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Self-aggregating polymeric micelles are novel promising vehicles to solubilize and targeting delivery hydrophobic food ingredients. Solubilization of β -carotene with octenylsuccinate oat β -glucan (OSG) micelles, in terms of the apparent solubility of β -carotene ([ S ] β -car ), was investigated in this study. Its dependence on the degree of substitution (DS) and molecular weight (M w ) of OSG and stirrer input power (IP) was explored with the aid of response surface methodology (RSM). More importantly, the freeze-thaw, thermal and storage stability of β- carotene-loaded OSG micelles were determined. Results from RSM revealed that the maximum [ S ] β -car (12.84 μg/mL) encountered with the intermediate DS (0.0183), high M w (17.1 × 10 4 g/mol) and IP (4.3 W). TEM images evidenced a minor deformation of OSG micelles upon β -glucan solubilization. In terms of size and polydispersity index, β -carotene-loaded OSG micelles exhibited good thermal stability, intermediate freeze-thaw stability and inferior storage stability. Furthermore, regarding to the retention of β -carotene, β -carotene-loaded OSG micelles were susceptible to thermal treatment and storage but kept stable against freeze-thaw treatment, but presented nice freeze-thaw stability. The loss of [ S ] β -car upon thermal treatment and storage was of temperature and time dependence. These results cast new light on the possible fortification of insoluble ingredients by OSG micelles in aqueous food systems.

In this study, the temporal and spatial variation of mechanical effects (ME) and sonochemical effects (SE), the degradation behavior of polyphenols as well as the correlation coefficients were comprehensively analyzed. The ME and SE showed inverse dependence along with the axial direction of transducer. Higher irradiation distance (50 mm) enhanced the ME but inhibited the generation of hydroxyl radicals (8.29 μmol/L). Rutin and cyanidin-3-glucoside, compared with thermal degradation (70°C, 6.41%, and 11.45%), were more susceptible to free radical degradation due to the boost of SE at low temperature (10°C, 20.23%, and 34.41%). The concentration of hydroxyl radicals at 70°C (18.38 μmol/L) was about 5.77 times lower than that at 10°C (3.22 μmol/L). No significant differences in the ME were observed for a wide range of temperatures (10–70°C). The impacts of increasing duty cycle on further promoting the ME and SE were limited. The concentration of hydroxyl radicals (0–23.37 μmol/L) increased linearly with sonication time (0–45 min) and the degradation of caffeic acid only occurred on a time scale (25 min). The free radical scavenger can minimize the degradation of polyphenols by inhibiting the hydroxyl radicals (23.37 μmol/L without t-BuOH; 12.17 μmol/L with t-BuOH). The above results showed that the degradation of polyphenols attacked by hydroxyl radicals presented a dose-response relationship. The correlation between the hydroxyl radicals and polyphenols as well as the mechanical effects and extraction yield indicated that the stability of polyphenols exposed to ultrasonic field depended on the structure-radical scavenging activity relationship and the extraction may be accompanied by the degradation.

Conventional thermal pasteurisation (90 °C and 30 s), high pressure processing (HPP: 600 MPa, 4 °C and 300 s), ultrasound processing (US: 50 °C, 750 W and 36 min) and microwave processing (MW: 800 W, 80 °C and 70 s) were evaluated by examining their effects on the sensory and nutritional qualities of mandarin juice. The treated samples had

Amphiphilic oat β-glucan derivatives carrying octenylsuccinic groups as hydrophobic moieties have been synthesized. Materials with a different degree of substitution (DS) and weight-average molecular weight (Mw) for oat β-glucan were prepared and characterized using elemental analysis, infrared (IR) spectroscopy, and high performance size exclusion chromatography (HPSEC). Dynamic light scattering (DLS), fluorescence spectroscopy, and transmission electron microscopy (TEM) revealed that octenylsuccinate oat β-glucan (OSG) can self-assemble into spherical micelles in water with an average size ranging from 175 to 600 nm. OSG micelles were negatively charged as indicated by ζ-potential measurement. The critical micelle concentration (CMC) of OSGs varied from 0.206 to 0.039 mg/mL, depending on the DS and Mw of the oat β-glucan. It was found that the presence of OSG micelles in aqueous solution could significantly enhance the solubility of curcumin by 880 fold. Thus, OSG might have great potential in applications as hydrophobic nutrient delivery carriers.

Composition and distribution of phenolic acids in Ponkan ( Citrus poonensis Hort. ex Tanaka) and Huyou ( Citrus paradisi Macf. Changshanhuyou) during maturity was investigated comprehensively in this study. High-performance liquid chromatography (HPLC) coupled with photodiode array (PDA) detector method was developed to separate and quantify protocatechuic, p -hydroxybenzoic, vanillic, caffeic, p -coumaric, ferulic, sinapic, and chlorogenic. For all of the phenolic acids, detection limits were about 0.01 μg/mL. Repeatability was 0.57–2.99% (relative standard deviation, RSD) for intraday and recovery ranged from 80.23% to 114.53%. In this study, phenolic acids were divided into four fractions: free, ester, glycoside and ester-bound. Generally, in each fraction, Ponkan had higher content of phenolic acids than Huyou, and with maturity there was a sharp decrease of them in both varieties, also peel contained more of them than flesh. Furthermore, chlorogenic acid and ferulic acid were the highest among the eight quantified phenolic acids, and content of caffeic acid was rather high at unripe stage, and hydroxycinnamic acids accounted for a larger portion compared with hydroxybenzoic acids especially for Ponkan. The total content of phenolic acids ranged from 180 μg/g DW (flesh of Huyou at ripe stage) to 5060 μg/g DW (peel of Ponkan at unripe stage). The data obtained here can be potentially used for discriminating the adulteration of citrus juices and may be useful for consumers and food technologists.

Ultrasound-assisted extraction (UAE) was used to extract phenolic compounds from Satsuma mandarin ( Citrus unshiu Marc.) peels (SMP), and maceration extraction (ME) was used as a control. The effects of ultrasonic time (10, 20, 30, 40, 50, and 60 min), temperature (15, 30, and 40 degrees C), and ultrasonic power (3.2, 8, 30, and 56 W) on phenolic compounds were investigated. High-performance liquid chromatography (HPLC) coupled with a photodiode array (PDA) detector was used for the analysis of phenolic acids after alkaline hydrolysis (bound phenolic acids) and flavanone glycosides. The contents of seven phenolic acids (caffeic acid, p-coumaric acid, ferulic acid, sinapic acid, protocatechuic acid, p-hydroxybenzoic acid, and vanillic acid) and two flavanone glycosides (narirutin and hesperidin) in extracts obtained by ultrasonic treatment were significantly higher than in extracts obtained by the maceration method. Moreover, the contents of extracts increased as both treatment time and temperature increased. Ultrasonic power had a positive effect on the contents of extracts. However, the phenolic acids may be degraded by ultrasound at higher temperature for a long time. For example, after ultrasonic treatment at 40 degrees C for 20 min, the contents of caffeic acid, p-coumaric acid, ferulic acid, and p-hydroxybenzoic acid decreased by 48.90, 44.20, 48.23, and 35.33%, respectively. The interaction of ultrasonic parameters probably has a complex effect on the extracts. A linear relationship was observed between Trolox equivalent antioxidant capacity (TEAC) values and total phenolic contents (TPC); the correlation coefficient, R(2), is 0.8288 at 15 degrees C, 0.7706 at 30 degrees C, and 0.8626 at 40 degrees C, respectively. The data indicated that SMPs were rich sources of antioxidants. Furthermore, UAE techniques should be carefully used to enhance the yields of phenolic acids from SMPs.

Juices from fifteen citrus varieties (seven mandarins, four sweet oranges, one lemon, one grapefruit, and two pummeloes) of China were investigated mainly on quality parameters, total carotenoid, phenolic compounds (total phenolics, flavanone glycosides (FGs), and phenolic acids), and antioxidant capacity (ferric reducing antioxidant power (FRAP) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay). Among the fifteen varieties, Bendizao had the highest content of total carotenoid (10.02 mg/L), Satsuma had the highest content of narirutin (288.12 mg/L), Yinzaocheng had the highest content of hesperidin (533.64 mg/L), and Huyou had the highest content of naringin (348.53 mg/L), neohesperidin (265.25 mg/L) and total FGs (746.08 mg/L). As for total phenolic acids, Liubencheng had the highest content (72.61 mg/L). Hybrid 439 achieved the highest AA content (631.25 mg/L), and the highest total phenolics (1555.49 mg/L) and the greatest inhibition of DPPH radical (61.62%). Hamlin had the highest ascorbic acid equivalent antioxidant capacity (AEAC: 899.31 mg/L) determined by FRAP assay. Correlation coefficients of AA, total phenolics (gallic acid equivalent), FRAP (AEAC), DPPH (I%), total FGs and total phenolic acids indicated that AA played a major role for the antioxidant capacity of citrus juices, and phenolics also played an important role, which may be mainly ascribed to FGs, whilst phenolic acids seemed to play a minimal role. Furthermore, Huyou and Hybrid 439 were considered two valuable varieties from the view of antioxidant capacity and nutrition.

The dependence of the curcumin loading capacity (CLC) of octenylsuccinate oat β-glucan (OSG) micelles on the structural parameters (degree of substitution, DS; molecular weight, Mw) of OSG was unknown and explored in this study. Meanwhile, the curcumin-loaded OSG micelle (COM) was first characterized. The results from response surface methodology revealed that the linear effects of Mw and stirrer input power, as well as the quadratic effect of DS, were significant (p < 0.05). The maximum CLC value of the OSG micelle was obtained as 4.21 μg/mg. Dynamic light scattering showed that the average size and ζ potential of the COM were 308 nm and -10.8 mV, respectively. Transmission electron microscopy and atomic force microscopy evidenced that the COM was elliptical in shape. Fourier transform infrared spectroscopy, differential scanning calorimeltry, and X-ray diffraction revealed that curcumin was loaded in OSG micelles in an amorphous form by interacting with OSG molecules.

Application of ultrasound to extract a variety of biologically active compounds from plant materials has been widely investigated. However, there are few reports on the local effect of ultrasonic irradiation on the yields of these compounds. In the present article, the local effect of ultrasonic treatment on total phenolic content (TPC) and antioxidant activities (ATT) of extracts from citrus peels was investigated. To optimize the extraction process, a response surface methodology (RSM) was used to evaluate the effects of ultrasonic variables including ultrasonic power, ultrasonic time, and extraction temperature on extracts from penggan (Citrus reticulata) peel. The results showed that TPC and ATT increased on increasing ultrasonic time and temperature. The maximum of TPC and ATT by ultrasonic treatment was observed in near ultrasonic irradiation surface, in which ultrasonic power appeared to be positive effect. Furthermore, when the effect of the 3 independent variables was evaluated simultaneously using RSM, the optimal ultrasonic conditions for responses were determined as: 42 to 45 W, 23 to 25 min, 31 to 34 degrees C. The results presented here emphasized that application of ultrasound should be considered both the optimization of ultrasonic variables and available ultrasonic device.

Hesperidin, an abundant and inexpensive bioflavonoid in Penggan (Citrus reticulata) peel, has been reported to possess a wide range of pharmacological properties. Ultrasonic extraction is an effective technique for the isolation of bioactive compounds from vegetable materials. In this study, the application of ultrasonic method was shown to be more efficient in extracting hesperidin from Penggan (C. reticulata) peel than the classical method. The effects of main ultrasonic-assisted extraction conditions on extraction yields of hesperidin from Penggan (C. reticulata) peel were evaluated, including extraction solvents, solvent volume, temperature, extraction time, ultrasonic power, ultrasonic frequency. Results showed that solvent, frequency and processing temperature were the most important factors for improving the extracting yields of hesperidin. When performed at the same temperature under the same time using three frequencies, methanol as the solvent improved the extraction yield evidently compared with ethanol or isopropanol; by comparison of the frequency influence, the yield of hesperidin was higher at 60 kHz than at 20 kHz and 100 kHz. The optimum ultrasonic conditions were determined as: methanol, frequency of 60 kHz, extraction time of 60 min, and temperature of 40 degrees C. In addition, the ultrasonic power had a weak effect on the yields of hesperidin within the experimental range. Extending ultrasonic treatment times did not result in degradation of hesperidin; the rotary beaker for materials can increase the yields of hesperidin.