Washing performance of Soap nut shells

  • University of Zagreb, Faculty of Textile Technology
To read the full-text of this research, you can request a copy directly from the authors.


Investigations of washing agents are interesting from the technological and environmental point of view. The trend towards natural ingredients is growing and vegetable-derived surfactants are gaining popularity in "green formulations". Soap nut tree, Sapindus mukorossi, is a source of natural surfactants, saponins. Surface active matter and pH of the aqueous extract have been analysed. Primary and secondary washing effect of soap nuts is studied at different temperatures, 60 and 90 °C, applying naturally soiled cotton fabrics. Simultaneously, reference and commercial powder detergents from Croatian market are tested. Good washing performance of soap nut shells evaluated through primary effect was obtained especially at 90 °C. Beneficial multiple washing performance of natural saponins have been confirmed through less ash content as well as low level of mechanical damage. Total washing performance of soap nut shells provides many benefits for consumer from technological and ecological point of view.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

ResearchGate has not been able to resolve any citations for this publication.
Full-text available
Every laundry is determined to maintain or constantly improve the quality of its services. This quality is defined by parameters, which are determined by standard methods. With the help of different industrial laundries a research on the influence of laundering procedure on the quality of laundering was conducted. For this purpose standard cotton fabrics were laundered 50 times or 25 times respectively by certain procedures. After laundering, the quality was assessed by determining the decrease in breaking strength, chemical wear, incineration residue, Ganz degree of whiteness, lightness and the Ganz-Griesser tint deviation. It was found that higher chemical and mechanical damages were mainly due to higher concentrations of hydrogen peroxide used at higher temperatures in longer laundering procedures with lower bath ratios. The quality of the investigated laundering procedures could be improved by adapting the dosage of detergents, bath ratio, temperature and duration as well as the sorting before laundering.
Washing is a very complex process due to the presence of many factors such as chemical and physical properties of textiles, variety and chemical properties of stains and their distribution on textiles, washing temperature, time, mechanical agitation and detergent ingredients. It is necessary to optimize all of them due to achieving proper quality of the washing process. Quality control is based on the prescribed criteria that can be defined by various systems. Hygiene is important, with particular regard to the laundering of textiles coming from hospitals, nursing homes, food-processing and pharmaceutical industry. Quality control mechanisms of washing process as well as disinfection effectiveness are based oil the criteria that are evaluated by methods defined by RAL. The propositions and requirements according to RAL-GZ 992 are presented in this review.
The present study demonstrates the use of soapnut, a naturally occurring surfactant for producing alumina ceramic foams. A range of slurry compositions with soapnut amounts ranging from 2 to 20 wt% in water, alumina loading of 35–55 vol% were studied. Though all slurry compositions foamed when subjected to mechanical agitation the formation of green ceramic foams free of macroscopic defects was found to be strongly dependent on conditions during drying of foamed slurries. Addition of guar gum to the slurries was shown to enhance foam stability and thus produce defect-free foams from compositions that otherwise either collapsed or resulted in other macroscopic defects during drying. Drying conditions also had a strong effect on microstructural parameters such as cell size and cell connectivity. Soapnut-based foams appear to have a greater connectivity between cells than foams produced by other comparable processes.
The methods used for saponin determination in plant materials are presented. It is emphasised that the biological and spectrophotomeric methods still being used for saponin determination provide, to some extent, valuable results on saponin concentrations in plant material. However, since they are sensitive to the structural variation of individual saponins they should be standardized with saponin mixtures isolated from the plant species in which the concentration is measured. However, one plant species may contain some saponins which can be determined with a biological test and others which cannot. That is why biological and colorimetric determinations do not provide accurate data and have to be recognized as approximate. Thin-layer chromatography on normal and reversed-phases (TLC, HPTLC, 2D-TLC) provides excellent qualitative information and in combination with on-line coupling of a computer with dual-wavelength flying-spot scanner and two-dimensional analytical software can be used for routine determination of saponins in plant material. The densitometry of saponins has been very sensitive, however, to plate quality, spraying technique and the heating time and therefore appropriate saponin standards have to be run in parallel with the sample. Gas-liquid chromatography has limited application for determination since saponins are quite big molecules and are not volatile compounds. Thus, there are only few applications of GC for determination of intact saponins. The method has been used for determination of TMS, acetyl or methyl derivatives of an aglycones released during saponin hydrolysis. However, structurally different saponins show different rates of hydrolysis and precise optimisation of hydrolysis conditions is essential. Besides, during hydrolysis a number of artefacts can be formed which can influence the final results. High performance liquid chromatography on reversed-phase columns remains the best technique for saponin determination and is the most-widely used method for this group of compounds. However, the lack of chromophores allowing detection in UV, limits the choice of gradient and detection method. The pre-column derivatisation with benzoyl chloride, coumarin or 4-bromophenacyl bromide has been used successfully in some cases allowing UV detection of separation. Standardisation and identification of the peaks in HPLC chromatograms has been based on comparison of the retention times with those observed for authentic standards. But new hyphenated techniques, combining HPLC with mass spectrometry and nuclear magnetic resonance are developing rapidly and allow on-line identification of separated saponins. Capillary electrophoresis has been applied for saponin determination only in a limited number of cases and this method is still being developed.
Saponins are a structurally diverse class of compounds occurring in many plant species, which are characterized by a skeleton derived of the 30-carbon precursor oxidosqualene to which glycosyl residues are attached. Traditionally, they are subdivided into triterpenoid and steroid glycosides, or into triterpenoid, spirostanol, and furostanol saponins. In this study, the structures of saponins are reviewed and classified based on their carbon skeletons, the formation of which follows the main pathways for the biosynthesis of triterpenes and steroids. In this way, 11 main classes of saponins were distinguished: dammaranes, tirucallanes, lupanes, hopanes, oleananes, taraxasteranes, ursanes, cycloartanes, lanostanes, cucurbitanes, and steroids. The dammaranes, lupanes, hopanes, oleananes, ursanes, and steroids are further divided into 16 subclasses, because their carbon skeletons are subjected to fragmentation, homologation, and degradation reactions. With this systematic classification, the relationship between the type of skeleton and the plant origin was investigated. Up to five main classes of skeletons could exist within one plant order, but the distribution of skeletons in the plant kingdom did not seem to be order- or subclass-specific. The oleanane skeleton was the most common skeleton and is present in most orders of the plant kingdom. For oleanane type saponins, the kind of substituents (e.g. -OH, =O, monosaccharide residues, etc.) and their position of attachment to the skeleton were reviewed. Carbohydrate chains of 18 monosaccharide residues can be attached to the oleanane skeleton, most commonly at the C3 and/or C17 atom. The kind and positions of the substituents did not seem to be plant order-specific.