Low Temperatures Affect the Physiological Status and Phytochemical Content of Flat Leaf Kale (Brassica oleracea var. acephala) Sprouts.

Stjepana Fistanić,Branka Salopek-Sondi,Ivana Radojčić Redovniković,Dunja Šamec,Valentina Ljubej

doi:10.3390/foods11030264

Stjepana Fistanić, Branka Salopek-Sondi + Show 3 more

Open Access

https://doi.org/10.3390/foods11030264

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Abstract

Consumption of plants in the juvenile stage becomes popular because sprouts are easy to grow, and they can be a tasty source of micro- and macro-nutrients and various phytochemicals. However, some environmental factors during sprout growth can affect their characteristics. In this article, we investigated how low temperatures during cultivation (8 °C) and additional exposure to freezing temperatures (−8 °C) affect the physiological status and phytochemical content of kale (Brassica oleracea var. acephala) sprouts compared to the control grown at 21 °C. We conducted five independent laboratory experiments and found that low temperature significantly increased proline content and decreased sprouts yield. In addition, low temperature caused a significant decrease in carotenoid and flavonoid content, while phenolic acid content and total glucosinolates content increased, but individual glucosinolates were differentially affected. Our results indicate that low temperatures affect the physiological status of kale sprouts and affect the content of phytochemicals.

Highlights

The consumption of plants in their juvenile stage, such as sprouts and microgreens, has become popular in recent years due to their richness in nutrients and bioactive compounds that have the potential to prevent malnutrition and chronic diseases [1]
In a study investigating the content of polyphenols, flavonoids and glucosinolates in seeds, sprouts and leaves of Tuscan black kale (B. oleracea ssp. acephala var. sabellica), the highest content of phytochemicals was observed in 10-day-old sprouts [12]
Sprouts exposed to additional temperature at –8 ◦ C did not differ from those at 8 ◦ C because they were exposed to freezing temperature for only 1 h, too short a time to observe differences, so we did not report these data here

Summary

Introduction

The consumption of plants in their juvenile stage, such as sprouts and microgreens, has become popular in recent years due to their richness in nutrients and bioactive compounds that have the potential to prevent malnutrition and chronic diseases [1]. Sprouts and microgreens of vegetables from the Brassicaceae family, often referred to as cruciferous or mustard family, constitute the most extensive reservoir of genetic resources for commercial production of microgreens and sprouts [8] Most vegetables from this family belong to the genus Brassica, to the species B. oleracea (broccoli, cauliflower, cabbage, kale, colard, Brussels sprouts, etc.) or B. rapa (pak choi, Chinese cabbage) [9]. They are known by the common name cruciferous and are considered as a good source of dietary fiber, vitamins, minerals and phytochemicals, especially from the group of polyphenols, carotenoids and glucosinolates [2,9,10,11,12]. According to the in vitro studies, sprouts or microgreens of Brassicaceae may be useful in preventing oxidative stress and inflammation-related diseases [15], cancers [16], liver damage [17], and type 2 diabetes mellitus [18]

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