Phytochemical characterization of raw and cooked traditionally consumed alimurgic plants.

Stefania Monari,Mirko Salinitro,Maura Ferri,Annalisa Tassoni,Beatrice Montecchi

doi:10.1371/journal.pone.0256703

Abstract

In the past, wild edible alimurgic plants became an important alternative food source when poverty, wars or drought made it difficult to access crops. These plants were considered rich in highly nutritional compounds and also frequently used as food-medicine given their health-promoting properties. With the aim of improving our knowledge on the content of beneficial or detrimental compounds in relation with past local dietary and curative traditions, 12 wild food plant species were collected from two study areas selected for their very different degree of industrialization, urbanization, and conservation of local past traditions among the population: the Bologna province (Northern Italy) and the Middle Agri Valley (Southern Italy). Protein, polyphenol flavonoid and biogenic amine (both free and conjugated) contents and antioxidant activity of raw and boiled wild food plant extracts, and of cooking water were analyzed by means of spectrophotometric and high-performance liquid chromatography methods. The results demonstrated that most of the phenolic compounds were released in the cooking water which also showed the highest antioxidant activity. Seventeen different phenolic compounds were identified, of which the health-related luteolin, luteolin-7-glucoside and rutin were the most abundant (e.g., S. pratensis L. and C. intybus L.). On the other hand, biogenic amines were absent or present at very low levels in cooking water of those very same species (e.g., S. pratensis L., T. officinalis Weber, C. vesicaria subsp. taraxacifolia and C. intybus L.) of which traditionally a decoction is used for therapeutic purposes. Free and conjugated spermidine and spermine were generally the most abundant biogenic amines, while none of the known detrimental monoamines (e.g., histamine) was detected. In conclusion, the present results seem to support past local popular traditions which indicated beneficial medical properties of some wild edible plant, as well as of their cooking water.

Highlights

Twelve wild food plants were selected among the species described in two previous ethnobotanical survey studies [6, 7]: six from the area of Bologna (Emilia Romagna region, Italy), namely Salvia pratensis L. BO1, Taraxacum officinale Weber BO2, Crepis vesicaria subsp
The highest protein concentrations were detected in cooking water of S. nigra L. (MA5, 27.8 mg bovine serum albumin equivalent (BSA) eq/g fresh weight (g FW)), B. vulgaris L. (MA1, 19.2 mg BSA eq /g FW) and U. dioica L. (BO5, 17.1 mg BSA eq /g FW)
Polyphenols were mostly released into the cooking water (Fig 2D) with highest contents observed in S. pratensis L. (BO1, 4.2 mg GA eq /g FW), U. dioica L. (BO5, 3.1 mg eq GA eq /g FW) and S. nigra L. (MA5, 2.6 mg GA eq /g FW), for which a high polyphenol content had previously been demonstrated [1, 35–37]

Summary

Introduction

Before the so-called economic boom (1950–1970), economy and society of most European countries were mainly based on agriculture. Poverty and wars made it difficult to access crops and wild edible plants ( called alimurgic plants) represented an alternative food source [1]. Wild food plant foraging and consumption practices became gradually part of the traditional local knowledge, and were slowly integrated into territory customs. One of the consequences was that wild food plant practices and related knowledge have been progressively disappearing. Today, these plant species are being revalued, receiving considerable attention from researchers and food scientists as well as from nutritionists and master chefs [1, 2]

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