Multi-year Quantitative Evaluation of Stilbenoids Levels Among Selected Muscadine Grape Cultivars.

Devaiah Kambiranda,Janana Snowden,Stephen Stringer,Sheikh Basha,James Obuya

doi:10.3390/molecules24050981

Abstract

Stilbenoids such as t-piceid, t-resveratrol, ε-viniferins, and t-pterostilbene can differ significantly among grape cultivars and years due to variation in environmental conditions and subsequent stressors encountered during a year. This study evaluated diverse muscadine grape cultivars for their ability to consistently produce four major stilbenoids such as t-piceid, t-resveratrol, ε-viniferins, and t-pterostilbene irrespective of environmental changes that can impact their production. Berries from forty-two muscadine grape cultivars were collected for three years (2013, 2014, and 2015) to measure stilbenoids. Results showed significant differences in the composition of four stilbenoids among the muscadine cultivars. The highest level of stilbenoids was observed in ‘Fry Seedless’ (270.20 µg/g fresh weight) in each of the three consecutive years tested followed by ‘Pride’ (46.18 µg/g fresh weight) while ‘Doreen’ produced the lowest level of stilbenoids (1.73 µg/g fresh weight). Results demonstrated that certain muscadine grape cultivars consistently produced varied levels of the four major stilbenoids year after year. Based on the total content of stilbenoids, the 42 muscadine cultivars studied were grouped into three categories such as High, Medium and Low stilbenoid-containing cultivars. This information will help establish new vineyards with cultivars that are less prone to variations in environmental conditions and can consistently produce stilbenoid-rich muscadine grape berries with enhanced market value to promote consumer health.

Highlights

Plant-based foods are a rich source of phytochemicals viz. anthocyanins, glucosinolates, isoflavones, terpenoids, and phenolic compounds, etc. [1]
Limited information exists on the extent of genetic variation and environmental impacts on the content of stilbenoids in muscadine grape cultivars
This study involved the evaluation of red and bronze wine and fresh fruit-type muscadine cultivars to determine the content of their stilbenoids for three consecutive years

Summary

Introduction

Plant-based foods are a rich source of phytochemicals viz. anthocyanins, glucosinolates, isoflavones, terpenoids, and phenolic compounds, etc. [1]. Some of the phytochemicals found in grapes are hydroxycinnamic acids, hydroxybenzoic acids, flavonoids, stilbenoids, and proanthocyanidins [2]. The muscadine grape (Vitis rotundifolia, Michx.) is native to the Southeastern U.S and its berries and products can be utilized as inexpensive phytochemical-rich nutraceuticals or dietary supplements for prevention and treatment of chronic diseases in humans [3,4]. Numerous phytochemicals found in muscadine grapes are believed to provide numerous health benefits, including serving as anti-diabetic, anti-inflammatory, anti-cancer, anti-obesity, can reduce risks related to certain cancers, heart disease, and other age-associated disorders [5,6,7,8]. Among the polyphenol compounds found in skin, pulp, and seeds of muscadine grape berries, stilbenoids are of particular interest due to their health. Stilbenoids are formed via the phenylpropanoid and acetate-malonate pathway with stilbene synthase (StSy) catalyzing the formation of trans-resveratrol via condensation of

Methods

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Discussion

Conclusion