Ultrasound-Assisted Extraction of High-Value Fractions from Fruit Industrial Processing Waste

Characterization of Ultrasound-Extracted Pouteria splendens Fruit Extracts: Phytochemical Profiling and Evaluation of Antioxidant and Cytotoxic Effects

This study investigated the bioactive potential of Pouteria splendens fruit through ultrasound-assisted extraction, analyzing peel and pulp. The pulp exhibited a higher phytochemical content, with 179.67 mg GAE/g d.w. and 208.48 mg QE/g d.w., approximately 1.5 times more than in the peel. Fifty phenolic compounds were identified by HPLC-MS, including four types of phenolic acids, with hydroxybenzoic (52%) and hydroxycinnamic (42%) as the two predominant ones, and six types of flavonoids, with flavonols (26.67%) and flavones (23.33%) as the two most prevalent. The pulp demonstrated greater antioxidant activity than the peel and the commercial controls (BHA and BHT) in the DPPH assay (IC50 2.54 mg/mL); however, it showed lower activity in the FRAP assay. Cytotoxic activity was evaluated in cancerous (MCF-7, HT-29, and PC-3) and non-cancerous (CCD 841 CoN and HEK-293) cell lines. Notably, the pulp exhibited remarkable cytotoxic activity against colon cancer cells (HT-29), with an IC50 of 50 µg/mL, and possible selectivity by not showing significant activity in non-cancerous cells (CoN and HEK). These results suggest that P. splendens, and particularly its pulp, is a valuable source of bioactive polyphenols, with potential for the food and pharmaceutical industries.

High-intensity ultrasound-assisted alkaline extraction of soy protein: Optimization, modeling, physicochemical and functional properties

This study examined the effect of high-intensity ultrasound-assisted alkaline extraction (HUAE) on the extraction yield and the physicochemical and functional properties of soy protein (SP) using the two-pot multivariate method for the first time. Plackett-Burman Design (PBD) coupled with Response Surface Methodology (RSM) was systematically utilized to select and subsequently optimize the HUAE parameters. Based on PBD results, the significant extraction factors were liquid to solid ratio (LSR), temperature, ultrasonic amplitude, and extraction time. The optimum conditions for the maximal extraction yield and minimal energy consumption were 50:1 mL/g LSR, 50 °C, 48 % ultrasonic amplitude, and 10 min extraction time. At optimum conditions, the extraction yield (35.28 %) was significantly improved compared to traditional extraction (26.39 %). Besides, HUAE resulted in modification of the protein secondary and tertiary structures due to the unfolding of protein molecules and the exposure of hydrophobic groups or regions as shown by FTIR spectroscopy, free sulfhydryl analysis, and scanning electron microscopy. These structural changes led to decreased solubility and emulsifying activity but improved emulsion stabilization and antioxidant properties. With future development, HUAE could potentially produce soy protein for targeted applications, broadening its utilization and meeting the need for more sustainable alternative processing.

The effect of maltodextrin edible coating containing pyracantha extract and potassium nano-carbonate on secondary metabolites, antioxidant capacity and microbiological properties of grape during cold storage

This study aimed to investigate the postharvest application of edible coating of maltodextrin containing potassium nanoparticles (KNPs; 0-2%) and pyracantha extract (PE; 0-1.5 %) on the maintenance of phenolic compounds, antioxidant capacity and microbial properties of 'Rishbaba' grape during 60 days at -1 °C using response surface methodology and central composite design. The results showed that the applied coating on Rishbaba grape maintained total phenol, total flavonoids, total anthocyanin, stilbenes (resveratrol and viniferin) and catechin. That also caused higher antioxidant capacity and lower mold and yeast growth in grape during the storage time. Finally, the best cold storage conditions of 'Rishbaba' grape were determined by using the edible maltodextrin coating containing 2 % KNPs and 1.5 % of PE for 34 days with a desirability of 0.728 in terms of investigated Characteristics. The optimized sample has the amount of total phenol (5.79 mg/g), total flavonoid (8.95 mg/g), total anthocyanin (6.48 mg/g) and the greatest ability to inhibit DPPH free radical (42.56 %) and the lowest growth rate of mold and yeast (21 Cfu/g).

Application of ultrasound technology for the effective management of waste from fruit and vegetable

Food waste presents a continuous challenge for the food industry, leading to environmental pollution and economic issues. A substantial amount of waste, including by-products from fruits and vegetables, non-edible food items, and other waste materials, is produced throughout the food supply chain, from production to consumption. Recycling and valorizing waste from perishable goods is emerging as a key multidisciplinary approach within the circular bio-economy framework. This waste, rich in raw by-products, can be repurposed as a natural source of ingredients. Researchers increasingly focus on biomass valorization to extract and use components that add significant value. Traditional methods for extracting these bio-compounds typically require the use of solvents and are time-consuming, underscoring the need for innovative techniques like ultrasound (US) extraction. Wastes from the processing of fruits and vegetables in the food industry can be used to develop functional foods and edible coatings, offering protection against various environmental factors. This comprehensive review paper discusses the valorization of waste from perishable items like fruits and vegetables using US technology, not only to extract valuable components from waste but also to treat wastewater in the beverage industry. It also covers the application of biomolecules recovered from this process in the development of functional foods and packaging.

Emerging trends in the appliance of ultrasonic technology for valorization of agricultural residue into versatile products

The utilization of agricultural residues to obtain biocompounds of high-added value has significantly increased in the past decades. The conversion of agro-based residues into valuable products appears to be an economically efficient, environment-friendly, and protracted waste management practice. The implementation of ultrasonic technologies in the conversion of value-added goods from agricultural waste materials through pre-treatment and valorization processes has imparted many advantageous effects including rapid processing, effective process performance, minimization of processing steps, minimal dependency on harmful chemicals, and an increased yield and properties of bio-products. To further enliven the literature and inspire new research investigations, this review covers the comprehensive work including theoretical principles, processes, and potential benefits of ultrasonic treatment technologies to assist the production of bio-products which emphasize the extraction yield and the characteristic of the end-product extracted from agriculture residues. A detailed evaluation of these methods and key aspects impacting their performance as well as the features and shortcomings of each ultrasound-assisted approach is also discussed. This review also addressed some of the challenges associated with using ultrasonic irradiation and proposed several potential techniques to maximize productivity. Understanding the concept of ultrasonication technique allow the academician and industrial practitioners to explore the possibility of applying a greener and sustainable approach of biomass extraction to be translated into higher scale production of commercial products.

Evaluation of the Extraction of Bioactive Compounds and the Saccharification of Cellulose as a Route for the Valorization of Spent Mushroom Substrate

The extraction of bioactive compounds and cellulose saccharification are potential directions for the valorization of spent mushroom substrate (SMS). Therefore, investigating the suitability of different extraction methods for recovering bioactive compounds from SMS and how the extraction affects the enzymatic saccharification is of uppermost relevance. In this work, bioactive compounds were extracted from Pleurotus spp. SMS using four extraction methods. For Soxhlet extraction (SoE), a 40:60 ethanol/water mixture gave the highest extraction efficiency (EE) (69.9-71.1%) among the seven solvent systems assayed. Reflux extraction with 40:60 ethanol/water increased the extraction yield and EE compared to SoE. A shorter reflux time yielded a higher extraction of carbohydrates than SoE, while a longer time was more effective for extracting phenolics. The extracts from 240 min of reflux had comparable antioxidant activity (0.3-0.5 mM GAE) with that achieved for SoE. Ultrasound-assisted extraction (UAE) at 65 °C for 60 min allowed an EE (~82%) higher than that achieved by either reflux for up to 150 min or SoE. Subcritical water extraction (SWE) at 150 °C resulted in the best extraction parameters among all the tested methods. Vanillic acid and chlorogenic acid were the primary phenolic acids identified in the extracts. A good correlation between the concentration of caffeic acid and the antioxidant activity of the extracts was found. Saccharification tests revealed an enhancement of the enzymatic digestibility of SMS cellulose after the extraction of bioactive compounds. The findings of this initial study provide indications on new research directions for maximizing the recovery of bioactive compounds and fermentable sugars from SMS.

Impact of Non-Thermal Technologies on the Quality of Nuts: A Review

Nuts are widely consumed worldwide, mainly due to their characteristic flavor and texture, ease of consumption, and their functional properties. In addition, consumers increasingly demand natural or slightly processed foods with high quality. Consequently, non-thermal treatments are a viable alternative to thermal treatments used to guarantee safety and long shelf life, which produce undesirable changes that affect the sensory quality of nuts. Non-thermal treatments can achieve results similar to those of the traditional (thermal) ones in terms of food safety, while ensuring minimal loss of bioactive compounds and sensory properties, thus obtaining a product as similar as possible to the fresh one. This article focuses on a review of the main non-thermal treatments currently available for nuts (cold plasma, high pressure, irradiation, pulsed electric field, pulsed light, ultrasound and ultraviolet light) in relation to their effects on the quality and safety of nuts. All the treatments studied have shown promise with regard to the inhibition of the main microorganisms affecting nuts (e.g., Aspergillus, Salmonella, and E. coli). Furthermore, by optimizing the treatment, it is possible to maintain the organoleptic and functional properties of these products.

Impact of Sample Pretreatment and Extraction Methods on the Bioactive Compounds of Sugar Beet (Beta vulgaris L.) Leaves

To find the most optimal green valorization process of food by-products, sugar beet (Beta vulgaris L.) leaves (SBLs) were freeze-dried and ground with/without liquid nitrogen (LN), as a simple sample pretreatment method, before ultrasound-assisted extraction (UAE) of polyphenols. First, the water activity, proximate composition, amino acid (AA) and fatty acid (FA) profiles, and polyphenol oxidase (PPO) activity of dried and fresh SBLs were evaluated. Then, conventional extraction (CE) and UAE of polyphenols from SBLs using water/EtOH:water 14:6 (v/v) as extracting solvents were performed to determine the individual and combined effects of the sample preparation method and UAE. In all the freeze-dried samples, the specific activity of PPO decreased significantly (p ≤ 0.05). Freeze-drying significantly increased (p ≤ 0.05) the fiber and essential FA contents of SBLs. The FA profile of SBLs revealed that they are rich sources of oleic, linoleic, and α-linolenic acids. Although freeze-drying changed the contents of most AAs insignificantly, lysine increased significantly from 7.06 ± 0.46% to 8.32 ± 0.38%. The aqueous UAE of the freeze-dried samples without LN pretreatment yielded the most optimal total phenolic content (TPC) (69.44 ± 0.15 mg gallic acid equivalent/g dry matter (mg GAE/g DM)) and excellent antioxidant activities. Thus, combining freeze-drying with the aqueous UAE method could be proposed as a sustainable strategy for extracting bioactive compounds from food by-products.