Structuring Vegetable Oils Through the Formation of Capillary Suspensions: Comparison of Wheat Middlings and Pure Cellulose Processed by High-pressure Homogenization

Reducing the intake of harmful trans-fats and saturated fats in the diet, by replacing detrimental fats with healthier oils, without affecting the organoleptic properties of the food product, represent a formidable challenge for the scientific community. In this scenario, this work explores a possible strategy for structuring sunflower oil by investigating the formation of capillary suspensions using wheat middlings (WM) and pure cellulose (CL) as a structuring solid fraction. High-pressure homogenization (HPH), a purely mechanical cell disruption technology, was directly applied to oil suspensions of WM or CL. Subsequently, the addition under high-shear mixing (HSM) of different amounts of an immiscible secondary fluid, water, to the oil suspensions, led to WM and CL particles bridging and network formation, through the development of attractive capillary forces among the particles. The effect of water and particles characteristics on the rheological behavior of the oil suspensions was investigated. The presence of water caused initially an increase in viscosity and then a decrease, as water concentration exceeded a critical value, with an inversion from a continuous oil phase to a continuous aqueous phase. Moreover, the oxidative stability of the capillary suspensions was evaluated, during accelerated aging. The proposed approach not only does not suffer the presence of water, but significantly improves the oxidation stability with respect to the pu

Recovery of Nanocellulose from Agri-food Residues Through Chemical and Physical Processes

This work proposes a biorefinery approach for the exploitation of agri-food by-products, such as tomato pomace (TP), through the combination of mild chemical hydrolysis and high-pressure homogenization (HPH) in water not only to promote the recovery of cellulose but also its defibrillation to obtain nanocellulose. In particular, the cellulose pulp was isolated from TP using different combinations of chemical and physical processes, by applying HPH treatment (i) directly on the raw material, (ii) after the acid hydrolysis, and (iii) after alkaline hydrolysis. Moreover, the isolated cellulose was deconstructed to obtain cellulose nanoparticles, also through the application of the HPH treatment, enhancing the polymer properties. The structural and physical features of cellulose nanoparticles from TP were analyzed through Fourier-transform infrared spectroscopy (FT-IR) analysis, ?-potential measurement, and morphological analysis with SEM. The results clearly showed that the HPH treatment (80 MPa, 20 passes) at different stages of the process caused only a slight increase in the yield of cellulose recovery, but significantly contributed to obtaining defibrillated cellulose particles, characterized by smaller irregular domains containing elongated needle-like fibers

Cellulose Isolation from Tomato Pomace Pretreated by High-Pressure Homogenization

This work proposes a biorefinery approach for the utilization of agri-food residues, such as tomato pomace (TP), through combining chemical hydrolysis with high-pressure homogenization (HPH), aiming to achieve the isolation of cellulose with tailored morphological properties from underused lignocellulose feedstocks, along with the valorization of the value-added compounds contained in the biomass. Cellulose was isolated from TP using sequential chemical hydrolysis in combination with mechanical pretreatment through HPH. The chemical and structural features of cellulose isolated from TP pretreated by HPH were compared with cellulose isolated from untreated TP through light scattering for particle size distribution, optical and scanning electron microscopy, and Fourier-transform infrared spectroscopy (FT-IR) analysis. HPH pretreatment (80 MPa, 10 passes) not only promoted a slight increase in the yield of cellulose extraction (+9%) but contributed to directly obtaining defibrillated cellulose particles, characterized by smaller irregular domains containing elongated needle-like fibers. Moreover, the selected mild chemical process produced side streams rich in bioactive molecules, evaluated in terms of total phenols and reducing activity. The liquors recovered from acid hydrolysis of TP exhibited a higher biological activity than those obtained through a conventional extraction (80% v/v acetone, 25 °C, 24 h at 180 rpm)

Impact of High-Pressure Homogenization on Enhancing the Extractability of Phytochemicals from Agri-Food Residues

The primary objective of the Sustainable Development Goals is to reduce food waste by employing various strategies, including the reuse of agri-food residues that are abundantly available and the complete use of their valuable compounds. This study explores the application of high-pressure homogenization (HPH), an innovative nonthermal and green treatment, for the recovery of bioactive compounds from agri-food residues. The results demonstrate that the optimized HPH treatment offers advantages over conventional solid/liquid extraction (SLE), including shorter extraction time, solvent-free operation, low temperatures, and higher yields of phenol extraction (an approximately 20% improvement). Moreover, the micronization of agri-food residue-in-water suspensions results in a decrease in the size distribution to below the visual detection limit, achieved by disrupting the individual plant cells, thus enhancing suspension stability against sedimentation. These findings highlight the potential of HPH for environmentally friendly and efficient extraction processes

Cellulose Isolation from Tomato Pomace Pretreated by High-Pressure Homogenization

This work proposes a biorefinery approach for the utilization of agri-food residues, such as tomato pomace (TP), through combining chemical hydrolysis with high-pressure homogenization (HPH), aiming to achieve the isolation of cellulose with tailored morphological properties from underused lignocellulose feedstocks, along with the valorization of the value-added compounds contained in the biomass. Cellulose was isolated from TP using sequential chemical hydrolysis in combination with mechanical pretreatment through HPH. The chemical and structural features of cellulose isolated from TP pretreated by HPH were compared with cellulose isolated from untreated TP through light scattering for particle size distribution, optical and scanning electron microscopy, and Fourier-transform infrared spectroscopy (FT-IR) analysis. HPH pretreatment (80 MPa, 10 passes) not only promoted a slight increase in the yield of cellulose extraction (+9%) but contributed to directly obtaining defibrillated cellulose particles, characterized by smaller irregular domains containing elongated needle-like fibers. Moreover, the selected mild chemical process produced side streams rich in bioactive molecules, evaluated in terms of total phenols and reducing activity. The liquors recovered from acid hydrolysis of TP exhibited a higher biological activity than those obtained through a conventional extraction (80% v/v acetone, 25 °C, 24 h at 180 rpm)

Biopolymer- and Lipid-Based Carriers for the Delivery of Plant-Based Ingredients

: Natural ingredients are gaining increasing attention from manufacturers following consumers' concerns about the excessive use of synthetic ingredients. However, the use of natural extracts or molecules to achieve desirable qualities throughout the shelf life of foodstuff and, upon consumption, in the relevant biological environment is severely limited by their poor performance, especially with respect to solubility, stability against environmental conditions during product manufacturing, storage, and bioavailability upon consumption. Nanoencapsulation can be seen as an attractive approach with which to overcome these challenges. Among the different nanoencapsulation systems, lipids and biopolymer-based nanocarriers have emerged as the most effective ones because of their intrinsic low toxicity following their formulation with biocompatible and biodegradable materials. The present review aims to provide a survey of the recent advances in nanoscale carriers, formulated with biopolymers or lipids, for the encapsulation of natural compounds and plant extracts

Edible Coatings Containing Oregano Essential Oil Nanoemulsion for Improving Postharvest Quality and Shelf Life of Tomatoes

Edible coatings have attracted significant interest in maintaining quality and improving the shelf life of fresh fruit and vegetables. This study aimed to improve tomato storability by using edible coatings, based on alginate cross-linked with calcium chloride, and containing an oregano essential oil (OEO) nanoemulsion as a natural antimicrobial. The coating formulations were preliminary optimized in terms of alginate and calcium chloride concentrations, using response surface methodology, to obtain a thin (~5 µm) and uniform layer on the tomatoes surface. The optimized coating (prepared using sequential dipping in a 0.5% w/w sodium alginate solution and in a 2.0% w/w calcium chloride solution) was enriched by incorporating an OEO nanoemulsion, formulated with lecithin as a natural emulsifier, at an OEO concentration of 0.17% w/w in the alginate solution. The nanoemulsion did not significantly affect the coating thickness and uniformity but improved the wettability of the tomato skin. More specifically, the alginate-based edible coatings exhibited a strong interaction with the hydrophobic tomato skin surface (higher than water), promoting surface adhesion. The addition of OEO nanoemulsion in the coating, by providing more hydrophobic sites, further improved the wetting capability and adhesion of the coating solution on the tomato surface. The developed edible coatings successfully contributed to prolonging the tomato shelf life, by reducing the growth of the endogenous microbial flora (total microbial load, yeasts, and molds) over 14 days at room temperature in comparison with the control, with significantly better performances for the edible coating containing the OEO nanoemulsion

Effects of Pulsed Electric Fields on Vacuum Drying and Quality Characteristics of Dried Carrot

This study investigates the effect of pulsed electric fields (PEF) on the kinetics of vacuum drying (VD) of carrot and on the preservation of the quality of dried carrot tissue. The impacts of PEF-treatment and VD on β-carotene content and color of carrot samples were studied. PEF treatment was applied with intensity E = 0.6 kV/cm and total treatment time tPEF = 0.1 s to reach a high level of carrot tissue electroporation. The VD was applied at the pressure p = 0.3 bar for different temperatures, Td = 25, 50, 75, and 90 °C. The spectrophotometric method was used to determine the β-carotene content. The color was measured using the CIE L* a* b* method. Obtained results indicated that PEF treatment let to a noticeable decrease of drying time (by 33–55% at Td = 25–90 °C). The activation energy was found to be 18.25 kJ/mol and 13.4 kJ/mol for untreated and PEF-pretreated samples, respectively. The reduction of drying time by PEF pretreatment was beneficial for the retention of β-carotene in dried samples. The application of PEF treatment resulted in smaller changes in color ∆E as compared with untreated samples; this tendency was observed for all studied temperatures