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

Exploring the Equilibrium State Diagram of Maltodextrins across Diverse Dextrose Equivalents

This study investigates the equilibrium state diagram of maltodextrins with varying dextrose equivalents (DE 10 and 30) for quercetin microencapsulation. Using XRD, SEM, and optical microscopy, three transition regions were identified: amorphous (aw 0.07-0.437), semicrystalline (aw 0.437-0.739), and crystalline (aw > 0.739). In the amorphous region, microparticles exhibit a spherical morphology and a fluffy, pale-yellow appearance, with Tg values ranging from 44 to -7 °C. The semicrystalline region shows low-intensity diffraction peaks, merged spherical particles, and agglomerated, intense yellow appearance, with Tg values below 2 °C. The crystalline region is characterized by fully collapsed microstructures and a continuous, solid material with intense yellow color. Optimal storage conditions are within the amorphous region at 25 °C, aw 0.437, and a water content of 1.98 g H2O per g of dry powder. Strict moisture control is required at higher storage temperatures (up to 50 °C) to prevent microstructural changes. This research enhances understanding of maltodextrin behavior across diverse dextrose equivalents, aiding the development of stable microencapsulated products.

Exploring fermentation with lactic acid bacteria as a pretreatment for enhancing antioxidant potential in broccoli stem powders

Fruit and vegetable industries face a major environmental challenge with food loss and waste. Broccoli stems, comprising 38% of the plant's total weight, are usually discarded by the industry producing fourth-range and ready-to-use products, despite being rich in antioxidants, vitamins, fiber, carotenoids, phenolic compounds, and glucosinolates. Addressing the challenge of reducing waste in this sector includes the production of stable and nutrient-concentrated powders, which can be consumed directly or used as ingredients in functional food formulation. This study investigated fermentation with lactic acid bacteria (Limosilactobacillus reuteri, Lactiplantibacillus plantarum, and Lactobacillus salivarius) as a pretreatment for enhancing antioxidant and probiotic potential in broccoli stem powders. Results showed maximum counts 24 h after inoculation, and no effect of the previous disruption intensity on microbial growth was observed. Fermenting broccoli stems for 24 h with the three microbial strains led to a significant increase in total phenols and flavonoids but to a general reduction in the samples' capacity to scavenge DPPH and ABTS free radicals. Overall, ground broccoli stems exhibited the most favorable antioxidant properties following the 24 h fermentation step. The subsequent freeze-drying and final grinding had minimal impact on the microbial population but significantly enhanced the extractability of the antioxidant compounds. This study offers a valuable reference for researchers and stakeholders exploring the development of new products and innovations from vegetable waste.

Impact of Fermentation Pretreatment on Drying Behaviour and Antioxidant Attributes of Broccoli Waste Powdered Ingredients

Valorisation of fruit and vegetable wastes by transforming residues and discards into functional powdered ingredients has gained interest in recent years. Moreover, fermentation has been recalled as an ancient technology available to increase the nutritional value of foods. In the present work, the impact of pretreatments (disruption and fermentation) on drying kinetics and functional properties of powdered broccoli stems was studied. Broccoli stems fermented with Lactiplantibacillus plantarum and non-fermented broccoli stems were freeze-dried and air-dried at different temperatures. Drying kinetics were obtained and fitted to several thin layer mathematical models. Powders were characterized in terms of physicochemical and antioxidant properties, as well as of probiotic potential. Fermentation promoted faster drying rates and increased phenols and flavonoids retention. Increasing drying temperature shortened the process and increased powders' antioxidant activity. Among the models applied, Page resulted in the best fit for all samples. Microbial survival was favoured by lower drying temperatures (air-drying at 50 °C and freeze-drying). Fermentation and drying conditions were proved to determine both drying behaviour and powders' properties.

Enhancing phytochemical parameters in broccoli through vacuum impregnation and their prediction with comparative ANN and RSM models

Amidst increasing demand for nutritious foods, the quest for effective methods to enhance health-promoting attributes has intensified. Vacuum impregnation (VI) is a promising technique to augment produce properties while minimizing impacts on biochemical attributes. In light of broccoli's growing popularity driven by its nutritional benefits, this study explores the impact of VI using ascorbic acid and calcium chloride as impregnation agents on enhancing its phytochemical properties. Response surface methodology (RSM) was used for optimization of the vacuum impregnation process with Vacuum pressure (0.6, 0.4, 0.2 bar), vacuum time (3, 7, 11 min), restoration time (5, 10, 15 min), and concentrations (0.5, 1.0, 1.5%) as independent parameters. The influence of these process parameters on six targeted responses viz. total phenolic content (TPC), total flavonoid content (TFC), ascorbic acid content (AAC), total chlorophyll content (TCC), free radical scavenging activity (FRSA), and carotenoid content (CC) were analysed. Levenberg-Marquardt back propagated neural network (LMB-ANN) was used to model the impregnation process. Multiple response optimization of the vacuum impregnation process indicated an optimum condition of 0.2 bar vacuum pressure, 11 min of vacuum time, 12 min of restoration time, and 1.5% concentration of solution for vacuum impregnation of broccoli. The values of TPC, TFC, AAC, TCC, FRSA, and CC obtained at optimized conditions were 291.20 mg GAE/100 g, 11.29 mg QE/100 g, 350.81 mg/100 g, 1.21 mg/100 g, 79.77 mg, and 8.51 mg, respectively. The prediction models obtained through ANN was found suitable for predicting the responses with less standard errors and higher R2 value as compared to RSM models. Instrumental characterization (FTIR, XRD and SEM analysis) of untreated and treated samples were done to see the effect of impregnation on microstructural and morphological changes in broccoli. The results showed enhancement in the TPC, TFC, AAC, TCC, FRSA, and CC values of broccoli florets with impregnation. The FTIR and XRD analysis also supported the results.

Immunomodulatory and Antioxidant Effects of Spray-Dried Encapsulated Kale Sprouts after In Vitro Gastrointestinal Digestion

The health-related compounds present in kale are vulnerable to the digestive process or storage conditions. Encapsulation has become an alternative for their protection and takes advantage of their biological activity. In this study, 7-day-old Red Russian kale sprouts grown in the presence of selenium (Se) and sulfur (S) were spray-dried with maltodextrin to assess their capacity to protect kale sprout phytochemicals from degradation during the digestion process. Analyses were conducted on the encapsulation efficiency, particle morphology, and storage stability. Mouse macrophages (Raw 264.7) and human intestinal cells (Caco-2) were used to assess the effect of the intestinal-digested fraction of the encapsulated kale sprout extracts on the cellular antioxidant capacity, the production of nitric oxide (NOx), and the concentrations of different cytokines as indicators of the immunological response. The highest encapsulation efficiency was observed in capsules with a 50:50 proportion of the hydroalcoholic extract of kale and maltodextrin. Gastrointestinal digestion affected compounds' content in encapsulated and non-encapsulated kale sprouts. Spray-dried encapsulation reduced the phytochemicals' degradation during storage, and the kale sprouts germinated with S and Se showed less degradation of lutein (35.6%, 28.2%), glucosinolates (15.4%, 18.9%), and phenolic compounds (20.3%, 25.7%), compared to non-encapsulated ones, respectively. S-encapsulates exerted the highest cellular antioxidant activity (94.2%) and immunomodulatory activity by stimulating IL-10 production (88.9%) and COX-2 (84.1%) and NOx (92.2%) inhibition. Thus, encapsulation is an effective method to improve kale sprout phytochemicals' stability and bioactivity during storage and metabolism.

Genus Brassica By-Products Revalorization with Green Technologies to Fortify Innovative Foods: A Scoping Review

Food losses and waste reduction are a worldwide challenge involving governments, researchers, and food industries. Therefore, by-product revalorization and the use of key extracted biocompounds to fortify innovative foods seems an interesting challenge to afford. The aim of this review is to evaluate and elucidate the scientific evidence on the use of green technologies to extract bioactive compounds from Brassica by-products with potential application in developing new foods. Scopus was used to search for indexed studies in JCR-ISI journals, while books, reviews, and non-indexed JCR journals were excluded. Broccoli, kale, cauliflower, cabbage, mustard, and radish, among others, have been deeply reviewed. Ultrasound and microwave-assisted extraction have been mostly used, but there are relevant studies using enzymes, supercritical fluids, ultrafiltration, or pressurized liquids that report a great extraction effectiveness and efficiency. However, predictive models must be developed to optimize the extraction procedures. Extracted biocompounds can be used, free or encapsulated, to develop, reformulate, and/or fortify new foods as a good tool to enhance healthiness while preserving their quality (nutritional, functional, and sensory) and safety. In the age of recycling and energy saving, more studies must evaluate the efficiency of the processes, the cost, and the environmental impact leading to the production of new foods and the sustainable extraction of phytochemicals.

Use of Roselle Calyx Wastes for the Enrichment of Biscuits: An Approach to Improve Their Functionality

The objective of the present study was to evaluate the use of powder made out of Roselle Calyx Wastes (RCP) in developing a biscuit formulation with acceptable sensory value. Roselle calyxes were infused in water in a 1:10 ratio. The residual infused calyxes were dried at 50 °C for 16 h, grounded, sieved through a 50 mesh, and stored in plastic bags until used. The biscuit formulations were enriched with RCP at 0% (BC), 5% (BRCP5), 10% (BRCP10), and 15% (BRCP15). The amount of RCP added to the biscuit formulation did not change the protein content. However, the addition of RCP significantly affected the biscuit’s color; the lightness parameter (L*) decreased as the RP content increased from 69.66 to 49.04. The sensory evaluation showed that the control biscuit and the biscuit enriched with 5% of RP were the best accepted. As for the antiradical activity, the formulation with the highest activity was presented by the BRCP15 (587.43 µmol Trolox/100 g dwb). On the other hand, BRCP5 presented 189.96 µmol Trolox/100 g dwb. Therefore, the biscuit formulation with RCP at a 15% enrichment could be used to commercialize a functional product.

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

In this study, vacuum drying (VD) was employed as an approach to protect the bioactive components of and produce dried broccoli powders with a high biological activity. To achieve these goals, the effects of temperature (at the five levels of 50, 60, 70, 80 and 90 °C) and constant vacuum pressure (10 kPa) were evaluated. The results show that, with the increasing temperature, the drying time decreased. Based on the statistical tests, the Brunauer-Emmett-Teller (BET) model was found to fit well to sorption isotherms, whereas the Midilli and Kucuk model fit well to the drying kinetics. VD has a significant impact on several proximate composition values. As compared with the fresh sample, VD significantly reduced the total phenol, flavonoid and glucosinolate contents. However, it was shown that VD at higher temperatures (80 and 90 °C) contributed to a better antioxidant potential of broccoli powder. In contrast, 50 °C led to a better antimicrobial and neuroprotective effects, presumably due to the formation of isothiocyanate (ITC). Overall, this study demonstrates that VD is a promising technique for the development of extracts from broccoli powders that could be used as natural preservatives or as a neuroprotective agent.

Glucosinolates and Polyphenols of Colored Cauliflower as Chemical Discriminants Based on Cooking Procedures

The impact of mild oven treatments (steaming or sous-vide) and boiling for 10 min, 25 min, or 40 min on health-promoting phytochemicals in orange and violet cauliflower (Brassica oleracea L. var. botrytis) was investigated. For this purpose, targeted ultra-high performance liquid chromatography–high-resolution mass spectrometry analysis of phenolics and glycosylates, combined with chemometrics, was employed. Regardless of cooking time, clear differentiation of cooked samples obtained using different procedures was achieved, thus demonstrating the distinct impact of cooking approaches on sample phytochemical profile (both, compound distribution and content). The main responsible components for the observed discrimination were derivatives of hydroxycinnamic acid and kaempferol, organic acids, indolic, and aromatic glucosinolates, with glucosativin that was found, for the first time, as a discriminant chemical descriptor in colored cauliflower submitted to steaming and sous-vide. The obtained findings also highlighted a strict relationship between the impact of the cooking technique used and the type of cauliflower. The boiling process significantly affected the phytochemicals in violet cauliflower whereas orange cauliflower boiled samples were grouped between raw and either steamed or sous-vide-cooked samples. Finally, the results confirm that the proposed methodology is capable of discriminating cauliflower samples based on their phytochemical profiles and identifying the cooking procedure able to preserve bioactive constituents.

In Vitro Antioxidant, Antibacterial and Mechanisms of Action of Ethanolic Extracts of Five Tunisian Plants against Bacteria

Pistacia lentiscus, Rosmarinus officinalis, Erica multiflora, Calicotome villosa, and Phillyrea latifolia were considered important medicinal herbs and were used to treat various ailments. The present study was designed to evaluate the antioxidant and antimicrobial activities of ethanolic extracts (EEs). P. lentiscus and R. officinalis were the richest species in phenolic compounds. Similarly, both species showed the highest values of flavonoids. While the EEs of P. lentiscus, E. multiflora, and C. villosa had higher amounts of tannins. These phenolic compounds were evaluated by two different tests, namely diphenyl picrylhydrazyl (DPPH) and ferric iron-reducing power (FRAP). The IC50 values were found to be significant (p < 0.05) for P. lentiscus and E. multiflora. Similarly, both plants showed the highest ferric-reducing antioxidant power (FRAP). This study has been conducted to evaluate the antibacterial potential of EEs against selected bacteria—Gram-positive bacteria (Staphylococcus aureus ATCC 29213, Listeria monocytogenes ATCC 7644) and Gram-negative bacteria (Escherichia coli ATCC 8739, Salmonella typhimurium NCTC 6017)—and determine their modes of action. The ethanolic extracts inhibited bacterial growth by producing concentration-dependent zones of inhibition. Treatment with these extracts at their minimum inhibitory concentrations (MICs) showed a significant reduction (p < 0.05) in the viability of bacteria. The extracts did not induce total lysis. Bacteria organisms treated with EEs at MICs showed a significant (p < 0.05) loss of tolerance to NaCl (5%). Our results highlighted the use of plant extracts as natural antibacterials that can be safely used in health care and led to the understanding of the antibacterial mechanism of plant extracts.

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

Prunus avium L. (sweet cherry) is one of the most appreciated fruit due to its organoleptic and nutritional value. Interestingly, cherry leaves, stems, and flowers are agri-food by-products rich in bioactive compounds that are mostly still unexploited. Stems and leaves have been used in folk medicine since ancient times. Recently, cherry flowers have also proved to be an interesting source of compounds with therapeutic properties. Phenolic compounds, namely hydroxycinnamic acids and flavonoids, are the most present phytochemicals in P. avium fruits and their by-products. These compounds have shown a good antioxidant potential to prevent oxidative stress-related diseases and glycemic control, fundamental in preventing and controlling diabetes mellitus. The present review summarizes the main phenolics found in P. avium stems, leaves, and flowers as compared to their fruits and describes their antioxidant and anti-hyperglycemic properties. Thus, these by-products are an accessible and low-cost source of bioactive constituents with interesting health-promoting properties, making their use promising in diabetes therapy.

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

The drying of fruit juices has advantages such as easy handling of powders, reduction in volume, and preservation of the characteristics of the fruit. Thus, in this work, the effect of the spray drying conditions of strawberry juice (SJ) with maltodextrin (MX) as a carrying agent on the microencapsulation of bioactive compounds and physicochemical properties was studied. The content of phenolic compounds and antioxidant activity showed higher values at low concentrations of MX, while the effect of drying temperature was negligible. The thermal characterization showed that the low molecular weight sugars in the juice decreased the glass transition temperature (Tg). The morphological analysis by scanning electron microscopy (SEM) indicated that at low concentrations of MX, the particles agglomerated, while at intermediate and high concentrations, the particles were observed as well separated. Through microstructural analysis by X-ray diffraction (XRD), the presence of amorphous state was confirmed in all the samples, which is beneficial for preventing chemical and biochemical reactions, and promoting the conservation of the microencapsulated bioactive compounds.