Search

Rosa roxburghii Tratt residue is rich in dietary fiber and a variety of active substances, but its dietary fiber is mainly insoluble dietary fiber, and the content of soluble dietary fiber (SDF) is low. To make full use of R. roxburghii Tratt residue, steam explosion (SE) pretreatment was used to treat the residue to determine its effect on the extraction yield of SDF and the functionality of dietary fiber (DF). Response surface methodology was used to determine the conditions of SE for optimizing the SDF extraction yield in the residue. When R. roxburghii Tratt residue was pretreated by SE at 60 mesh for 97 s, combined with 0.87 MPa, the content of SDF was increased from 9.31 ± 0.07% to 15.82 ± 0.31% in comparison with the control and DF extracted by SE showed the high cholesterol adsorption, glucose adsorption, cation exchange, nitrite adsorption, and hydroxyl radicals inhibition. Practical applications: Due to the rough texture and poor taste, the high content of DF in the Rosa roxburghii Tratt residue is often discarded during the processing of freshly squeezed juice. SE can significantly improve the utilization of DF, which is a more economical modification method. This work provides a theoretical basis for the R. roxburghii Tratt by‐product as a new source of high‐quality dietary fiber. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) has been widely used in food packaging due to its excellent comprehensive properties, but has relatively low barrier properties towards small molecules. In this study, whey protein isolate (WPI)/chitosan (CS)/microcrystalline cellulose (MCC) solution was sprayed evenly on PET which pretreated by corona discharge (CD) and uniform glow discharge (UGD) plasma to prepare WPI/CS/MCC/PET bilayer film, and the properties, structure, and morphology of films were characterized. The water contact angle of UGD treated PET was significantly decreased by 79.01% due to increased polar functional groups. After coated with WPI/CS/MCC film, the reduced oxygen and carbon dioxide transmission rates of untreated and pretreated PET was in the range of 71.74–94.64%, and UGD pretreatment was more efficient to improve gas barrier properties than CD, but the mechanical and water vapor barrier properties of pretreated bilayer film weakened a little. There was a high intermolecular interaction between hydroxyl and amino groups of WPI/CS/MCC film and polar groups, such as COC and CH bonds, carbonyl, and methyl groups, of UGD‐pretreated PET, as verified by Fourier transform infrared with attenuated total reflection. In conclusion, UGD‐pretreated WPI/CS/MCC/PET bilayer film was significantly efficient to enhance the gas barrier properties of single‐layer PET. Practical Applications: Polyethylene terephthalate (PET) has relatively low barrier properties and its application has been limited in food high air tightness packaging. The present study aimed to develop biopolymer‐based high barrier bilayer film using surface‐pretreated PET substrate. The thermogravimetric analysis, mechanical, and barrier properties were investigated, and the structural characterization and morphology of bilayer films were investigated by Fourier transform infrared with attenuated total reflection analysis, environmental scanning electron microscopy, and atomic force microscope. This work provides a foundation for enhancing the gas barrier properties of single‐layer PET using the combination of biopolymer‐based coating and surface pretreatment. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the protective effect and mechanism of Letinous edodes foot peptides on ethanol‑induced L02 cells. A cell model of ethanol‑induced damage was established in vitro to study the effects of the Letinous edodes foot peptides on human L02 hepatocytes. The expression and activity of superoxide dismutase (SOD), malondialdehyde (MDA), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH), following treatment were examined to determine the anti‑alcoholism and hepatoprotective functions of Letinous edodes foot peptides. Taking Letinous edodes foot peptides prior to ethanol exposure was more beneficial, which significantly increased SOD activity and the mRNA expression of ADH and ALDH suppressed by ethanol. In addition, the intracellular MDA content, and AST and ALT activity decreased in ethanol‑induced L02 cells pretreated with the peptides, when compared with the control. Furthermore, Letinous edodes foot peptides inhibited the ethanol‑induced activation of the proinflammatory cytokines, interleukin‑6 and tumor necrosis factor‑α, and promoted the metabolic regulation factors, AMP‑activated protein kinase‑α2 and peroxisome proliferator‑activated receptor‑α. [ABSTRACT FROM AUTHOR]

BACKGROUND Spirulina platensis is rich in β-carotene, which possesses many important biological activities. This study investigated the ultrasound-assisted extraction and purification of β-carotene from Spirulina platensis by using response surface methodology ( RSM), determined its antioxidant capacity in vitro and explored its hypoglycaemic effect in diabetic mice. RESULTS The raw β-carotene extract with a concentration of 1942.14 ± 10.03 µg mL−1 was obtained at the optimised condition by RSM (0.40 of the solid-liquid ratio, 51% of the extraction power, and 17 min of the extraction time), and the purity of evaporated β-carotene extract reached 816.32 ± 10.57 mg g−1 after purified by a NKA-9 resin with a sampling and elution rate of 1 mL min−1. The β-carotene extract scavenged 1,1-diphenyl-2-picrylhydrazyl and hydroxyl free radicals with the highest ratios of 44 ± 0.26% and 35 ± 0.45% respectively, and exhibited strong inhibiting capacity on anti-lipid peroxidation. The blood glucose level of streptozotocin-induced diabetic mice was significantly reduced from 15.81 ± 1.71 mmol L−1 to 8.10 ± 0.88 mmol L−1 after 10 d administration of the β-carotene extract [100 mg kg−1 body weight ( BW)], and the increased food and water intakes in the diabetic mice were also significantly relieved after β-carotene treatment. CONCLUSION Our results suggested that extraction of β-carotene from Spirulina platensis had potential prospects in scaled-up industrialisation and healthcare applications. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Practical Application Fermented walnut meal (FW) has antifungal activity against Penicillium victoriae, a fungus responsible for Rosa roxbughii Tratt spoilage. This study characterized and applied ultrasonic‐assisted antifungal film loaded with FW to preserve R. roxbughii Tratt during near‐freezing temperature (NFT). Results showed that O2 and CO2 transmission rates decreased by 80.02% and 29.05%, respectively, and antimicrobial properties were improved with ultrasound at 560 W for 5 min and 1% FW. Fourier transform infrared spectroscopy and X‐ray diffraction results revealed ultrasound improved hydrogen bonds and inductive effect via ─NH, ─OH, and C═O bonds. The addition of FW led to the formation of CMCS‐GL‐FW polymer via C═O bond. Thermogravimetric analysis and transmission electron microscope results demonstrated thermal degradation process was decomposed by ultrasound, and the internal structure of P. victoriae was accelerated by the addition of FW. Compared to the U‐CMCS/GL group, the vitamin C content, peroxidase, and catalase activities of U‐CMCS/GL/FW were enhanced by 4.24%, 8.52%, and 14.3% during NFT (−0.8 to −0.4°C), respectively. Particularly, the fungal count of the U‐CMCS/GL/FW group did not exceed 105 CFU g−1 at the end of storage, and the relative abundance of P. victoriae decreased to 0.007%. Our findings provide an effective route for agricultural waste as natural antifungal compounds in the active packaging industry.In this study, the barrier and antimicrobial properties of film were successfully improved by ultrasonic treatment and loaded fermented walnut meal. The ultrasonic‐assisted antifungal film loaded with fermented walnut meal effectively delayed the degradation of nutrients and reduced microbial invasion of Rosa roxburghii Tratt. These results provide a theoretical basis for the application of agricultural waste in the food packaging industry. [ABSTRACT FROM AUTHOR]

The antihypertensive effect of an angiotensin I-converting enzyme (ACE) inhibitory peptide Ile-Gln-Pro (IQP), whose sequence was derived from Spirulina platensis , was investigated in spontaneously hypertensive rats (SHRs) for 1 week. The weighted systolic blood pressure (SBP) and diastolic blood pressure (DBP) of the peptide IQP-treated group were significantly lower than those of the negative control group from the third and fourth days, respectively. Accompanying the blood pressure reduction, a significant regulation of the expression of major components of the renin-angiotensin system (RAS) was found in the treatment group, including downregulation of the mRNA levels of renin, ACE, and the angiotensin II type 1 (AT1) receptor in the kidney, as well as serum angiotensinogen (Ang), ACE, and angiotensin II (Ang II) concentrations. The treatment group also showed upregulation of mRNA expression of the angiotensin II type 2 (AT2) receptor in the kidney. Our findings suggested that IQP might be of potential use in the treatment of hypertension.