Compositional and morphological analyses of wax in northern wild berry species

Abstract

Aerial surfaces of plants are covered by a waxy cuticle protecting plants from excessive water loss and UV light. In the present study, composition and morphology of cuticular waxes of northern wild berry species bilberry (Vaccinium myrtillus L.), lingonberry (V. vitis-idaea L.), bog bilberry (V. uliginosum L.) and crowberry (Empetrum nigrum L.) were investigated. Scanning electron microscopy (SEM) revealed differences in epicuticular wax morphologies and gas chromatographymass spectrometry (GC-MS) analysis confirmed variation in chemical composition of cuticular waxes between the berry species. The dominant compounds in bilberry and lingonberry cuticular waxes were triterpenoids while fatty acids and alkanes were the dominant ones in bog bilberry and crowberry, respectively. Wax extracted by supercritical fluid extraction (SFE) from industrial press cakes of bilberry and lingonberry contained linoleic acid and γ-linolenic acid as the dominant compounds. Furthermore, in vitro sun protection factor (SPF) of berry waxes depicted good UV-B absorbing capacities.

Analysis of biosynthesis and composition of cuticular wax in wild type bilberry (Vaccinium myrtillusL.) and its glossy mutant

“…The chemical composition of ripe WT bilberry fruit cuticular wax corroborates with our previous study (Trivedi et al , 2019a). However, the wax composition showed changes during the course of bilberry fruit development with the proportion of major compound classes generally varying similarly in both WT and GT fruits.…”

“…The result implies that glossy appearance in GT bilberry fruits could be due to the high reduction in amount of ketones. In supporting this hypothesis, our previous study showed that glaucous appearing bilberry (rod-like epicuticular morphology) and bog bilberry (coiled rodlet morphology) contain ketones while glossy appearing lingonberry and crowberry are devoid of ketones as well as rod-like structures (Trivedi et al ., 2019a). Ketones have earlier been reported to be responsible for the formation of transversely rigid rodlets (Meusel et al ., 1999).…”

“…Derivatization of fatty acids and GC-MS analysis was performed as described previously by Trivedi et al (2019a). GC-MS analysis was performed using a PerkinElmer Clarus 580 system equipped with a Clarus SQ 8 C mass-selective detector (Waltham, MA, USA) and an Omegawax 250 column (30 m × 0.25 mm, 0.25 µm, Darmstadt, Germany).…”

“…As an abundant resource in Northern forest, wild bilberries play a significant role in food industry. The berries provide also an excellent raw material for extraction of health beneficial products, like anthocyanins, but the leftovers of food industry (berry press cakes) can also be utilized for extraction of bioactive wax compounds (Lara et al ., 2014; Trivedi et al ., 2019a).…”

Vaccinium myrtillus L. Fruits as a Novel Source of Phenolic Compounds with Health Benefits and Industrial Applications - A Review

“…The use of anthocyanins as food colourings, especially in more acidic foods, which may favour their stability, has exponentially raised. The exploitation of V. myrtillus fruits for medicine and human diet purposes has gained significant attention, being the economically most important wild berries of Northern Europe, widely used by the food industry [94]. This fruit is consumed not only in a fresh manner, but also in processed products (press cake) and derivatives (juice, jam and liqueur) [95,96].…”