Low-frequency and high-power ultrasound-assisted production of natural blue colorant from the milk and unripe Genipa americana L

Genipin, a natural blue colorant precursor: Source, extraction, properties, and applications

Natural cross-linkers are extensively employed due to their low toxicity and biocompatibility benefits. Genipin acts as a precursor for producing blue colorants. The formation of these colorants involves the cross-linking reaction between genipin and primary amines present in amino acids, peptides, and proteins. Genipin is extracted from Gardenia jasminoides and Genipa americana. This article explains the cross-linking mechanism of genipin with proteins/polysaccharides to provide an overall understanding of its properties. Furthermore, it explores new sources of genipin and innovative methodologies to make the genipin recovery process efficient. Genipin increases food products' texture, gel strength, stability, and shelf life. The antibacterial, anti-inflammatory, and antioxidant properties of chitosan, gelatin, alginate, and hyaluronic acid increased after genipin cross-linking. Lastly, drawbacks, toxicity, and directions regarding the genipin cross-linking have also been addressed. The review article covers how to recover and cross-link genipin with biopolymers for industrial applications.

Recent Advances in Acoustic Technology in Food Processing

The development of food industry technologies and increasing the sustainability and effectiveness of processing comprise some of the relevant objectives of EU policy. Furthermore, advances in the development of innovative non-thermal technologies can meet consumers' demand for high-quality, safe, nutritious, and minimally processed foods. Acoustic technology is characterized as environmentally friendly and is considered an alternative method due to its sustainability and economic efficiency. This technology provides advantages such as the intensification of processes, increasing the efficiency of processes and eliminating inefficient ones, improving product quality, maintaining the product's texture, organoleptic properties, and nutritional value, and ensuring the microbiological safety of the product. This review summarizes some important applications of acoustic technology in food processing, from monitoring the safety of raw materials and products, intensifying bioprocesses, increasing the effectiveness of the extraction of valuable food components, modifying food polymers' texture and technological properties, to developing biodegradable biopolymer-based composites and materials for food packaging, along with the advantages and challenges of this technology.

Extraction of phenolics and anthocyanins from purple eggplant peels by multi-frequency ultrasound: Effects of different extraction factors and optimization using uniform design

In this work, multi-frequency ultrasound (working modes for the single-, dual- and tri-frequency in simultaneous ways) was applied to extract bioactive compounds from purple eggplant peels. The single-factor experiments were performed by varying six independent variables. A six-level-five-factor uniform design (UD) was further employed to evaluate the interaction effects between different factors. It was found that extraction temperature and extraction time significantly affected the total phenolic content (TPC), whereas the total monomeric anthocyanins (TMA) was mainly influenced by ethanol concentration, extraction temperature and solid-liquid ratio. Based on partial least-squares (PLS) regression analysis, the optimal conditions for TPC extraction were: 53.6 % ethanol concentration, 0.336 mm particle size, 44.5 °C extraction temperature, 35.2 min extraction time, 1:43 g/mL solid-liquid ratio, and similar optimal conditions were also obtained for TMA. Furthermore, the TPC and TMA extraction were investigated by ultrasound in different frequencies and power levels. Compared with single-frequency (40 kHz) and dual-frequency ultrasound (25 + 40 kHz), the extraction yield of TPC and TMA with tri-frequency ultrasound (25 + 40 + 70 kHz) increased by 23.65 % and 18.76 % respectively, which suggested the use of multi-frequency ultrasound, especially tri-frequency ultrasound, is an efficient strategy to improve the TPC and TMA extracts in purple eggplant peels.

Crystallization of lipids and lipid emulsions treated by power ultrasound: A review

The actual food system with fat is always complex and fat crystal and fat crystal networks have important effects on the physical properties of food. Recently, power ultrasound (PU) had been widely recognized as an auxiliary technology of fat crystallization to modify food properties. This review expounded on the mechanism of ultrasonic crystallization, and summarized effects of various factors in the process of ultrasonic treatment on fat crystallization. Based on the above, combined with the application of ultrasound in emulsions, the ultrasonic fat crystallization effect in the emulsion system was judged and described. Research results indicated that PU could shorten the induction time of crystallization, accelerate the formation of crystal nuclei, and change the polymorphism of fat crystals. The product treated by PU formed smaller and more uniform crystals to produce a more viscoelastic fat crystal network. In emulsion systems, ultrasonic treatments showed the same effect, but the effect of ultrasonic crystallization on the emulsion stability was different due to fat crystals in different emulsion systems. Meanwhile, the importance of ultrasonic crystallization in lipid emulsions was emphasized, thus ultrasonic crystallization had great potential in emulsion systems.

Whey Beverage Emulsified System as Carrying Matrix of Fennel Seed Extract Obtained by Supercritical CO2 Extraction: Impact of Thermosonication Processing and Addition of Prebiotic Fibers

Whey beverages that were enriched with fructooligosaccharides (FOS) and xylooligosaccharides (XOS) were used for carrying Foeniculum vulgare extract that was obtained by the supercritical CO₂ extraction technique to produce novel functional products. Fennel-based whey beverages were subjected to thermosonication processing (100, 200, and 300 W at 60 °C for 15 min) to verify the performance of the dairy colloidal system for protecting the bioactive fennel compounds. The impacts of thermosonication processing on the quality attributes of the functional whey beverages were examined according to their droplet size distribution, microstructure, kinetic stability, color parameters, browning index, total phenolic content (TPC), and antioxidant capacity by DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2-Azino-bis-(3-ethylbenzothiazoline)-6-sulphonic acid) assays. The enrichment of the whey beverages with FOS and XOS did not affect their kinetic stability. However, the addition of prebiotic dietary fibers contributed to reducing the mean droplet size due to the formation of whey protein–FOS/XOS conjugates. The thermosonication treatments did not promote color changes that were discernible to the human eye. On the other hand, the thermosonication processing reduced the kinetic stability of the beverages. Overall, the colloidal dairy systems preserved the antioxidant capacity of the fennel seed extract, regardless of thermosonication treatment intensity. The whey beverages enriched with FOS and XOS proved to be effective carrying matrices for protecting the lipophilic bioactive fennel compounds.

Recent advances and trends in extraction techniques to recover polyphenols compounds from apple by-products

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Apple by-products are a source of phenolic compounds associated with bioactivities.

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Apple processing industries generate by-products that could be better used.

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This work provides an up-to-date literature overview on extraction techniques.

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Gaps and future trends related to apple by-products are critically presented.

Apple is one of the most consumed fruits worldwide and has recognized nutritional properties. Besides being consumed fresh, it is the raw material for several food products, whose production chain generates a considerable amount of by-products that currently have an underestimated use. These by-products are a rich source of chemical compounds with several potential applications. Therefore, new ambitious platforms focused on reusing are needed, targeting a process chain that achieves well-defined products and mitigates waste generation. This review covers an essential part of the apple by-products reuse chain. The apple composition regarding phenolic compounds subclasses is addressed and related to biological activities. The extraction processes to recover apple biocompounds have been revised, and an up-to-date overview of the scientific literature on conventional and emerging extraction techniques adopted over the past decade is reported. Finally, gaps and future trends related to the management of apple by-products are critically presented.

Thermosonication Process Design for Recovering Bioactive Compounds from Fennel: A Comparative Study with Conventional Extraction Techniques

This study aimed to examine the impact of the combination of acoustic energy at the nominal powers of 100, 200, 300, and 400 W with moderate heat processing at 40, 50, and 60 °C on the extraction of phytochemical compounds from Foeniculum vulgare. Thermosonication processing, based on high-intensity ultrasound combined with an external heat source, can potentialize the extraction of soluble solids from plant material. However, the excessive temperature increase generated by the two energy sources during thermosonication treatment may degrade the thermolabile bioactive compounds. Regardless of the temperature condition, fennel extracts obtained at 400 W presented lower total phenolic content (TPC) than those obtained at 300 W. The cavitation heat and mechanical stress provided at 400 W may have degraded the phenolic compounds. Thereby, the best extraction condition was 300 W and 60 °C. The fennel extract presented the highest content of TPC (3670 ± 67 µg GAE/g) and antioxidant activity determined by DPPH and ABTS methods (1195 ± 16 µg TE/g and 2543.12 ± 0.00 µg TE/g, respectively) using this treatment. Thermosonication can be an innovative technique for extracting phytochemicals because it provides good results in shorter processing times, with 73% and 88% less energy consumption than Percolation and Soxhlet techniques, respectively.

Low-Frequency Ultrasound Coupled with High-Pressure Technologies: Impact of Hybridized Techniques on the Recovery of Phytochemical Compounds

The coupling of innovative technologies has emerged as a smart alternative for the process intensification of bioactive compound extraction from plant matrices. In this regard, the development of hybridized techniques based on the low-frequency and high-power ultrasound and high-pressure technologies, such as supercritical fluid extraction, pressurized liquids extraction, and gas-expanded liquids extraction, can enhance the recovery yields of phytochemicals due to their different action mechanisms. Therefore, this paper reviewed and discussed the current scenario in this field where ultrasound-related technologies are coupled with high-pressure techniques. The main findings, gaps, challenges, advances in knowledge, innovations, and future perspectives were highlighted.

Ultrasound stabilization of raw milk: Microbial and enzymatic inactivation, physicochemical properties and kinetic stability

The aim of this study was to evaluate the effects of non-thermal and thermal high-intensity ultrasound (HIUS) treatment on the microbial and enzymatic inactivation, physicochemical properties, and kinetic stability of the raw milk by applying different energy densities (1, 3, 5, and 7 kJ/mL). Two HIUS treatments were evaluated based on different nominal powers, named HIUS-A and HIUS-B, using 100 W and 475 W, respectively. HIUS-A treatment was non-thermal processing while HIUS-B was a thermal treatment only for the energy densities of 5 and 7 kJ/mL since the final temperature was above 70 °C. The HIUS-B treatment showed to be more efficient. Log reductions up to 3.9 cycles of aerobic mesophilic heterotrophic bacteria (AMHB) were achieved. Significant reductions of the fat globule size, with diameters lower than 1 µm, better color parameters, and kinetic stability during the storage were observed. Also, HIUS-B treatment inactivated the alkaline phosphatase and lactoperoxidase. The HIUS-B treatment at 3 kJ/mL worked below 57 °C being considered a border temperature since it did not cause unwanted physicochemical effects. Furthermore, a microbial inactivation of 1.8 ± 0.1 log cycles of AMHB was observed. A proper inactivation of only the Alkaline phosphatase and a significant reduction of the fat globules sizes, which kept the milk kinetically stable during storage was achieved.