Advanced Materials Research Vols. 550-553

Abstract: Fragrance constituents in essential oils from the off-cuts of Eaglewood (A) and Chinese Eaglewood (B) in Guangdong have been analysed by GC-MS. Essential oil A was extracted by microwave additional extraction method, and oil B was provided by a flavors company. SPME-GC-MS analyses revealed that two oils possessed 29 same compounds, and their main fragrance compositions were sesquiterpene accounting for 94.99% and 94.19% of total essential oils, respectively. However, oil A exhibited 61 volatile compounds with agarospiro (17.32%), guaiac acetate (15.99%), guaiol (15.53%) and beta-Ionon (13.61%) being the major constituents. Oil B had 59 ones, and the major constituent was spathulenol (56.45%). In the first 60 min, oil B showed 28 distinctive compounds. And in 78~91 min, oil A displayed 14 fragrance compositions, while, oil B showed 1. The results explained that two essential oils possessed similar scent. However, their aroma quality was very different. Oil A showed longer holding fragrance. However oil B exhibited richer top note. This study demonstrated that offcuts of Eaglewood would also be used to extract essential oil to provide new variety of material for perfume industry.

Abstract: A chemiluminescence immunoassay with polyclonal antibody for detecting zearalenone in corn samples was developed. The optimized reaction conditions include the concentration of coating antigen (0.253 μg/ml), the polyclonal antibody (1:7500) and HRP labeled goat anti-mouse antibody (1:40000), the competition time (60 min), pH of dilution buffer (7.4), the concentration of methanol (10%) and the ratio of luminol to ρ-iodophenol (2:5) were all investigated. Based on optimum conditions, the chemoluminscence ELISA detect range was f 0.05 - 54.34 ng/ml, with IC50 was 2.93 ng/ml, and the limit of detection was 0.02 ng/ml. The chemiluminescence immunoassay shows a good agreement with commercial ELISA kit for detection zearalenone in the spiked samples. The chemiluminescence immunoassay is easier in pretreating, and more sensitive when compared with other detection methods include chromatography methods and immunoassays.

Abstract: Safe food packaging is of great significance in solving food safety problem, which can ensure the quality of the food. At the same time protecting the environment should be taken into consideration, and therefore sound food packaging is not only safe to human health but also green to the environment. In this paper potential safety hazards in food packaging materials and how to develop green food packaging are discussed at length.

Abstract: A rapid real-time polymerase chain reaction (PCR) based on Taqman technique has been developed for the qualitative analysis of pork in high temperature processed food. Specific primers and probe were designed to the conserved region of the mitochondrial cytochrome b gene, amplifying a 98bp fragment. Speciation was achieved using this assay, showing no cross-amplification with cattle, sheep, chicken and duck DNA while Ct (cycle threshold) of PCR for negative sample was limited to 35 cycles. This assay was sensitive to detect 1pg of pork template DNA. Meat mixtures spiked with 1-10% pork were successfully tested, which demonstrated the suitability of the assay for determination of swine-derived ingredient in food. The system is highly sensitive and specific, and will be useful for swine species identification of animal-derived processed products.

Abstract: Chestnut is one of popular dry fruit due to its rich nutrients, flavor, taste and unique antioxidant activity in the world. Blight canker symptom is one of the serious problems for Chestnut growth and preservation. At present, fungi and parasite are regarded as the dominant roles for blight canker. A kind of likely virus was observed accidentally from Chinese chestnut by electron microscope. Virus might be another reason for blight canker. Little information is available referring to virus from Chinese chestnut presently. The primary shape observed by electron microscope was introduced in this paper. The isolation, identification, and characters of this virus analogue is in progress and further investigated.

Abstract: Strawberry fruit easily suffers from fruit disease caused by fungus infection because of its great susceptibility to microbial spoilage. In present paper the fungus pathogen was isolated from infected strawberry fruits. The molecular method was used to identify the species of the fungus. The internal transcribed spacer (ITS) region was amplified by PCR with the pair of ITS universal primers after extracting the genomic DNA from the isolate. The sequence alignment results indicated that the identity was 95% between the strain F1 and the fungus(GenBank: FN667943). Then the phylogenetic tree was constructed based on the sequence of ITS region of the fungal rRNA operon. According to the sequences of ribosomal DNA-ITS and phylogenetic analysis, the fungi was preliminaryly identified as Trichocomaceae. So the pathogen isolated from the infected strawberry fruits in Tianyi strawberry ecology located in Changping district, Beijing, China is a species of Trichocomaceae.

Abstract: In resent years food safety accidents have been come thick and fast, which is a lingering nightmare for Chinese people. The food safety accidents mainly result from the food enterprises and the governmental supervision. The food enterprises shall strengthen their own food safety management and the government shall strengthen the supervision of food safety, and both the food enterprises and the government shall positively explore the long long-term mechanism for food safety.

Abstract: The effects of packaging container on quality characteristics of peanut oil were investigated in this paper. Peanut oils were stored in two containers respectively: folding Polyethylene terephthalate (PET) bottles and common PET bottles. Peroxide value (PV), tocopherol and fatty acid composition of peanut oils were determined after 9 weeks of storage. Results showed that the PV of peanut oils in folding PET containers was significantly less than that of common PET bottle during storage period. The decrease extent of unsaturated and saturated fatty acid of peanut oils in folding PET containers was less than that of common PET sample. The degradation speed of fatty acid could be restrained by folding PET container. α-, and δ-tocopherol losses of peanut oil in the folding PET container were significantly reduced.

Abstract: In this paper, two types of carboxymethyl cellulose samples (CMCe and CMCm), which served as stabilizer to improve the taste and the shelf life of milk beverage, were prepared at different bath ratio and reaction media system. The influencing factors of samples’ discrepancy structure with the ways of preparation were invested. After this, its application basic properties of the samples were searched in milk beverage. The macromolecule structure and morphologies and application performances were analyzed by NMR and SEM. The effect of molecular structures and their acid salt tolerance property of two CMC on milk beverage such as sedimentation ratio and stability of milk micelle were also investigated. The results showed that the distribution of the CH2COO- group on anhydroglucose unit (AGU) of CMCe obtained at low bath ratio in ethanol was C2> C6> C3, whereas C6＞C2＞C3 which showed the highest substitution in C6 position, was observed in CMCm prepared in mixed isopropanol and ethanol at high bath ratio. In comparison with CMCe at same viscosity, the CMCm showed higher ratio of acidity to viscosity (AVR), higher temperature resistance, lower precipitation ratio (AVR) and better stability. As shown in SEM image of treated milk powder made from milk beverager, the structure of milk protein with CMCm formed continuous network and homogeneous morphology. However the structure of milk protein with CMCe showed tendency of aggregation.

Abstract: Through sampling from production enterprise, and testing methods design, the risk of aflatoxin contamination of Camellia oleifera seed was explored. It was proved that the chance of aflatoxin contamination is very small, for mainly processing happened in wintry and spring. After 7 days, 14 and 21 days artificial inoculation, the aflatoxin B1 in the cake was 1.7, 3.6 and 9.9 μg/kg, respectively, while the quality in camellia benevolence was 2.6, 1.8 μg/kg and below the detection limit 0.2 μg/kg. The results explained that Camellia oleifera seed can be untainted by aflatoxin in hot and humid climate conditions. The study answered the question whether the Camellia oleifera seed could be contaminated by aflatoxin, which wa an unresolved problem for a long-term. Also the conclusion was a warning for the safety of storage and production of Camellia oleifera seed in high temperature seasons.