Citrus pectin obtained by ultrasound-assisted extraction: Physicochemical, structural, rheological and functional properties

Abstract

Tangerine (Citrus reticulata. CRP) and grapefruit (Citrus paradisi. CPP) pectins obtained by ultrasound-assisted extraction (UAE) and conventional extraction (CE) using citric acid were characterized to establish their potential uses as an alternative source of commercial pectin. The pectins obtained by UAE and CE presented a pseudoplastic fluid characteristic with shear thinning behavior, a high esterification degree (CRP 82.30-71.81% and CPP 84.25-72.15%) and were of commercial quality based on galacturonic acid content (CRP 76.03% and CPP 76.03-71.01%). CPP presented greater viscosimetric molecular weight than CRP. Meanwhile, CRP presented greater polyphenol and protein content with respect CPP. The functional properties were influenced by citrus source and extraction method. UAE favored greater yields in a shorter time (CPP: 26.05%, 30 min; CRP: 13.46%, 15 min) compared to CE. UAE combined with the use of citric acid offers an effective alternative for obtaining high-quality pectins with lower polluting effluent, time and energy requirements. Pectina cítrica obtenida por extracción asistida por ultrasonido: propiedades fisicoquímicas, estructurales, reológicas y funcionales RESUMEN Pectinas de mandarina (Citrus reticulata, PCR) y pomelo (Citrus paradisi, PCP) obtenidas vía extracción asistida por ultrasonido (EAU) y convencional (EC) con ácido cítrico fueron caracterizadas para establecer su potencial uso como una fuente alternativa de pectina comercial. Las pectinas obtenidas por EAU y EC presentaron características de fluido pseudoplástico con un comportamiento de adelgazamiento por cizalladura, alto grado de esterificación (CRP 82.30-71.81% and CPP 84.25-72.15%), y calidad comercial por el contenido de ácido galacturónico (CRP 76.03% and CPP 76.03-71.01%). PCP presentaron mayor peso molecular viscosimétrico comparado a PCR. Mientras PCR presentaron mayor contenido de polifenoles, y proteínas con respecto a PCP. Las propiedades funcionales fueron influenciadas por la fuente cítrica y el método de extracción. La EAU favoreció los mayores rendimientos a menor tiempo: PCP (26.05±0.49%, 30 min) y PCR (13.46±1.79%, 15 min) comparada con EC. La EAU representa una alternativa eficaz para la obtención de pectinas de alta calidad, con menores efluentes contaminantes, tiempo y energía.

Production of Pectin as a Relevant Tool for by-Products Management Resulting from Four Tropical Edible Fruits Processing: Extraction Yield, Physicochemical and Functional Properties of Pectin Powder

“…However, the report of Eaks and Sinclair [30] revealed that avocado pectin content was very low around 0.7 to 1.5%, which may explain this information scarcity. However, except lemon pectin, pectin yield value of others fruits was below the range (20-30%) reported for commercial pectin from citrus peels [29]. Nevertheless, pectin extraction yields in our study seem to be high compared to those reported in the literature.…”

“…Moreover, De Moura, et al [12] reported similar but slightly lower pectin yield (17.96%) from orange pomace. As regards grapefruit, similar trend of pectin yield (15.76%) was reported by Polanco-Lugo, et al [29] using acid extraction method. Furthermore, information on avocado pectin in literature is rare.…”

“…Likewise, Sharma, et al [7] have previously demonstrated that soil mixed with pectin based-nanoparticle contributed to retain water for long time compare to reference native soil, providing plant growth favorable condition. This could be due to swelling capacity of pectin by holding water on their surface by sorption or trapping in microcapillaries or interparticle voids because of the greater number of free hydroxyl group in the pectin structure and also their particle properties [29]. These results illustrate the important role of polymers such as pectin in improving soil moisture.…”

“…In addition, blanching favored weakening of cell wall which enhance the pectin solubilisation during extraction process [32]. In addition, powdering peels decreased particle size but increased surface exchange contact between plant material and extraction solution, leading to high mass transfer increasing in pectin solubilisation [29,33] thus the increase in extraction yield occurred. Furthermore, pectin quantity and quality was also affected by various extraction factors such as extraction solvent, extraction time, pH, raw material, material variety and maturity stage, and pectin drying temperature [22,34].…”

Physico-chemical properties of fruit and vegetable juices as affected by ultrasound: a review

“…[52] (Continued) Also, US changes in inter-and intra-molecular interactions would account for either an enhance or decline in texture and AV, antioxidant properties, emulsifying capacity, of a number of polymercontaining systems. [67][68][69][70] The application of ultrasonic process as a unique preservation factor is unable to effectively kill all the microorganisms since the high levels needed could adversely modify nutritional and sensory properties of the juices. This limitation has suggested that US could be more effective when used in combination with other methods such as heat treatment (pasteurization or thermosonication (TS)), supercritical carbon dioxide, pressure, antimicrobial compounds (vanillin, citral benzoate, and citrus extract), organic acids (lactic acid and acetic acid), chitosan, ultraviolet (UV), pulsed electric field and pulsed light for inactivation of some pathogenic and spoilage microorganisms.…”