Lemon juice Subject

Compared with other subjects, chemistry is commonly believed to be more difficult, at least at the introductory level. There is some justification for this perception for one thing, chemistry has a very specialized vocabulary. However, even if this is your first course in chemistry, you already have more familiarity with the subject than you may realize. In everyday conversations we hear words that have a chemical connection, although they may not be used in the scientifically correct sense. Examples are electronic, quantum leap, equilibrium, catalyst, chain reaction, and critical mass. Moreover, if you cook, then you are a practicing chemist From experience gained in the kitchen, you know that oil and water do not mix and that boiling water left on the stove will evaporate. You apply chemical and physical principles when you use baking soda to leaven bread, choose a pressure cooker to shorten the time it takes to prepare soup, add meat tenderizer to a pot roast, squeeze lemon juice over sliced... 

When a single 500-mg dose of erythromycin ethylsuccinate was taken by 9 healthy subjects with two 150-mL alcoholic drinks (one immediately and the other 2.5 hours later) the erythromycin AUC was decreased by about 27% and its absorption was delayed. One subject had a 185% increase in absorption. The alcoholic drink was pisco sour, which contains lemon juice, sugar and pisco (a brandy-like liqueur). Blood alcohol levels achieved were about 50 mg%. ... 

Studies in healthy subjects clearly demonstrate that citrate markedly increases the absorption of aluminium iiom the gut. The absorption is increased threefold if taken with lemon juice, eight to tenfold if taken with orange Juice,"- and five to 50-fold if taken with eitrate, " but the reason is not understood. It eould be that a highly soluble aluminium eitiate eomplex is formed. ... 

Several postharvest treatments to citrus fruits have been tested in an effort to improve the quality of the extracted juice. Bruemmer and Roe subjected citrus fruits to anaerobic conditions for periods of 20 to 32 hours at 32.2 to 43°C (228, 229). This treatment reduced the titratable acidity and increased the Brix-acid ratio by about 10%. The decrease in acidity was accompanied, however, by a 20-fold increase in ethanol (229). Since the soluble solids-acid ratio is a major criterion of citrus juice quality, this procedure, if perfected, could allow earlier harvesting of fruit and a more consistent supply of fruit during the processing season. Bitterness of products from navel oranges, lemons, and grapefruit is related to limonin content. A 3-hour treatment of fruit with 20 ul ethylene/1 of air lowered the limonin content, reduced bitterness, and the juice was judged more palatable than juice from untreated fruit (230). 

Foo and Lemon (1997) assessed the acute effects of kava, alone and in combination with alcohol, on subjective measures of impairment and intoxication and on cognitive performance. This was a placebo-controlled study, with ten subjects in each of four conditions placebo, kava, alcohol, and kava plus alcohol. The placebo was pure fruit juice and fruit juice was added to kava and alcohol as well to maintain double blind conditions. A battery of tests was included to measure outcomes, including subjective measures of impairment and intoxication, and visual-motor and cognitive performance. These measures were performed before (time = 0), and 30, 60 and 90 minutes after consumption of the drinks. Each test trial took about 12 minutes. Kava consumption produced no significant effects on perceived or measured competence, while alcohol caused motor and cognitive impairments. However, when kava and alcohol were combined, kava potentiated both the perceived and measured impairment produced by the alcohol alone. This potentiation effect is in accord with the findings of Jamieson and Duffield (1990) on the positive interaction of ethanol and kava resin in mice. 

---