The profile of amino acids and mono- and disaccharides in conventional polyfloral honey originated from Latvia and Tajikistan and less found in nature bumblebee honey from Russia was investigated. The analysis of free amino acids (FAAs) accomplished by multiple reaction monitoring (MRM) using triple quadrupole mass selective detection (HPLC-ESI-TQ-MS/MS) revealed the presence of 17 FAAs. The concentration of FAAs varied in the range of 0.02–44.41 mg 100 g⁻¹ FW. Proline was the main representative of FAAs, contributing to the total amount of FAAs from 41.7% to 80.52%. The highest concentration of proline was found in bumblebee and buckwheat honey, corresponding to 44.41 and 41.02 mg 100 g⁻¹, respectively. The concentration of essential amino acids (AAs), i.e., leucine, and isoleucine was found to be the highest in buckwheat honey contributing up to 12.5% to the total amount of FAAs. While, the concentration of branched-chain AAs fluctuated within the range of 1.08–31.13 mg 100 g⁻¹ FW, with buckwheat honey having the highest content and polyfloral honey the lowest, respectively. The results of this study confirmed the abundance of FAAs both in honeybee and bumblebee honey. However, the concentration of individual FAAs, such as proline, aspartic acid, leucine, and isoleucine in bumblebee honey was many folds higher than observed in honeybee polyfloral honey.

The main purpose of the study was to determine changes of polyphenol concentrations in hybrids of Nante type carrots during storage. Fresh Nante type ‘Forto’ variety carrots and carrot hybrids ‘Bolero’ F1, ‘Champion’ F1, and ‘Maestro’ F1 were cultivated in the Zemgale region of Latvia. Carrots were stored for six months in air (+3 ± 1 °C, RH = 89 ± 1%) and polyphenol compound concentrations were determined at two month intervals. High-performance liquid chromatography was used to determine concentrations of eight polyphenols in carrots: gallic acid, catechin, epicatechin, caffeic acid, chlorogenic acid, ferulic acid, vanillin, and rutin. Significant differences occurred in polyphenol concentrations of fresh Nante type variety ‘Forto’ carrots and several hybrids (‘Bolero’ F1, ‘Champion’ F1, and ‘Maestro’ F1) during storage. After six months of storage, the concentration of polyphenol compounds of Nante type carrots decreased — caffeic acid by 64.6%, chlorogenic acid — by 37.9% and vanillin — by 81.5%. However, during storage, concentration of some polyphenol compounds increased, as catechin by 30.5%, epicatechin by 85.2%, gallic acid by 48.5% and ferulic acid by 87.9%.

Winter wheat (Triticum aestivum L.) is one of the most widespread and economically beneficial crops in Latvia. Wheat grain yield and quality are strongly related to the growing conditions of crop that are possible to improve agronomically by carrying out an appropriate soil tillage and growing it in a well-planned crop sequence. The aim of the study to determine soil tillage system and precrop influence to winter wheat flag leaf parameters and grain yield quality indicators. A two-factor field trials was set up in the Latvia University of Life Sciences and Technologies training and research farm “Peterlauki” in 2022/2023: 1. soil tillage system and 2. precrop. The basic indicators of flag leaf length, width (cm) and flag leaf area (cm2) of a winter wheat were detected using a scanner STD4800 and the specialized computer program WinFOLIA Regent Instruments Software were determined from 10 plants in each variant. Three samples from each variant were taken for yield determination and structural elements of crops. Winter wheat 1000 grain weight and grain quality indicators were determined in Grain and Seed study and research laboratory of LBTU. Winter wheat precrop did not significantly affect (p>0.05) grain yield in the trial year, but the lowest yield was obtained in the conventional soil tillage system where wheat was grown in repeated sowings (5.1 t ha-1), and the highest yield in the minimal soil tillage system where precrop was field beans (7.0 t ha-1). The larger winter wheat flag leaf area was determined in both soil tillage systems, if the winter wheat precrop was field beans, the relationships are not significant (p>0.05). ;

Fresh-cut herbs satisfy consumer demand owing to the convenience of buying them in food shopping malls as quickly accessible products. Food packaging has an important role in the food industry nowadays, because it helps to preserve the quality of fresh-cut food products at the production and sales sites and provides safety during storage. The aim of this research was to evaluate the quality changes of fresh-cut rosemary packed and stored in biodegradable film packaging. Rosemary has been packed in several materials – two biodegradable packaging materials, NatureFlex^TM NVS INNOVIA film, Nature Works® PLA P-360 containers with hermetically pressed PLA cap and “breathable” conventional BOPP Propafilm^TM P2GAF film. The samples were analysed over time at 0, 3, 5, 8, 10 and 12 days of storage at a temperature of +5 ±1 °C in terms of physicochemical quality: O₂ and CO₂ concentration, mass loss, pH, content of soluble solids (ºBrix) and tested sensory evaluation. The analysis of the obtained results showed that the cellulose based biodegradable NatureFlex^TM NVS INNOVIA film was a good way to prolong the storage time of fresh-cut rosemary and ensure sensory quality and high physiochemical quality during the preservation period.