2020, Vol. 18, Special Issue 3

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/6066

Sirvi

Nüüd näidatakse 1 - 20 25

Acceptance of low-sugar yoghurt among Latvian teenagers
(2020) Zagorska, J.; Ciprovica, I.; Straumite, E.; Majore, K.
Over a thousand year history, yoghurt has become one of a widely consumed product in the world. Its reputation as a healthy food has been undermined recently by concerns over the high sugar content. The majority of consumers expects and prefers yoghurts to be sweet. However, governments across Europe are calling for significant cuts in the amount of added sugar used in yoghurt production. The aim of the study was to evaluate the acceptance of low-sugar yoghurt produced by different commercial β-galactosidases by teenagers. Standardised milk with fat content 2.0% (SC Tukuma piens) was pasteurized at 95 ± 1 °C 5 min, cooled down till 43 ± 1 °C and fermented with β-galactosidase and starter YC-X11 (Chr. Hansen, Denmark) and fermented till pH 4.50 ± 0.20. Different commercial β-galactosidases: Nola™ Fit 5500, Ha-Lactase 5200 (Chr. Hansen, Denmark), GODO-YNL2 (Danisco, Denmark) and BrennZyme (Brenntag PolskaSp, Poland) were used. Fermented samples were gently mixed and cooled down till 6 ± 1 °C and 5% (w/w) of sugar was added to each sample. Sensory evaluation of the yoghurt’s samples was performed by teenagers (14–18 years, n = 50) at Aizputes Secondary School (Latvia). Lactose and monosaccharides concentration prior to sugar addition was detected by HPLC (Shimadzu LC 20 Prominence, Japan). The lactose hydrolysis into glucose and galactose by the use of β-galactosidase helps to increase sweetness through an occurrence of natural sugars in milk. During sensory evaluation, teenagers admitted the yoghurt with reduced sugar as sweet, significantly sweeter (P < 0.05) was yoghurt sample with Nola™ Fit 5500. The results demonstrated that it is possible to reduce sugar in yoghurt production and to gain consumer acceptance through the occurrence of glucose and galactose, but it is problematic to offer lactose-free or reduced lactose products to consumers without lactose intolerance.
Analysis of safety indicators for poultry products produced in subsidiary farms in penitentiary facilities
(2020) Chernikova, O.; Pityurina, I.; Terentyev, A.; Rakhmaev, E.
The production of poultry, eggs and their processed products is growing rapidly worldwide. Poultry products are in great demand; however, they are a source of a number of risks: physical, chemical, as well as microbiological. Ensuring food safety is currently the main aspect for the global food industry, including for the production of poultry products. The article discusses the safety and quality of poultry products produced in subsidiary farms of correctional facilities of the penal system. Attention is drawn to the risks and threats of sanitary and epidemiological well-being that arise in connection with the intensification of the impact of negative environmental factors. In the subsidiary farms of correctional facilities, the cage-type bird keeping system and the frequency of feeding are regulated depending on the age of the bird. The results of the analysis have shown that poultry and chicken eggs comply with established sanitary standards. Thus, the average heavy metal content in poultry meat was: Hg - 0.0061 mg kg-1 , Cd - 0.0233 mg kg-1, As - 0.0501 mg kg-1, Pb - 0.1765 mg kg-1; in the egg: Hg - 0.0072 mg kg-1 , Cd - 0.0198 mg kg-1, As - 0.0485 mg kg-1, Pb - 0.1812 mg kg-1. Antibiotics, radionuclides and dioxins were not found in poultry meat. The pesticide content in poultry meat was below the permissible level: by 2.2 times of DTM and its metabolites, and hexachlorocyclohexane (a, b, g - isomers) - by 5 times. Coliforms, Staphylococcus aureus, Proteus, as well as pathogenic salmonella, listeria were not found in poultry meat and eggs. NMAFAnM in meat amounted to 0.5×104 , in the egg - 1×103 CFU g-1 incl. In general, poultry products produced in correctional facilities are of high enough quality and can be used to prepare various dishes not only for adults but also for baby food. These estimates allow us to conclude about a fairly high level of quality and safety of this product.
Antioxidant content of dark colored berries
(2020) Ozola, B.; Dūma, M.
Blackberries (Rubus caesius), elderberries (Sambucus nigra L), highbush blueberries (Vaccinium corymbosum L) and black currants (Ribes nigrum) were selected for research on their content of phenolic compounds, including anthocyanins and comparing their content in these berries. Samples were also assayed for ascorbic acid and soluble solid content. The unifying mark of these fruits is purple-black color, which indicates high content of anthocyanins. Analyses of these fruits showed that they contain high biological activity components that justify the uses of these fruits. The research was done at the Department of Chemistry, Latvia University of Life Sciences and Technologies, year 2019. Berry samples were bought at the supermarket (highbush blueberries) or collected from garden in Jelgava, Latvia (blackberries, elderberries and black currants). All berries were at full maturity. The content of ascorbic acid, total phenols, anthocyanins, flavonoids as well as soluble solids was determined. Descending order of ascorbic acid content in berries is: black currants > blackberries > elderberries > highbush blueberries. Elderberries had the highest content of anthocyanins, total phenols and flavonoids on average 161.5, 537.9 and 112.6 mg 100 g -1 FW, respectively. The content of soluble solids changes from 5.83 Brix (elderberries) to 13.67 Brix (black currants).
Applying beetroot as food ingredient in ice-cream production
(2020) Evstigneeva, T.; Iakovchenko, N.; Kuzmicheva, N.; Skvortsova, N.
The development of new food products with functional ingredients of plant origin is highly promising and relevant direction in food industry. Assortment of products, including ice cream is constantly expanding due to the introduction of various plant ingredients into its composition, enriching the product with health beneficial nutrients. In this study, beetroot (Beta vulgaris) was selected as a plant component for ice cream production. The roots of common beets contain many useful inorganic and organic substances, such as carbohydrates, proteins, organic acids, mineral salts, betalaines, vitamins, folic acid and betaine. The influence of different thermal treatment techniques of beetroots on the content of dry substances and organoleptic properties of beetroot puree have been compared and analyzed. The heat exposure technique recommended for beetroots is microwave processing for 9 minutes at a power of 800 watts. This method of heat treatment ensures the culinary readiness of vegetable raw materials while preserving dry substances in it, including betanine. The effect of the beetroot puree dose on the formation of the ice cream quality was studied. The recommended dose of the beetroot puree was established as 20%.
Biochemical composition and quality of herring preserves with addition of bio-protective cultures
(2020) Bazarnova, J.; Korableva, N.; Ozerova, O.; Moskvicheva, E.
Herrings rich in vitamins B12, A, D, minerals, including calcium, potassium, magnesium, iodine, possess high levels of lysine, tyrosine, phenylalanine and tryptophan, as well as omega-3 unsaturated fatty acids, namely eicosapentanoic, docosahexoenoic and docosapentoenoic. To suppress the microbiological spoilage of fish preserves, it is promising to use bio-protective cultures that have minimal impact on the production process and product properties. Bacterial strains are able to exert a static effect on the microflora, which causes biodeterioration of food products. Microorganisms as part of bio-protective cultures are included in the fermentation process, so they can be attributed to ordinary food ingredients, so there is no need to put separate information on the packaging. The chemical composition of the frozen Atlantic and Pacific herring fillet, the amino acid composition of proteins, and the fatty acid composition of lipids were studied. The difference between Atlantic and Pacific herrings was detected, which consists in a significantly higher content of docosahexaenoic acid. The difference in the fractional composition of triacylglycerols for the Atlantic and Pacific herring was established. The microflora of SafePro B-2 biological product (Chr. Hansen GmbH), containing multiple strains of Lactobacillus sakei, and the viability of the culture in preserves fillings were studied. The experimental development of canned food with SafePro B-2 additives was carried out. Microbiological, organoleptic and biochemical indicators of the preserves quality during cold storage were studied. The influence of introduced culture on the dynamics of preserves curing period and their shelf life was established.
Biochemical responses of 5 buckwheat (Fagopirum esculentum Moench.) cultivars to seed treatment by Azospirillum brasilense
(2020) Honchar, L.; Mazurenko, B.; Sonko, R.; Kyrpa-Nesmiian, T.; Kovalenko, R.; Kalenska, S.
Cultivation condition have a large effect on efficiency of buckwheat. Drought, high temperatures and their fluctuations, salinity, oxygen deficit in the soil, ultraviolet radiation, and abnormal nutrient content in the soil are the most common reasons of decreasing productivity of plants. Suboptimal parameters of the cultivation technology can also cause abiotic stress. Plant can decrease its efficiency from 30% to 50% depend on stress conditions. Using bacterial cultures is one of the preventive approaches to overcoming the negative impact of stressors. Microorganisms produce biologically active substances that stimulate plant growth, increase their resistance to abiotic factors. They are growth regulators and long-acting anti-stressants as well. Malondialdehyde (MDA) is formed as a result of the oxidative degradation of polyunsaturated fatty acids. Fructans are polysaccharides that are derived from D-fructose residues found in higher plants, green algae and bacteria. Fructans are involved in the adaptation of plants to the action of abiotic stressors and are valuable nutrients. The effect of Azospirillum brasilense pre-sowing treatment of buckwheat seeds on physiological and biochemical processes of MDA and fructan content was researched. Seed treatment with Azospirillun brasilense reduced the content of MDA in Ukrayinka and Syn 3/02. Sofia and Olga had a low level of MDA, but seed treatment increase it. Seed treatment increased the efficiency of photosynthesis (Fv / Fm) in Syn 3/02 from 0.58 to 0.72; in other varieties this effect was negligible. All cultivars have a strong relation between MDA and fructan content, that shows their participation in responses on cultivation conditions. Efficiency of photosynthesis in flowering–seed formation stage (BBCH 65–75) was close to maximum in field condition(0.70 ± 0.05) and seed treatment can increase it.
Changes in α-amylase activity in honey during the freeze-drying process
(2020) Keke, A.; Cinkmanis, I.
Honey is a natural product, which is appreciated for its sweetness, high nutritional value and health benefits all over the world. Despite all benefits, the usage of honey in food industry is limited due to its high viscosity. The use of dried honey could be an alternative to liquid honey, and would allow to use it as an additive in a range of many different food products such as sauces, beverages, yogurts etc. There are many parameters, which are used to determinate the quality of honey. α-amylase (diastase) activity is one of the most important criteria to determine the quality and freshness of honey. The aim of the present study was to investigate and compare α-amylase activity in liquid honey samples and freeze-dried honey samples. Overall, 18 honey samples were dehydrated using a freeze-drying method. Freeze-drying of the samples was carried out at – 50.6 °C and the pressure was 0.036 mbar for 72 hours. α-amylase activity in the honey samples was tested using Amylazyme test tablets. The obtained results showed variability in α-amylase activity after the freeze-drying process. As hydroxymethylfurfural (HMF) is another important quality parameter of honey, the content of HMF was determined in the samples by high performance liquid chromatography. In some samples the concentration of HMF after freezedrying increased and was higher than it is allowed according to the International Honey Commission (for example, 55.75 mg kg-1 ).
Development of formulation and technology of non-dairy soy-coconut yogurt
(2020) Kosterina, V.; Yakovleva, A.; Koniaeva, V.; Iakovchenko, N.
Yogurt provides an organism with probiotics, which can help digestion. However, many people do not consume dairy for a lot of reasons such as lactose intolerance, milk protein allergy, environmental and ethical concerns. The aim of the research was to develop formulation and technology of plant-based yogurt made of coconut and soy milk. The possibility of using the composition of coconut and soy milk was investigated. The effect of using different ratios of coconut and soy milk on rheological and sensory acceptability was studied. Soy milk containing 20, 30, 40 and 50% coconut milk were used in the production of soy yoghurt using commercially available yoghurt starter. The physico-chemical composition, water activity, rheological and organoleptic properties, fatty acid composition and microorganism viability were investigated. Presented production procedure enables the manufacture of a product with satisfactory functional properties and organoleptic properties.
Development of metabolic engineering approaches to regulate the content of total phenolics, antiradical activity and organic acids in callus cultures of the highbush blueberry (Vaccinium corymbosum L.)
(2020) Ramata-Stunda, A.; Valkovska, V.; Borodušķis, M.; Livkiša, D.; Kaktiņa, E.; Silamiķele, B.; Borodušķe, A.; Pentjušs, A.; Rostoks, N.
Blueberry (Vaccinium corymbosum L.) is increasingly cultivated to produce high quality berries for consumption and potential applications in medicine, nutrition and as industrial precursors. Seasonal availability sets limitations on chemical compound isolation from cultivated plants. Biotechnological solutions, such as tissue cultures and metabolic engineering, can provide sufficient amounts of plant material with reasonably high metabolite levels, which may be adjusted by different strategies. Here, we describe our approach to modifying total phenolic content (TPC), antiradical activity (ARA) and amounts of selected organic acids in in vitro cultures of two varieties of V. corymbosum by varying the growth media. TPC, ARA and acid levels were determined in mature leaves of field-grown plants and in stable callus cultures derived from leaves of varieties ‘Bluecrop’ and ‘Duke’ grown on Murashige-Skoog (MS) and Woody plant (WP) media supplemented with varying concentrations and combinations of different plant growth hormones. TPC varied from 83 mg g -1 dry weight (DW) to 142 mg g -1 DW in leaves of ‘Bluecrop’ and ‘Duke’, respectively, and correlated with their ARA with ‘Duke’ at the lead. For callus cultures the highest ARA, as well as the highest TPC of 94 mg g -1 DW was observed in ‘Bluecrop’ grown on WP medium with 2,4-dichlorophenoxyacetic acid (2,4-D). High level of quinic acid was found in the mature leaves of all tested varieties, while callus cultures exhibited relative increase in amounts of malic, succinic and citric acids instead. Oxalic acid was found only in callus cultures.
Effect of different sugar sources on P. rhodozyma Y1654 growth and astaxanthin production
(2020) Kanwugu, O.N.; Shatunova, S.A.; Glukhareva, T.V.; Kovaleva, E.G.
Phaffia rhodozyma (also known as Xanthophyllomyces dendrorhous) is one of the most promising natural sources of commercial astaxanthin. It has high growth rates, easy cultivation conditions and able to utilize different carbon substrates. This provides an opportunity to further lower production cost by using industrial waste such as molasses. This research therefore evaluates the growth dynamic and astaxanthin production of P. rhodozyma Y1654 growing on soy and sugar beet molasses-based media. Liquid growth media based on soy molasses (SM), sugar beet molasses (SBM) and glucose (control) as main sugar source with peptone and yeast extract supplementation were inoculated with 48 h old seed culture (grown in standard glucose media: 2.0% glucose, 1.0% peptone, 0.2% yeast extract) and incubated at 20 °C with stirring speed of 180 rpm for 7 days. Samples were taken daily throughout the study period to assess; cell count, dry cell weight (DCW) and amount of astaxanthin. Soy molasses-based media resulted in the highest biomass yield (7.7 g L -1 ) followed by SBM (5.8 g L -1 ). Generally, more than 90% of initial fermentable sugar was consumed at the end of the study. However, about 40% of total sugar in SM was unassimilable by P. rhodozyma Y1654. The highest astaxanthin yield was observed in the control media (77 µg g -1 of DCW). Cultivation of P. rhodozyma Y1654 in SBM resulted in as much as twice (32.8 µg g -1 of DCW) the astaxanthin yield of SM (12.4 µg g -1 DCW). Molasses-based media are good for growth of P. rhodozyma Y1654 but for astaxanthin production, they need further optimization.
Effect of simultaneous inoculation of commercial yeast starter cultures on Kombucha fermentation
(2020) Abel, Maarja; Andreson, Helena; Estonian University of Life Sciences. Institute of Veterinary Medicine and Animal Sciences. Chair of Food Science and Technology
Kombucha – a spontaneously fermented tea beverage, produced by SCOBY (a symbiont of bacteria and yeasts), has become popular in recent years. Its functional properties and features for industrial production and treatment remain largely unknown, however. Our aim of using additional yeast cultures during the primary fermentation was to modify and ultimately improve the sensory properties of the kombucha beverage. During five fermentation experiments the total viable count (TVC) of microbes was determined both in Kombucha and SCOBY samples. The first four fermentation experiments were conducted to stabilize the growth of SCOBYs that were initially of different origin. The last (5th) fermentation contained the simultaneous inoculation of three different active S. cerevisiae cultures into the sweetened black tea together with the SCOBY and was followed by a sensory analysis. Two samples remained as control samples without additional yeast starter culture. The yeast starter cultures affected the microbial counts of Kombucha, but the effect on the microbial count of SCOBY was not statistically significant (p >0.05). The Kombucha containing wine yeast culture had the lowest sensory quality, while Kombucha containing brewer's yeast had the most pleasant flavour and aroma. In conclusion, the simultaneous fermentation with commercial yeast cultures had a minor effect on the microbial counts in SCOBY when compared to the fermentation time, but all added cultures clearly modified the taste and aroma properties of the Kombucha drinks.
The effect of yeast growth stages on the absorption of polyphenols
(2020) Harbah, R.A.; Meledina, T.V.; Morozov, A.A.
Colloidal stability of beer is one of the most critical challenges facing the brewing industry. In brewing, stabilization agents are widely used to remove colloids such as proteins and polyphenols. However, the removal efficiency of polyphenols depends on the yeast, which adsorbs these compounds on its surface. The adsorption of polyphenols on the yeast surface is associated with the zeta potential of the cell wall, which correlates with the mannan content in them. The purpose of the study was to investigate the role of yeast strains in adsorption of polyphenols (increasing colloidal stability of beer) and the correlation of this property with the mannan content in the cell wall during the fermentation. Two S. cerevisiae strains were used in this study, and the specific growth rate of yeast, the specific rate of change in the polyphenol content and the mannan content were determined. The results of this study showed that the highest mannan content in yeast was after 9 hours (the end of exponential growth phase). Its content was 10.97% by weight of dry matter in the yeast S. cerevisiae Californian Lager (M54), and 13.69% in the yeast S. cerevisiae Belgian Wit (M21). The desorption of polyphenols was observed during the period from 9 to 24 hours of fermentation, where an increase in the content of polyphenols in the medium was observed. Based on these results, it is necessary to remove the yeast at the end of the exponential growth phase to increase the colloidal stability of the beer.
Enrichment of the low-fat yoghurt with oat β-glucan and EPS-producing Bifidobacterium bifidum improves its quality
(2020) Ibrahim, M.; Barakova, N.; 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. ERA Chair for Food (By-) Products Valorisation Technologies of the Estonian University of Life Sciences
The addition of β-glucan or EPS-producing bacteria is mainly used to improve the quality and the acceptability of low-fat yoghurt. The purpose of this study was to investigate the effect of adding β-glucan, EPS-producing Bifidobacterium bifidum, or both on physical properties, fermentation time, and organoleptic criteria of low-fat yoghurt, additionally to the viability of L. bulgaricus and B. bifidum. Two types of low-fat yoghurt (1.5% fat) were prepared, with the addition of standard oat β-glucan by 0.15% or without its addition. Each type of yoghurt mixture was inoculated with two kinds of starters: traditional and probiotic (B. bifidum) culture. The physicochemical properties, the count of viable bacterial starter culture, and the organoleptic evaluation for all yoghurt types were evaluated after storage 24 h at 4 °C. Moreover, the fermentation time was monitored. The incorporation of both β-glucan and EPS in yoghurt resulted in the highest viscosity (13.7 mPa.s) and WHC (55.94%), besides to the lowest syneresis (28.47%). The acidity and pH of the yoghurt samples were significantly affected (p > 0.05) by the β-glucan addition. The yoghurt type Bifidobacterium glucan had the shortest fermentation time (215 min), and the maximum viability of both B. bifidum (7.63 Log CFU g -1 ) and L. bulgaricus (7.50 Log CFU g -1 ). The β-glucan had a pronounced effect on the overall acceptability of yoghurt more than the EPS. In conclusion, enriching the low-fat yoghurt with oat β-glucan and EPS-producing B. bifidum is the highest effective method for improving the yoghurt’s quality and the viability of probiotics.
The influence of milk quality and composition on goat milk suitability for cheese production
(2020) Marcinkoniene, L.; Ciprovica, I.
The goat milk production sector is growing in Latvia, therefore detailed studies are required to examine goat milk suitability for cheese production. There is still not enough information about the chemical composition and quality of goat milk, and its connection with milk renneting properties. The objective of this study was to analyse the impact of milk composition and quality on goat milk renneting properties. Fat, protein, lactose, urea content, somatic cell count and freezing point were measured by infrared spectroscopy. The curd firmness was analysed by Texture Analyser TA.HD.plus (Stable Micro Systems, UK). In total, 34 samples, including bulk milk samples (n = 3) were analysed. The analysed breeds included the Latvian Native (n = 9), Saanen (n = 14) and milking crosses (closer to Anglo Nubian) (n = 8). The samples were arranged according to the lactation, somatic cell count and breeds. Obtained fat content varied from 1.72 to 4.67%, and the protein content – from 2.93 to 4.57% in individual goat milk samples. The highest fat to protein ratio was established in the Saanen breed goat milk (0.96), but the lowest – in milking crosses’ milk (0.80). The highest somatic cell count was determined in the second lactation goat milk (1421 thous mL-1 ) and in milking crosses’ goat milk (1027 thous mL-1 ). The somatic cell count influences curd firmness in cheese, and the highest fat to protein ratio was established in the first group samples with lower somatic cell count.
The influence of the flour amylolytic enzymes activity, dosage of ingredients and bread making method on the sugar content and the bread quality
(2020) Savkina, O.; Kuznetsova, L.; Burykina, M.; Kostyuchenko, M.; Parakhina, O.
The aim of this study was to study the effect of the sugar dosage, improver dosage, type of bread making methods and the amylolytic activity of five different types of wheat flours on the sugar content and the bread quality. The sugar content in the bread crumb was determined using the Bertrand’s method and was counted for sucrose. When the dough was prepared using accelerated technology, the improver affected the sugar content in the bread due to the starch enzymatic hydrolysis. The effect of improver dosages and sugar dosages on the sugar content in the bread was established. When using the improver, the sugar content exceeded the permitted amount in 1.25 times. No correlation was found between sugar dosage in recipe and bread quality when accelerated bread making way was used because of short fermentation time. The influence of wheat flour amylolytic activity (falling number) on the sugar content in bread was established, including when sugar was absent in the formulation. When sugar presented at bread formulation, the flour amylolytic activity did not significantly affect the bread quality, except the acidity. The bread making way had a greater influence on bread quality than falling number of flour. When sugar absent at bread recipe, the higher was the flour amylolytic activity, the higher was the sugar content in bread made by traditional way due to the starch deterioration. Obtained data have shown that when a baking method is selected, the flour amylolytic activity must be taken into account.
Low–fat high–protein fermented milk product with oat extract as a nature stabilizer
(2020) Morozova, O.; Ashikhmina, M.; Zabodalova, L.
Nowadays, the use of plant components in terms of their pronounced functional properties is of high relevance. Oat extract contains gums, β–glucans, vitamins (A, B1, B5, B9, PP, H), minerals (Fe, I, K, Si, Mn, Cu, Mo, etc.) and essential amino acids. It has been proven that a long–term use of β–glucans showed the reduction of the risk of cardiovascular disease and diabetes and the regulation of cholesterol and blood sugar. β glucans also have immunoprotective, anti–inflammatory, antimicrobial, prebiotic effects and improve intestinal motility. The aim of study was to develop the technology of low–fat high–protein fermented milk product with functional characteristics. Oat extract was used as a natural stabilizer and a source of β–glucans. Maceration technique was used for the extraction. The recommended extraction parameters were established and physicochemical characteristics of the extract were studied. The recommended doses of oat extract when introduced into milk and the optimal heat treatment conditions of the milk–oat mixture were determined. The influence of temperature on the gel–forming properties of oat extract was investigated. The effect of oat extract on rheological behavior, water–holding ability and shelf life of the finished product was studied. Regular consumption of lactic acid microorganisms has a positive effect on the digestive system and metabolism. Based on the organoleptic characteristics and physicochemical changes during the fermentation process in comparison with the control sample (without oat extract), the recommended starter culture combinations (Lactobacillus acidophilus, Lactococcus lactis subsp, Lactobacillus bulgaricus) were proposed.
The possibility of using microwaves to obtain extracts from berry press residues and jelly products with bioactive characteristics
(2020) Nilova, L.; Ikramov, R.; Malyutenkova, S.
The paper explores the possibility of development a microwave technology for obtaining water extracts from berry press residues (wild bilberries and cranberries as the objects) and jelly products based on them, which will allow using the waste of freshly squeezed juices in business, such as restaurants and catering services. The antioxidant activity (DPPH and FRAP methods), content of phenolic compounds, flavonoids, anthocyanins, ascorbic acid were determined in berries and in berry press residues. The antioxidant activity of bilberry press residues was due to anthocyanins, and the activity of cranberry press residues was due to flavonoids. Using the microwave oven (magnetron power 800 W, frequency 2,450 MHz), water extracts were obtained in the ratio: for cranberries 1.5:10, for bilberries 1:10. The antioxidant activity of extracts depended on the type of berries and was greater in extracts from bilberry press residues. Extracts of bilberries and cranberries and their compositions (sugar-free and sugaradded) with gelatin as a gelling agent were used to produce the jelly products. Combining bilberry and cranberry extracts (70:30) with gelatin makes it possible to obtain jelly products without sugar. Heating of the ready recipe mixture after preliminary swelling of gelatin and without swelling of gelatin was carried out in the microwave oven. The antioxidant activity of jelly products was higher when using bilberry extracts than cranberries. An increase in the antioxidant activity of the extracts led to a slowdown in structure formation, but increased the plasticity of the products.
Quality and safety problems of sports nutrition products
(2020) Volf, E.; Simakova, I.; Eliseev, Yu.; Perkel, R.; Malyshev, E.; Zinin, A.
The purpose of this work was to study the quality and safety of some sports nutrition products. The objects of study were sports nutrition products: protein bars of ‘ProteinBar’ (Russia) and ‘Bombbar’ (Russia); capsule forms of dietary supplements ω–3, ω–6, ω–9 firms ‘Sportline’ (Russia), ‘Multipower’ (Germany) and ‘Maxler’ (USA). According to the research results, the normalized safety indicators of the fat component of the studied products for sports nutrition (acid number and peroxide) are within acceptable values. The standardized safety indicators of the fat component do not fully reflect the safety requirements for the fat component of sports nutrition products, since there are no standards for the most important indicators of fat safety – the content of secondary oxidation products – copolymers insoluble in petroleum ether and epoxides. The results obtained in the course of the work showed that in almost all of the studied samples are content of epoxides (7.5–47.6 g -1 ) and secondary oxidation products – 1% or more.
Radiation use efficiency by tomato transplants grown under extended photoperiod
(2020) Rakutko, S.; Avotiņš, A.; Berzina, K.; Rakutko, E.; Alsina, I.
The study focused on the effect of an extended photoperiod on the radiation use efficiency (RUE) by the tomato transplants (Solanum lycopersicum L.) in the pre–reproductive period. In two consecutive series of experiments, the photoperiod was 16 and 22 hours. The photon irradiance at the plant tops was maintained at low, medium and high levels: 100, 170 and 240 μmol m–2 s –1 , respectively. The plants were grown under two lighting systems with different light quality. The difference was7% higher blue flux share in Spectrum II. The use of an extended photoperiod, especially in combination with high irradiance level, resulted in the plant leaf chlorosis. When varying the radiation dose components, the deviation from the reciprocity law was recorded. By the analysis results, the chlorophyll degradation was a response to the extended photoperiod rather than the radiation dose. Without additional blue flux, under a regular photoperiod, RUE reduced by 8% at the high irradiance level. Under extended photoperiod, the shift from the low to high irradiance level reduced RUE by 20–37%, with bigger reduction values being observed at higher irradiance levels. Seven percent addition of blue flux made it possible to increase RUE by 5–8% at the same and lower irradiance levels and under the regular photoperiod. With the extended photoperiod under these conditions, RUE decreased by 8–21%. The study results verify a great influence of an extended photoperiod on RUE, while the degree of influence depends on other parameters of light environment – light quality and irradiance level.
Review article: Current research trends in fruit and vegetables wastes and by-products management-Scope and opportunities in the Estonian context
(2020) Malenica, Dunja; Bhat, Rajeev; Estonian University of Life Sciences. Insitute of Veterinary Medicine and Animal Siences
Globally on an annual scale, considerable amounts of fruit and vegetables wastes (FVW) are generated in the agri-food industrial sector. Costs insured for safe disposal of FVW remains uneconomical and they can pose a serious environmental hazard if left untreated. However, FVW have high potential for reuse, recycle and recovery, which is an indication that there are productive, sustainable and affordable ways of reducing and tackling them at the industrial levels. Recent years have seen progressive innovative research on FVW management strategies, which has been developed with an idea of reducing wastes and fully exploiting its potential. Further, FVW represents a potential source of valuable compounds and bioactive ingredients. Today, there are many proposed innovative approaches for handling the FVW. These include reintroducing sub-standard fruit and vegetables (small sized or misshaped fruit and vegetable) in the market, reusing FVW for soil amendments, composting, or as an animal feed, and much more. In addition, the extracted bioactive compounds from FVW and by-products can find wide applications as a natural additive in food, cosmetics and/or in pharmaceutical applications. Currently, novel cost effective strategies have been developed for effective valorisation of agri-food wastes and by-products. The field of FVW management is still limited, thus leaving a wide gap for new ideas, novelty and applications of more efficient green techniques for complete utilization of agri-food wastes and by-products. Some of the interesting aspects on wastes and by-products management are discussed in relevance to Europe and in Estonia.

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