Physicochemical Properties and Antioxidant Activity of Spray-Dry Broccoli (Brassica oleracea var Italica) Stalk and Floret Juice Powders

Abstract

This research presents the microencapsulation and conservation of antioxidants of broccoli juice processed by spray drying, and proposes the use of a by-product as a technological application. Broccoli juice (BJ) extracted from two sources, stalks and florets, was spray-dried employing maltodextrin (MX) as a carrier agent at concentrations of 5, 7.5, and 10%, and inlet temperatures of 150 and 220 °C. The total phenolic content (TPC), and antioxidant activity (AA) of the BJ-MX powders were determined together with the physicochemical characteristics, including particle morphology, microstructure, and thermal properties. Based on the TPC and AA, the optimal processing conditions found were 5% of MX and a drying temperature of 220 °C. However, the florets showed higher TPC, while stalks presented higher AA under those processing conditions. The particles exhibited micrometric sizes and a mixture of spherical-shape particles and pseudo-spherical particles. The diffractograms indicated an amorphous microstructure in all samples. The glass transition temperature (Tg) was determined in the range of 50 °C for the samples dried at 150 °C and 55 °C for those dried at 220 °C. This suggested that powders might be stored at temperatures below the Tg without presenting any loss of antioxidants.

Prunus avium L. (Sweet Cherry) By-Products: A Source of Phenolic Compounds with Antioxidant and Anti-Hyperglycemic Properties—A Review

“…According to Gonçalves et al [18], catechins and procyanidins were the flavan-3-ols found in sweet cherry fruits. Their presence has already been reported in other studies [6,11,55]. Furthermore, procyanidins were identified in sweet cherry fruits from different cultivars (values ranging from 6.2 to 290.6 µg/g dw), representing less than 18% of the total non-colored phenolics [18].…”

Comprehensive Evaluation of the Bioactive Composition and Neuroprotective and Antimicrobial Properties of Vacuum-Dried Broccoli (Brassica oleracea var. italica) Powder and Its Antioxidants

“…In addition, ITCs have been recognized as potential candidates for new antimicrobial compounds with a broad spectrum of activity due to their ability of reducing oxygen consumption and depolarizing the mitochondrial membrane in bacterial cells [ 13 ]. Due to the featured medicinal advantages of broccoli florets, their consumption has increased over 940% over the last 35 years [ 14 ]. In fact, global production of broccoli and cauliflower has increased by about 6 million ton in the last 10 years, with approximately 26.92 million ton produced in 2019 [ 4 ].…”

Strawberry Juice Powders: Effect of Spray-Drying Conditions on the Microencapsulation of Bioactive Components and Physicochemical Properties

“…The extraction was conducted under constant stirring for 1 h. After this period, the extracts were centrifuged for 15 min at 11,000 rpm and 4 °C; the supernatant was filtered and stored at 4 °C in amber bottles to protect them from light damage. Next, the precipitate was re-suspended in a methanol solution (70%) and stirred for 1 h, and the extracts were centrifuged, filtered, and mixed with the previous supernatant [ 10 ]. Extracts were prepared in duplicate.…”

“…These observations suggested that the powder microstructure was better conserved at the intermediate and highest MX concentration. Saavedra-Leos et al 2021 and Araujo-Díaz et al 2017 indicated that agglomerated structures are related to a collapse of the microstructure during spray drying [10,15]. Przybył et al 2018 reported the morphology of strawberry powders-with different quality, the bad batches presented large particle sizes and conglomeration of particles, while the good batches were presented as spherical with deflated shape [37].…”

“…They reported that a concentration of 25% of maltodextrin (MX) and processing temperature of 210 • C were the optimal conditions for obtaining the highest yield and content of 3-D-galactoside. Recently, Saavedra-Leos et al 2021 also tested the drying conditions of broccoli juice on the conservation of antioxidants [10]. They found that the total phenolic content (TPC) and antioxidant activity (AA) were optimal at a concentration of 5% of MX and inlet temperature of 220 • C. In these works, maltodextrins have been employed as high molecular weight additives to increase the overall glass transition temperature of the product [11].…”