Application of the brine method to extend the shelf life of zucchini (Cucurbita pepo L.) flowers: Changes in antioxidant activity, total phenolic contents and phytochemical profile

Abstract

Edible flowers, demanded by consumers for their distinct sensory properties and health benefits, have a short shelf life. This study aimed to apply the brine method to extend the shelf life of zucchini (Cucurbita pepo L.) flowers, one of the edible flowers. The phytochemical profile of the samples was determined using LC-MS/MS, a method that allows the amount of 56 different phytochemicals to be determined. In this context, zucchini flowers were stored in brines containing 5% and 10% NaCl for the 7th, 14th, 21st and 28th days. The highest antioxidant activities were found in DPPH (19.23±0.74 mgTE/g extract) and CUPRAC (181.43±1.08 mmol Trolox Eq/g) on the 7th day of brining at 10% salt concentration. The highest TPC (32.10±0.33 mg GAE/g) was determined on 7th day of brining and at 10% salt concentration. The dominant phytochemicals were determined as quinic acid, fumaric acid, protocatechuic acid, 4-OH-benzoic acid, routine, hesperidin, isoquercitrin, nicotifluorine, quercetin and kaempferol at 10% salt concentration on the 7th and 14th days. This study demonstrates that the brine method can be used as an appropriate processing technology to extend the shelf life of zucchini flowers and also to broaden their application. Additionally, the findings of this study contributed to optimizing the storage time and salt concentration of brined zucchini flowers. It is thought that brined flowers can gain a place in the market as a commercial food product.