Evaluation of foam properties of saponin from Ilex paraguariensis A. St. Hil. (Aquifoliaceae) fruits

Abstract

Saponins are natural compounds able to form abundant foam, a desirable quality required in some chemical, foods, cosmetic and pharmaceutical processes. Ilex paraguariensis A. St. Hil. (Aquifoliaceae) known as mate, is a South American widely cultivated specie due to the preparation of a tea-like beverage from its leaves. Moreover, its green fruits are a rich source of non-toxic and very low haemolytic saponins. In this study, mate saponin fraction (MSF) was evaluated as a foam former, focusing on its foamability, foam lifetime, and film drainage in the presence of different electrolytes (ionic strength I = 0.024 M). Sodium dodecyl sulphate (SDS) and polysorbate 80 (Poly-80) were used as reference surfactants. The critical micelle concentration (CMC), the minimum attainable surface tension (gCMC), surface excess concentration (G) and cross-section molecular surface (A) values of MSF were comparable to those of Poly-80. The foamability of MSF and both reference surfactants was equivalent. The addition of MgCl 2 resulted in a negative effect on MSF foamability. The salts NaCl, KBr, and KNO 3 exhibited a negative influence on MSF foam lifetime. Similar behavior was observed for MSF film drainage (order of activity: Na 2 HPO 4 > MgCl 2 ≈ NaCl ≈ KNO 3 > KBr), where a primary fast film drainage rate was followed by film thinning stabilization after around 5 min. The behavior described above seems to be uncorrelated to the solutions' zeta potential. Uniterms: Ilex paraguariensis/Aquifoliaceae/Mate/saponins/Surfactants/foam/assay.As saponinas são compostos naturais capazes de formar espuma abundante, qualidade desejável exigida em alguns processos químicos, alimentícios, cosméticos e farmacêuticos. Ilex paraguariensis A. St. Hil. (Aquifoliaceae), mais conhecida como mate, é uma espécie largamente cultivada devido ao consumo do chimarrão. Além disso, seus frutos verdes representam uma fonte rica de saponinas pouco tóxicas e pouco hemolíticas. Nesse trabalho avaliou-se a fração de saponinas de mate (MSF) como formadora de espuma, com ênfase na espumabilidade, permanência da espuma e drenagem do filme na presença de diferentes eletrólitos (I = 0,024 M). Dodecil sulfato de sódio (SDS) e polissorbato 80 (Poly-80) foram utilizados como tensoativos-referência. Os valores de concentração micelar crítica (CMC), tensão superficial na CMC (γCMC), concentração de excesso de superfície (G ) e área do grupamento polar na interface (A) referente à MSF foram comparáveis ao Poly-80. A espumabilidade da MSF e de ambos os tensoativos-referência foram equivalentes. A adição de MgCl 2 resultou em um efeito negativo sobre a espumabilidade de MSF. Os sais NaCl, KBr e KNO 3 tiveram influência negativa sobre a estabilidade da espuma. Em relação à drenagem do filme de MSF, após 60 min. seguiu-se a ordem Na 2 HPO 4 > MgCl 2 ≈ NaCl ≈ KNO 3 > KBr, caracterizando uma drenagem inicial acelerada seguida pelo equilíbrio hidrodinâmico do filme após 5 min. O comportamento observado parece não estar relacionado com o potencial zeta das soluções.

Usability of soapwort and horse chestnut saponin extracts as foaming agents in foam mat drying of pomegranate juice

“…4 In a study on the effects of tea saponins and different synthetic surfactant mixtures on foam properties, a synergistic effect was reported between saponins and cetyltrimethylammonium bromide or sodium dodecyl sulfate. 5 Canto et al 6 examined the effects of five different electrolytes on foams produced using mate saponin and reported that the foaming power of the saponins did not change according to the electrolytes except for magnesium chloride. However, in all electrolyte solutions, there was a significant decrease in foam height after 1 h. 6 Böttcher and Drusch 1 compared the foaming properties of six different saponin extracts from various plants, with the results showing that tea seed, horse chestnut, quillaja, and soapwort formed stable foams.…”

Surfactant Characterization of Crude Saponin Extracts of Guaiacum Officinale Leaf and Stem

“…[6,7] The high activity of Quillaja saponin could be attributed to the fact that the extract used by Mitra and Dugan (1997) was that of a commercially available purified powder, while the extracts of Guaiacum used in the present study as well as the extracts of the other mentioned plants are enriched extracts prepared by phase fractioning. The high saponin content in the commercial sample is likely to produce better results because of higher concentrations of saponin in the extract.…”

“…The reductions in surface tension of water due to Guaiacum officinale leaf and stem saponin [6] Similarly, a crude extract of Sapindus mukorossi reduced the surface tension of water to 51.7 mN m −1 . [7] Glycyrrhiza glabra saponin extract reduced the surface tension of water to approximately 46 mN m −1 .…”

Hydrothermally extraction of saponin from Acanthophyllum glandulosum root – Physico-chemical characteristics and antibacterial activity evaluation

“…2 B, highest foamability observed in the solutions which those were extracted using highest amount of plant root powder and pH value, or minimum amount of the plant root and pH value. Obtained results can be related to the point that, by raising the amount of A. glandulosum root, saponin content also increased which that causing higher foamability [ 22 ]. On the other hand, at strong basic and acidic solutions, surrounded layer made of pectic, cellulosic and hemi cellulosic compounds, which those cover the saponin, were hydrolyzed and maximum amounts of the saponin could be extracted.…”