Climatic conditions for soybean cultivation in Latvia are challenging because of their variability. In addition, the sum of sunlight hours and the ratio of temperature and precipitation required to produce a quality crop are unpredictable. There is a risk that even early soybean varieties will not ripen due to weather conditions in a region. Studies show that soybean plants, including the green part of the crop, are well suited for animal nutrition prepared as hay or silage. The aim of this study was to evaluate the chemical composition of different soybean varieties harvested before ripening and assess them as hay or silage raw material. Weight, protein, fat, ash, fibre, acid detergent fibre (ADF) and neutral detergent fibre (NDF) of soybean varieties ‘Erica’, ‘Bolgar’ and ‘Viola’ green mass were determined at different stages of maturity. The results of the study showed a significant increase in protein (from 9.18% to 12.06%) and fat (from 1.18% to 4.40%) content of the dry matter variety ‘Bolgar’ from September to October. The protein content of the dry soya green mass was not affected by variety at the same developing stage but significantly changed among different stages of maturity. As the plant develops, the sucrose content in the green mass increases, the same as the total sugar content.

Pastry cream contains wheat flour, which is not suitable for celiac patients who require a gluten-free diet. Potatoes are known as a good source of starch, minerals and vitamins. They also contain protein, dietary fibre and various phytochemicals. Their addition to pastry cream can both serve as a texturizing agent and enrich the nutritional value of the final product. This study aimed to evaluate the suitability of potatoes as a replacement for wheat flour in pastry cream. For study purposes, the physicochemical attributes of eleven potato varieties were evaluated. Among other varieties, the boiled potato variety Gala exhibited higher fibre, fat, phosphorus and potassium content; however, significantly higher protein (12.48 ± 0.08 g 100 gE−1 DW) and iron (3.12 ± 0.02 g 100 gE−1 DW) content. Higher antiradical activity (18.72 ± 0.74 mM TE 100E−1 g DW) was detected in potatoes of the variety Blue Congo. After preliminary investigation, wheat flour was replaced with mashed potatoes, making up 30% of the cream weight, and its impact on the pastry cream was studied. It was established that potatoes had a significant effect on pastry cream colour and texture. American Rose, Imanta, Rigonda and Viviana were selected as the most suitable from the eleven varieties tested. The addition of potatoes in pastry cream doubled its fibre and potassium content, whereas, other changes in nutritional value of the creams were variety dependent.