products with caraway + salt + agave syrup (41.5 ± 0.12 GAE mg 100g - 1 DW) and sweet pepper powder + salt + agave syrup (42.39 ± 0.80 GAE mg 100g - 1 DW) comparing to other extruded products (p < 0.05). The highest content of rutin and quercetin (p < 0.05) was established in extruded buckwheat product with garlic powder + salt + agave syrup, whereas the highest content of catechin and epicatechin – in extruded buckwheat product with vanilla sugar + stevia. The extruded buckw heat product with caraway + salt + agave syrup in addition contained luteolin, kaempferol and isoquercitrin. The results of research showed that some added ingredients used for taste improvement can significantly influence the total phenolic content and fl avonoid content.
A study of commercial β-galactosidase stability under simulated in vitro gastric conditions
(2018) Žolnere, K.; Ciproviča, I.; Ķirse, A.; Cinkmanis, I.
β-Galactosidase activity in milk may be affected by several factors, such as temperature, pH, milk composition, and metal ions. It is important to note that digestive proteases and gastrointestinal pH can affect enzyme activity during transit through the gastrointestinal tract. For the investigation of commercial β - galactosidase stability in human and animal gastric tracts, human gastrointestinal tract (GIT) models were employed, enabling prediction of enzyme activity under in vivo conditions. The aim of this study was to analyse and compare commercial β - galactosidase stability under simulated in vitro gastric conditions. Commercial enzymes (Ha Lactase 5200 produced by Kluyveromyces lactis and NOLA™Fit5500 produced by Bifidobacterium bifidum expressed in Bacillus lichenifo rmis , Chr. Hansen, Hørsholm, Denmark; GODO - YNL2 produced by Kluyveromyces lactis , Danisco, Copenhagen, Denmark) were used for this study. Commercial enzymes were added to GIT models at 1 and 5 mL L – 1 . The enzyme activity was assessed as the percentage of l actose hydrolysis by the enzymes from Kluyveromyces lactis and Bacillus licheniformis using HPLC after digestion. β - Galactosidase extracted from yeast ( Kluyveromyces lactis ) and bacteria ( Bacillus licheniformis ) was found to be effective as a strategy for improving lactose tolerance.
Encapsulation of Gallic acid in solid lipid core surrounded with maltodextrin shell
(2018) Sepelevs, I.; Reineccius, G.A.
Multiple phase capsules had been prepared in a single spray drying process. The main goal of the present study was to investigate whether the conversion of a portion of the modified starch (wall material used in spray drying) to resistant starch (RS) would offer added protection of encapsulated material. To achieve this, dry gallic acid (GA; a model water soluble phenol compound used in the present study) was initially dispersed in palm oil and stabilized with Polyglycerol Polyricinoleate (PGPR 4175) as an emulsifier. This dispersion was homogenized with a modified starch (MS, dextrose equivalent of 15) solution, that was previously treated with high pressure and increased temperature to achieve starch retrogradation, and then spray dried. It was possible to produce only small amounts of RS from modified starch, varying from 0.1 to 0.2% of total carbohydrate content. GA content in the lipid phase of the capsule was determined by lipid droplet size in the O/W emulsion (the feeding solution), as smaller droplet s results in the significantly bigger surface area, and more intensive GA diffusion from O to W phase. Maltodextrin shell wall was able to prevent leaking of the melted palm oil form the capsule core to the surface during seating tests, preventing agglomer ation of capsules. This could be very important for the storage/transportation of capsules in the uncontrolled temperature conditions.
Development of the composition and technology of the frozen dessert without sugar, using sesame flour
(2018) Lugova, M.V.; Arseneva, T.P.
The article presents the results of the analysis of the entry dose of stevioside, topinambur syrup, sesame flour and the type of stabilizer added to the milk ice cream formula , theoretically calculated, using solids according to GOST 31457 - 2012 for development of a functionally oriented dessert with low content of fat and without sugar. It has been established that the entry dose of the stevioside and the topinambur syrup in an amount of 0.03 and 5% respectively to the mixture mass of the frozen dessert allows us to get the product with pleasant flavor and scent. The use of the PGX - 1 stabilizer (Germany) with an entry dose of 0.4 to the mixture mass allows us to get the product with the best indicators for whipping, thawing resistance, density and uniformity of consistency. It has been determined that the entry dose of sesame flour added to the mixture mass varies from 1.5 to 2 % . It is expedient to put it into the normalize mixtu re after the process of homogenization before milling, pre - brewing with water in the ratio of 1:10 for 15 – 20 minutes to humidity (80 ± 1) % . It has been found that the expiration date of the frozen dessert without sugar with the use of sesame flour is 6 mo nths at a temperature of – 18 ° C.
Influence of technological parameters on chemical composition of triticale flakes
(2018) Kruma, Z.; Straumite, E.; Kince, T.; Klava, D.; Abelniece, K.; Balgalve, A.
Triticale is hybrid crop developed by crossing wheat ( Triticum ) and rye ( Secale ) and in last years it become more popular for food applications, including flake production. Different approaches are developed to improve flakes technology by applying different cooking, rolling, toasting parameters resulting in high quality products. All these technologies influence also nutrition quality of product due to the diffe rent stability of these compounds during mechanical and thermal treatment. The aim of current experiment was to investigate the influence of technological parameters on chemical composition of triticale flakes. In current experiment triticale grains and tr iticale flakes obtained by different technologies was tested. For evaluation of the influence of technological parameters, different flaking and rolling parameters were tested. For all samples were determined composition of basic nutrients (fats, proteins, fibres, sugars, ash), minerals (Ca, Mg, K, Zn, P), vitamins, total phenolics and antioxidant activity. Triticale has high nutritional quality, containing significant amounts of protein, fibres, vitamins and minerals. Technological processes significantly influence cereals composition, but it depends on parameters tested. Control sample showed lower results and hierarchical cluster analyses showed that samples 1/3/1, 2/1/2/1, 2/1/3/1, 2/1/4/1 are similar in composition of bioactive compounds. Results showed that for selection of the best method for flaking physical and/or sensory properties should be taken in account.
Contents of tocols in different types of dry shell fruits
(2018) Hejtmánková, A .; Táborský, J.; Kudelová, V.; Kratochvílová, K.
The aim of this study was to identify all forms of vitamin E in different kinds of dry shell fruits (generally called ‘ nuts ’ ) obtained from different sources and to perform their mutual comparison . All tocols were determined by reversed phase HPLC using is ocratic elution with fluorescence detection. Almonds were evaluated as the most important source of α - tocopherol (average value 1 , 132 mg kg - 1 ), β - tocopherol was present in all samples as a minor component, its maximum content was found in hazelnuts (9.6 mg kg - 1 ). γ - T ocopherol was found in all kinds of nuts and the highest content was found in pistachios (584 mg kg - 1 ), very high amount of δ - tocopherol was contained in Brazil nuts (2 , 29 8 mg kg - 1 ). Tocotrienols were found in a smaller number of nut kinds than tocopherols. α - Tocotrienol was found only in three kinds of nuts - Brazil nuts, which contained the highest amount (399 mg kg - 1 ), pine nuts and hazelnuts grown in the Czech Republic, which were analyzed soon after harvest. Similarly, γ - tocotrienol w as det ermined only in four kinds of nuts (pistachios, macadamias, cashew and walnuts grown in the Czech Republic ) , which were analyzed soon after harvest ; t he most significant amount was found in pistachios (34.8 mg kg - 1 ) , β - and γ - tocotrienols were below the detection limit . In the Czech Republic, walnuts and hazelnuts are the most widely cultivated and consumed nuts. While in walnuts the most important form is γ - tocopherol (459 ± 40 mg kg - 1 ), in hazelnuts it is α - tocopherol ( 863 ± 10 mg kg - 1 ).
Sonochemical effects on food emulsions
(2018) Krasulya, O.; Potoroko, I.; Tsirulnichenko, L.; Khmelev, S.; Bogush, V.; Anandan, S.
Acoustic cavitation of food emulsions is widely applied as the main processing method to improve the quality of a finished product and its organoleptic characteristics, as well as to increase production performance. To identify the optimal modes of ultrasonic emulsification, we propose a model of emulsion droplet breakup in an acoustic cavitation field, which allows us to determine the dependence of emulsion droplets’ diameter on exposure time and intensity of action. The developed models enabled us to pioneer complex research of the dependence of emulsion droplets’ diameter on time given the maximum radius of cavitation bubbles and physical properties of liquid phases in the emulsion composition. We carried out the fi rst complex theoretical and practical research of how shapes and positions of absolutely fixed boundaries influence the propagation of oscillations in a activating liquid medium (food emulsion). To verify the adequacy of the obtained theoretical models, we studied the dependence of emulsion droplets’ breakup rate (by the example of a model water/oil emulsion) on the exposure time and the intensity of ultrasonic action. The calculation results revealed that the results of a series of experiments and the resu lts obtained with the use of the developed mathematical model are consistent. Based on the theoretical data obtained, we designed an industrial flow - type acoustic cavitation device aimed at acting on food emulsions; it differs from analogous devices in th at it has within it a cylindrical wave acting through solid walls of the tunnel for transmitting processed liquid.
Optimisation of biologically active compounds ultrasound assisted extraction from potatoes using response surface methodology
(2018) Zarins, R.; Kruma, Z.; Skrabule, I.
Potato ( Solanum tuberosum L.) is source of p henolic compounds and from plant matrixes can be extracted by several methods. In recent years ultrasound assisted extraction has become more popular due to its efficiency for recovery of phenolic compounds and antioxidants and response surface methodology is an effective tool for optimisation of extraction procedure by evaluating different variables and their interaction. The aim of the current research was to optimize ultrasound assisted extraction of biologically active compounds from potatoes by respons e surface methodology. For experiment purple - flesh potato variety ‘Blue Congo’ was selected. Control sample was extracted by stirring for 1 hour. Box - Behnken design was used for optimization of extraction conditions from fresh potatoes and as variables wer e selected: ethanol concentration (% v/v), hydrochloric acid concentration (molarity) and time (min). For extracts as responses total phenolic, total flavonoid, total anthocyanin content and antioxidant activity (DPPH, ABTS+ scavenging activity) were deter mined using a spectrophotometric methods. Significant models were obtained for antocyanins, total phenols and DPPH radical scavenging activity. Optimisation of extraction showed that for maximising all responses optimal HCl concentration is 2.5M, ethanol c oncentration 79.4% and extraction time 60 minutes, resulting in following responses: 57.41 mg 100 g - 1 of anthocyanins, 238.52 mg 100 g - 1 of TPC, 24.58 mM TE 100 g - 1 of DPPH scavenging activity and 12.99 mM TE 100 g - 1 of ABTS scavenging activity. Convention al extraction method showed significantly lower results. It could be concluded that ultrasound assisted extraction is effective method for recovery of phenolic compounds and solvents and extraction time is significant parameter influencing efficiency.
Single cell protein production from waste biomass: review of various agricultural by-products
(2018) Spalvins, K.; Ivanovs, K.; Blumberga, D.
Agricultural waste constitutes for most of the manmade waste streams. Processing of biodegradable waste materials ensures the treatment of harmful substances and allows to reduce environmental pollution. In addition, conversion of these waste materials in value - added products makes these recycling methods more economically viable. Single - cell protein is one of the value - added products that can be produced by microbial fermentation of waste materials. In this review various biodegradable agricultural by - prod ucts as substrates for production of SCP are categorized and compared.
Changes in the nutritional value of breakfast cereals containing germinated spring grain flakes during storage
(2018) Kruma, Z.; Galoburda, R.; Tomsone, L.; Gramatina, I.; Senhofa, S.; Straumite, E.; Klava, D.; Kince, T.; Cinkmanis, I.; Zagorska, J.; Kunkulberga, D.
Th e aim of current research was to assess the nutritional value of breakfast cereals containing germinated spring grain flakes and its changes after 6 month storage. Three types of breakfast cereals were prepared and packaged in two types of Standup pouches – Pap50g/Alu7/Pe60 (AL), Pap40g/PELD20/PE40 (PE). For the accelerated shelf life test the samples were stored at 35 ± 2 °C and dietary fibre, protein, fat, B - group vitamins, sugars, total phenol content and DPPH, ABTS+ radical scavenging activity were dete rmined. Developed breakfast cereals have high nutritional value and all are high in fibre and thiamine. Additionally, sample S2 is source of protein, riboflavin, niacin, and S3 – is source of riboflavin and high in niacin. Comparing total phenolic content and antioxidant capacity of tested samples S3 showed the highest values. Storage and selected packaging influenced stability of nutrients, and for S1 and S2 AL showed bett er results whereas for S3 – PE.
The effect of sapropel extracts on microflora and physicochemical parameters of Dried Distillers’ Grain
(2018) Nsengumuremyi, D.; Barakova, N.V.; Romanov, V.A.; Mityukov, A.S.; Guzeva, A.V.
This article is devoted to the effect of ultradispersed humate sapropel extracts, obtained from air - dry samples of sapropel, from Seryodka deposit (Pskov region, Russia) by alkaline extraction under the action of ultrasonic radiation, on microbial and phys icochemical parameters of Distillers’ grain (DG) during storage. At the end of the distillation , wet DG was divided and treated with sapropel extract. The untreated sample served as a control. Both (treated and untreated ) were then dried to 10% moisture content . Microbial and physicochemical parameters (moisture content, pH, titrable acidity (TA), acid value (AV) of fats) were assessed before storage of dried DG. A similar experiment was repeated after one week of storage but on microbial load. The microb ial counts ranged from 2.3 × 10 4 CFU g 1 (untreated) to 1.77 × 10 4 CFU g - 1 (treated) before storage while 2.5 × 10 4 CFU g - 1 to 2.18 × 10 4 CFU g - 1 accounted for after a week of storage. The pH had increased from 4.5 ± 0.1 to 6.1 ± 0.1 before and after treatm ent respectively. TA likewise decreased from 3.2 ± 0.4 to 2.03 ± 0.06%. The results showed that sapropel extracts had effects on microflora and physicochemical parameters of DDG.
Effect of impact-activating-disintegration treatment on grain protein fraction of autumn rye
(2018) Sabirov, А.А.; Barakova, N.V.; Samodelkin, Е.А.
This paper studies the distribution of rye protein fractions according to their mass and amino acid composition while milling by machines with different work tools. The research was conducted on the autumn rye of harvest year 2017 with kernel moisture con tent of 8%. Cereals were milled in the machine of an impact - activating - disintegrating type DEZI - 15 with three - row and five - row rotors which rotate at 120 s - 1 , and in the laboratory mill with a knife - rotor work tool. The milling grain size was determined by a diffraction - type grain analyser Malvern Mastersizer 2000. The average grain size obtained from three - row disintegrating rotor was 167 μm , from the five - row rotor 158.1 μm , and from the laboratory knife - rotor mill 384 μm , respectively. The free amino aci ds composition in flour samples was investigated using the size exclusion chromatography method (SEC - method). The polypeptide composition of total grain protein has been determined by One - dimensional SDS - acrylamide gel electrophoresis. According to the ele ctropherogram results obtained from all the the content of high - protein fraction of 200 kDa . The glutelin fraction with molecular weight of 116.25 kDa is definitely observed in the sample obtained from the three - row disintegrating rotor. Whereby the lowest glutelin content has been detected in the flour sample obtained from the five - row disintegrating rotor. Fractions with molecular weight of 60 – 75 kDa – globulin fractions – come up frequently in the sample obtained from the three - row disintegrating rotor. Prolamine fractions of 45 – 47 kDa are clearly observed in the flour sample obtained from the laboratory knife - rotor mill. The albumin fraction with molecular weight of 17 – 28 kDa are mostly observed in the samples obtained by three - row and five - row disintegr ating rotors. Few LMW fractions (from 6.5 to 15 kDa ) are found in samples obtained using the impact - activating - disintegrating technique, mostly in the sample milled in the laboratory knife - rotor mill. Based on the data of free amino acid content in sample investigated it can be concluded that the impact - activating - disintegrating techniques does not cause reduction in protein biological value. The albumin rich flour milled in the disintegrator can be used for production of functional food. Due to the low con tent of glutelin protein fraction the flour obtained from the five - row disintegrating rotor offers the greatest promise for production of gluten - free foods.
The measurement of energy consumption during milling different cereals using the sieve analyses
(2018) Chladek, L.; Vaculik, P.; Vagova, A.
This paper deals with the measurement of energy consumption required for disintegration of different cereals depending on the desired fineness of obtained grist. The energy consumption necessary for milling was compared with the results of a sieve analysi s before and after the disintegration process. The obtained results were compared with energy expended during the disintegration of cereals and were analysed to determine the coefficients of the ratio of fineness of milling/energy consumption. They was fou nd to have good conformity. Special attention was paid to the RRSB distribution for determination of statistic average particle size and specific area of malt grist. Specific area of grist particles from different cereals was determined by calculation of t he limited area and x axis in diagrams, this effort is necessary for optimisation of the disintegration process with impact on the quality of final food.

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