Browsing by Subject "sugar"

Gelatin-based confections are one type of gummy confections. Their main ingredients are water, sucrose, glucose syrup and gelatin, which causes gel-like texture. The literature review focused on the raw materials, the manufacturing process and the properties of gelatin- and starch-based gummy confections. The aim of this study was to find out how invert sugar, when it replaces sucrose and glucose syrup, affects structural properties and short-term shelf life of gelatin-based confections. In addition, changes in the sensory quality were observed. In the experimental research, the gelatin-based confections were manufactured on a laboratory scale according to simplex-centroid mixture design, where the total sugar content was constant, but sucrose, glucose syrup and invert sugar mass fractions were varied. Measurements for the samples were rheological properties, sugar content and dry matter content of confection paste and mechanical properties (hardness, stickiness and relaxation parameters), dry matter content, water activity and water sorption of confections. In addition, a few samples were manufactured with coloring and flavoring agents for sensory observation. The results were analyzed with the PLSR (Partial Least Squares Regression). Finnsugar Ltd.'s product development department offered the topic of this study and raw materials, but all the experiments were carried out in the Department of Food and Environmental Sciences in the University of Helsinki. The PLSR model contained five components, and the coefficient of determination R2 was 74.1%, the adjusted R2 was 63.3% and the coefficient of prediction Q2 was 43.6%. The model determined all response variables well, but predicted some of them poorly. Almost all response variables regression models were statistically significant at 5% significance level, but some of the models were incomplete (plof<0.05). The variables important in projection (VIP) in the PLSR model were mass fraction of invert sugar, mass fraction of glucose syrup and their interactions with mass fraction of sucrose. The PLSR model was best for rheological properties of confection pastes and mechanical properties of confections, and poorest for water activity and dry matter content of confections. Even at low mass fraction of invert sugar viscosity of confection paste decreased. Invert sugar also reduced hardness of confections, and speeded up their structures recovery after compression. Sensory observation shows the positive effects of invert sugar, such as softness of structure and stronger taste. The present study showed that the sugars have interactions, which also affect properties of the gelatin-based confections, and invert sugar content alone is not the significant factor. Based on the results of this study it seems that invert sugar affected stronger most of the response variables if it replaced relatively more glucose syrup than sucrose.

Protected cultivation of raspberries (Rubus idaeus L.) has increased its popularity in Finland. One reason is that the fruit is extremely sensitive to rainy weather during its development. The raspberry plant itself is sensitive to wind and low temperatures, which can reduce growth. In Europe most of the raspberry is grown in protected cultivation, and this technology is now becoming popular in Finland. A high tunnel is a cost-efficient way to protect the plants against rainy weather and extend the harvest season. The protected cultivation has been shown to increase the yield and cropping potential of raspberry and reduce the gray mold in the berries. In human diet, berries are among the richest sources of antioxidants. In raspberry, the most important antioxidants are vitamin C (20 %) and phenolic compounds (80 %). Among phenolic compounds, ellagitannins and anthocyanins give the greatest contribution to antioxidant activity. The aim of this thesis was to study the yield, sensory quality, nutritional quality and shelf life of three floricane fruiting raspberry cultivars grown in high tunnel and open field. Cultivars ’Glen Ample, ’Glen Dee’ and ’Maurin Makea’ were used in the study. Sugar and acid content of raspberry were examined to get an overview of sensory quality. The nutritional quality was studied with an antioxidant activity assay (using FRAP method) and total phenolics assay (using Fast Blue BB method). The shelf life was tested both in +5 °C and in room temperature. The average total yield per cane was 99 % greater in tunnel than in the open field, whereas both sugar and acid content of the berry were greater in open field. Berry weight and total phenolics content were strongly cultivar dependent characteristics. The results of the antioxidant activity assay did not show significant differences between either growing conditions or the cultivars. The shelf life in room temperature was equally weak for all samples, but in +5 °C storage the open field raspberries developed symptoms of gray mold earlier than those picked from the tunnel. The conclusion is that contents of health beneficial compounds in berries were not affected in tunnel cultivation, but berry taste may be affected, as differences in sugar and acid contents were observed.