Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences.
Latest Publications


TOTAL DOCUMENTS

88
(FIVE YEARS 88)

H-INDEX

1
(FIVE YEARS 1)

Published By Walter De Gruyter Gmbh

2255-890x

Author(s):  
Klinta Kārkliņa ◽  
Solvita Kampuse

Abstract A fruit juice and coffee drink is an interesting combination that provides the necessary bioactive compounds and caffeine for the whole day. The coffee brewing method changes not only the amount of caffeine but also the taste of fruit juice and coffee drink. The least bitter taste is felt in cold brewed coffee, making it an ideal ingredient for a fruit juice and coffee drink. The aim of this study was to evaluate the influence of preparing technologies for creating an innovative fruit juice and coffee drink with a high content of bioactive compounds. Four different types of medium-roasted “Lofbergs” coffee beans were compared, as well as two brewing techniques: French press (hot coffee) and cold-brew. Concentration of vitamin C, pH, soluble solids content, titratable acids, total phenol content, DPPH antiradical activity, and sensory analyses were determined for all prepared samples. Concentration of vitamin C in juice with coffee was from 10.36 to 22.60 mg·100 g−1, and the highest vitamin C concentration was preserved in the pasteurised juice and coffee drink with cold-brew coffee preparation technique. Concentration of soluble solids was from 12.3 to 12.6%, titratable acids from 0.79 to 0.87%, pH from 2.68 to 2.88, total phenols from 54.31 to 129.26 mg·100 g−1, and the highest total phenol concentration was obtained in the pasteurised fruit and coffee drink with smooth and sweet coffee beans prepared using the cold-brew technique. DPPH antiradical activity was from 126.24 to 177.89 mg·100 g−1 in the tested samples, and the highest DPPH antiradical activity was detected in the pasteurised fruit and coffee drink with sweet and nutty coffee beans prepared with cold-brew technique. The best sensory profile was for coffee and juice drinks with “Lofbergs” Medium roast Fruity and Velvety Rwanda coffee beans and “Lofbergs” Medium roast prepared with cold-brew technology.


Author(s):  
Sanita Sazonova ◽  
Lolita Tomsone ◽  
Ruta Galoburda ◽  
Ilze Grāmatiņa ◽  
Thierry Talou

Abstract High-pressure processing (HPP) is well suited to combine consumer demand for meat products with minimal heat treatment without compromising product safety. In turn, herbs have antioxidant and antimicrobial properties. The aim of this study was to evaluate the application of hurdle technology combining microencapsulated horseradish root and leaf juice with HPP (300 MPa; 15 min) for extending of the raw pork meat shelf life. Water activity (aw), pH, colour, hardness, and micro-biological parameters of meat were evaluated during 21-day storage. Total plate count (TPC) in HPP treated samples was significantly smaller (p < 0.05) compared to untreated samples during storage until the day 14. On day 21, the TPC in processed samples was still slightly lower, however, at this point significance was not established between samples. Water activity dynamics in the HPP-treated microencapsulated pork meat samples differed significantly from other samples. Hardness decreased during storage, but no significant differences were found between samples. The L* values and pH of the meat were not significantly influenced by the added microencapsulated juice, but by high pressure treatment. Treatment with microencapsulated horseradish juice had a positive effect on the TPC and aw of the meat sample.


Author(s):  
Dalija Segliņa ◽  
Inta Krasnova ◽  
Sanita Alsiņa

Abstract Lonicera caerulea L., also known as honeysuckle berries, are rich in biologically active compounds, which makes them a valuable raw material for the development of functional foods. The objects of the research were three honeysuckle cultivars (‘Zoluška’, ‘Siņaja Ptica’, ‘Goluboje Vereteno’), four genotypes (No 2A; No 3; No 5; No 8) and kefir, enriched with various amounts (3–10%) of fruit puree. Physical and chemical analyses to determine the qualitative indicators of raw materials and products were performed. The degree of liking of kefir was assessed using sensory analysis: hedonic and line scales. The results obtained showed that among the cultivars the highest content of anthocyanins (1103.5 mg·100 g−1), total phenols (693.3 mg·100 g−1), flavonoids (753.9 mg·100 g−1), and tannins (1.6 mg·100 g−1), were found in ‘Siņaja Ptica’ berries, while among the genotypes, berries of No 8 had the highest concentration of the aforesaid compounds. Both samples also showed the highest antiradical activity: ABTS+• on average by 71.7% and DPPH− by 43.7%. According to the sensory evaluation, kefir with 10% honeysuckle puree was rated the highest. Honeysuckle berries could be used as a promising source of natural anti-oxidants in future research aimed at developing different new products that could meet consumer expectations.


Author(s):  
Ingrīda Augšpole ◽  
Anda Liniņa ◽  
Ingmārs Cinkmanis ◽  
Sanita Vucāne

Abstract Winter wheat wholemeal is an important component of the human diet and may be a significant source of antioxidants. The objective of this study was to determine individual phenolic compounds in five winter wheat varieties: ‘Fredis’, ‘Edvins’, ‘94-5-N’, ‘Skagen’, and ‘SW Magnific’ wholemeal, grown according to organic and conventional agricultural practices. Ten phenolic compounds (vanilin, rutin, catechin hydrate, quercetin, p-coumaric acid, ferulic acid, 3.4-dihydroxybenzoic acid, 2-hydroxycinnamic acid, trans (3)-hydroxycinnamic acid, and gallic acid) were detected using high-performance liquid chromatography (Schimadzu Prominence HPLC). Catechin hydrate and quercetin were the main phenolic compounds in the grain of all tested winter wheat varieties. Significant differences (p < 0.05) among the analysed winter wheat cultivars in the concentration of individual phenolic compounds were observed. Concentrations of vanillin in organic and conventional winter wheat wholemeal were significantly lower (0.28 ± 0.02 to 0.65 ± 0.04 µg·g−1 DW), although the differences in the levels of phenolic were not large. The obtained results showed a statistically significant trend (p < 0.05) towards higher levels of phenolic compounds in organic wheat wholemeal samples.


Author(s):  
Ēvalds Raits ◽  
Asnate Ķirse-Ozoliņa ◽  
Sandra Muižniece-Brasava

Abstract A one-day ration can be supplied to a soldier in the form of one ration pack for 24 hours or three packs of meal ready-to-eat, which equals one 24-hour ration. Based on the physical activity level and consequently energy requirements, there are two categories of military operations: a) normal operations, comparable to urban police work or firefighting, and b) combat operations which represent missions involving light-infantry. The aim of this study was: a) to analyse the EU market on the subject of a main course (MC) product in flexible packaging (n = 184), in the context of military use, and b) to develop thermostabilised MC aligning with modern health and nutrition recommendations for military use, i.e. protein, carbohydrate, fat, total energy intake, and essential amino acid composition. The greatest amount of ready-to-eat meals with shelf-life over one year are produced in the United Kingdom (n = 48) and most of the MC meals are preserved using freeze-drying (n = 135). While 90% of analysed products meet fat criteria for a physically active consumer (i.e. soldier), 39% meet carbohydrate criteria, 21% meet energy intake criteria, only 1% of the products are able to fulfill protein requirements. In this study, nine MC meals with shelf-life of three years were developed, which provide the necessary protein amount for a highly physically active consumer and cover its daily essential amino acid requirements.


Author(s):  
Diāna Dancīte ◽  
Jeļena Zagorska ◽  
Tatjana Ķince ◽  
Vita Šterna

Abstract Nowadays consumers are looking for new food products with added nutritional value. Therefore, producers and scientists develop new recipes and technologies with the aim to enrich products with fibres, vitamins, and probiotics. Since naked barley contains high concentration of soluble dietary fibre, including β-glucans, which have stabilising properties, it has a good potential for fermented dairy food development. The goal of the current study was to assess the application of hull-less barley grain ‘Kornelija’ for development of fibre-enriched yogurt. Milk was fermented with freeze-dried starter (Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus thermophilus) by adding flour of ungerminated, 24 and 36 hours germinated barley grain (amount 2%, 3%, 4%) at 41 ± 1 oC up to pH 4.7 ± 1.0. pH of samples during fermentation, the colony forming units of lactic acid bacteria, viscosity, and concentration of fibres were determined. Results of the current study showed that flour from ungerminated, and 24 and 36 hours germinated barley grain, fortified yogurt with dietary fibre (from 0.89 to 1.77 g·100 kcal−1), promoted growth of lactic acid bacteria in the product, increased the viscosity and shortened fermentation time, but the significance of effects depended on the amount and type of added flour.


Author(s):  
Diāna Arāja ◽  
Vita Rovīte ◽  
Modra Murovska ◽  
Anna Terentjeva ◽  
Diāna Vaidere ◽  
...  

Abstract In circumstances of COVID-19 epidemiological uncertainty, the causes and consequences of the disease remain important issues. The aim of this study was to investigate obesity as a potential predisposition and chronic fatigue syndrome (CFS) as a possible consequence of COVID-19. The study was conducted in two parts: a theoretical part, in which a literature review was performed, and an empirical part, in which COVID-19 patient survey data were analysed. To identify the main findings regarding the relationship between obesity and COVID-19, the literature review was focused on the investigation of systematic reviews and meta-analyses by three databases — Med-line (via PubMed), Cochrane COVID-19 Study Register, and PROSPERO (International prospective register of systematic reviews). The patient survey was performed to investigate the relationship between obesity and severity of the disease, as well as the presence of CFS symptoms in COVID-19 patients in Latvia. The main findings of the literature review showed that obesity increases the risk of hospitalisation, disease severity, clinical complications, poor outcomes, and mortality. The results of the patient survey showed that overweight and obesity were more critical factors for men (males) suffering with COVID-19 than for women (females) in Latvia. The patient group with obesity caused almost half of all hospitalisations. The research data assumed that CFS patients were not a high-risk group for COVID-19, but COVID-19 caused CFS-like symptoms in patients and potentially increased the number of undiagnosed patients. In the context of further epidemiological uncertainty and the possibility of severe post-viral consequences, preventive measures are becoming increasingly important.


Author(s):  
Silvija Ābele ◽  
Laila Meija ◽  
Valdis Folkmanis ◽  
Lilian Tzivian

Abstract The objective of the study was to investigate the potential of a specific carbohydrate diet and selected dietary supplements in reducing some autistic spectrum disorder (ASD) symptoms in children. This was a quantitative, non-blinded, non-randomised three-month pilot study of a dietary and nutritional intervention. The study participants were 17 children from Latvia and the United Kingdom with a diagnosis of ASD or autistic symptoms waiting to be diagnosed (intervention group n = 10, control group n = 7). The intervention group received a specific carbohydrate dietary plan — Specific Carbohydrate Diet / Gut and Psychology Syndrome diet (SCD/GAPS) — and a few dietary supplements (omega-3 essential fatty acids, ascorbyl-palmitate, probiotics, vitamin D, and vitamin C). Family compliance to the dietary guidelines was 40–80%. Autistic and digestive symptoms were evaluated by parents using validated questionnaires. By the end of the study, gastrointestinal symptoms decreased in both groups (p = 0.01 for the intervention group, p = 0.02 for the control group), especially abdominal pain and bloating. The Overall Autism Treatment Evaluation Checklist (ATEC) score decreased by 23% in the intervention group (p = 0.05), with the largest improvement in Socialising (p = 0.03) and Health/Behaviour (p = 0.02) aspects. The Aberrant Behaviour Checklist (ABC) score decreased by 29% in the intervention group (p = 0.01), with the largest improvement in Irritability (p < 0.01) and Hyperactivity (p = 0.02) subcategories. Overall Parent Global Impressions — Revised-2 (PGI-2) evaluation showed a 43% improvement in the intervention group in comparison to 14% in the control group, p = 0.02. The specific carbohydrate diet (SCD/GAPS) and supplements were found to be a safe and effective approach for reducing some symptoms of ASD in children.


Author(s):  
Kristīne Majore ◽  
Vita Šterna ◽  
Māra Bleidere ◽  
Sanita Reidzāne ◽  
Inga Ciproviča

Abstract Barley (Hordium vulgare L.) grain is an important food ingredient due to the presence of essential compounds like β-glucans, proteins, resistant starch, phenolic compounds etc. β-glucans are able to lower cholesterol level in blood plasma and the glycaemic index, to enhance lipid metabolism and to reduce the risk of colon cancer. Hulless barley cultivars are more suitable to the human diet, because the hulls can be easily removed, as well as minimal grain processing in food production contributes to the full benefit of the whole grain. Several studies show that hulless grains have a higher digestible energy, and they have higher protein content compared to hulled grains. Different cultivars have unique composition and physical properties. The hulless barley cultivars are less studied than hulled barley and oats. The aim of this study was to evaluate the fermentation characteristics of flakes of different hulless barley cultivars in vitro and to analyse the fermentation pattern of β-glucans and proteins. Samples of six hulless barley cultivar flakes with different β-glucan (4.17–6.59%), soluble dietary fibre (18.1–32.0%) and resistant starch (0.74–10.65%) content were boiled in water 10 min, and the obtained porridge samples were treated under in vitro fementation conditions. The concentration of fermented porridge solids as well as β-glucans and proteins was measured. The concentration of undigested solids varied from 38.3 to 61.0% depending on barley cultivar. The concentration of protein was not significantly changed, but β-glucan concentration was significantly decreased after in vitro digestion comparing to indigestible samples.


Author(s):  
Māris Bērtiņš ◽  
Alise Klūga ◽  
Laila Dubova ◽  
Pēteris Petrēvics ◽  
Ina Alsiņa ◽  
...  

Abstract The concentration of nitrogen in the Earth’s atmosphere is about 78%, but most plants are not able to acquire it directly from the atmosphere. One of the most common ways for binding atmospheric nitrogen is the development of an efficient symbiotic system between legumes and rhizobia. The aim of this study was to compare how different legumes and rhizobia symbiosis systems affect the concentrations of nutrients and other elements in soya and faba beans. Seeds of plants were inoculated with a preparation of rhizobia just before sowing. Plant samples were collected at the flowering stage (vegetative parts) and during harvest (seeds). Samples were air-dried and analysed with inductively coupled plasma mass spectrometry (ICP-MS). Total nitrogen and carbon concentrations were determined with an elemental analyser (EA). The obtained results showed that inoculation of legume plants with rhizobia not only affected nitrogen uptake by plants but also uptake of other elements. Inoculation had an effect on mineral element uptake for both faba bean and soybean leaves, where a significant increase in Mg, P, K, and Ca was observed. Treatment of legume plants with rhizobia caused a decrease of P and K concentrations in seeds, and there were changes in Fe and Mn concentrations.


Sign in / Sign up

Export Citation Format

Share Document