Recovery of aqueous phase of broccoli obtained by MHG technique for development of hydrogels with antioxidant properties

Potential therapeutic benefits of unconventional oils: assessment of the potential in vitro biological properties of some Rubiaceae, Cucurbitaceae, and Brassicaceae seed oils

Introduction

Seed oils are versatile in the food sector and for pharmaceutical purposes. In recent years, their biological properties aroused the interest of the scientific world.

Materials and methods

We studied the composition of fatty acids (FAs) and some in vitro potential therapeutic benefits of five cold-pressed commercial oils obtained from broccoli, coffee, green coffee, pumpkin, and watermelon seeds. In particular, we assayed the antioxidant activity (using diphenyl-1-picrylhydrazyl (DPPH) and azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays). In addition, through the fatty acid composition, we calculated the atherogenicity index (AI) and thrombogenicity index (TI) to evaluate the potential impact of such oils on cardiovascular diseases. Furthermore, we assessed the in vitro anti-inflammatory capacity of the oils (evaluated through their effectiveness in preventing protein degradation, using bovine serum albumin as protein standard) and the ability of the oils to inhibit in vitro activity of three among the essential enzymes, cholinesterases and tyrosinase, involved in the Alzheimer's and Parkinson's neurodegenerative diseases. Finally, we evaluated the capacity of the oils to inhibit the biofilm of some pathogenic bacteria.

Results

The unsaturated fatty acids greatly predominated in broccoli seed oil (84.3%), with erucic acid as the main constituent (33.1%). Other unsaturated fatty acids were linolenic (20.6%) and linoleic (16.1%) acids. The saturated fatty acids fraction comprised the palmitic (6.8%) and stearic acids (0.2%). Broccoli seed oil showed the best AI (0.080) and TI (0.16) indexes. The oils expressed a good antioxidant ability. Except for the watermelon seed oil, the oils exhibited a generally good in vitro anti-inflammatory activity, with IC₅₀ values not exceeding 8.73 micrograms. Broccoli seed oil and green coffee seed oil showed the best acetylcholinesterase inhibitory activity; coffee seed oil and broccoli seed oil were the most effective in inhibiting butyrylcholinesterase (IC₅₀ = 15.7 μg and 20.7 μg, respectively). Pumpkin and green coffee seed oil showed the best inhibitory activity against tyrosinase (IC₅₀ = 2 μg and 2.77 μg, respectively). In several cases, the seed oils inhibited the biofilm formation and the mature biofilm of some gram-positive and gram-negative bacteria, with Staphylococcus aureus resulting in the most sensitive strain. Such activity seemed related only in some cases to the capacity of the oils to act on the sessile bacterial cells' metabolism, as indicated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric method.

Fabrication and characterization of novel antibacterial chitosan/dialdehyde guar gum hydrogels containing pomegranate peel extract for active food packaging application

This study aimed to investigate synthesis and structural characteristics of the chitosan (CS) - modified dialdehyde guar gum (DAGG) hydrogel through the Schiff base reaction. The highest swelling capacity was achieved as about 12,000% of dry weight of the freeze-dried powder at CS: DAGG hydrogel with the mixing ratio of 30:70. The swelling ratio was not affected by changes in pH, which could be considered as an important property in the control of moisture in absorbent pad. The FTIR results indicated that the new amide groups have been formed at 1680 cm^-1, which can be attributed to the covalent bond between the amide groups of CS and the aldehyde groups of GG. Based on a SEM image, the prepared hydrogel showed the porous structure so it verified the crosslinking formation between the two polymers. Rheological analyses confirmed that formation compact and porous structure led to some noteworthy improvements in the strength of hydrogel prepared with a high ratio of DAGG. The hydrogel loaded with 5% pomegranate peel extract (PPE) showed both good antioxidant (81.13%) and antimicrobial activities. The hydrogel was observed to have a good potential to be used as an antibacterial pad.

Phytotherapy and food applications from Brassica genus

Plants of the genus Brassica occupy the top place among vegetables in the world. This genus, which contains a group of six related species of a global economic significance, three of which are diploid: Brassica nigra (L.) K. Koch, Brassica oleracea L., and Brassica rapa L. and three are amphidiploid species: Brassica carinata A. Braun, Brassica juncea (L.) Czern., and Brassica napus L. These varieties are divided into oily, fodder, spice, and vegetable based on their morphological structure, chemical composition, and usefulness of plant organs. The present review provides information about habitat, phytochemical composition, and the bioactive potential of Brassica plants, mainly antioxidant, antimicrobial, anticancer activities, and clinical studies in human. Brassica vegetables are of great economic importance around the world. At present, Brassica plants are grown together with cereals and form the basis of global food supplies. They are distinguished by high nutritional properties from other vegetable plants, such as low fat and protein content and high value of vitamins, fibers along with minerals. In addition, they possess several phenolic compounds and have a unique type of compounds namely glucosinolates that differentiate these crops from other vegetables. These compounds are also responsible for numerous biological activities to the genus Brassica as described in this review.

Mechanical Characterization of Biopolymer-Based Hydrogels Enriched with Paulownia Extracts Recovered Using a Green Technique

This study deals with the development and mechanical characterization of innovative starch- and gelatin-based hydrogels enriched with hydrothermal aqueous extracts from Paulownia (i.e., bark, leaves, petioles). The color, rheology, and texture properties of formulated biopolymer-based hydrogels depending on the processing conditions of the extracts was evaluated for the different Paulownia fractions. Results indicated that a clear impact on color features of the tested hydrogels was observed with the incorporation of Paulownia extracts. Rheological testing showed that weak and intermediate strength hydrogels were identified for starch- and gelatin-based hydrogels independently of used extract. A relevant softening of all gelled matrices was observed in the presence of recovered liquor extracts involving the following trend (leaves > barks > petioles). For all fractions, the highest viscoelastic features were achieved for hydrogels made with extracts recovered at 140 °C. Texture outcomes confirmed the rheological achievements. No syneresis was observed in developed hydrogels after two weeks of cold storage.

Retention of total phenolic content and antioxidant activity in the concentration of broccoli extract by progressive freeze concentration

A conventional evaporation is known to involve high temperature process which could destroy the heat-sensitive compound in a plant extract. In this study, a green and low-cost alternative concentration technique namely progressive freeze concentration (PFC) has been introduced to concentrate broccoli extract. A stirred cylindrical crystallizer was used to freeze the added solvent (water) in the extraction process. The changes in effective partition constant (K), antioxidant activity (AA) and total phenolic content (TPC) of the extract, were analysed at a different reading of coolant temperature, freezing time and stirring rate. From the findings, it was found that an amount of 0.003180 mg GAE/g of total phenolic content and 86.10% of antioxidant activity were retained through the PFC process at a coolant temperature of −6 °C, freezing time of 45 min and stirring rate of 100. Besides, the lowest K value achieved was 0.08 which outstandingly portrays an efficient PFC process.

Microwave Hydrodiffusion and Gravity (MHG) Extraction from Different Raw Materials with Cosmetic Applications

Microwave hydrodiffusion and gravity (MHG) and ethanolic solid-liquid extraction were compared using selected plant sources. Their bioactive profile, color features, and proximate chemical characterization were determined. MHG extracts, commercial antioxidants, and three distinct types of thermal spring water were used in a sunscreen cream formulation. Their bioactive capacity, chemical and rheological properties were evaluated. MHG Cytisus scoparius flower extract provided the highest bioactive properties. Pleurotus ostreatus MHG liquor exhibited the highest total solid extraction yield. The Brassica rapa MHG sample stood out for its total protein content and its monosaccharide and oligosaccharide concentration. Quercus robur acorns divided into quarters supplied MHG extract with the lowest energy requirements, highest DPPH inhibition percentage, total lipid content and the highest enzyme inhibition. The chemical and bioactive capacities stability of the sunscreen creams elaborated with the selected MHG extracts and the thermal spring waters showed a similar behavior than the samples containing commercial antioxidants.