Processing and properties of jelly candy

Jelly candy is produced by forming a gel with gelling agents in starch mould, followed by drying for days at about 45 °C chamber and obtaining the final products. The main ingredients of jelly candy are gelling agents, sweeteners, acidulants, coloring and flavorings. Gelling agents are the indispensable ingredients that give the gelatinous texture. Psyllium husk powder, konjac glucomannan and gellan gum are novel tested in jelly candy as gelling agents which can at the same time increase dietary fiber content of the candies. It was reported that psyllium husk powder and konjac glucomannan made jelly candy less sticky and springy. In this thesis, jelly candies were made with modified potato starch blended with psyllium husk powder, or konjac glucomannan, or gellan gum. The first aim is to study the effect of different contents of gellan gum on jelly candy properties. The second aim is to compare the effect of psyllium husk powder, konjac glucomannan and gellan gum on jelly candy properties. To achieve these goals, rheological properties of jelly candy mass was studied. Mechanical properties, water content and water activity of the jelly candy were analyzed directly after preparation. Mechanical analysis was made again after the jelly candies stored for two weeks. The raw data were analyzed by MATLAB and then computed by PLS. The results showed that, with the increasing of gellan gum content from 0% to 0.8%, hardness, adhesiveness and elasticity of jelly candies increased. At the same time, yield stress, coefficient of consistency and thixotropy of candy mass also increased. Psyllium husk powder and konjac glucomannan decreased hardness, adhesiveness and elasticity of jelly candies when comparing with gellan gum. They also decreased yield stress, coefficient of consistency and thixotropy of candy mass. Furthermore, along with storage, all the jelly candies became harder and stickier. In conclusion, increasing the content of gellan gum helped to make harder and more chewable jelly candies. The stability of gel structure was also increased and the flowing of candy mass became more difficult. When comparing with gellan gum, psyllium husk powder and konjac glucomannan contributed to softer and less chewable jelly candies. They decreased stability of gel structure and made candy mass flowing easily