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Despite the latest pursuit to discover novel phenolic compounds in hempseed and its biological properties, it remains a mystery whether they can be absorbed in the human body. Extrusion treatment and extraction of the free phenolic fraction significantly (p < 0.05) improved human Caco-2 intestinal cell absorption for hempseed hull lignanamides including cannabisin B (Papp value of 1.35 × 10-5 ± 1.0 × 10-6) as compared to the bound fraction of raw hull (Papp value of 2.82 × 10-6 ± 5.2 × 10-7). Co-supplementation of the flavonoid naringenin (20 μM) further improved these absorption rates. Higher cellular antioxidant activity was observed in the free extraction fractions. Treatment with the free phenolic fraction of extruded hempseed hull (100 mg/mL) alleviated tert-butyl hydroperoxide's (25 μM) negative effects on cell viability, intracellular malondialdehyde levels, apoptosis induction, glutathione S-transferase, and glutathione levels. RNA-sequencing with the limma method unveiled a total of 2795 differentially expressed genes in 21 day-old Caco-2 intestinal cells, suggesting the changes in cell metabolism after exposure to extruded hempseed hull extract. This study could promote the utilization of extrusion technology to improve the absorption and antioxidant capacities of bioactive phenolics in plant food processing byproducts.

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.

Bayberry juice was fined with the methods of xanthan/chitosan (XC) or gelatin/bentonite (GB), and then filtered with diatomaceous earth filtration (DF) or ultrafiltration (UF, MWCO 100 kDa). Their effects on juice haze formation were investigated. The XC fining method was more effective than the GB method in removal of the total monomeric anthocyanin, total phenolics, and protein, with less haze formed in the XC fined juice. The DF reduced 2−5% of the total phenolics and 21−23% of protein, while UF reduced 19−24% of the total phenolics and 34−38% of protein, respectively. The results showed that fining and then UF can reduce but cannot eliminate haze formation in bayberry juice. The storage temperature was a critical factor affecting haze formation, and the juice was more stable when stored at lower temperature (4 °C). Copyright © 2007 American Chemical Society.

Fresh bayberries (Myrica rubra Sieb. et Zucc.) were processed into juice at an industrialized scale with four treatments: control, SO2 addition, pasteurization of the crushed pulp, and blanching before fruit crushing. Changes in anthocyanin pigments and polyphenolics (hydrobenzoic acids and flavonol glycosides) were monitored during processing. Centrifuged juice yield ranged from 73 to 78% (w/w), but only 12-27% of the anthocyanins and 20-32% of the polyphenolics were recovered in the ultrahigh-temperature (UHT) juices. Fifty-two to 58% of anthocyanins and 30-35% of polyphenolics were present in the centrifuged cakes. The initial processing steps of blanching, crushing, pasteurization, and depectinization caused a great loss of total and individual polyphenolics. Total monomeric anthocyanins were significantly higher (p < 0.05) in pasteurization- and blanching-treated samples than those in the SO2 treated samples, whereas those in the SO2-treated sample were significantly higher (p < 0.05) than those in the control juice. Overall polyphenolic levels were significantly higher (p < 0.05) in pasteurization- and blanching-treated samples than in the SO2-treated and control samples after each processing step. Important changes occurred in the polyphenolic profile with a 50-150% of hydroxybenzoic acids increase due to the free gallic acid from the flavonol glycoside-gallates during the initial processing steps. Flavonol deoxyhexosides were more stable than the flavonol hexosides during bayberry juice processing.