| This study was conducted to establish the methods to determine solanine in potato and animal feeds. Comparison was firstly made of ethanol and ethanol-acetic acid as the solvents to distill solanine (Expt. I) and in animal feeds (Expt. 11). Colorimetry method was then compared with high-pressure liquid chromatograph (HPLC) to determine the solanine (Expt. 111). Mice were used to determine the safety limitation of solanine in term of the lethal dose 50% (LD50) (Expt. IV).In Expt. I , ethanol and ethanol-acetic acid were used as solvents to distill solanine in potato. Based on either of the solvents, the quantity of solanine increased with the amount of potato significantly (P<0.01). The coefficient of the determination (R2) were 0.997 and 0.9929, respectively, when ethanol and ethanol-acetic were used. There was no significant (P>0.05) difference between two linearities. Recoveries of solanine based on ethanol-acetic acid or ethanol were 87.3 or 89.0% in fresh potato (P<0.05), and 85.7 or 90.9% (P<0.01) in dry potato, respectively. The coefficient of variation from the method of ethanol-acetic and ethanol was 8.7 and 3.3%, respectively. These results indicated that both ethanol and ethanol-acetic may be used as solvent to distill the solanine in potato, while ethanol method was superior to ethanol-acetic in terms of accuracy and convenience.Expt. II was carried out to compare the method of ethanol-acetic acid and ethanol to distill the solanine in three feeds: sows, pork and chickens. There was a significant correlation (p<0.01) between the amounts of solanine and the potato addedin feeds, while the regression coefficient of both linearities was not significant (p>0.05). However, the recovery of solanine in any feeds was very low, 41.4-73.3% for ethanol and 38.0-70.8% for ethanol-acetic acid, respectively. The contents of fat were so high as 4.7-9.3% in three feeds, and it was found that the recovery was negatively related the fat content. Therefore, when the feeds were degreased to reduce the content of ether extracts to less than 1%, the recovery of solanine in feed was increased to over 81.6% for both solvents. It is inferred that animal feeds with a fat content above 1% should be degreased so that the solanine could be determined accurately.In Expt. Ill, methods of colorimetry and HPLC were compared to quantify the solanine. The solanine content was significantly (P<0.01) related to the spectral absorption in colorimetry and to the apex area in HPLC with retention time for 2.34 min. The high coefficient of determination (0.9968 and 0.9996) and high recovery (90.9 and 92.7%) for the colorimetry and HPLC indicated that both methods could be used to quantify the solanine content.Toxicity of solanine was examined using Kunming mice in Expt. IV. Differernt doses of solanine were administrated per so in two trials, with doses of 75-420 mg/kg BW in trial-1, and Ml'-747 mg/kg BW in trial-2, respectively. Seventy mice were used in trial 1 and divided into 7 equal groups. Sixty mice were used in trial 2 and divided into 7 equal groups. In both trials, the mice were free access to water and fed once one day at 0900 am. Observation was made on action and death of mice for 5 days after administration of solanine. Not all mice were dead even at the highest dose (420 mg/kg BW) in trial-1, so the LD50 could not be estimated. In trial-2, all the mice at solanine level of 747 mg/kg BW were dead on the 3rd day. It was found that solanine was toxic to liver, spleen and kidney of mice and the adverse effects were more severe with increasing dose of solanine. The LD50 of solanine was estimated to be 434 mg/kg BW in mice.In summary, ethanol may be used to substitute for ethanol-acetic acid as solventto distill solanine in potato and in animal feeds. Colorimetry is a convenient method to quantify the solanine. Feeds with a high fat content should be degreased before determination of solanine in order to increase the accuracy. The solanine is toxic to liver, spleen and kidney of animal, and its lethal do... |
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