Chlorogenic acid retention in white and purple eggplant after processing and cooking

ZARO, MARÍA JOSÉ; ORTIZ, LEIDY CAROLINA; KEUNCHKARIAN, SONIA; CHAVES, ALICIA R; VICENTE, ARIEL R; CONCELLÓN, A

LEBENSMITTEL-WISSENSCHAFT UND-TECHNOLOGIE-FOOD SCIENCE AND TECHNOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 64 p. 802 - 808

0023-6438

It is accepted that the stability of vegetable antioxidants in response to processing and cooking treatments may be affected by the varietal type. However, the information available in the literature is very limited. In this work we determined the influence of the eggplant type (white and purple) on pulp chlorogenic acid content (5-O-caffeoyl-quinic acid; CQA) and antioxidant capacity (AC) in response to common pre-processing (cutting, salting or blanching), processing (air- vacuum- solar- and freeze-drying, slow- and fast-freezing) and cooking methods (microwaving, baking, grilling, steaming, boiling or pressure cooking). Fresh purple eggplants showed higher AC and CQA content (16%) than white fruit. Fruit pre-processing caused significant losses of AC, with the effect being higher in the purple cultivar. Hot air- and sun-drying almost depleted CQA in both genotypes studied. In contrast, white eggplants retained higher AC upon freezing and microwaving. Wet cooking methods (boiling and pressure cooking) markedly increased fruit AC indicating that these preparation procedures improved antioxidant extractability. The eggplant cultivar has a major influence in antioxidant retention during processing and cooking; the white variety proved in general, more suitable for processing in terms of antioxidant retention than the purple genotype.