Zhejiang Key Laboratory for Agro Food Processing

Hangzhou, China

Zhejiang Key Laboratory for Agro Food Processing

Hangzhou, China
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Li X.,Zhejiang University | Li X.,Zhejiang Key Laboratory for Agro Food Processing | Li X.,Zhejiang nter for Food Technology and Equipment | Pan J.,Zhejiang University | And 9 more authors.
Journal of Chinese Institute of Food Science and Technology | Year: 2017

To compare the chemical compositions as well as the antioxidant effects in vitro of two kinds of P. thornsonii Benth, the basic chemical components including moisture, crude protein, crude fat, crude fibre, ash, starch and total isoflavones of both Pueraria lobata were determinated. Besides, the major isoflavones including puerarin, daidzein, daidzein, genistin, genistein, formononetin, biochanin A and isoliquiritigenin were determinated quantificationally with a HPLC method. Then, the antioxidant activities of the two kinds of P. thomsonii Benth were evaluated by DPPH, ABTS and FRAP method in vitro. The results show that the starch content of Cangwuxiye cultivar (66.36±4.27 g/100 g DW) is higher than that of Dayezi cultivar (53.73±1.52 g/100 g DW), while the total isoflavones of Dayezi cultivar (4.72±0.11 g/100 g DW) higher than that of Cangwuxiye cultivar (1.51±0.10 g/100g DW), and puerarin is the largest proportion in total isoflavones of Radix Puerariae isoflavones. The content of puerarin in Dayezi cultivar (18.69±0.22 mg/g DW) is higher than that of Cangwuxiye cultivar (5.74±0.82 mg/g DW). The antioxidant activity in vitro shows that Dayezi cultivar has higher antioxidant activity than that of Cangwuxiye cultivar, which is related to the content of total isoflavones. Therefore, Cangwuxiye cultivar is a suitable raw material for preparing the starch, while Dayezi cultivaris suitable to extract pueraria isoflavones, and the pueraria isoflavone is a kind of natural antioxidants, for it has a relatively high antioxidant activity. Radix puerariae © 2017, Editorial Office of Journal of CIFST. All right reserved.

Wu Y.,Zhejiang Key Laboratory of Food Microbiology | Wu Y.,Zhejiang Key Laboratory for Agro Food Processing | Ji X.,Zhejiang Key Laboratory of Food Microbiology | Ji X.,Zhejiang Key Laboratory for Agro Food Processing | And 11 more authors.
Advance Journal of Food Science and Technology | Year: 2013

This research was to study the effects of lactic acid bacteria fermentation on the quality of little yellow croaker. The effects of the LAB starter composed of Lactobacillus plantarum and Lactobacillus acidophilus on the quality of little yellow croaker were studied through a 72 h fermentation process in this study. During 72 h fermentation at 30°C, little yellow croaker inoculated with the LAB starter not only resulted in a rapid pH decrease and suppression of spoilage bacteria, but also receded chemical changes such as total volatile base nitrogen and biogenic amines, its texture profile and whiteness also satisfying. Besides, Scanning Electron Micrograph (SEM) images indicated some microstructure changes in LAB fermentation. The results demonstrated that the LAB starter could be developed as bio-preservatives to improve the quality of little yellow croaker in storage. © Maxwell Scientific Organization, 2013.

Ding T.,Zhejiang University | Ding T.,Zhejiang Key Laboratory for Agro Food Processing | Ge Z.,Zhejiang University | Shi J.,Agriculture and Agri Food Canada | And 4 more authors.
LWT - Food Science and Technology | Year: 2015

This study investigated the effect of ultrasonic treatment on the physicochemical properties (pH, available chlorine concentration (ACC), oxidation reduction potential (ORP), spectrophotometric characteristics) of slightly acidic electrolyzed water (SAEW). The effects of individual treatments (ultrasound and SAEW) and their combination on microbial loads and quality of cherry tomatoes and strawberries were also studied. The results indicated that a 10min ultrasonic treatment had no effect on pH, ACC, or ORP of SAEW. Ultrasound enhanced the bactericidal activity of SAEW which resulted in 1.77 and 1.29log reductions on total aerobic bacteria, and 1.50 and 1.29log reductions on yeasts and molds, respectively for cherry tomatoes and strawberries. The firmness of cherry tomatoes decreased while all other qualities considered were unaffected. This research indicates that SAEW in combination with ultrasound treatment has potential as a sanitization treatment to improve the efficacy of microbial inactivation on fresh produce without compromising product quality. © 2014 Elsevier Ltd.

Ding T.,Zhejiang University | Ding T.,Zhejiang Key Laboratory for Agro Food Processing | Xuan X.-T.,Zhejiang University | Liu D.-H.,Zhejiang University | And 7 more authors.
International Journal of Food Engineering | Year: 2015

Electrolyzed water offers several advantages over other sanitizers for sanitation of both food contact and non-contact surfaces. However, current electrolyzed water-generating process has low fluid output. To overcome such limitations, a circulating electrolyzed water-generating system has been developed in this study. The effects of NaCl/HCl concentration and electrolysis time were investigated. The free chlorine form (HClO and ClO-) of circulating electrolyzed water, and NaClO with the available chlorine concentrations of 50, 100, 200 mg/L were analyzed by using an ultraviolet spectrophotometer. The results show that the main chlorine form was HClO when the pH of solution was 6.44-6.53. The only ClO- in NaClO solutions when the pH of solution is 11.90. With the dilution of circulating electrolyzed water, the HClO concentration decreased while its proportion account for total available chlorine concentration increased (from 56.99% to 74.29%). The results indicated the potential application of diluted circulating electrolyzed water with high available chlorine concentration. The developed circulating electrolyzed water system in this study could be considered as a potential sanitizer due to its high stability, strong antimicrobial activity with high concentration of HClO and minimized equipment requirements for production. © 2015 by De Gruyter.

Cai H.,Zhejiang University | Cai H.,Fuli Institute of Food Science | Cai H.,Zhejiang Key Laboratory for Agro Food Processing | Cai H.,Zhejiang R and nter for Food Technology and Equipment | And 16 more authors.
Journal of Food Safety | Year: 2014

The DNA microarray was employed in this study to investigate the gene expression profiles of Escherichia coli treated by oil in water (o/w) microemulsion in order to better understand the antimicrobial mechanism of the microemulsion as a promising food-grade antimicrobial system. Among 5,440 open reading frames of E.coli, a total of 634 and 501 were highly induced and repressed, respectively. According to the annotation and analysis in the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, it was found that the differently expressed genes were mainly involved in the biosynthesis of cell wall components and membranes, phosphate-related metabolism and some other biosynthetic pathways, suggesting that the main antibacterial mechanisms of the o/w microemulsion were the attacks to the cell surface structure, especially the cell wall, and its influences on the metabolism of phosphate of the E.coli cells through phosphate absorption inhibition. Practical Applications: In the panorama of the increasing need to search for novel strategies in order to prevent foodborne outbreaks, microemulsion systems have been of great interest to researchers for their broad antimicrobial properties. In our group, a series of food-grade or pharmaceutical microemulsion systems based on glycerol monolaurate have been established for antimicrobial applications. It was found that the prepared microemulsions possessed excellent broad-spectrum antimicrobial activities due to the disruption and dysfunction of biological membranes and cell walls, as suggested by the transmission electron microscopy observations and membrane permeability experiments. The antimicrobial mechanisms analysis of the microemulsion mediated by DNA microarray in this work will be of great importance in exploring the structure-activity relationship of the o/w microemulsion at molecular biological levels in future work, in order to provide a guideline in designing food-grade antimicrobial microemulsions. © 2014 Wiley Periodicals, Inc.

Huang H.,Zhejiang University | Huang H.,Zhejiang Key Laboratory for Agro Food Processing | Sun Y.,Zhejiang University | Sun Y.,Zhejiang Key Laboratory for Agro Food Processing | And 4 more authors.
Food Chemistry | Year: 2014

The traditional method of chemical extraction (i.e., extracts), combined with chemical antioxidant activity assays cannot assess the real antioxidant activity. In vitro digestion (i.e., digesta) with a cellular antioxidant activity (CAA) assay was developed for the determination of antioxidant activity in Chinese bayberry fruits. In this study, pretreatment methods were studied and the results showed that digesta had more free phenolic acids (FPA) but less total phenolic content (TPC) and total anthocyanin content (TAC) than extracts. Antioxidant activity assays, including ABTS, FRAP, DPPH, ORAC and CAA, were compared. Digesta had lower ABTS, FRAP and DPPH values but higher CAA values than extracts. FPA were better correlated with the chemical antioxidant assays in digesta. The correlations were high between TPC and CAA values in digesta (R2 = 0.96) but not extracts (R2 = 0.58). Higher correlations were also obtained between CAA and chemical assays in digesta. © 2013 Elsevier Ltd. All rights reserved.

Wang W.,Zhejiang University | Wang W.,Zhejiang Key Laboratory for Agro Food Processing | Wang W.,Zhejiang R and nter for Food Technology and Equipment | Ma X.,Zhejiang University | And 16 more authors.
Food Chemistry | Year: 2015

The extraction of pectin from grapefruit peel by ultrasound-assisted heating extraction (UAHE) was investigated using response surface methodology and compared with the conventional heating extraction (CHE). The optimized conditions were power intensity of 12.56 W/cm2, extraction temperature of 66.71 °C, and sonication time of 27.95 min. The experimental optimized yield was 27.34%, which was well matched with the predicted value (27.46%). Compared with CHE, UAHE provided higher yield increased by 16.34% at the temperature lowered by 13.3 °C and the time shortened by 37.78%. Image studies showed that pectin extracted by UAHE showed better color and more loosen microstructure compared to that extracted by CHE, although Fourier Transform Infrared Analysis indicated insignificant difference in their chemical structures. Furthermore, UAHE pectin possessed lower viscosity, molecular weight and degree of esterification, but higher degree of branching and purity than CHE pectin, indicating that the former was preliminarily modified during the extraction process. © 2015 Elsevier Ltd. All rights reserved.

Chen Q.,Zhejiang University | Chen Q.,Zhejiang Key Laboratory for Agro Food Processing | Xu S.,Zhejiang University | Wu T.,Zhejiang University | And 6 more authors.
Journal of the Science of Food and Agriculture | Year: 2014

BACKGROUND: Essential oils such as citronella oil exhibit antifungal activity and are potential alternative inhibitors to chemical synthetic fungicides for controlling postharvest diseases. In this study the antifungal activity of citronella oil against Alternaria alternata was investigated. RESULTS: In vitro, citronella oil showed strong inhibition activity against A. alternata. The minimum inhibitory concentration in potato dextrose agar and potato dextrose broth medium was determined as 1 and 0.8 μL mL-1 respectively. In vivo the disease incidence of Lycopersicon esculentum (cherry tomato) treated with citronella oil was significantly (P < 0.05) reduced compared with the control after 5 days of storage at 25 °C and 95% relative humidity. The disease incidence at oil concentrations of 0.2-1.5 μL mL-1 was 88-48%. The most effective dosage of the oil was 1.5 μL mL-1, with 52% reduction, and the oil had no negative effect on fruit quality. Scanning electron microscopy observation revealed considerably abnormal mycelial morphology. CONCLUSION: Citronella oil can significantly inhibit A. alternata in vitro and in vivo and has potential as a promising natural product for controlling black rot in cherry tomato. © 2014 Society of Chemical Industry.

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