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This study explored the use of mandarin peels as an important source of health-promoting compounds by utilizing green methods (i.e., pulsed electric field and ultrasound-assisted extraction), along with conventional stirring. The impact of several extraction parameters, such as extraction duration, temperature, and solvent composition, on the recovery of bioactive compounds was evaluated through a response surface methodology. To identify the most effective conditions for all assays, a partial least-squares analysis was implemented. It was revealed that a combination of the above techniques was optimal at 80 °C for 30 min, with 75% v/v of ethanol in water as the extraction solvent. The concentration of bioactive compounds in the optimum extract had a total polyphenol content of 18.69 mg of gallic acid equivalents (GAE) per gram of dry weight (dw), and an ascorbic acid concentration of 18.25 mg/g dw. However, correlation analyses revealed a rather negative relationship between these bioactive compounds. The chromatographic analysis of optimum extracts supported this result by quantifying 20.53 mg/g dw of total individual polyphenols, with hesperidin being the dominant compound (13.98 mg/g dw). The antioxidant assays, including ferric-reducing antioxidant power and DPPH• inhibition activity, were measured at 123.21 and 65.12 μmol of ascorbic acid equivalents (AAE) per gram of dw, respectively. This research enhances the valorization of mandarin peels as a renewable source of bioactive compounds, providing the opportunity to generate high-added-value products from food waste in the food and pharmaceutical sectors.

Each year, a substantial amount of food is discarded around the globe. A significant portion of this waste consists of by-products derived from Citrus fruits such as lemons. The purpose of this research is to examine the polyphenol extraction and the antioxidant ability of lemon peel using cloud point extraction (CPE), a sustainable approach. CPE was conducted using three steps with a 20% w/v concentration of Span 20 as the surfactant, which has a critical micellar concentration of 6.13 × 10−5 mol/L. The pH was set at 7 and a salt concentration of 20% was maintained at 45 °C for 20 min. The subsequent outcomes of the analysis were obtained: total polyphenol content (TPC): 526.32 mg gallic acid equivalents per liter; total flavonoid content (TFC): 90.22 mg rutin equivalents per liter; FRAP, DPPH, and hydrogen peroxide assays: 2.40, 2.68 and 1.03 mmol ascorbic acid equivalents per liter, respectively, and 168.63 mg/L ascorbic acid content. The quantification of the polyphenolic compounds through High-Performance Liquid Chromatography showed that the most abundant compounds in the lemon peels are eriocitrin (159.43 mg/L) and hesperidin (135.21 mg/L). The results indicate that the proposed CPE technique is successful in extracting antioxidant compounds from lemon peels. The generated extracts have the potential to be exploited as dietary additives to enhance human health and can also be utilized for nutraceuticals or pharmaceutical purposes.

The current investigation examines the application of pulsed electric fields (PEFs) for isolating polyphenols from Cannabis sativa var. Futura 75 leaves. Firstly, the solvent composition, which included ethanol, water, and various mixtures of the two, was explored, along with the liquid-to-solid ratio. Subsequently, the primary parameters associated with PEFs (namely, pulse duration, pulse period, electric field intensity, and treatment duration) were optimized. The extracted samples were analyzed to determine their total polyphenol content (TPC), and individual polyphenols were also evaluated through high-performance liquid chromatography. In addition, the antioxidant activity of the extracts was assessed through ferric-reducing antioxidant power (FRAP) and DPPH assays. The extracts prepared utilizing PEFs were compared to the extracts obtained without PEFs in terms of their TPC, FRAP values, and DPPH activity. The results indicate that the most effective extraction parameters were a pulse duration of 10 μs, a pulse period of 1000 μs, and an electric field strength of 0.9 kV/cm after 25 min of extraction. The most efficient solvent was determined to be a 50% (v/v) mixture of ethanol and water in a 20:1 liquid-to-solid ratio. The extract obtained under the optimal conditions exhibited a ~75% increase in TPC compared to the extract obtained without any application of PEFs, while some individual polyphenols exhibited an increase of up to ~300%. Furthermore, significant increases of ~74% and ~71% were observed in FRAP and DPPH assays. From the information provided, it was observed that the tested variables had an impact on the recovery of polyphenols from C. sativa leaves.

The objective of this study was to determine the optimal conditions for the recovery of bioactive and antioxidant compounds in aqueous solutions of Cistus creticus leaves and then employ the optimal extract for the enrichment of yogurt samples. The optimal conditions were established by a response surface methodology and were determined to be a liquid-to-solid ratio of 48 mL/g at 76 °C for 41 min. The optimum extract yielded TPC 157.17 mg GAE/g dw and TFC 2.38 mg QE/g dw, while FRAP and DPPH values were 1258.52 and 933.67 μmol AAE/g dw, respectively. HPLC-DAD was utilized to identify and quantify specific polyphenols, like myricetin rhamnoside, in the extract. The optimal extract was then added to yogurt desserts during their preparation at three different concentrations to study how the physicochemical characteristics of the yogurt, as well as the antioxidant capacity added during enrichment, were affected. Statistical analysis of the results was carried out in order to obtain more valid data. It seems that the most suitable concentration for yogurt fortification was 0.1% w/v of the extract as, at this concentration, the yogurts exhibited higher antioxidant capacity, and their physicochemical characteristics were improved.

Stone fruits, such as the apricot (Prunus armeniaca L.), are frequently consumed. As such, a substantial volume of apricot waste is generated at each stage of the food supply chain, including harvesting, processing, packaging, warehousing, transportation, retailing, and eventual consumption. This generates tons of waste annually on a global scale. The significant amounts of phenolics present in these wastes are primarily responsible for their antioxidant capacity and the subsequent health advantages they provide. As such, apricot pulp by-products could be a valuable reservoir of bioactive compounds, such as tocopherols, polyphenolic compounds, proteins, dietary fibers, etc. Moreover, apricot kernels are also recognized for their abundance of bioactive compounds, including polyphenols and tocopherols, which find utility in diverse sectors including cosmetology and the food industry. Both conventional and green methods are employed, and generally, green methods lead to higher extraction efficiency. The antimicrobial properties of apricot kernel essential oil have been widely recognized, leading to its extensive historical usage in the treatment of diverse ailments. In addition, apricot kernel oil possesses the capacity to serve as a viable resource for renewable fuels and chemicals. This review examines the potential of apricot waste as a source of bioactive compounds, as well as its utilization in diverse applications, with an emphasis on its contribution to health improvement.

Opuntia macrorhiza, commonly referred to as red prickly pear, is a type of cactus fruit. The Opuntia macrorhiza (OM) fruit is rich in polyphenols and contains a high amount of ascorbic acid and betalains. The fruit peels have demonstrated many biological abilities, including antioxidant, antifungal, and antibacterial activities. Ultrasound probe-assisted extraction (UPAE) is a highly promising method for efficiently extracting valuable molecules from natural sources. The objective of this study is to optimize the parameters of UPAE, including the appropriate solvent, liquid-to-solid ratio, extraction duration, and pulsation level. The aim is to maximize the yield of bioactive compounds (polyphenols, betalains, and ascorbic acid) from OM fruits (pulps and peels) and assess their antioxidant activities using Taguchi design. The optimal extraction conditions through the partial least squares method for OM pulp were determined to be aqueous extraction for 12 min with a liquid-to-solid ratio of 60 mL/g and 48 pulses/min, while for OM peels they were determined to be aqueous extraction for 20 min with a liquid-to-solid ratio of 60 mL/g and a pulsation of 48 pulses/min. The optimum UPAE conditions were compared with the values obtained from the optimum extraction under stirring extraction (STE). Overall, UPAE exhibited higher yields than STE. The obtained total polyphenol content ranged from 10.27 to 13.07 mg gallic acid equivalents/g dry weight, while the betalain content ranged from 974 to 1099 μg/g dry weight. Overall, these fruits demonstrated potential as new components for food and medicinal uses due to their good health effects and lack of toxicity.

Consuming fruits and vegetables necessitates discarding the inedible parts, which raises issues such as waste management and contamination of the environment. Numerous studies have been conducted in recent years in an effort to identify alternatives that reduce the negative effects of food and agricultural waste. This study aims to investigate the polyphenol recovery and the antioxidant capacity of overripe banana peel through cloud point extraction (CPE), which is a green method. The optimal conditions of the CPE were three steps of CPE with 10% w/v lecithin, which was used as surfactant, pH 7, and a salt concentration of 15% at 45 °C for 20 min. The total polyphenol content (TPC) was determined to be 541.25 mg GAE/L, the total flavonoid content (TFC) was determined to be 226.38 mg RtE/L, and FRAP and DPPH assays were found to be 2.52 and 2.91 mmol AAE/L, respectively. According to the results, the antioxidant compounds from banana peels can effectively be extracted with the proposed CPE procedure. The as-prepared extracts can potentially be used as food additives to improve human well-being and even as feed additives for a similar purpose.

In this study, the objective was to ascertain the optimal extraction method for the recovery of polyphenols from two peach cultivars, namely ‘Andross’ and ‘Everts’, at unripe and ripe stages. Two extraction techniques were explored: conventional extraction and cloud-point extraction (CPE), utilizing various solvents, including water, ethanol, 60% ethanol, and the surfactant Tween 80. Moreover, the conditions of CPE (such as pH, ionic strength, surfactant concentration, etc.) were optimized. To elucidate the antioxidant activity of the extracts, the total polyphenol content (TPC), the ferric-reducing antioxidant power (FRAP) assay, and the DPPH antiradical scavenging were measured. Our findings indicate that CPE is a superior method for polyphenol recovery. Unripe fruits had more antioxidants than ripe ones. Unripe ‘Andross’ fruit has a TPC of 1465.32 mg gallic acid equivalents per kilogram (mg GAE/kg). FRAP and DPPH levels were 7.33 and 5.12 mmol ascorbic acid equivalents (AAE/kg), respectively. With a TPC of 1714.53 mg GAE/kg, the unripe fruit from the ‘Everts’ cultivar has even more antioxidant capacity. Additionally, its FRAP and DPPH values were increased at 8.57 and 6.08 mmol AAE/kg, respectively. These findings underscore the efficacy of CPE as a preferred method for polyphenol extraction while also highlighting the enhanced antioxidant potential of unripe peaches, particularly in the ‘Everts’ cultivar.

The food processing industry is a continuously developing sector that uses innovative technologies to efficiently process food products. During processing, food industries generate substantial amounts of by-products in the form of waste materials. This food waste consists of organic matter rich in bioactive compounds, such as polyphenols, carotenoids, and flavonoids. Improper management of food waste can adversely affect both the environment and human health, leading to environmental pollution and the release of greenhouse gas emissions. Thus, proper food waste management has become an urgent global issue. The presence of bioactive compounds (mainly polyphenols, flavonoids, and anthocyanins, but also carotenoids, alkaloids, proteins, lipids, and carbohydrates) in food waste holds the potential to transform them into valuable resources. Several sectors, including food and energy, have recognized food waste as an innovative source. Recently, much emphasis has been placed on optimizing the extraction yield of such bioactive compounds through the utilization of environmentally friendly and sustainable methodologies and solvents. Pulsed electric field (PEF)-assisted extraction is an emerging technique that holds promise for the utilization of waste materials. PEF technology can efficiently optimize the extraction of valuable compounds within a shorter time while minimizing solvent and energy consumption. In this review, we provide a comprehensive overview of the current state of PEF technology and its implications for recovering bioactive compounds from food waste. The integration of innovative technologies like PEF in the food processing industry can play a crucial role in managing food waste sustainably, reducing environmental impact, and harnessing the full potential of bioactive compounds contained in these waste materials. The objective of this critical review is to provide an overview of the utilization of PEF pretreatment for food by-products and to conduct a comparative analysis with other extraction techniques.

Recently, there has been a significant transition in the dietary preferences of consumers toward foods containing health-promoting compounds. In addition, as people’s environmental awareness increases, they are increasingly looking for sustainable solutions. Palm oil, an oil used extensively by the food industry, does not fit these criteria. This study investigated the development of a complex oil blend consisting of commonly used vegetable oils such as corn, rapeseed, sunflower, and palm oil. The aim was to find the optimal blended oil and compare this combination with palm oil in terms of its oxidative stability, antioxidant capacity, and the composition of bioactive compounds (i.e., fatty acids, tocopherols, and carotenoids). Palm oil was found to have greater oxidative stability as a result of its increased concentration of saturated fatty acids. The optimal blended oil, which consisted of corn and rapeseed oil at a ratio of 4:3 w/w, inhibited the superior antioxidant activity, showing a ~33% increase in DPPH• inhibition activity. ATR-FTIR spectra further verified the existence of a significant quantity of saturated fatty acids in palm oil and unsaturated fatty acids in the blended oil. Finally, several correlation analyses revealed interesting connections between oil samples and investigated parameters. This work has the potential to establish a basis for the mass production of oil blends that possess high concentrations of antioxidant compounds and reduce the use of palm oil.

In recent years, the production of food biomass waste has been increasing rapidly. This necessitates urgent measures to be taken so as to utilize them. Since most food biomass waste contains useful bioactive substances, cloud-point extraction (CPE) has emerged as a promising solution to valorize waste. CPE is an extraction method employed for the extraction and preconcentration of various chemical compounds, including polyphenols and flavonoids. As with any other extraction procedure, CPE isolates the target compound(s) from the sample, resulting in increased recovery. One major advantage of CPE is that the extraction is carried out without special equipment or harmful reagents. Moreover, other significant advantages are its effectiveness, simplicity, safety, and rapidity. This review focuses on the extraction of bioactive compounds from food-based waste using CPE and highlights the important parameters that can be tuned to improve the performance of CPE. Furthermore, the potential in promoting environmentally friendly practices within the food industry is also discussed.

This study explores the bioactive compound extraction from laurel (Laurus nobilis L.) leaves using a pulsed electric field (PEF) as a standalone extraction technique. The primary parameters impacting the extraction process were optimized through response surface methodology. Specifically, solvent composition (ethanol and water mixtures) and liquid-to-solid ratio, along with other key PEF conditions (i.e., electric field intensity, pulse period, and pulse length) were examined. The antioxidant capacity was evaluated through DPPH and FRAP assays, whereas total polyphenol content was also measured. A comparison was also made between the extracts produced with and without PEF. The results showed that after 30 min of extraction, the best parameters were a pulse period of 355 μs, a pulse duration of 55 μs, and an electric field intensity of 0.6 kV/cm. A liquid-to-solid ratio of 10 mL/g was chosen, whereas the best solvent was determined to be 25% (v/v) ethanol/water mixture. The PEF-treated extract contained 77% more polyphenols compared to the untreated sample. In addition, PEF-treated samples had a rise of up to 288% for certain individual polyphenols. Correlation analyses also revealed interesting trends among bioactive compounds and the antioxidant capacity of the extracts. The effect of the investigated parameters on polyphenol recovery was demonstrated, indicating that comparable investigations should consider these parameters to optimize polyphenol extraction yield. Regarding green and non-thermal standalone techniques, PEF outshines other extraction techniques as it could also be used as a sustainable way to swiftly generate health-promoting extracts from medicinal plants.

Watermelon (Citrullus lanatus) is a popular fruit worldwide due to its refreshing taste and its high water content (92% of its weight). According to the phytochemistry of the plant, carbohydrates, saponins, glycosides, steroids, alkaloids, polyphenols, flavonoids, and tannins can be detected in watermelons. C. lanatus generates by-products and, as such, can be characterized by its seeds and rinds. These by-products’ phytochemicals are nutritious and functional. Watermelon seeds contain many phytochemical compounds with beneficial biological activities, according to numerous scientific studies. This fact promotes watermelon seed consumption and encourages food and pharmaceutical companies to use this innovative ingredient. The watermelon rind has all the nutrients of the pulp and also more antioxidants, minerals, vitamins, and bioactive substances. Numerous studies show that watermelon peel is high in fiber and nutrients and can be used in a variety of culinary products. These residues need to be utilized for creating innovative functional food products with added value for the food chain’s sustainability. More studies of watermelon by-products are required to promote functional food, nutraceutical, and pharmaceutical applications. This review aims to shed light on the underutilized portion of watermelon and its chemical properties in order to pave the way for future research.

Prunus spinosa fruit, commonly known as blackthorn or sloe, possesses a wide range of health-promoting properties, including antioxidant and antibacterial activities. In this study, we investigated the effects of various extraction parameters, such as temperature, time, and solvent composition, on the extraction of bioactive compounds from P. spinosa fruit. Response surface methodology was employed to optimize these parameters and evaluate their impact on the antioxidant properties of the extracts. Furthermore, techniques such as ultrasound (US) and pulsed electric field (PEF) were applied, both individually and in combination, to explore their potential effects on the extraction process. The optimal extraction technique proved to be the combination of PEF and US, followed by stirring. The most suitable solvent was 75% ethanol, whereas the optimum extraction time and temperature were 30 min and 80 °C, respectively. Our findings revealed that under the optimum extraction parameters, a significant improvement in the extraction efficiency of bioactive compounds from P. spinosa fruit was achieved. More specifically, the optimal conditions, according to partial least squares (PLS) analysis, were a combination of all three extraction modes (PEF-US-ST), the shorter extraction time of the present study (30 min), and the corresponding higher temperature (80 °C). As expected, the presence of ethanol was considered necessary, even in an amount of 25%. The total polyphenol content was found to be 30.74 mg gallic acid equivalent (GAE)/g, the total flavonoids content 3.23 mg rutin equivalents (RtE)/g and the total anthocyanins 125.2 μg cyanidin-3-O-glucoside equivalents (CyE)/g. HPLC-DAD analysis showed that neochlorogenic acid was the polyphenol with the highest concentration (4.13 mg GAE/g) in P. spinosa fruit. The antioxidant activity of the optimized, according to PLS analysis, extract was evaluated and found to be 146.09 μmol ascorbic acid equivalent (AAE)/g determined by ferric reducing antioxidant power (FRAP) assay, and by the radical scavenging activity (DPPH) assay was 18.56 μmol AAE/g. Additionally, the ascorbic acid was determined to be 119.4 mg/100 g. Overall, this study contributes valuable insights into the extraction optimization process and the potential applications of P. spinosa fruit in the development of functional foods and pharmaceutical products.

The study focused on the examination of eight commercial hypertonic, isotonic, and hypotonic beverage samples that were packaged in aluminum cans or polyethylene terephthalate (PET) bottles. The pH value, caffeine content, and concentration of thirty elements were determined. Caffeine quantification was performed by a high-performance liquid chromatography method. Element determination was conducted by using inductively coupled plasma–optical emission spectrometry. The results showed that pH values were much more acidic in all samples, ranging from 2.68 to 3.97. Caffeine concentrations ranged from 0.02–38.93 mg/100 mL between the samples and were found to be below the acceptable daily level (~400 mg) established by the relevant food regulatory authority. The measurable quantity of caffeine (~10 mg/100 mL) was found in two functional beverage samples where caffeine was labeled as an ingredient. Element concentration varied with statistically significant differences (p < 0.05) among all samples. Elements such as arsenic, cadmium, chromium, and lead were measured below the corresponding permissible levels set by the European Commission; however, daily consumption of functional beverages should be examined to deteriorate several health risks. Aluminum was quantified above the parametric value by 21 to 117% in the canned samples, whereas antimony was only measured in PET-bottled samples at approximately 3 μg/L. Multivariate methods were applied to investigate any possible correlation between the samples and the examined parameters. Strong positive correlations with statistically significant differences (R > 0.9, p < 0.05) were observed between zinc and copper and between calcium and silver. Finally, similarities and differences between the samples and the examined parameters resulted in satisfactory discrimination of them regarding not only their caffeine content but also their tonicity. Excessive consumption of functional beverages could represent a major public health issue due to elevated amounts of caffeine and elements. Consequently, the results of this research could facilitate the formulation of stricter standards in beverage consumption by revealing potential health hazards to consumers.