Fruit acids

from Wikipedia, the free encyclopedia

The term fruit acids is a collective term for the organic hydroxycarboxylic acids , dicarboxylic acids and tricarboxylic acids found in fruit . These substances do not have to be labeled as additives when used in food .

Many fruit acids are α- hydroxy carboxylic acids ( AHA , of Engl. Α - H ydroxy- A cids ) and some dicarboxylic acids . Some belong to both groups. The fruit acids include malic acid , citric acid , fumaric acid , gluconic acid , glycolic acid , mandelic acid , lactic acid , oxalic acid , salicylic acid , α-hydroxycaprylic acid and tartaric acid .

history

The term “fruit acids” originally only referred to α-hydroxycarboxylic acids found in fruits and plants such as malic acid, citric acid, glycolic acid, lactic acid and tartaric acid. The term was later also extended to dicarboxylic acids (oxalic acid, fumaric acid), as these were also found in fruits. A special case is the aromatic β-hydroxycarboxylic acid called salicylic acid, which is a phenolic acid . It occurs in many plants, but shows, despite similar applications, also great differences in effect, e.g. B. on human skin.

Occurrence, properties, manufacture and use

Fruit acids occur naturally in many plants, mainly in their fruits. Together with sugars, they have a decisive influence on the taste of fruit . The total content of organic acids in fruit is around one to three percent. In the metabolism of all organisms, the anions of the acids are important metabolic intermediates. For industrial use, fruit acids are synthesized using biotechnological processes such as fermentation or enzymatic oxidation .

Fruit acids and their salts are used in large quantities as acidulants in foods. Citric acid is used for preservation purposes. The salts are only slowly absorbed in the human intestine and therefore act as osmotic laxatives .

Fruit acids are also used in cosmetics (e.g. chemical peeling ) and acne therapy. Salicylic acid is known to have an antimicrobial effect in addition to the keratolytic effect in dermatological use .

Occurrence in fruits (content)

The following table lists the occurrence of all organic acids and selected fruit acids in various fruits:

fruit Σ Organic acids Malic acid Citric acid Oxalic acid Salicylic acid Other acids
pineapple 0.7 g 95 mg 630 mg - 2.1 mg -
Apple 0.6 g 550 mg 16 mg 0.5 mg 0.31 mg -
apricot 1.4 g 1000 mg 400 mg 7 mg 3 mg -
banana 0.6 g 360 mg 270 mg - - -
pear 0.3 g 170 mg 140 mg 6.2 mg - -
blackberry 1.7 g 900 mg 18 mg 12 mg - 810 mg
strawberry 1.0 g 140 mg 870 mg 16 mg 1.4 mg -
Grapefruit 1.6 g 180 mg 1370 mg - 0.68 mg -
Blueberry 1.4 g 850 mg 525 mg - - 120.2 mg
raspberry 2.1 g 400 mg 1720 mg 16 mg 5.1 mg -
Currant, red 2.4 g 290 mg 2070 mg 10 mg 5.1 mg -
sweet cherry 1.0 g 940 mg 13 mg 7.2 mg 0.85 mg -
kiwi 1.5 g 500 mg 990 mg traces 0.32 mg -
mango 0.4 g 75 mg 295 mg 35 mg 0.11 mg 80 mg
Mirabelle 0.9 g 890 mg - 11 mg - -
orange 1.2 g 160 mg 1060 mg - 2.4 mg -
quince 0.9 g 930 mg - - - -
peach 0.6 g 330 mg 240 mg - 0.58 mg -
plum 1.3 g 1220 mg 35 mg 12 mg 0.14 mg -
Gooseberry 1.4 g 720 mg 720 mg 19 mg - 120 mg
Grape 0.6 g 540 mg 25 mg 8 mg 1.4 mg 530 mg
lemon 4.9 g - 4920 mg - 0.18 mg -

The quantities given are based on the content in 100 g edible portion .

Fruit acid occurrence (selection in pictures)

  • pineapple

  • Apples

  • Apricots

  • Bananas

  • Pears

  • Blackberries

  • Strawberries

  • Grapefruit

  • Raspberries

  • Cherries

  • Kiwi fruit

  • Oranges

  • Peaches

  • Plums

  • rosemary

  • Black currants

  • Lemons

Individual evidence

  1. ↑ Gerald Rimbach, Jennifer Möhring, Helmut F. Erbersdobler : 9.6.5 Organic acids / fruit acids. In: Food product knowledge for beginners. Gabler Wissenschaftsverlage, 2010, ISBN 978-3-642-04485-4 , p. 238.
  2. ↑ Doris Fanta, Christine Messeritsch-Fanta: Acne 1999: do we still need a dermatologist? In: The dermatologist . 50, 1999, pp. 900-911. doi : 10.1007 / s001050051009
  3. ↑ A. Fratila: Fruit acid treatment in acne therapy. In: The dermatologist. 47, 1996, pp. 937-938. doi : 10.1007 / s001050050537
  4. ↑ A. Fratila, M. Uerlich: Fruchtsäurepeeling - The dermatological and aesthetic-corrective application of alpha-hydroxy acids (AHA). In: The dermatologist. 50, 1999, pp. 448-460. doi : 10.1007 / s001050050942
  5. ^ AA Hartmann: The influence of various factors on the human resident skin flora. In: Seminars in Dermatology . 9 (4), Dec 1990, pp. 305-308. PMID 2285575 .
  6. ↑ a b fruit acids. and some fruit acids of various fruits. In: Lexicon of Biology.