Preharvest treatments with malic, oxalic, and acetylsalicylic acids affect the phenolic composition and antioxidant capacity of coriander, dill and parsley

- Preharvest treatments with MA, OA and ASA on the bioactivity of herbs were assayed.
- Leaf spray of organic acids (MA, OA and ASA) was very positive in coriander plants.
- Leaf spray of organic acids led to intermediate improvements in dill plants.
- Leaf spray did not show significant beneficial effects in parsley plants.
- Antioxidant capacity responding better to these preharvest treatments was FRAP.

The effects of a preharvest treatment with malic (MA), oxalic (OA), or acetylsalicylic (ASA) acid at three concentrations (1, 2 and 3 mM) on the bioactivity and antioxidant capacity of coriander, dill, and parsley were investigated. The antioxidant capacity of the herbs extracts was assayed by spectrophotometric methods by using three different analytical methods: ORAC, FRAP, and ABTS; the effects of treatments were very positive in coriander, produced intermediate results in dill, and no effects were found in parsley plants. Polyphenol compounds were identified by LC-MS-QTof and quantified by UPLC-PDA-FL. Thirty phenolic compounds were identified in these three herbs. The major compounds were (i) coriander: dimethoxycinnamoyl hexoside and quercetin-3-O-rutinoside, (ii) dill: neochlorogenic acid and quercetin glucuronide, and (iii) parsley: apigenin-7-apiosylglucoside (apiin) and isorhamnetin-3-O-hexoside. The application of these three organic acids favored the accumulation of phenolic compounds in coriander plants, but had no significant positive effects on dill and parsley. The treatments leading to the best results in all three plants were the application of MA or OA at 1 mM.