Both the rowanberries (Sorbus) and the chokeberries (Aronia) belong to the family Rosaceae. The berries of these cultivars are suitable for production of health-food products. The main components in the dry matter of fruits are carbohydrates, primarily sugars. The aim of this experiment was to determine the content of simple sugars and sorbitol in different fresh rowanberry cultivars and chokeberries and to compare the composition of these compounds after freezing and thawing of berries. The experiments were done in the Customs laboratory of the National Customs Board, State Revenue Service (Latvia). The rowanberries were picked in the Pure Horticultural Research centre, and black chokeberries were obtained from farm 'Ceplīši' (rural municipality of Pure). The contents of dry matter and soluble solids were analyzed in fresh berries, and the contents of sugars and sorbitol were analyzed both in fresh berries and in berries after freezing and thawing of 13 different cultivars of rowanberries and one black chokeberry. For determination of the soluble solids content, the refractometric method was used, and for determination of the glucose, fructose, sucrose and sorbitol content, high performance liquid chromatography was used. The results showed that rowanberries and chokeberries contained 3.24-7.24 g 100 gE-1 of sorbitol which was the dominant compound in all investigated berries. The highest content of sorbitol was found in the wild rowanberries and rowanberries Sorbus aucuparia var. sibirica, but fruits of rowanberry×pear 'Alaya Krupnaya' contained the least content of sorbitol. After freezing and thawing of berries, the content of sugars and sorbitol were decreased by 5-23% with some exclusion.

A study was done at the Latvia State Institute of Fruit-Growing, evaluating new domestic plum (Primus domestica L.) selections, for which in 2008 -2010 some fruit quality characteristics were studied. In result of evaluation four new cultivars were selected from the breeding material and in 2010 handed in for cultivar registration in Latvia. Cultivar 'Ance' is early ripening one month before 'Victoria'. Cultivar 'Adele' is medium ripening one week before 'Victoria'. Fruits keep well in cool storage. Cultivar 'Sonora' is medium ripening one week after 'Victoria' and self-fertile. Fruits of this cultivar keep well in cool storage, too. Cultivar 'Lotte' is medium-late ripening two weeks later than 'Victoria', and is partially self-fertile. Average of three years, the highest soluble solids content was found for cultivar 'Adele' (13.28 Brix%), but cultivar 'Sonora' had the total content of acids (1.28 g 100 gE-1). Significant changes in flesh firmness were observed at different storage times for cultivars 'Ance' and 'Lotte'. Significant variations in the total content of acids were determined for 'Ance'. Whereas cultivar 'Sonora' demonstrated substantial fluctuations in soluble solids content. Correlations between firmness and soluble solids content were observed for cultivars 'Ance' (r=-0.731), 'Adele' (i=-0.436) and 'Sonora' (r=0.526). Cultivar 'Lotte' produced correlations between firmness and total content of acids (i=-0.536). Significance of interaction was determined within cultivars, years, and years x cultivars.

Highbush blueberries are thought to provide protection against oxidative damage of free radicals and contribute to positive health benefits. They have been studied little in Latvia; therefore, the aim of study was to evaluate the soluble solids content, titratable acidity and sugar content of berries harvested in 2010. Seven varieties of cultivated highbush blueberries (Vaccinium corymbosum L.) grown in Latvia were analysed. Analyses were done for frozen berries of varieties ‘Bluecrop’, ‘Chandler’, ‘Chippewa’, ‘Duke’, ‘Northblue’, ‘Patriot’ and ‘Polaris’. All experiments were performed at the Latvia University of Agriculture, Faculty of Food Technology. The content of titratable acids (TA) was detected using standard method ISO 750:1998 by titration with 0.1N NaOH. Soluble solids content (SSC) was analysed using standard method ISO 2173:2003 by hand refractometer. Sugars (fructose, glucose and sucrose) were analysed by high-pressure liquid chromatography HPLC analysis. Results showed that there are significant differences between varieties (p is less than 0.05) for all parameters. TA content varied from 0.4 – 1.2%, SSC - 8.5 – 10.8 degBrix and total sugars from 7.6 to 9.3 g 100 gE-1. The highest ratio between sugars and titratable acids was for ‘Polaris’ while the lowest – ‘Chandler’ and ‘Bluecrop’.

Oats contain more beta-glucan (2-7%) than other croppers. Beta-glucan is the most essential water-soluble dietary fibre. It lowers cholesterine level in blood as well as stimulates elimination of carcinogens from the body. In order to enlarge possibilities of use of oats in a diet, they can be separated in water-soluble and insoluble fractions. The aim of the present study is to determine the amount of beta-glucan in hydrolysed oat soluble and insoluble fractions. Gelatinized, hydrolysed and steeped oatmeal prior to hydrolyse, which was separated in water-soluble and insoluble fractions, was used in experiments. Not more than 6% of gelatinized (non-hydrolysed) oatmeal dry matter dissolved in water. The outcome of fermentative hydrolysed dry matter of water-soluble oatmeal was 40-52%. The content of beta-glucan in soluble and insoluble oatmeal fraction was determined by using McClearly method. The content of beta-glucan fraction of gelatinized oatmeal decreased for 78% in comparison to the content of beta-glucan in oatmeal used in the experiments. The content of beta-glucan in the soluble fraction of hydrolysed oatmeal decreased for 8.1% to 9.2%, and increased for 35-42% in the insoluble fraction if compared with the content of beta-glucan in oatmeal.