Pectin was extracted using 0.1 N HCl at 90 8C for 120 min at pH 1.5 and 2.0 from pomelo peel and characterized in this study. Influence of various concentrations of extracted pomelo peel pectin on physicochemical, bioactive compounds, color, and sensory attributes of carrot jam during storage was also studied. Pectin extracted at pH 2.0 had higher ash content, equivalent weight, and total anhydrouronic acid content than that extracted at pH 1.0. Extracted pomelo peel pectin was categorized as high-methoxyl pectin based on the degree of esterification. The b-carotene and total phenol content were increased in jam after 90 days of storage. Ascorbic acid content decreased with increasing storage period. Jam prepared using commercial pectin had higher DE values than jam prepared using pomelo peel pectin. Physico-chemical properties were influenced by pectin concentrations and storage time. Overall acceptability was similar for all samples on the basis of sensory evaluation. The results showed that pomelo peel might be used as a rich source of pectin and pomelo peel pectin could be used as an alternative to commercial pectins for carrot jam preparation.
Practical applicationsPectin is one of the main ingredients for jam and jelly making. Citrus fruits are main sources of pectin. Usually pomelo peels are discarded as waste materials. However, it could be a good source of pectin. In this article, pectin was extracted from pomelo peel and its application was observed as carrot jam during storage. Therefore, it can be concluded that extraction of pectin from pomelo peel might be used as an alternative to commercial pectin for carrot jam preparation.
| I N TR ODU C TI ONThe most widely cultivated citrus fruits are the following: orange, lemon, lime, mandarin, grape fruit, and pomelo. Citrus fruit pulp consists of 60-65% peels, 30-35% segment, pulp, and 0-10% seeds (Afshar & Naser, 2008). Citrus by-products are considered as rich sources of phytochemicals, pectin, and dietary fibers (Afshar & Naser, 2008). Pectin is the methylated ester of polygalacturonic acid, which contains 1,4-linked a-D-galacturonic acid residues (Mesbahi, Jamaliana, & Farahnaky, 2005).Pectin can be divided into two types based on the degree of esterification (DE): high-methoxyl pectin (DE > 50%) and low-methoxyl pectin (DE < 50%) (Mesbahi et al., 2005). The main sources for commercial pectin production are apple pomace and citrus peels (Mesbahi et al., 2005). The extracted pectin from pomelo peel could be used as ingredient in jam production. Therefore, the objectives of this study were to characterize pomelo peel pectin, as well as produce carrot jam, using various concentrations of pomelo peel pectin and compare with commercial pectin by performing nutritional quality and sensory evaluation during storage.
| M A TE RI A L S A ND M E TH ODS
| Sample collection and preparation of pomelo peel powderPomelo was purchased from the local market of Dinajpur, Bangladesh. The pomelos were washed carefully with tap water to remove dirt soil from the s...