Types of Solvent, Extraction Conditions and Properties of Oil from Eri-silk Pupa (<I>Samia ricini</I>)

Abstract

The study was carried out by extraction oil from Eri-silk pupa (Samia ricini) which were fed either with cassava leaves or castor leaves. The extraction solvents were hexane or petroleum ether. The amount of oil extracted from pupa fed with cassava leaves was higher than those fed with castor leaves (p ≤ 0.05). The extraction by hexane gave higher amount of oil than petroleum ether (p ≤ 0.05). Optimum conditions for extraction of pupa oil was using solvent : pupa at the ratio of  7.8 : 1 ( volume by weight) with temperature of 56 ºC for 16 min. The physical properties of the extracted pupa oil were refractive index 1.473 ± 0.001 at 25^oC, relative density 0.88 ± 0.02 g/ml and brightness (L value) 51.73 ± 0.38, the redness (a* value) 10.09 ± 0.19, and the yellowness (b* value) 61.81 ± 0.62. The chemical properties of extracted pupa oil were acid value 16.00 ± 0.00 mg KOH/g of crude oil, and 0.55 ± 0.01 mg KOH/g of refined oil, iodine value    28 ± 2 g iodine / 100 g oil, peroxide value 0.55 ± 0.12 milliequivalent/kg oil, saponification number 190.54 ± 4.46 mg KOH/g oil, unsaponifiable matter 3.22 ± 0.15 g/kg oil, water and volatile matters at 105ºC  0.14 ± 0.01 % w/w, insoluble impurities  0.08 ± 0.01 % w/w and pH  7.42 ± 0.00.