In this study, the content composition and antioxidant activity of goji berry fruits from two species (Lycium barbarum and Lycium chinense) were assessed. The total carbohydrate and phenolic contents were evaluated using attenuated total reflection Fourier-transform infrared (ATR-FT-IR) spectroscopy, while the antioxidant activity of fruits was examined with two in vitro methods, which are based on the scavenging activity of the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2’-azino-bis(3-ethyl-benzthiazoline-sulfonic acid) (ABTS•+) free radicals. The fatty-acid profile was determined using gas chromatography coupled with mass spectrometry (GC-MS). The results of this study indicate that the fruits of L. barbarum present higher concentrations in carbohydrates and phenolics than L. chinense Mill. fruits. Furthermore, the antioxidant activity based on the half maximal inhibitory concentration (IC50) measurements of DPPH• and ABTS•+ free-radical scavenging was higher in L. barbarum than L. chinense Mill. Also, the GCMS analysis confirms the high levels of linoleic, palmitic, and oleic acids contained in the fruits of both species. Finally, the results of this study clearly show that the concentration of bioactive and antioxidant molecules is higher in L. barbarum than in L. chinense fruits, which was also confirmed by ATR-FT-IR measurements.

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Popularity of goji berry fruit extracts as functional ingredients is growing rapidly. “Green” aqueous extraction technologies are preferable to organic solvent‐based processes as they improve the bioactivity and added value of these extracts. This work aimed at optimizing the ultrasound assisted aqueous extraction (UAE) of Lycium barbarum for both locally produced and imported fruits and comparing the bioactivity in relation to extraction conditions and origin of fruits, using a response surface model. The optimal solvent/extracted material ratio, extraction temperature, ultrasonic power, and extraction time were determined to achieve the following optimal quality/bioactivity indices: total solids, carbohydrates, phenolics, and antioxidant capacity based on IC‐50 values of the DPPH method. Fruits of different origin had mostly similar optimal extraction conditions and antioxidant capacity but differed significantly in carbohydrate content, which was higher for locally produced fruits (1.1 ± 0.17 g/L extract) compared to imported ones (0.89 ± 0.19 g/L extract). Practical applications In this study, the UAE process for goji berry extracts was successfully optimized using response surface methodology, and the most preferable conditions for optimal extraction performance and optimal bioactivity were determined. With regard to extraction yield, the optimal water/raw material ratio (33.9%), extraction temperature (32.02°C), ultrasonic power (30.95 w/cm2), and extraction time (32.03 min) were determined. Under optimal extraction conditions, locally produced fruits had no significant difference in extraction yield, and antioxidant capacity (IC50 values) compared to imported ones. However, locally produced fruits had significantly higher carbohydrate content and somewhat lower polyphenol content under optimal UAE conditions, showing that fruit origin may affect the composition of fruit extracts. These findings are a useful tool for producers of goji berry extracts to achieve an effective and economically viable extraction process as well as optimal composition and bioactivity in terms of antioxidant capacity, which are indeed important traits of these fruit extracts.

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The interest in using plant by-product extracts as functional ingredients is continuously rising due to environmental and financial prospects. The development of new technologies has led to the achievement of aqueous extracts with high bioactivity that is preferable due to organic solvents nonuse. Recently, widely applied and emerging technologies, such as Simple Stirring, Pressure-Applied Extraction, Enzymatic Extraction, Ultrasound-Assisted Extraction, Pulsed Electric Fields, High Hydrostatic Pressure, Ohmic Heating, Microwave Assistant Extraction and the use of “green” solvents such as the deep eutectic solvents, have been investigated in order to contribute to the minimization of disadvantages on the extraction of bioactive compounds. This review is focused on bioactive compounds derived from pomegranate (Punica granatum) peels and highlighted the most attractive extraction methods. It is believed that these findings could be a useful tool for the pomegranate juices industry to apply an effective and economically viable extraction process, transforming a by-product to a high added value functional product.

The global interest in the use of plant by-product extracts as functional ingredients is continuously rising due to environmental, financial and health benefits. The latest advances in extraction technology have led to the production of aqueous extracts with high bioactive properties, which do not require the use of organic solvents. The purpose of this study was to optimize the conditions applied for the extraction of pomegranate peels (PP) via a “green” industrial type of vacuum microwave-assisted aqueous extraction (VMAAE), by assessing the potential bioactivity of the extracts (in terms of phenolic content and antioxidant activity), using a response surface methodology. The extraction conditions of temperature, microwave power, time and water/PP ratio were determined by the response surface methodology, in order to yield extracts with optimal total phenolics concentrations (TPC) and high antioxidant activity, based on the IC50 value of the scavenging of the 2,2-diphenyl-1-picrylhydrazyl (DPPH●) radical. The values of the optimum extraction parameters, such as extraction temperature (61.48 and 79.158 °C), time (10 and 12.17 min), microwave power (3797.24 and 3576.47 W) and ratio of water to raw material (39.92% and 38.2%), were estimated statistically for the two responses (TPC and IC50 values), respectively. Under these optimal extraction conditions, PP extracts with high TPC ((5.542 mg Gallic Acid Equivalent (GAE)/g fresh PP))/min and radical scavenging activity (100 mg/L (1.6 L/min)) could be obtained. Our results highlighted that the optimized industrial type of VMAAE could be a promising solution for the valorization of the PP by-products.

The aim of the present work was to investigate the potential prebiotic action of Goji berry powder on selected probiotic bacteria grown in a nutritive synthetic substrate and in simulated gastric and intestinal juices. Different probiotic strains of Bifidobacterium and Lactobacillus were grown in these substrates with or without the addition of encapsulated goji berry extracts of different polysaccharide and polyphenol contents. The results proved that the addition of the extracts promoted the proliferation of probiotic strains and, in particular, increased the number of bacterial colonies of Bifidobacterium animalis subsp. lactis (Bb12), Bifidobacterium longum (Bb46), and Lactobacillus casei by 2, 0.26, and 1.34 (log cfu/mL), respectively. Furthermore, the prebiotic effect seems to be correlated to Goji berry polysaccharides and/or polyphenols, higher contents of which (under the tested concentrations) could increase the stress tolerance of B. lactis and B. longum in a simulated gastrointestinal environment. According to the findings of the present research, it can be suggested that the Goji berry encapsulated extracts could be used as prebiotic additives in food or nutraceuticals, in order to stimulate growth or protect the viability of probiotic strains of Bifidobacterium and Lactobacillus.Microorganisms 2020, 8, 57 2 of 14 lung disorders, and anticancer activity [10][11][12], thanks to which, L. barbarum fruit has recently gained increasing popularity in Europe and North America [12].Recently Goji berries have been also positively evaluated for their prebiotic potential in foods like yogurt [13], since their polysaccharides may be selectively utilized by some probiotic bacteria [14], although a potential prebiotic effect may be also linked to other molecules like polyphenols, which may stimulate the growth of probiotic bacteria in the gut, or inhibit the growth of antagonistic bacteria in the complex intestinal microbiota [15].Gut colonization by beneficial probiotic bacteria is recognized as an essential parameter for intestinal health, and human health in general. It occurs in early life, as Bifidobacterium and Lactobacillus species attach to the gastrointestinal tract, which is necessary for establishing the gut mucosal barrier, maturation and modulation of the immune system, preventing infections by enteric pathogens and improving gastrointestinal function, digestion, and metabolism [16][17][18][19][20]. Nowadays, the presence (or supplementation) of certain probiotic bacteria, prebiotics or symbiotics (mixed preparations of probiotics and prebiotics) in the gastrointestinal tract is linked to prevention or reduced risk of ulcer, gastroenteritis, inflammation, colon cancer and metabolic syndrome (the latter involving hypolipidemic, hypocholesterolemic and potential hypoglycemic activity) as well as preterm birth and neonatal gastrointestinal disorder [21][22][23][24][25][26][27][28][29]. However, gut microbiota are not stable throughout life, and significant changes can occur naturally throughout the life...

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