Bleached Lac Factors Which Influnece the Keeping Quality

Characterisation and discrimination of various types of lac resin using gas chromatography mass spectrometry techniques with quaternary ammonium reagents

“…Research at the PMA has suggested that bleached shellac, or "white lac", experienced a period of popularity from the nineteenth into the early twentieth century, both by artists and, in this case, as a restoration varnish [22]. The bleached resin is known to develop problems such as insolubility with age, however, likely related to the presence of residual chlorine [52]. Characterisation of the Signorelli varnish was therefore important to interpret its behaviour during treatment and to inform decisions about appropriate cleaning methods.…”

Volumetric Estimation of Lac on Glazed Candies

“…A manufacturer of candies, well before the law went into effect, asked the authors to render analysis on the lac content of his candies, in order to modify his manufacturing procedure if necessary and to ascertain that his products are within the law. A search of the literature showed no methods for the estimation of lac on glazed candy, but various articles (J, 3,7,8,11) dealing with the chemical composition of shellac, none of which could be used for quantitative estimation in a complex system such as candy. The United States Department of Agriculture, Food and Drug Administration, advised (9) that they had had little or no occasion to determine glaze on candy quantitatively; hence they have no immediately available method for quantitative analysis of glazed candy for shellac content.…”