The research focuses on the study of physically-chemical and microbiological parameter changes in Latvian wild cranberries during convective drying. The research was accomplished on fresh Latvian wild cranberries. The following quality parameters were controlled during the experiments: moisture content (oven-dry method), content of vitamin C (LVS EN 14130:2003), content of polyphenol (HPLC), preparation of samples for microbiological testing (LVS EN ISO 7218:2007), enumeration of yeasts and moulds (ISO 21527-2:2008(E)), counting of lactic acid bacteria (LVS ISO 13721:1995), and total plate count (LVS EN ISO 4833:2003A). The research detected the following optimal convective drying parameters of wild cranberries: temperature – +50±1 deg C and drying time – 20.3 hours. The moisture content of dried berries equalled to 9.0±0.1%. The content of vitamin C decreased 1.9 times in wild cranberries dried at the temperature of +50±1 deg C compared with the content of vitamin C in non-dried cranberries and was 13.05 mg 100 gE-1 in dry matter. The results of current experiments show, that the content of such polyphenols as gallic, caffeic, and epicatechin acids decreased 9.70, 9.90, and 11.68 times, respectively, during the treatment at temperatures up to +50±1 deg C compared with the initial content of these compounds in non-dried berries. The drying temperature substantially influences the microflora development in cranberries. It is possible to decrease significantly the content of LAB, mould, and fungi in berries provided the drying temperature of the wild cranberries does not exceed +50±1 deg C, thus prolonging the ready product shelf-life.

The task of the research was to study the chemical composition of sea buckthorn and raspberry marc as well as of high milling wheat bread with berry marc. Wheat bread, i.e. the control sample and the bread samples with 3%, 5% and 7% (from the flour mass) of raspberry and sea buckthorn marc, was baked in the experimental bakery. The content of sugar, fat, protein, fibre and titratable acids was determined by using standard methods. The content of vitamin E, carotene, pectin and phenol compounds was determined by using spectrophotometric method. The obtained results prove that sea buckthorn and raspberry marc have fibre, fat, sugar acids, carotene, phenol compounds, vitamin E, and pectin. The content of fibre and carotene increased in wheat bread samples when raspberry and sea buckthorn marc was added. Depending on the amount of marc added to the bread, the changes in the content of fat, sugar, and carotene in wheat bread samples were studied. The wheat bread with raspberry and sea buckthorn marc contained vitamin E and phenol compounds.