Pineapple juice's composition varies depending on geography, season and how the fruit is harvested and processed. The "Handbook of Fruit and Vegetable Flavors" describes pineapple as one of the most popular non-citrus tropical fruits. Its balance of sugar and acid contributes to the fruit's refreshing flavor. Consuming large quantities of fresh pineapple juice can cause mouth and esophagus soreness. The irritation results from the combined action of the acids, bromelain enzymes and calcium oxalate crystals.
Citric acid makes up 87 percent of the acidic content of pineapple juice, according to a 1973 article on "Nonvolatile Acids in Pineapple Juice" based on a study by researcher Harvey T. Chan Jr. and published in the Journal of Agricultural and Food Chemistry. The high level of citric acid in fresh, unsweetened pineapple juice may cause an upset stomach if large quantities are consumed, especially on an empty stomach, according to the website PineappleJuice.
Malic acid makes up 13 percent of pineapple juice's acidic content. It is a natural substance found in fruit and vegetables and is present in your body's cells. Malic acid is also beneficial to your health. It boosts immunity; promotes smooth, firm skin; helps maintain oral health; and reduces the risk of toxic metal poisoning.
In a study on the “Short-Term Effect of Weather on Malic Acid in Pineapple Fruit,” published online in the Journal of Food Science in 2006, food technologist Willis A. Gortner found that the malic acid content of the juice of the pineapple plant is sensitive to weather and changes in sunlight or any conditions that increase evaporation of water. The relationship of the malic acid in pineapple and the forces causing evaporation may be related to Crassulacean acid metabolism, a strategy that plants such as the pineapple use to survive and conserve water in hot, dry, desert weather, according to professor Janet L. Stein Carter of the University of Cincinnati - Clermont College Biology Department.
Pineapple juice contains ascorbic acid and is a good source of Vitamin C. Ascorbic acid or vitamin C fights bacterial and viral infections, is an effective antioxidant and helps the body absorb iron. Half a cup of pineapple juice provides 50 percent of an adult's daily-recommended amount of vitamin C.
Pineapple juice also has small amounts of other acids, including n-valerianic acid, isocapronic acid, acrylic acid, quinic acid and b-methylthiopropionic acid methyl ester with ethyl ester.
- "Handbook of Fruit and Vegetable Flavors"; Y. H. Hui, Ph.D.; 2010
- Journal of Agricultural and Food Chemistry: Nonvolatile Acids in Pineapple Juice
- Journal of Food Science: A Short-Term Effect of Weather on Malic Acid in Pineapple Fruit
- Stockbyte/Stockbyte/Getty Images
This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.