Document Type : Research Paper
Abstract
Pectin is used as gelatinizing agent in food industry. In this study pectin was extracted from five commercial sugar beet varieties namely: Doroty, Rasul, 7112, Br1 and Ic using pre-hydrolysis technique. Experiments were conducted using factorial design to verify the effect of temperature, time, percentage of HCl and water requirements on the extraction rate of pectin. The qualitative factors of pectins extracted were compared with high methoxyl (HM) and low methoxyl (LM) pectins as control. Most suitable hydrolysis was maintained using the mixture of 2.5 parts of dried pulp and 5% HCl (v/v) at the temperature of 45ºC and time of 48 hours. The most favorable results were obtained by addition of 450 ml H2O during extraction. Also qualitative analysis of pre-hydrolysed pectin was resulted in 14.96% extraction efficiency, 58.63% estrification value, 63.92% galactronic acid and 14.95% amide substitution value. The estrification degree of pectin obtained by pre-hydrolysis technique was 10% higher and 10% lower than those for the pectins obtained by acid extraction technique and commercial extraction method, respectively. Amide substitution degree using pre-hydrolysis technique was 6.5% and 7.5% higher than those for the acid and commercial extraction, respectively. Since, pre-hydrolysis technique of pectin extraction gained better results as compared to other methods, therefore, it can be concluded that the pre-hydrolysis technique is better than extraction by acid method. Moreover, cultivars 7112 and Rasul had significantly higher pectin content than cultivars Ic and Br1. Considering that the presence of pectin during the sugar-making process is not desirable for the processing of sugar, it is of great importance to decrease the pectin content of sugar beet during breeding programs.
Keywords
)