Phenolics and Carotenoid Contents in the Leaves of Different Organic and Conventional Raspberry (Rubus idaeus L.) Cultivars and Their In Vitro Activity.

Ponder Ponder,Hallmann Hallmann

doi:10.3390/antiox8100458

Abstract

Raspberry leaves are a source of carotenoids and polyphenols, including ellagic acid and salicylic acid. The results of scientific research suggest that they have potential pro-health properties that contribute to human health. The aim of this study was to determine the polyphenolic and carotenoid profiles in the leaves of selected raspberry cultivars and their in vitro activity. The second aim was to determine the impact of organic and conventional farm management on the polyphenol, carotenoid, and chlorophyll contents in different raspberry cultivars: ‘Polana’, ‘Polka’, ‘Tulameen’, ‘Laszka’ and ‘Glen Ample’. Compared with conventional raspberry leaves, organic raspberry leaves were characterized by a significantly higher content of dry matter, total polyphenols, total phenolic acids, chlorogenic acid, caffeic acid, salicylic acid and quercetin-3-O-rutinoside; moreover, the organic leaves were characterized by higher antioxidant activity. Among examined cultivars, ‘Polka’ c. was characterized by the highest antioxidant status. However, raspberry leaves from conventional farms contained more total carotenoids, violaxanthin, alpha-carotene, beta-carotene, total chlorophyll and individual forms of chlorophylls: a and b.

Highlights

Raspberry (Rubus ideaus) is recognized by consumers as a tasty and healthy fruit
We observed that organic plants, compared with conventional plants, contained significantly more quercetin-3-O-rutinoside (p = 0.0009)
The results showed that raspberry leaves from conventional farming contained significantly more total carotenoids (p = 0.0014), violaxanthin (0.026 mg 100 g−1 FW and 0.017 mg 100 g−1 FW), alpha-carotene

Summary

Introduction

Raspberry (Rubus ideaus) is recognized by consumers as a tasty and healthy fruit. Recent research indicates that the leaves of berry plants, such as strawberries, raspberries, blueberries and blackcurrants, are a potential source of bioactive compounds with strong, pro-health, anticancer and anti-inflammatory properties [1,2,3,4]. Berry leaves are by-products of berry plant cultivation Their traditional therapeutic use against several diseases, such as the common cold, inflammation, diabetes, and ocular inflammation, has been almost forgotten [5]. Two chemical compounds deserve special attention: ellagic and salicylic acids [7,8]. These compounds show strong biological effects in vitro that have been connected to pharmacological and nutritional effects [9]. They are mainly related to the prevention of cardiovascular diseases [10]. Plants produce salicylic acid as a response to biotic (pest and diseases) stresses [13,14]

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