Optimization of Process Conditions for Pectin Extraction from Citrus Peel

Abstract

Pectin is a complex polysaccharide and natural food additive extracted from citrus peel and apple pomace in the form of brownish powder. It is widely used as a jelling and thickening agent and the food industry especially in jams and jellies. It is also recommended for use as fat replacer and also lowers blood cholesterol by increasing viscosity in the intestinal tract thus lowering cholesterol absorption. Peel of sweet oranges was chopped to small pieces in a vegetable cutter and dried in an electrical drier to 8-10% moisture contents. The dried peel was ground and then subjected to pectin extraction using water as solvent. Three treatments with different levels i.e., pH (1, 2, 2.5, 3, 3.5, 4, 4.5 and 5), temperature of solvent (70, 85 and 95°C) and extraction time (0.5, 1, 2, 3, 4 and 5 h) were evaluated. Development of an economical processing method for pectin extraction from citrus peel, that offers energetic properties nearly identical to those prepared by other methods (soxhlet method and microwave) using other substrates, is reported. Dried citrus peel contains about 30% pectin It has been found that 30 min heating at 70°C and pH level 2.5 resulted in 21% pectin extraction followed by 1 h heating at 85°C at pH level 3.0 and a similar pectin yield. Up to 17% yield was obtained for heating at 95°C at pH level 1 irrespective of the time of heating. It can be inferred from these experiments that pH range between 2.0-2.5 and heating at temperature of 70°C for 30 min seems to be the most suitable condition for pectin extraction as time and energy efficient process conditions.

Optimization of oil and pectin extraction from orange (Citrus sinensis) peels: a response surface approach

“…This compares favorably with the findings of other researchers on pectin yield from orange peels. El-Nawawi and Shehata (1987) and Marin et al (2007) obtained pectin yield between 21-30 and 13-23%, respectively, while Hashmi et al (2012), Kanmani et al (2014), Dehankar et al (2015), and Khan et al (2015) reported maximum pectin yields of 20.12, 29.41, 20, and 21%, respectively. These differences could have been due to the nature of the fruits and extraction process vis-à-vis the processing conditions.…”

“…For oil extraction, extraction temperatures (80,85,90,95, and 100 o C) and extraction times (120,150,180,210, and 240 min) were chosen, while for pectin extraction, extraction temperatures (80,85,90,95, and 100 o C), extraction times (60, 75, 90, 105, and 120 min) and pH (1, 1.5, 2, 2.5, and 3) were selected. The dependent factors considered in this study were considered as the most important factors affecting oil and pectin yield (Gama et al 2015;Khan et al 2015).…”

“…The amount of pectin contained in orange peels is estimated by experiments. According to Rouse and Crandall (1976), May (1990), and Khan et al (2015), dried citrus peel contains about 30% pectin (on dry basis). During pectin extraction from orange peels, several factors affect the process which include the pH, temperature, solvent used for extraction, time of extraction, agitation rate, and liquid solid ratio (LSR) amongst others.…”

Physicochemical properties of dragon fruit peel pectin and citrus peel pectin: a comparison

“…Several studies using different sources of pectin also resulted in a different amount of moisture content (Castillo-Israel et al, 2015; FULL PAPER Figure 1. Structure of pectin (Khan et al, 2015) Figure 2. Infrared spectra of functional group for dragon fruit peel pectin (a) and commercial pectin (b).…”

Pectin‐[(3‐acrylamidopropyl) trimethylammonium chloride‐co‐acrylic acid] hydrogel prepared by gamma radiation and selectively silver (Ag) metal adsorption

“…Pectins are naturally occurring water‐soluble complex polysaccharides mainly composed of 1–4 linked α‐ d ‐galacturonic acid and found in citrus, apple, and other higher plants. Pectin is used as stabilizer, thickener, gelling agent, and anticancer drug . Due to the presence of both COOH and OH groups, pectin's hydrogels are more effective in water absorption, metal adsorption, and drug delivery .…”