LEM′ON AC′ID. See Citric acid.
LEM′ON FLA′VOUR. See Essence of Lemon.
LEM′ON JUICE. Syn. Limonis succus (B. P.), Succus limonum (Ph. L. & D.), L. The juice of the lemon, obtained by squeezing and straining. When freshly expressed, it is turbid, owing to the presence of mucilage and extractive matter. These substances render the juice liable to decomposition, and various methods have from time to time been proposed for preserving it. Amongst these may be mentioned the addition to the fresh juice of one per cent. of bisulphite of calcium, or ten per cent. of proof spirit.
“We have examined the juice expressed from two varieties of lemons, viz. Palermo and Messina, with the following results:
| Palermo. | Messina. | |
| “Ounces of juice yielded by 100 lemons | 108 | 96 |
| Specific gravity of juice | 1044·85 | 1038·56 |
| Percentage of citric acid | 8·12 | 7·04 |
| Percentage of ash | 0·289 | 0·301 |
“100 parts of the ash of the juice of Palermo lemons gave:
| “Sulphuric acid | 10·59 |
| Carbonic acid | 16·33 |
| Chlorine | 0·81 |
| Phosphoric acid | 6·74 |
| Ferric phosphate | 1·32 |
| Lime | 8·89 |
| Magnesia | 3·02 |
| Potash | 47·84 |
| Soda | 3·32 |
| Silica | 0·72 |
| Loss | 0·42 |
| ——— | |
| 100·00 |
“If lemons are kept a few months before squeezing, the yield of juice is slightly increased, but its specific gravity and percentage of citric acid remains unaltered. It is erroneous to suppose that the acid of the lemon is, by keeping, changed into sugar. We have kept lemons for 12 months, and found that the percentage of acid was not diminished. A certain proportion of sugar was formed, but at the expense of the soluble starch contained in the cell-walls of the lemon. Lemon juice on being kept is found to decrease in density, but the amount of acid remains the same.” (Harkness.)
Lemon juice may be preserved by heating it to 150° Fahr., filtering, and setting it aside in bottles completely filled. If this process be performed in the winter, the juice, it is said, may be kept perfectly good for 12 months. Fresh lemon juice is prevented from decomposition and rendered fit for exportation by mixing it with 1⁄10th of alcohol. (Schweitzer.)
The Merchant Shipping Act of 1867 requires