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Morinda citrifolia, widely known as "noni", provides fruits of which it is a raw material not only for the preparation of foods, such as beverages, but is also used, for example, in the preparation of cosmetics. However, processing the fruit results in the generation of waste, in which the leaves represent the majority. Taking into account that noni leaves are proven to hold a high amount of bioactive compounds with phytotherapeutic properties, this study proposes the application of multi-stage block freeze concentration performed through the passive thaw method with the aid of the microwave-assisted technique to promote a greater speed and efficiency in the process of concentration of the bioactive components present in Morinda citrifolia L. leaves. The effect of the cryoconcentration steps on the physical, chemical and biological characteristics of the concentrated fractions and residual ice was evaluated in order to quantitatively verify presence and content of phenolics and total solids, viscosity, antioxidant activity, and bioavailability gastrointestinal in vitro. An increase in the phenolic and total solids values was observed at the end of the process, resulting in efficiency in the retention of phenolics above 90%. High-performance liquid chromatography assay detected catechin as bioactive compound of the largest amount in the final product. The use of the microwave-assisted concentration system allowed concentrated fractions with high biological, nutritional and phytotherapic value; indicating that the technique can contribute as a reference in the use of a sustainable technology in the generation of a promising product of high biological value, since the execution and elaboration of the microwave-assisted method allows for a lower energy consumption and waste production, in addition to providing less expensive and easy-to-operate tests. [ABSTRACT FROM AUTHOR]

The effects of gravitational (GC) and microwave‐assisted (MWC) cryoconcentration were studied on the total phenolic content (TPC) and antioxidant activity of aqueous guava leaves extract. An increase in the TPC was observed for all the concentrated fractions by both methods. The concentration efficiency for the GC and MWC processes was 80% and 73% and the concentration index obtained for TPC was 3 and 9, respectively. The antioxidant activity also increased next to 3 and 11 folds, for GC and MWC, respectively, after cryoconcentration. Catechin and vescalagin were the main compounds found. Although both the cryoconcentration processes generated extracts rich in TPC, the bioaccessibility was greater for the MWC concentrated extract during the in vitro simulated gastrointestinal condition steps, which characterizes this extract at the fourth stage as the one with the best functional properties. Practical applications: Several emerging technologies have been studied as alternatives to the conventional concentration process, such as cryoconcentration. In this context, the use of cryoconcentration to concentrate bioactive compounds of guava leaves aqueous extract may represent a way to increase and maintain the antioxidant properties. This study demonstrated that cryoconcentration assisted by microwave reduced the processing time in half, which generates energy savings, maintenance of compounds, and an increase in the antioxidant capacity next to 11‐times. The study contributes to recent research that suggests cryoconcentration as a promising technology to be adopted in the food industry. [ABSTRACT FROM AUTHOR]

This review covers the application and brings perspectives of ultrasound as a tool for microbial inactivation, plant-based foods functionalization, and improvements in their functional food potential. Fruit juices, fruit and vegetable-based products, and dairy alternatives were the main plant-based foods evaluated. Ultrasound could inactivate spoilage and pathogenic micro-organisms when used alone or associated with temperature (thermosonication). Furthermore, it promoted functionalization of plant-based products by increasing the bioactive compounds content (phenolics, flavonoids, carotenoids, anthocyanins, condensed tannins, flavonols, ascorbic acid, minerals, lycopene, oligosaccharides, organic acids, chlorophyll, amino acids, glucoraphanin, and sulforaphane) and their bioaccessibility, and improving the antioxidant and antidiabetic (α-amylase and α-glucosidase inhibitions) properties of the products. Finally, it could increase the functional food potential of plant-based products by improving probiotic growth and promoting the biotransformation of compounds to more bioactive ones. The technological (natural color, increased cloudiness, decreased sedimentation index) and sensory characteristics could also be improved. The ultrasound device, process parameters (processing times, amplitudes, intensity, temperature, nominal power), food matrix, and probiotic characteristics (strain type and growth phase) are factors to be considered for achieving results. Our review summarizes for the first time the potential of ultrasound to functionalize and improve functional food potential of plant-based foods by improving probiotic growth and metabolic activity, increasing bioactive compounds content, bioaccessibility, and functional properties, and improving technological and sensory properties. We highlight opportunities for ultrasound on postbiotic production and the need for more in vitro and in vivo studies. This review is important for the plant-based functional foods area. • Ultrasound can be used as a tool for functionalizing plant-based products. • Ultrasound reduced fermentation time and improved probiotic growth and biotransformation. • Ultrasound increased contents of bioactives and their stability over storage. • Ultrasound increased antioxidant and antidiabetic properties and improved technological and sensory characteristics. • There are opportunities for using ultrasound on postbiotic production. [ABSTRACT FROM AUTHOR]

In this study, yoghurt samples were fortified with 0.25% and 0.5% freeze‐dried stevia extract (FSE). The control and stevia‐fortified yoghurts were evaluated and compared for the viability of the starter cultures, physicochemical properties, total phenolic content (TPC) and antioxidant activity throughout 30 days of storage. In addition, TPC and antioxidant activity were evaluated during in vitro gastrointestinal digestion. The results showed that the yoghurt matrix preserved the TPC, antioxidant capacity and total solids during storage, while the acidity, synaeresis and counts of the starter cultures of the final product were not significantly affected. However, addition of 0.5% FSE exerted a buffering effect on the system. After simulated digestion, the values of TPC and antioxidant activity of the fortified yoghurts increased in relation to the undigested fractions. These findings showed the feasibility of employing FSE as a functional ingredient in the manufacture of yoghurts with potential antioxidant properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biopolymeric nanoparticles (NPs) can be produced by anti-solvent precipitation. • Solute, solvent, anti-solvent, and surfactant alter the production of these NPs. • Polysaccharides and proteins are frequently used to produce biopolymeric NPs. • Bioactive compounds can be stabilized with biopolymeric NPs. The anti-solvent precipitation method has been investigated to produce biopolymeric nanoparticles in recent years. Biopolymeric nanoparticles have better water solubility and stability when compared with unmodified biopolymers. This review article focuses on the analysis of the state of the art available in the last ten years about the production mechanism and biopolymer type, as well as the used of these nanomaterials to encapsulate biological compounds, and the potential applications of biopolymeric nanoparticles in food sector. The revised literature revealed the importance to understand the anti-solvent precipitation mechanism since biopolymer and solvent types, as well as anti-solvent and surfactants used, can alter the biopolymeric nanoparticles properties. In general, these nanoparticles have been produced using polysaccharides and proteins as biopolymers, especially starch, chitosan and zein. Finally, it was identified that those biopolymers produced by anti-solvent precipitation were used to stabilize essential oils, plant extracts, pigments, and nutraceutical compounds, promoting their application in functional foods. [ABSTRACT FROM AUTHOR]

Guava leaves (Psidium guajava) are popularly known due to their effects antidiabetic, antihypertensive, anti-inflammatory, antidiarrheal, and functional properties. Processes for the concentration of these extracts are necessary since their pharmacological effects are dose-dependent. In this work, guava leaves aqueous extract (GE) concentration was carried out in nanofiltration (NF) equipment. Process performance was evaluated in terms of permeate flux, flux decline modeling, and extract quality (compounds characterization, total phenolic content and antioxidant activity). NF allowed an increase in phenolic compounds next to 20-times, retention coefficients of total phenolic compounds (99%) and enhanced antioxidant capacity (an increase of 4 and 9-fold for ABTS and DPPH, respectively) compared to the initial GE. Forty-two phenolic compounds were identified, being catechin (594.56 mg mL−1) and vescalagin (295.39 mg mL−1) the main compounds. All phenolics presented a significant increase (p < 0.05) after the concentration suggesting that NF is efficient for the recovery and concentration of bioactive compounds and poses as an alternative to obtain functional products and improve added value in agro-industrial residues. • Retention coefficients were higher than 99% demonstrating the membrane efficiency. • Nanofiltration allowed an increase in phenolic compounds next to 20-times. • Antioxidant activity enhanced between 3 to 9-times. • Catechin was the major phenolic compound of guava leaves aqueous extract. • Nanofiltration is an alternative to add value to agro-industrial residues. [ABSTRACT FROM AUTHOR]

Gravitational (GC) and microwave-assisted (MWC) block freeze cryo-concentration was carried out to obtain extracts rich in phenolic compounds from beet leaves extract. The performance of both processes was evaluated and cryo-concentrated and ice fractions were analyzed for physicochemical properties, bioactive compounds content, and in vitro gastrointestinal simulation. After four concentration cycles using GC, the total and soluble solids were approximately 6 and 5 times higher the initial condition, whilst MWC allowed to 4 and 4.5, respectively. GC and MWC presented an increase in the bioactive compound concentration, reaching an efficiency process of 90% (stage 4) and 80% (stage 3), respectively. Consequently an increase in the antioxidant activity was observed. Comparing GC and MWC was observed a reduction in the processing time from several hours (GC) to only a few minutes (MWC), besides the high retention of bioactive compounds, as well as notabl values in terms of solutes and process parameter. [ABSTRACT FROM AUTHOR]