Optimization and Preliminary Physicochemical Characterization of Pectin Extraction from Watermelon Rind (Citrullus lanatus) with Citric Acid

Watermelon rind was used for the pectin extraction with citric acid as the extractant solvent. The effects of pH (2.0-3.0), extraction time (45-75 min), and liquid-solid ratio (10 : 1 to 40 : 1 mL/g) on the pectin yield, degree of esterification, methoxyl content, and anhydrouronic acid content were investigated using Box-Behnken surface response experimental design. The pH was the most significant variable for the pectin yield and properties. The responses optimized separately showed different optimal conditions for each one of the variables studied in this work. Therefore, the desirability function was used to determine the sole theoretical optimum for the highest pectin yield and highest anhydrouronic acid content, which was found to be pH of 2.0, extraction time of 62.31 min, and liquid-solid ratio of 35.07 mL/g. Under this optimal condition, the pectin yield, degree of esterification, methoxyl content, and anhydrouronic acid content were 24.30%, 73.30%, 10.45%, and 81.33%, respectively. At optimal conditions, watermelon rind pectin can be classified as high methoxyl and rapid-set pectin with high quality and high purity. Practical Applications. This study evaluated the pectin extraction from watermelon rind and carried out an optimization of multiple responses as a function of pH, time, and liquid-solid ratio to obtain the best preliminary quality parameters (pectin yield and anhydrouronic acid content). The results revealed that watermelon rind waste can be an inexpensive source to obtain good pectin quality and high purity. According to the chemical characterization and physicochemical properties studied, the extracted pectin from watermelon rind would have a high potential to be used in food industry.

Preparation of Pectin Films from Coffee Cherry and Its Antibacterial Activity

This study aimed to utilize the waste from the coffee bean production process as high value-added material. Pectin extracted from the coffee pulp was classified as low methoxyl pectin (LMP) with the Degree of Esterification (DE) at 33.33 % For further application or upscaling production, the coffee pulp was boiled to retrieve the highest yield at 15.68 g/100 g DW. The antimicrobial assays of crude pectin via minimum inhibition concentration (MIC) showed that coffee pectin could inhibit the growth of Staphylococcus aureus TISTR 1466 in the range of 2.5 - 0.62 mg, while the commercial apple pectin exhibited the inhibition only slightly. The pectin film from the coffee pectin blended with the commercial apple pectin also exhibited antimicrobial activity against S. aureus TISTR 1466. This study shows that coffee pectin could be an alternative material for antibacterial film and other applications. HIGHLIGHTS Pectin extracted from the coffee pulp by this extraction method is classified as low methoxyl pectin with the degree of esterification (DE) at 33.33 % which retrieve the highest yield at 15.68 g/100 g DW of coffee pulp The minimum inhibition concentration (MIC) of the coffee pectin against Staphylococcus aureus TISTR 1466 in the range of 2.5 - 0.62 mg, while the commercial apple pectin did not exhibit antimicrobial activity The pectin film from the coffee pectin 5 % blended with the commercial apple pectin also exhibited antimicrobial activity against aureus TISTR 1466 Given its antibacterial activities, as well as the ability to form film, coffee pectin could be potentially used for application in biomedical or pharmaceutical fields. Importantly, pectin from the coffee pulp could add more value to coffee by-products GRAPHICAL ABSTRACT

Pharmaceutical Applications of Pectin

Pectin, a natural ionic polysaccharide found in the cell wall of terrestrial plants undergoes chain–chain association to form hydrogels upon addition of divalent cations. Based on its degree of esterification, pectin has been classified into two main types. The high methoxyl pectin with a degree of esterification greater than 50%, which is mainly used for its thickening and gelling properties and the low methoxyl pectin, which is widely used for its low sugar-content in jams, both applications being in the food industry. Pectin is mostly derived from citrus fruit peels, but can also be found in other plants such as waterleaf leaves, cocoa husk, and potato pulps. Pectin has been used as an excipient in pharmaceutical formulations for various functions. This chapter will focus on the various applications to which pectin has been used in the pharmaceutical industry.

PERSPECTIVE SEARCHES OF MEDICINAL PLANT RAW MATERIALS AS SOURCE OF POLYSACCHARIDES

The purpose of the conducted researches was studying of cones of a pine ordinary as source of polysaccharides in complex processing of raw materials. Cones of a pine ordinary were assembled during pollination. For the purpose of development of complex processing of raw materials researches on studying of the cones which remained after receiving pollen are conducted. Researches showed prospects of use of cones of a pine ordinary as source of polysaccharides after receiving pollen. The pectin content in ordinary pine cones, established by the oxalate method, was 1,2 ± 0,1%. Qualitative determination of pectin is proposed by colour reaction with solution of carbazole with alcohol 0,5%. Reaction with 10% lead (II) basic acetate was also used to identify pectin. One indicator of the detoxifying activity of pectin is the degree of esterification (ratio of esterified and free carboxyl groups). Low esterified pectins (esterification rate below 50%) are used as detoxicant. Important is the fact that the complex processing of ordinary pine cones will make it possible to obtain pectin actually from pollen production waste. In the developed scheme of complex processing of ordinary pine cones for hydrolysis-extraction of pectin-high substances from raw materials, it is proposed to use citric acid solution with pH 1,8-2,0. Methods for identifying and quantifying pectin in an object are valid. As a result of all the studies, a method was developed for producing pectin from ordinary pine cones in the complex processing of raw materials, the content of which was 1,2±0,1%, and the degree of esterification 13,20 ± 0,5%. The results of the conducted studies showed that the content of tannins in the studied raw materials of pine cones was 0,66±0,02%. As a result of all studies, a method of producing pectin from ordinary pine cones in complex processing of raw materials has been developed. The obtained results make it possible to recommend the obtained pectins as an effective detoxifying agent and a source of polysaccharides, tannins.

Effects of Molecular Weight and Degree of Esterification of Soluble Soybean Polysaccharide on the Stability of Casein under Acidic Conditions

The effects of molecular weight (MW) and degree of esterification (DE) of soluble soybean polysaccharide (SSPS) on the stability of casein under acidic conditions were investigated. The ability of SSPS to stabilize casein was characterized by the content of SSPS–casein complex, the LUMiSizer instability index, average particle size, zeta potential, and storage experiments. The long-term storage stability of the mixtures was related to their ability to combine casein and the stability of the complexes. At the same DE, SSPSs with medium MW formed more complexes with casein than SSPSs with high or low MW; and at the same MW, SSPSs with medium or low DE formed more complexes than SPSSs with high DE. In addition, SSPSs with higher MW had a better stabilizing behavior due to the large steric repulsion between complexes. SSPSs with high MW and low DE showed the best ability to stabilize casein under acid conditions.

Optimization and Physicochemical Characterization of Pectin Extraction from Watermelon Rind (Citrullus lanatus) with Citric Acid

Watermelon rind was used for the pectin extraction with citric acid as the extractant solvent. The effects of pH (2.0-3.0), extraction time (45-75 min) and liquid-solid ratio (1:10-1:40 g/ml) on the pectin yield, degree of esterification, methoxyl content and anhydrouronic acid content were investigated using Box-Behnken surface response experimental design. The pH was the most significant variable for the pectin yield and properties. The responses optimized separately showed different optimal conditions for each of the variables studied in this work. Therefore, the desirability function was used to determine the sole theoretical optimum for the highest pectin yield and highest anhydrouronic acid content, which was found to be: pH of 2.0, extraction time of 62.31 min and liquid-solid ratio of 35.07 g/mL. Under this optimal condition, the pectin yield, degree of esterification, methoxyl content and anhydrouronic acid content were 24.30%, 73.30%, 10.45% and 81.33%, respectively. At optimal conditions, watermelon rind pectin can be classified as high methoxyl and rapid-set pectin with high quality and high-purity.

Volatile Compounds of Lemon and Grapefruit IntegroPectin

An HS-SPME GC-MS analysis of the volatile compounds adsorbed at the outer surface of lemon and grapefruit pectins obtained via the hydrodynamic cavitation of industrial waste streams of lemon and grapefruit peels in water suggests important new findings en route to understanding the powerful and broad biological activity of these new pectic materials. In agreement with the ultralow degree of esterification of these pectins, the high amount of highly bioactive α-terpineol and terpinen-4-ol points to limonene (and linalool) decomposition catalyzed by residual citric acid in the citrus waste peel residue of the juice industrial production.

Volatile Compounds of Lemon and Grapefruit IntegroPectin

The HS-SPME GC-MS analysis of the volatile compounds adsorbed at the outer surface of lemon and grapefruit pectins obtained via hydrodynamic cavitation of industrial waste streams of lemon and grapefruit peels in water only suggests important new findings en route to understanding the powerful and broad biological activity of these new pectic materials. In agreement with the ultralow degree of esterification of these pectins, the high amount of highly bioactive α-terpineol and terpinen-4-ol points to limonene decomposition catalyzed by residual citric acid in the citrus waste peel residue of the juice industrial production.