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2019, Vol. 17, Special Issue 2

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Nüüd näidatakse 1 - 20 22
  • Kirje
    The effect of humic acids on the natural resistance of the body of broiler chickens and the quality of their meat
    (2019) Korsakov, K.; Simakova, I.; Vasilyev, A.; Lifanova, S.; Gulyaeva, L.
    The aim of the work is to study the effectiveness of the concentration of humic acids of Reasil Humic Vet feed additive on the increase of the feed bioavailability for poultry and the probability of its negative impact on the safety and marketable characteristics of the final product. Studies were conducted on the basis of the Saratov State Agrarian University in two similar groups of broiler chickens ‘Cobb 500’, 100 heads each. Poultry feeding consisted of the same complete feed, but the drinking water for the broilers of the experimental group was enriched by humates in the amount of 0.5 ml L -1 . Based on the data obtained by daily weighing of the poultry and considering the feed intake, a positive trend of the influence of the feed additive on the average daily weight gain and feed conversion per unit of production was noted. The results of slaughter and anatomical cutting of broiler carcasses revealed that metabolic processes were more active in the body of an experimental poultry, reflected in the intensive growth of muscle tissue and fat deposition, which contributed to an increase in the yield of edible parts from carcasses by 9.9%. Studies of composition of broiler blood indicate non-toxicity of the recommended concentration of humates in the feed additive, its stimulation of non-specific resistance of the organism, contributing to the functioning of the immune system and the development of internal organs and, as a consequence, ensuring the safety of the products obtained from them.
  • Kirje
    Development of formulation and technology of yogurt with prolonged shelf life enriched with biologically active substances from fennel seed extract
    (2019) Dubrovskii, I.I.; Arseneva, T.P.; Evstigneeva, T.N.; Gorshkova, S.B.; Bazarnova, Y.G.; Iakovchenko, N.V.
    Spray drying is most common drying technology in food industry and can be used as an alternative to freeze drying method for the production of extracts in powder form. Fennel seeds are used to treat diabetes, bronchitis and chronic cough. They possess antibacterial, antifungal, antithrombotic, anti-inflammatory, hepatoprotective and antidiabetic activities. The aim of this study was to obtain fennel extract in dry form and investigate the influence of dry fennel extract incorporation on the possibility of yogurt production. The effect of inlet temperatures on wettability, solubility, moisture content and water activity of spray-dried fennel seed extract obtained by decoction technique was investigated. The inlet temperature 165 °C was preferred. Lactic acid accumulation during fermentation occurs faster in the sample with fennel powder. Based on the results of rheological, organoleptic, physico-chemical properties, water-holding capacity and shelf life of the finished product, the recommended doses of dried fennel powder for yogurt manufacture is not more than 1%.
  • Kirje
    Development of formulation and technology of fermented dairy beverage for musculoskeletal disease prevention
    (2019) Hurda, M.; Lepeshkin, A.; Iakovchenko, N.
    According to the data of World Health Organization, 20–33% of people across the world suffer from painful musculoskeletal conditions, which lead to restricted mobility, dexterity and functional mobility. The aim of the research was to develop formulation and technology of yogurt for prevention of musculoskeletal disease. The results of sensory characteristics, physicochemical parameters, rheological characteristics, fatty acid composition have shown that it is possible to create the new product with curcumin, grape seed oil, hyaluronic acid and chondroitin sulfate, which are recommended to use for improving various symptoms of musculoskeletal disease. However, the chosen components increase the manufacturing process. It was observed that fermentation time increase was caused by addition of curcumin, which inhibits the lactic acid bacteria growth within 2.5–3 h. The combination Tween 80 and lecithin allows to obtain stable product during the storage period.
  • Kirje
    Phenolic and volatile compound composition influence to specialty coffee cup quality
    (2019) Laukaleja, I.; Kruma, Z.
    With increasing specialty coffee consumption, more attention is focused not only on the cup quality (sensory quality) of the coffee beverage but also about the impact of coffee on health. The beneficial effects of coffee on human health are mainly based on a wide range of biologically active components, including phenolic compounds. The aim of the study was to evaluate the influence of phenolic and volatile compound composition to specialty coffee cup quality. Seven specialty coffees from two Latvian roasteries were selected and analysed. Total phenolic and flavanoid content and radical scavenging activity by DPPH and ABTS assay were determined spectrophotometrically. Sensory evaluation (cup quality) was performed by trained panellist team using the SCAA protocols cupping specialty coffee. Volatile compounds were extracted by SPME and analysed by Gas Chromatography-Mass Spectrometry (GC–MS). Coffee final cup quality score ranged in amplitude of 83–90.25 points. HON_2 with dry fruits and melon characteristics has shown the highest final cup quality score. Almost detected volatile compounds in KEN_1 is associated with positive specialty coffee characteristics. In ETH_1 coffee with the final cup quality score 88.25 was detected highest floral, fruity compounds and highest coffee– like roasted notes. The highest total phenolic content and DPPH, ABTS•+˙ value showed Roastery_1 coffee samples (HON_1; KEN_1; COL_1) and the lowest values Roastery_2 coffee samples (HON_2; ETH_1; HON_3; SAL_1).The results indicate that the roastery specific roasting process parameters could influence not only volatile compounds profile and cup quality but also the total and individual phenolic compound content.
  • Kirje
    The impact of plant powders on acrylamide content in bakery products
    (2019) Nilova, L.; Malyutenkova, S.; Kruchina-Bogdanov, I.
    This work is devoted to studying acrylamide (ACR) formation and the changes in its levels display during the storage in bakery products (BP) made of wheat flour enriched with plant powders (in the optimal amounts established earlier): blueberry – 3%; pine nut – 6%; rowan – 5%; sea buckthorn – 5%. BP were baked at two temperatures – 220 and 200 °C. ACR level was determined with the use of ‘Kapel 105 M’ capillary electrophoresis system in various BP parts (crust, sub-crust layer, crumb) 3 and 24 hours after baking. ACR formation differed in different BP layers. All plant powders slowed down its formation in the crust and the sub-crust layer. The process was influenced by formation of heterocyclic compounds (lactams) as a result of the Maillard reaction. In the crumb, ACR formation depended on the type of the used plant powder. In BP cooked with blueberry and rowan powders, the ACR level decreased, while in BP cooked with sea buckthorn and pine nut powders, it increased in comparison with other layers. Lowering the baking temperature helped to decrease acrylamide formation by 15–20% in the crumb and by 25–35% in the crust. After storing BP for 24 hours, a decrease in the ACR level was found, mainly in the crust and crumb. The intake of ACR in the human body of 70 kg when used with 100 g of BP enriched with plant powders will come to 0.16–0.2 μg. Lowering the baking temperature will decrease ACR level by 3–6%.
  • Kirje
    Use of lipids of Chlorella microalgae in poultry meat marinades and sauces recipes
    (2019) Bazarnova, J.; Kuznetsova, T.; Aronova, E.; Toumi, A.
    The aim of this study is to develop formulations and technologies for fermented poultry meat products with the addition of whey and lipid extracts obtained from Chlorella microalgae. Lyophilized microalgal biomass was obtained from cell suspensions of Chlorella sorokiniana (strain 211-8k) cultivated in a closed photobioreactor under laboratory conditions. For the cell wall disintegration, the biomass samples were homogenized using a high-speed homogenizer at 10,000 vol min-1 for 5 minutes. The lipid extraction was performed on a Sohxlet apparatus Buchi E-812 SOX with the solvent extraction system ethanol: n-hexane (1: 9). The higher fatty acids composition of the obtained microalgal lipid extracts was determined by gas chromatography with flame-ionization detection using nitrogen as a carrier gas. The ω-3 and ω-6 content represented 26.59% and 19.05% respectively, which indicates that these lipid extracts have high nutritional values. The curd whey was obtained from cow's milk of summer and winter production from 2017 to 2018 (Lomonosov district auxiliary farm, Leningrad region); and lyophilized Direct Vat Set (DVS) cultures (Ch. Hansen, Denmark). The organic acids and carbohydrate content in the serum was determined by ion-exclusion HPLC. The FD-DVS CHN-19 culture was selected to produce a serum with improved organoleptic characteristics and a lower propionic acid content (0.01 g L -1 ). To obtain an optimal ω-3 / ω-6 ratio, a phyto-additive mixture based on sunflower oil and lipid extracts from C. sorokiniana microalgae at a ratio of 5–10: 1 is proposed to be used in recipes and technologies of sauces and marinades. It is established that the use of curd whey marinades allow to increase the water-holding capacity (WHC) by 6−8% and to reduce losses during heat treatment of poultry meat from 2 to 11%.
  • Kirje
    Utilization of image analysis for description of drying characteristics of selected tropical fruits
    (2019) Wasserbauer, M.; Herak, D.; Mizera, C.; Hrabe, P.
    This study is focused on the utilization of image analysis for description of dimensions, and colours changes of fruits during drying process. Selected tropical fruits such are banana (Musa acuminata), mango (Magnifera indica) and pineapple (Ananas comosus) originally from North Sumatera in Indonesia were used in this experiment. Sliced pieces of the fruits were dried in experimental oven under temperature 90 °C for period of time 180 min and image of fruits samples were recorded by digital camera with HD resolution continuously throughout drying process. With aid of image analysis using Image J software and regarding to drying characteristics the colours and dimensions of the samples were analysed.
  • Kirje
    The determination of impact of malt grist moisture on porosity and permeability using measurement of differential air pressure
    (2019) Vagová, A.; Chládek, L.; Vaculík, P.
    This article is focused on determination of malt grist and spent grains porosity and permeability using measurement of differential pressure of the air passing through the layer of malt grist and spent grains. For preparation of malt grist were used different disintegration equipment (two roller mill and disc mill). The method of differential pressure measuring is used for the determination of porosity of malt grist layer, defined as fraction of the volume of voids over the total volume. Measurement confirmed the logical assumption; the higher-pressure difference is above and below the spent grain layer, the lower value of porosity.
  • Kirje
    Investigation of various factors on the germination of chia seeds sprouts (Salvia hispanica L.)
    (2019) Nadtochii, L.A.; Kuznetcova, D.V.; Proskura, A.V.; Apalko, A.D.; Nazarova, V.V.; Srinivasan, M.
    Salvia hispanica L. is capable to produce a large amount of green matter, which can be used as a source of biologically active substances. The purpose of this research was to select the optimal factors for the chia seed sprouts (Salvia hispanica L.) germination. Dark variety chia seeds (100 grains/sample) were investigated. The most significant factors for the process of sprouting were selected as the study factors, such as the water mass fraction, the temperature and the light exposure for seed germination. The output parameters of the experiment were seed germination energy, germination of seeds, speed of germination and seedling vigor. It was revealed that the mass fraction of added water had the greatest influence on the growing process of chia seed sprouts. The optimal amount of water for producing the chia seed sprouts was in the average of 4 mL/sample. As a result, it was noted that an insufficient or excessive amount of water had a negative effect on the chia seed sprouts germination. The optimum temperature for germination of chia seed sprouts was 25 °C. The optimal light factor was also determined; in particular light exposure peaks occur in the red spectrum with a wavelength of 660 nm and a blue spectrum with a wavelength of 450 nm.
  • Kirje
    Impact of using the developed starter culture on the quality of sourdough, dough and wheat bread
    (2019) Savkina, O.; Kuznetsova, L.; Parakhina, O.; Lokachuk, M.; Pavlovskaya, E.
    There is no technological necessity of sourdough usage when preparing wheat bread as it can be prepared without sourdough but only with yeast using. However, sourdough helps to solve such problems as fast microbial spoilage, unexpressed taste and smell, crumbling crumb. The use of sourdough prepared with directional cultivation of microorganisms allows to produce high-quality competitive bread. Developing a starter culture with an optimized microbial composition was the purpose of this study, allowing the quality and the microbiological stability of wheat bread improving. A new starter microbial composition for the sourdough was developed. Lactic acid bacteria strains L. plantarum Е90, L. brevis Е120 and yeast S. cerevisiae Y139 were selected for the new composition. It was proven that the rice products using to microorganism immobilization allows saving the largest number of living cells after drying and during storage. The rate of acid accumulation in sourdough was established. The sourdough dynamic viscosity decrease at the end of fermentation by 2.2 times was established, which means that the fermentation process leads to the sourdough liquefactio. The optimal dosage was established (5–10% flour in sourdough). This dosage provided good physico-chemical and organoleptic quality indicators of bread. It was proved that the sourdough usage allows getting good-quality bread even when the flour with unsatisfactory amylolytic activity (high drop number) is used. Slowing down the microbial spoilage in sourdough bread was proven. In general, the developed sourdough wheat bread biotechnology improves bread quality and its resistance to the ropy-bread disease.
  • Kirje
    Effect of concentrate supplementation on fattening performance and carcass composition of finished meat-goat kids
    (2019) Aplocina, E.; Degola, L.
    A study on the effective usage of the concentrated feed supplement to Boer meat goat kids was carried out within the framework of the project ‘Zootechnical and economic efficiency of feeding of fodder pulses to ruminant’s meat production’. Since the Boer goat breed in Latvia is still very rare, there is a lack of experience in the feeding and production of meat goat for better carcass traits and meat quality. This study was arranged in autumn period, using the Boer cross breed male kids born in 2018. In control group (OG) four kids were kept together with mothers till finishing and were fed by oats as concentrated feed supplement. In research group (BG) four goat kids were weaned from mothers and placed in shed to explain influence of mix of 85% of oats and 15% of fodder beans as protein supplement to the fattening outcomes. In the trial kids were weighed at the starting and ending of the trial. Carcass quality is assessed according to the European standard for the classification of carcasses of sheep, where EUROP letter designations have been used to denote musculature development, and the fat deposition level is indicated by numbers 1–5. The length of the carcass and the circumference of the hips were measured using the tape measure. The carcasses were analyzed by type of tissue: muscle, bone, fat. The fastest growing rate during the fattening period of 72 days was given to BG kids with a mean daily live weight gain of 72 g, while the OG kids achieved 69 g. After slaughter, the carcass yield of OG kids was from 42.5% to 51.4%, but for BG kids was 38.5% to 42.5%. The quality of the obtained carcasses was an average, and score for musculature was from R to P class, but the average score for fat deposition was from 2.25 to 2.75 points and higher fat cover was observed in BG kids. Higher proportion of lean meat (59.1%) and fat tissues (16.3%) were observed to OG kids, but higher proportion of bone (25.9%) was in BG kid’s carcasses. The consumption of concentrated feed for 1 kg of live weight gain indicates the conversion of feed nutrients. The consumption of oats per kilogram of live weight gain was 3.21 kg for OG kids, but the consumption of the feed mix of oats and beans for BG kids was 2.83 kg. Based on physical parameters of goat kid carcass and high level of lean meat, fattening of Boer cross breed goat kids by using of oats or feed mix can be an ideal choice for farmers, which try to find new products and free market for consumers.
  • Kirje
    Effect of high pressure processing on raw pork microstructure and water holding capacity
    (2019) Sazonova, S.; Gramatina, I.; Klava, D.; Galoburda, R.
    High pressure processing (HPP) is widely used as an alternative to thermal food preservation technologies, including processed meats treatment. This technology affects food texture and water-holding capacity, which may have beneficial effect on product yield. After thermal treatment, meat partially releases water together with water-soluble proteins, which is concerned as a loss. It is very important not only because of changes in taste properties, but also economic aspects such as reduced final product weight. The aim of the study was to evaluate changes in the meat microstructure and water-holding capacity upon high pressure treatment. Pork samples were treated at various pressures and holding times, namely, 300 and 600 MPa with a 1 and 15 minutes holding time at each pressure. Untreated sample was regarded as a control. Microstructure of pork meat was evaluated after the paraffination of the samples. Fibre cross section area and space between fibres were measured and reported. Water-holding capacity was measured by centrifugation of meat samples over filter and calculating released amount of juice. Results indicated that fibre size did not change significantly after treatment at 300–600 MPa pressure comparing to the control sample – untreated meat. However, high pressure can affect hydrophobic properties of myofibrillar protein. The experimental results showed that waterholding capacity increases with the high pressure treatment. It is an important issue in meat processing industry, because HPP treatment allows reducing the water loss in fresh pork.
  • Kirje
    The study of physical properties of spray dried whey and milk permeates lactose
    (2019) Žolnere, K.; Ciproviča, I.
    The aim of this study was to investigate substrate and environment effect on the physical state of lactose crystals, their stability and behaviour comparing with pure lactose which traditionally used in an analysis. Sweet and acid whey permeate as well as milk permeate were analysed. Mini spray-drier (BÜCHI B-290, Labortechnik AG, Switzerland) was used for the study. Lactose optical rotation was measured with a polarimeter, structural characteristic was carried out by X-ray diffractometer and glass transition analyses was made by TGA/DSC. α-Lactose monohydrate (Sigma-Aldrich, Germany) was used as a control. All spray-dried permeates samples showed amorphous state lactose crystals. The DSC analysis demonstrated a glass transition in the interval of 85–95 °C, melting 202–204 °C for spray-dried permeates lactose. In turn, the control sample showed crystallization at 158 ± 0.5 °C and a melting peak at 226 ± 0.5 °C. Optical rotation of spray-dried lactose obtained from sweet and acid whey permeate and milk permeate was in the range from 18 to 28°, control sample 52°. The study results showed that substrate, sample pH, ingredients and their derivatives impact lactose glass transition and mutarotation. The current study highlights the essential physical properties of spray-dried permeates lactose and the importance of its purity in food, cosmetic and pharmaceutical industry.
  • Kirje
    The effect of cadmium and lead pollution on growth and physiological parameters of field beans (Vicia faba)
    (2019) Alle, V.; Osvalde, A.; Vikmane, M.; Kondratovics, U.
    Research on the impact of soil contamination on crops is important as plants directly take up heavy metals from the soil through the roots, so heavy metals can enter the food chain. The aim of this study was to investigate the impact of cadmium (Cd) and lead (Pb) pollution on growth and physiological parameters of field beans. Plants in the vegetation experiment were grown under controlled conditions. Changes in growth and physiological parameters were studied at five levels of Cd (0–25 mg L -1 ) and at 6 levels of Pb in substrate: from (0–1,000 mg L -1 ) at the first day of the experiment, to (0–2,000 mg L -1 ) at the end of the experiment after gradual Pb additions after every sample collecting day. Methods used for analysing the plant material: the content of amino acid proline and photosynthetic pigments were determined by spectrophotometry; chlorophyll a fluorescence parameters – using continuous excitation chlorophyll fluorimeter. The fresh weight of plant above-ground parts and roots was detected. The growth and development of field beans was slightly influenced by increasing amount of Cd and Pb in substrate only at the end of the experiment. The highest Cd treatments (Cd20 and Cd25) caused 2.5 and 1.3 times increased proline concentration in bean leaves. The chlorophyll a + b content and chlorophyll a fluorescence parameter Fv/Fm changed differently throughout the experiment. In general, during the experiment, there was a tendency for the content of proline in leaves for Pb treatments to be increased compared to control. At the end of the experiment the content of proline in field bean leaves of the highest Pb treatments (Pb600 + 100 + 400 + 500, Pb800 + 100 + 400 + 500 and Pb 1,000 + 100 + 400 + 500) was 1.66, 1.44 and 1.55 times higher, respectively, than that of the control plant leaves. The negative impact of exposure to Pb on chlorophyll a + b, chlorophyll a fluorescence parameter PIndex and Fv/Fm in bean leaves was less pronounced compared to Cd. The obtained results confirm that field beans until their flowering stage can grow and develop in the presence of a large amount of Cd and Pb in substrate without significant growth inhibition and detrimental impact on physiological parameters, if optimal cultivation conditions are provided.
  • Kirje
    Effect of ultrasonic treatment on the dissolution of milk solids during the reconstitution of skim milk powder
    (2019) Popova, N.; Potoroko, I.; Kretova, Y.; Ruskina, A.; Tsirulnichenko, L.; Kalinina, I.
    The producing reconstituted milk products that retain the same sensory properties as those of raw milk products is of high interest to the food industry In the technology of producing reconstituted milk processing products, the most significant factor that determines the component transition degree and the usefulness of the product being produced is the recombination process. It determines the possibility of bringing the organoleptic characteristics of reconstituted milk to the properties of the genuine one. One promising method to improve the process of milk powder recombination is ultrasonic exposure. The aim of the present study is to improve the process of milk powder recombination using ultrasonic exposure. The results of the conducted studies show that the ultrasonic treatment eliminates the agglomerates of dried milk particles in water and provides more accessible interaction between the particles and water, and as a result, improves the recombination process. The application of ultrasonic treatment during the reconstitution of the skim milk powder improved the dissolution of milk solids, as evidenced by around a 75% reduction in the amount of centrifuged insoluble sediment. The mass fractions of protein and lactose have increased by 4.8 and 6.5%, respectively.
  • Kirje
    The effect of ageing on chosen quality characteristics of skeletal muscles of Aberdeen Angus bulls
    (2019) Soidla, Riina; Kerner, Kristi; Tepper, Marek; Tänavots, Alo; Kaart, Tanel; Jõudu, Ivi; Estonian University of Life Sciences. Institute of Veterinary Medicine and Animal Sciences. Chair of Food Science and Technology; Estonian University of Life Sciences. Institute of Veterinary Medicine and Animal Sciences. Chair of Animal Breeding and Biotechnology
    The objective of the trial was to study the qualitative parameters of two muscles of Aberdeen Angus bulls with 250–300 kg carcass weight. After slaughter, longissimus thoracis et lumborum (LD) muscle and unseparated semimembranosus and adductor femoris(SMA) muscles were removed from the chilled carcasses. Muscles were vacuum-packed and wet aged at +2 °C for 10, 14, 18 and 20 days. Meat pH, electrical conductivity, shear force and colour were measured in all ageing times. Two thermal treatment methods (sous-vide (SV) and grilling) were used to determine cooking losses. The effects of muscles, ageing times and muscles by ageing times interaction was found with two-factorial analysis of variance. The effects of muscles, ageing times and muscle groups by ageing time interaction for raw and SV treated meat shear force was significant. Ageing decreased SV treated meat shear force from day 10 (40.8 N) to 18 (29.7 N). Fresh and SV treated LD muscle was tougher compared to the SMA muscle group, but SM showed a better response to the tenderness within 20 days of ageing. Redness and yellowness value was higher in the SM group in comparison to LD. Muscles showed good colour (lightness, redness and yellowness) stability within ageing for 20 days. No interactions were found between muscle groups and ageing times for SV treated and grilled beef cooking losses. However, SV treated meat lost more weight than grilled meat slices. The present study suggests that the optimal ageing time for meat is 18 days when the grilled meat cooking loss is the lowest.
  • Kirje
    Accelerated technology of rye bread with improved quality and increased nutritional value
    (2019) Dubrovskaya, N.; Savkina, O.; Kuznetsova, L.; Parakhina, O.; Usova, L.
    Accelerated bakery technologies do not always ensure high bread quality. The taste and smell of bread is less pronounced when compared with the traditionally prepared bread and it is quickly subjected to microbial spoilage. The aim of the research was to develop an improved composite mixture for the accelerated technology of rye bread, which would improve its quality, nutritional value, extend shelf life and microbiological stability. Rowan powder (botanical species Sorbus aucuparia) as unconventional raw ingredients of high nutritional and biological value was used. Rowan powder has high acidity (40 degrees or 5.7% in terms of malic acid) and contains a wide range of organic acids, including volatile acids (2–3%) and preservative acids (such as sorbic acid), as well as other micro- and macronutrients. New acidifying additive with rowan powder was created. The optimal dosage of rowan powder in the new acidifying additive by 13% per 100 kg of flour allows bread making with higher specific volume, acidity and porosity of the crumb compared with the control sample. The research proves that rowan powder usage in the accelerated bread technology improves its organoleptic and physico-chemical indicators and also increases the content of dietary fiber, vitamins and minerals. The content of fibers in custard bread with rowan powder was 1.85 times higher than in the control sample. The rowan powder usage has a positive effect on the preservation of bread freshness during its storage. The rowan powder usage slows down the custard bread mould disease.
  • Kirje
    Winter rye grain quality of hybrid and population cultivars
    (2019) Linina, A.; Kunkulberga, D.; Kronberga, A.; Locmele, I.
    Rye (Secale cereale L.) is an important European crop used for food that is grown primarily in Eastern, Central and Northern Europe. Consuming rye grain products provides a rich source of dietary fibre as well as several bioactive compounds with potentially positive health implications. The goal of the research was to compare the rye grain quality of hybrid and population cultivars. A field trial was carried out in Priekuli Research Centre, Institute of Agricultural Resourses and Economic (in Latvia) during a three-year period: 2014/2015, 2015/2016, and 2016/2017. The trial included population winter rye cultivars ‘Kaupo’, ‘Amilo’, ‘Dankowskie Amber’ and hybrid rye cultivars ‘Brasetto’, ‘Su Drive’, ‘Su Mephisto’. Rye grain quality indices were analysed at Latvia University of Life Sciences and Technologies, in Grain and Seed Research laboratory. Average data in our investigation (three years) show that cultivar, crop-year (weather conditions) and cultivar×crop-year interaction significantly (P < 0.05) affected rye grain protein content, starch content and Hagberg falling number. A significant negative correlation was found between protein content and starch content r = -0.937 (population cultivars grain), r = -0.944 (hybrid cultivars grain), medium strong negative correlation was found between protein content and falling number, respective r = -0.549 and r = -0.573. Differences between hybrid cultivar grain protein content, falling number and starch content comparing with population cultivar grains were not observed. The results of the current research show that the quality of all the studied cultivars meets the requirements for high-grade rye grains for food consumption.
  • Kirje
    Biosynthesis of glycosidase inhibitors on wheat bread wastes hydrolysate medium by Streptomyces sp. 170
    (2019) Sharova, N.; Ibrahim, M.; Prensiva, A.; Vybornova, T.; Barakova, N.; Manzhieva, B.
    The aim of the present study is to investigate the potential effect of bread hydrolysate as a novel nutrient medium for cultivating Streptomyces sp. 170 (S.170). Moreover, it evaluates the productivity and inhibitory activity of pancreatic α-amylase inhibitors (PAAI). Bread hydrolysate medium (BHM) and corn starch hydrolysate medium (CHM) prepared with αamylase enzyme concentrations (1.5 and 2.5 units g -1 bread) and (1.5 units g -1 corn starch), respectively were utilized in the study. The Seherde-Blair and modified Akulova methods were applied to evaluate the carbohydrates concentration and the inhibitory activity of the media respectively. Results of bread and corn media were compared to each other. Furthermore, the activity of PAAI synthesized by S.170 was compared to other Streptomyces species. The results showed a significant difference (P < 0.05) between the total simple sugars (glucose + maltose) concentration produced in CHM (27.5%) and BHM prepared with α-amylase 1.5 units (45.1%). Besides, BHM produced by α-amylase 2.5 units demonstrated the maximum total concentration of simple sugars (49.9%). In addition, 48 h of S.170 incubation were quite enough to exhibit the highest inhibitory activity (2,632 IU mL-1 ) in BHM prepared with α-amylase 2.5 units. The analysis demonstrated a non-significant difference in the inhibitory activity of PAAI in CMH (1,300 IU mL-1 ) and BMH with α-amylase 1.5 units (1,111 IU mL-1 ). Also, compared to other Streptomyces species, S.170 conferred highly active PAAI. In conclusion, BHM showed its efficiency to a great extent in the cultivation of S.170 and production of PAAI with a notable high activity.
  • Kirje
    Surface wax composition of wild and cultivated Northern berries
    (2019) Klavins, L.; Kviesis, J.; Klavins, M.
    Surface wax of plants is the outer layer, which protects the plant from dehydration, extreme temperatures, UV radiation and changes in the environment, as well as attacks from moulds and bacteria. Studies of berry surface wax are of importance to understand metabolism character (factors affecting wax layer composition in different berry species) as well as to increase the shelf life of berries and increase the microbial resistance. The aim of this study was analysis of surface wax composition of commercially grown 8 blueberry (Vaccinium corymbosum) varieties, wild bilberry (Vaccinium myrtillus L.) and bog bilberry (Vaccinium uliginosum L.). More than 80 different compounds were identified and quantified belonging to 9 groups of compounds, namely, alkanes, phytosterols, alcohols, fatty acids, phenolic acids, ketones, aldehydes, esters and tocopherols. Significant differences were found between blueberry (Vaccinium corymbosum) and bog bilberry (Vaccinium uliginosum L.) surface wax composition. Amongst studied berries differences were found in concentrations of triterpenes (up to 62% in blueberries), and fatty acids (up to 26% in bilberries) identifying species related differences influencing associated functional properties of berry wax (antimicrobial activity, stress caused by environmental changes). Blueberry variety ‘Polaris’ had the highest amount of ursolic acid (9.30 g 100 g -1 ), alpha-amyrin (11.07 g 100 g -1 ) and lupeol (10.2 g 100 g -1 ). Research on berry surface wax composition could help reduce loss of commercially produced berries due to environmental impacts or microbial attacks, prolonging shelf life and overall quality of fruits and vegetables post-harvest.