Showing 4 results for Pectin
D. Qujaq, S.e. Mousavi,
Volume 6, Issue 1 (4-2002)
Abstract
The objective of this investigation is to measure pectinesterase activity by a simple method. The assay is done at 25°C. Oranges were obtained at a local supermarket in winter. They were peeled and 5 gr sections of the peeled tissue were homogenized in 10% NaCl and 0.5 M phosphate buffer in a homogenizer. The homogenates were centrifuged at 3500 rpm for 20 min. The supernatants were collected, their pH levels were raised to 7.25 using NaOH and the reaction was monitored at 485 nm in a spectrophotometer. The activity of pectinesterase was expressed as micromoles of methanol released per minute.
The results show that this method is reliable, sensitive, and capable of measuring pectinesterase activity of as low as 0.05 unit. The assay method proposed is a very useful analytical tool for the determination of the activities of pectinesterase.
G. R. Mesbahi, J. Jamalian,
Volume 6, Issue 2 (7-2002)
Abstract
Pectin is used in a number of foods as a gelling agent, thickener, texturizer, emulsifier and stabilizer. Sugar-beet pulp, the residue left from sugar extraction, is a rich source of pectin. It was the purpose of this study to develop a procedure for the extraction of pectin from sugar-beet pulp and to improve the functional properties of this pectin for more potential uses. To extract pectin, pressed beet pulp was dried and powdered. Then, it was extracted under various conditions (pH 1 and 1.5, temperatures of 80oC and 90oC and extraction periods of 1, 2, 3 and 4 hr). The highest yield (22.35%) was obtained at 90oC after 4 hr at pH 1. Chemical composition of the extracted pectin and that of commercial citrus pectin were determined and compared. Also, the beet pulp pectin was used in certain foods and its functional properties were compared with those of the commercial citrus pectin. The effects of ammonium persulfate and high pH levels on the above mentioned properties were investigated. Finally, the effects of the beet pulp pectin and the commercial citrus pectin on the flavor of certain foods were evaluated. The results indicate that the extracted beet pulp pectin can be used in certain foods such as ketchup sauce as a thickener or as an agent increasing the viscosity however, it does not have the ability to form firm gels in food.
J. Keramat, G. H. Kabir, B. Ghanaati,
Volume 6, Issue 4 (1-2003)
Abstract
Citrus juice and concentrate are among the major industrial products in Iran. Large quantities of citrus peels with considerable amounts of pectin are also produced. Pectin could be extracted from the peels to be used as a gelling agent in some food products. Unfortunately, all pectin used in the food industry is imported. This study was carried out to find the best conditions of pectin extraction from orange peels. Samples of orange peels were collected from a concentrated orange juice factory. Pectin was extracted by sulfuric, nitric and hydrochloric acids. Certain qualitative and quantitative tests, such as yield of extraction and cost of extraction were determined. Also, food safety aspects as a result of using the above acids were considered. Hydrochloric acid was found to be the most suitable acid. In the second part of the research, the effects of temperature (85 and 90˚C), time (40, 50 and 60 minutes) and pH (1.6, 1.8 and 2.0) on the yield of extraction, purity, gelling ability, percentage of methoxylation and degree of esterification of the extracted pectins were measured. Statistical analysis of the results showed that the best conditions for the extraction of pectin include a pH level of 1.6, a temperature of 90˚C and a period of 50 minutes.
M Mousavi Nasab, Gh Mesbahi, L Maghsodi,
Volume 12, Issue 46 (1-2009)
Abstract
Pectin is a hydrocolloid with different characteristics and applications. In this study, the cryoprotective effect of pectin on frozen surimi was investigated. In this research, Kapoor surimi was made for the first time in Iran. Surimi was mixed with 1% pectin solution with the ratio of 1 to 3 (w/v). Then, pectin-containing surimi samples and control samples were packaged, frozen and stored at -20oC. Water binding capacity (WBC), salt extractable protein and drip loss of samples were measured at after 0, 2 and 4 months of storage. The results showed that the loss of WBC in pectin-containing surimi and control samples was 20% and 58%, respectively, after 4 months storage at -20oC. It means pectin could improve the WBC up to 38% in the frozen product. The loss of SEP in pectin containing surimi samples was 21% and in control samples was 25% after 4 month frozen storage, indicating pectin was again effective in maintaining the quality of frozen products. Furthermore, the increase in drip loss in pectin containing surimi was about 7% and in control samples 37%. In this case pectin also helped to decrease the loss of water soluble nutrients. Overall, the results indicate that pectin as a cryoprotectant can improve the quality of frozen surimi.
