The concept of the “omega3 (n-3) index” is proposed by Harris and von Schacky［1］ in 2004, which is by measuring red cell membrane eicosapentaenoic acid (EPA; C20:5n-3) and docosahexaenoic acid (DHA; C22:6n-3) content (% of total fatty acids), as a biomarker to reflect the customary dietary n-3 polyunsaturated fatty acid (PUFA) intake. Omega3 index is a risk factor of sudden cardiac death［2］, which is similar with low density lipoprotein cholesterol, a risk factor for coronary artery disease. Omega3 index is significantly negatively correlated with coronary heart disease mortality, and it has a strong cardioprotective effect. Coronary heart disease mortality will be reduced by more than half when the n-3 index is greater than or equal to 8%, however, cardioprotective effect will be least when the n-3 index is less than or equal to 4%［1］. It is generally considered that arterial thrombosis was converted from stable acute ischemic heart and brain lesions. Among the clinical manifestations of unstable angina, the acute thrombotic infarction, sudden death and diseases of the cardiovascular system, the arterial thrombosis plays the protagonist role. The platelet aggregation is the initial stage of the thrombus formation［3］. EPA and DHA protective effect on the cardiovascular system is by the following mechanisms: The platelet aggregation is initiated by thromboxane A2 (TXA2), which is a powerful platelet aggregation factor and vasoconstrictor, and is generated by the platelet membrane from the arachidonic acid (AA)［3］. Increased dietary intake of n-3 PUFA, especially EPA and DHA, will increase the tissue membrane concentration of EPA and DHA. Released EPA from the platelet membrane phospholipids competitive binding of the cyclooxygenase (COX) with AA, thereby generating an alternative form of thromboxane A3 (TXA3), it is relatively nonplatelet aggregation and vasoconstriction activity, so it leads to a reduced formation of TXA2. Thereby results in the formation of thrombotic tendency. Meanwhile, it produces 3series prostaglandins and prostacyclin and 5series leukotriene (LT) and lipoxins (lipoxin)［4］, which have antiinflammatory, antiplatelet aggregation and smooth muscle relaxation activity. Marine oil is rich in EPA and DHA with a beneficial effect on the secondary prevention of myocardial infarction. In addition, EPA and DHA may prevent fatal arrhythmias, increase heart rate changes, reduce the level of serum triacylglycerol (TAG), lower systolic and diastolic blood pressure, regulate the flow of ions in myocardial cells, inhibit inflammatory cytokine production and activity［5］, and reduce plasma homocysteine concentration［6］. EPA and DHA may regulate the expression of many genes, for example, EPA and DHA can downregulate protein glycans decomposing enzyme (aggrecanases) proinflammatory cytokines (interleukin1α and TNFα), COX2 fatty acid synthase, acetyl coenzyme A carboxylase, methionine adenosyltransferase, S14 protein and stearyl coenzyme A desaturase, and they can upregulate the lipoprotein lipase fatty acidbinding protein, acetyl coenzyme A synthetase, carnitine palmitoyl transferase enzyme 1, acetyl coenzyme A dehydrogenase, acetyl coenzyme A oxidase, cytochrome P450 4A2, peroxisome proliferatoractivated receptor α［5］ and cystathionineglyase［7］. In most biological membranes, the major component of the phospholipid is fatty acid, in which the long chain n-3 and n-6 PUFAs have an important role in maintaining the structure of the cell membrane and function. In the retina and the brain of humans and other mammals, there is a high content of DHA, which plays an important role in order (fluidity) of the membrane, the activity of the membrane enzymes, ion channels, and the conduction of information. DHA is an indispensable substance of maintaining visual and brain functions because of its cell membrane fluidity. It has an important role in membrane fluidity, thereby affecting the function of the membra

Crocodile is covered in treasure. Its leather has a high reputation in the world, and its armour contains a lot of bone collagen, protein, calcium, phosphorus and so on, and its gallbladder contains more than 20 kinds of bile acids and bilichols, which has a great medicine value. Its blood with antibacterial and antitumor activity is getting the attention of researchers both at home and abroad. There has been growing interest in commercial marketing of the crocodiles meat for human consumption in China, Thailand, America and Australia, which are all artificially breeding Siam alligator, Estuarine crocodile and Nile crocodile etc. Siam alligator is also called Siam freshwater crocodile, Singapore small crocodile, and is commonly known as Thai crocodile. It is getting more and more attention in China. With the increased amount of breeding, the deep processing for the meat of Siam alligator will be the focus of future research. Hence, our objectives were to identify the volatile components of Siam alligator muscle and evaluate its nutritional value. Odors in the muscle of Siam alligator were collected and determined by solid phase microextraction (SPME) and gas chromatographymass spectrometry (GCMS) before and after deodorization, and the nutritional components in the muscle of Siam alligator were analyzed by common methods. The result showed that there were 72 kinds of volatile compounds detected, in which hexaldehyde was the main component of the odors, along with others constituted the peculiar smell of Siam alligator meat. The contents of moisture, protein, fat and ash in Siam alligator meat were 76.8%, 19.8%, 2.0% and 1.0% respectively. Sixteen types of amino acids in muscle were contained with accounting for 70.44% of the muscle dry matter content and including seven essential ones for human being. The constitutional rate of the essential amino acids was in accordance with the FAO (Food and Agriculture Organization) standard. According to the nutrition evaluation in amino acid score (AAS) and chemical score (CS)，the essential amino acid index (EAAI) was 60.63%. The muscle also contained a variety amount of unsaturated fatty acids, in which the contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were 1.44% and 2.96%, respectively. The Siam alligator meat also contained rich minerals and trace elements, especially the most calcium content. Consequently, the meat of Siam alligator is a kind of highquality one with high protein and low fat, rich in a variety of unsaturated fatty acids and minerals.

Squid (Dosidicus gigas) has become one of important aquatic protein resources nowadays because of its appetizing, nourishing quality, low price as well as large fishing amount. However, because of its high insoluble myostromin (11.0%) and connective tissue with longitudinal, radial and circular orientations in squid muscle, its meat was sensitive to heat processing which made the traditional squid product taste tough and hard, as a result hindering greatly the edibility of old people and infant. Until now, the methods of activating endogenous protease or adding exogenous enzymes were usually used for improving the quality of squid meat, while the enzymic method would damage its appearance and was harmful for maintaining the quality. Ultrahigh pressure technology is one kind of physical technology with high efficiency. Previous studies had found that ultrahigh pressure technology could improve the quality of meat. This study aims to evaluate the quality of squid meat processed by ultrahigh pressure based on fuzzy mathematic method and to find out the optimal ultrahigh pressure processing conditions. Based on weight analysis of sensory evaluation about the color, texture, flavor and taste of treated squid slice by ultrahigh pressure processing, a sensory rating system was established. An overall rating by fuzzy mathematics comprehensive evaluation method was also made on the pressure, the processing time, and the temperature of ultrahigh pressure. At the same time, the texture and color of squid slice treated by ultrahigh pressure were also investigated to verify the feasibility and accuracy of fuzzy mathematics comprehensive evaluation method. The results showed that the quality weight collection of squid slice was K=(color 0.25, texture 0.15, flavor 0.35, taste 0.25), and the sensory quality appeared to be the best when the squid slice was treated by 300 MPa at 25 ℃ for 10 min by fuzzy mathematics comprehensive evaluation method. Meanwhile, the texture and whiteness of treated sample by instrument measurement were influenced in descending order as follows: pressure > temperature > time, and the optimal condition was 300 MPa at 25 ℃ for 10 min, which was correspondence with the result of fuzzy mathematics sensory evaluation. Under this optimal condition, the squid meat was with the best elasticity, the lowest shear force, and the optimal sensory quality. It is concluded that the ultrahigh pressure treatment can improve the quality of squid meat, and it is further confirmed the feasibility and accuracy of the fuzzy mathematics sensory evaluation and instrumental analysis.

Obesity and disorder of lipid metabolism, also called dyslipidemia, have been one of the most important diseases threating people health worldwide, and is closely connected with hypertension, high serum glucose and other cardiaccerebral vascular diseases. The high fat diet is the main pathogenic cause of obesity and dyslipidemia, how to regulate blood lipid and control body mass effectively has been hotspots on nutriology research nowadays. Agents from natural products that inhibit fat digestion and absorption are of theoretical benefit in the treatment of obesity and dyslipidemia. Among them, lotus (Nelumbo nucifera) leaf is a kind of natural plant material used both in food and medicine, which contains multiple useful components. In modern research, scientists found that alkaloids were one of the main bioactive ingredients in them, helping lowing the serum lipid level and controlling body mass. Thus, this study aims to investigate the effect of lotus leaf total alkaloids on the body mass and lipid regulation in in vivo and in vitro experiments, and to find a new potential food additive to prevent effectively obesity from abnormal fat accumulation. Lipidlowering efficacy in vivo of lotus leaf total alkaloids was determined by animal experiment. After adapting to the feeding environment for 10 days, 30 experimental rats were randomly divided into six experimental groups according to their serumlipid level and body mass, including general diet group (blank group), high fat diet with lotus leaf total alkaloid (high, moderate, low doses) groups, positive drug control group and high fat diet group (model group). Except for the general diet group feeding normal diet, the other five groups were fed high fat diet for 40 d to set up the model of hyperlipidemia rats. Then, the contents of TC (total cholesterol), TG (triglyceride), LDLC (low density lipoproteincholesterol), HDLC (high density lipoproteincholesterol), the levels of AST (aspartate aminotransferase) and ALT (alanine aminotransferase) in serum were assayed in hyperlipidemia rats which had been fed lotus leaf total alkaloids of 20, 40, 80 mg/(kg·d) and positive drug of 10 mg/(kg·d) simvastatin for another 40 days, respectively. In addition, the body mass and liver mass, body length, tail length were measured. Lipidlowering efficacy in vitro of lotus leaf total alkaloids was determined by measuring the inhibitory activity against pancrelipase by monitoring the hydrolysis of pNPb, which released the yellow chromogen pnitrophenol, and the buffer solution was adjusted to the condition of 37 ℃, pH=7.4. The results showed that, compared with high fat diet group (model group), the body mass decreased significantly in the high fat diet with lotus leaf total alkaloid (high, moderate, low doses) groups, as well as the Lee’s index, liver and spleen mass of rats; moreover, the contents of TC, TG, LDLC, the levels of AST and ALT in serum and atherosclerosis index (AI) were significantly decreased and the ratios of HDLC/TC and apoAI/apoB increased in the hyperlipidemia rat fed with lotus leaf total alkaloids. The maximum inhibitory rate of lotus leaf total alkaloids of 600 μg/mL against pancrelipase activity was 25.6%. Based on the LinweaverBurk plots, the lipase inhibitor demonstrated noncompetitive inhibition for pancrelipase. It is concluded that the lotus leaf total alkaloids are effective in significant reduction of body mass, body fat and obesityrelated body indicators, and can inhibit lipase activity. Also, it is sure that the alkaloids from lotus leaves have potential to prevent effectively obesity from abnormal fat accumulation.

The fruit shell of Camellia oleifera Abel is the byproduct in C. oleifera processing, which is greatly wasted by abandoned or burnt in actual production. In recent years, some studies indicated that the fruit shell of C. oleifera had some biological activity such as antioxidant activity, indicating that the fruit shell components can be further exploited as some food additive or taken as some raw material of industry. Insoluble dietary fiber (IDF) in the fruit shell of C. oleifera has various physiological functions against some diseases, such as diabete, cardiovascular disease, intestine cancer, constipation etc., which give it higher health care value and dual performance in economy and society. In order to turn the waste residue of C. oleifera into wealth and dietary fibercontaining functional food, IDF from the wasted part of the shell was extracted with alkali treatment, and the optimal extraction condition and physicochemical properties were studied. The results showed that: 1) After investigating the single factor influencing the extraction yield, the optimal point for each factor was as follows: 0.35 mol/L for the concentration of sodium hydroxide, 80 ℃ for extraction temperature, 2 hours for extraction duration and 1∶18 for the ratio of solid to liquid. 2) Through orthogonal experiment, the optimal extraction condition of IDF was as follows: the ratio of solid to liquid of 1∶14, sodium hydroxide of 0.35 mol/L with the reaction at 80 ℃ for 3 h. The influential order of each factor on the IDF extraction was alkali concentration > solidliquid ratio > temperature > extraction time. Under this optimal condition, the extraction yield of IDF from C. oleifera shell was 40.4% and the purity was 91.52%. 3) The water holding capacity of IDF from C. oleifera shell was 2.04 g/g and the degree of swell was 1.2 mL/g. Meanwhile, the physicochemical properties of IDF were quite stable in the normal food system with different conditions of pH, sugar, salt or preservative. In conclusion, the shell from C. oleifera contains rich dietary fiber, and the IDF is quite stable in normal food system. It is worth developing food additive products by adding IDF extraction in the future food production development.

Fatty acids are ubiquitous molecules, which are typically bounded to other compounds such as glycerol, sugar or phosphate head groups to form various derivatives. They have diverse and potent biological activities, such as antiinflammatory, antitumor, antiprotozoan, antiviral, antifungal and antibacterial activities. Although the antimicrobial activity of fatty acids and their derivatives has been well known for many years, the structural and functional features causing them to prevent microbial growth or survival are still unknown. The purpose of the present study was to find out the correlation between structural features and the antimicrobial activities. At first step, it was necessary to evaluate the efficacy of various fatty acids and their derivatives to control the growth of Escherichia coli O157:H7 and Candida albicans. The microorganisms used for screening studies were common in food (E. coil O157:H7) and clinical specimens (C. albicans) and were individually maintained through monthly transfers to the respective fresh medium (E. coil O157:H7 in trypticase soy broth at 37 ℃; C. albicans in SabouraudDextrose broth at 30 ℃) and were stored at 4 ℃. Stock cultures were inoculated and grown on respective broth for 1824 h to prepare active and working cultures. The tested samples included 10 kinds of saturated fatty acids, six different unsaturated fatty acids, nine kinds of monoacylglycerols, two types of fatty acid methyl esters, three kinds of fatty acid ethyl esters and four classes of fatty alcohols. They were dissolved in 95% ethanol, sterile Tween80 (final concentrations of ethanol and Tween80 were 1.5%, respectively) and then were filtersterilized using a 0.22 μm pore size membrane filter. Ethanol and Tween80 controls were used for each experiment to ensure that any observed inhibition was not due to them. Antibiotics were dissolved in 1.5% ethanol and tween80 used as positive controls. The respective broths which contained 0.015, 0.007 5 mol/L fatty acids and their derivatives were inoculated with approximately 1.0×1055.0×105 CFU/mL of active cultures, then they were incubated for 24 h at the optimum temperature. Samples (100 μL) were removed and immediately diluted 10fold in sterile physiological saline. The number of viable microorganisms was determined through a standard plate count technique. All the tested mediumchain fatty acids (C812) and their corresponding chain monoacylglycerols, longchain unsaturated fatty acids (>C12) showed more antimicrobial activities than fatty alcohols. Longchain fatty acids, fatty acid methyl esters and fatty acid ethyl esters had feeblish antimicrobial activity. Of the saturated fatty acids, The C13 fatty acids; as compared with their saturated counterparts, the C14:1, C16:1, C16:2 unsaturated fatty acids were more highly active, however, the linolenic acid (C18:3) was not very active. The fatty acid etherified with the alcohol and methanol showed no inhibition. The 1, 3dilaurin was less active than the fatty acid. The monoglyceride was proved to be more active. In sum, the chain length, substituent, numbers and position of double bond are the important factors influencing the antimicrobial activity of fatty acids and their derivatives.

Ganoderma lucidum as a Chinese traditional medicine has been used as a medicine and food for a very long time. Ganoderma spore oil, a sort of lipin extracted from Ganoderma spore (the reproductive organs of Ganoderma lucidum), is rich in ganodenic acid, unsaturated fatty acid, Reishi polysaccharides and so forth. The reports on immunoregulation and antioxidation of Ganoderma spore oil are few at present. Cyclophosphamide (CPA) is a common antineoplastic agent which can cause immunodepression. In order to reduce clinically immunocompromised side effects caused by CPA, the immunedeficient mouse model was established to study the immunoregulation effect of Ganoderma spore oil on immunocompromised mice. Ganoderma spore oil was given to hypoimmune model induced by injecting Kunming mice with CPA. The mice were randomly divided into nomal control group, model control group, Ganoderma spore oil group. Ganoderma spore oil group accepted 0.01 mL/g of 150 mg/kg Ganoderma spore oil for 30 d. Normal control group and model control group were given corn oil of 0.01 mL/g for 30 d. Model control group and Ganoderma spore oil group were given 40 mg/kg CPA once a day for 1, 3, 5, 17, 19, 21 d respectively, to establish immunedeficient mouse model. Nomal control group was injected subcutaneously with normal saline. The spleen and thymus index, lymphocyte transformation and delayedtype hypersensitivity (DTH), hemolysin antibody level and hemolysin content, natural killer (NK) cell activity were measured at the 30th day. The results showed that compared with normal control group, the measured parameters were low for model control group. However, the related parameters for Ganoderma spore oil group were higher than model control group and the difference was obvious (P<0.05), indicating that the Ganoderma spore oil could increase the spleen index, thymus index, lymphocyte transformation and DTH level, and improve the content of serum hemolysin in immunocompromised mice. In addition, the Ganoderma spore oil had remarkable promoting effect on immune regulation of immunocompromised mice, including cell immunity, humoral immunity and nonspecific immunity. These results indicate Ganoderma spore oil can stimulate both specific and nonspecific immune function in mice, and enhance the immunoregulation functions of the immunocompromised mice according to the Chinese Theory Evaluating Procedure and Test Method of Health Foods.

Jumi, the flower bud of Chrysanthemum indicum L., is a special tea from Shilian, Zhejiang Province, and it is famous for its unique fragrance. Jumi essential oil has numerous efficacies and applications in the field of pharmacy and cosmetic industry, therefore developing effective oil extracting method which can keep both biological activity and fragrance is of considerable significance. At present, steam distillation has been reported as essential oil extract method, but this method can not keep the unique fragrance of Jumi due to the decomposition of fragrant component at high temperature. However, the supercritical fluid of CO2 (SFECO2) is a low temperature processing technique and can fully keep the unique fragrance of Jumi, which is an efficient, nontoxic, pollutionfree, and nonresidual method to extract and separate Jumi essential oil. The objective of this paper is to evaluate the quality of Jumi essential oil extracted by SFECO2and determine its biological activity. The chemical compositions of Jumi essential oil were determined by GCMS and their inhibitory activities against Staphylococcus aureus and Escherichia coli were analyzed by filter paper tablet bacteriostatic method and minimum inhibitory concentration (MIC). The results showed that the 28 types of components with the similarity of more than 70% were identified in Jumi essential oil by GCMS analysis, which were mainly terpenes and their derivatives, and the former mainly include monoterpene and sesquiterpene, and the latter was mainly alcohols, for example, the contents of hexamethylbenzene, 2(2, 4hexadiynylidene)1,6dioxaspiro［4, 4］ nonane3ene and (2RCis)1, 2, 3, 4, 4a, 5, 6, 7octahydro.alpha., .alpha., 4a, 8tetramethyl2naphthalenemethanol were higher than 9%, respectively. Bacterial inhibition tests indicated that Jumi essential oil could inhibit the growth of S. aureus and E. coli, and its MIC was 1.6 mg/mL. It is indicated that the Jumi essential oil extracted by SFECO2 is nontoxic and pollutionfree and it offers a scientific evidence about developing Jumi essential oil with high additional value and goodquality in cosmetic and food additive.

Capsicum annuum is one of the world largest consumptive vegetables. As the biggest producer, consumer and exporter of C. annuum in the world, the development of China capsicum industry has an important influence on the development of global C. annuum industry. The C. annuum industry mostly focuses on its fruit, while C. annuum leaves, as a kind of easily wasted vegetables, which are rich in resources and nutrients, have not yet been widely developed. In order to better develop C. annuum leaves, we explore the αglucosidase inhibitory activity using 70% ethanol extracts of C. annuum leaves. The pnitrophenylαDglucopyranoside (pNPG) method was adopted to determine the inhibitory activity of C. annuum leaf extracts against αglucosidase. The results showed that the αglucosidase inhibitory activity of C. annuum leaf extracts was up to 60%, which was 10 times more than its fruit, and there were significant differences in the αglucosidase inhibitory activity among different cultivars. As to different target enzymes, C. annuum leaf extract showed different activity, for example, it could inhibit the activity of sucrase and maltase from animal, but it had no effect for microbial enzyme. The C. annuum leaf extract were validated with a strong hypoglycemic activity by animal glucose load test. In conclusion, The C. annuum leaf extract has high inhibition against αglucosidase and can be used for the development of a new type of hypoglycemic food.

In 2002, the discovery of acrylamide contaminant in heat processing foods got a worldwide attention because of its genetic and reproductive toxicities as well as mutagenic and carcinogenic properties. Therefore, it is necessary to find effective additive agents to reduce the formation of acrylamide in Maillard reaction. We investigated the effects of flavonols on the reduction of acrylamide in an equimolar asparagineglucose Maillard reaction system using potato matrix and microwave heating. To investigate the doseresponse effect, six different levels of flavonols were added into the selfprepared Maillard reaction system and different levels of acrylamide were generated and observed. Meanwhile, the correlation between the inhibitory rate of acrylamide affected by flavonols and the change of Trolox equivalent antioxidant capacity (ΔTEAC) in Maillard reaction products was also evaluated. Acrylamide levels in Maillard reaction products were determined by ultrahigh performance liquid chromatography coupled with tandem mass spectrometry (UHPLCMS/MS) and quantified with multiple reaction monitoring (MRM) mode after the pretreatment of final products. ΔTEAC values were simultaneously measured by three representative antioxidant evaluation methods, i.e. DPPH (1,1diphenyl2picrylhydrazyl), ABTS (2,2azinobis3ethylbenzothiazoline6sulfonic acid) and FRAP (ferric reducing ability of plasma). The results indicated a nonlinear relationship between addition levels of flavonols and inhibitory rate of acrylamide. The optimal addition level of all six flavonols, i.e. kaempferol, kaempferol3oglucoside, quercetin, quercetin-3oglucoside, myricetin and rutin was 1×10-9 mol/L, which exerted their maximal inhibitory effect against the generation of acrylamide. The inhibitory rate ranged from 48.9% to 69.3% when different types of flavonols were used at the optimal addition level. Taking ΔTEAC as the antioxidant measurement index, the correlation coefficients between ΔTEAC determined by three different antioxidant evaluation methods (DPPH, ABTS and FRAP) and inhibitory rate of acrylamide were 0.885 3, 0.834 2 and 0.805 3 respectively, indicating a close correlation between the inhibitory effects of flavonols against the generation of acrylamide and the antioxidant capacity in Maillard reaction products. Based on microwave heating and Maillard reaction system, this study not only describes novel experimental system for investigating the inhibitory effect of phytochemicals (e.g. flavonols) against the generation of acrylamide, but also provides substantial evidence of the correlation between the inhibitory rate of acrylamide and antioxidant capacity in Maillard reaction products.

Only a small amount of vitamin B12 is absorbed and utilized by human body. The suitable vitamin B12 levels can improve the utilization efficiency of folic acid. Excessive intake of vitamin B12 may cause allergic reactions, while vitamin B12 deficiency in infancy can lead to anemia. At present, most of the infants are not breastfeeding. Formula food supplemented with a suitable level of vitamin B12 is an important nutrient guarantee for healthy growth and development of infants. Thus, it is very necessary and important to develop a sensitive, efficient and accurate method for determination of vitamin B12. Currently, the commonly used methods for the determination of vitamin B12 in infant formula foods are microbial analysis methods. But they usually lead to get higher results than the real amounts because they do not distinguish vitamin B12 from its analogues. In addition, liquid chromatography technologies are also applied to analyze vitamin B12 in infant formulas. However, they have some disadvantages including long sample preparation time and high analysis costs. In the present study, a new method using solid phase extraction (SPE) coupled to twodimensional liquid chromatography with ultraviolet detector was developed for the quantification of vitamin B12 in infant formulas. The different forms of vitamin B12 were transformed to cyanocobalamin by reacting with potassium cyanide solutions after the dissolved samples were digested with amylase. The extracts of samples were purified through the HLB SPE cartridges before they were injected into a dual gradient pump series liquid chromatography system in large volume injection. The samples were separated and enriched in ZORBAX GF250 column (9.4 mm × 250 mm, 4 μm) with the mobile phase of 7.5% acetonitrile in water. Afterwards they were switched into Agilent ZORBAX BonusRP column to analyze in gradient elution using 0.4% triethanolamine in water (pH=6) and 75% acetonitrile in water (including 0.4% triethanolamine, pH=6) as the mobile phases. The contents of vitamin B12 in samples were determined at the wavelength of 550 nm using external standard method. The developed method showed a good linearity (R2>0.999) when the calibration curve ranged from 2 to 40 ng/mL. The limit of detection and the limit of quantitation were evaluated as the signaltonoise 3∶1 and 10∶1, and they were 1.0 and 2.5 μg/kg, respectively. The accuracy of the method was evaluated by employing the standard addition method. The spiked samples with 5.0, 10.0 and 50.0 μg/kg vitamin B12 standard (six portions for each spike level) were prepared and analyzed. The results showed that the spike recoveries were 88.0%94.8% with the relative standard deviation (RSD) of 2.54%4.87% at the three spiked levels. The sample pretreatment of the established method involved enzymic hydrolysis using amylase, in order to maximize the extraction of vitamin B12. The transformation of vitamin B12 from different forms to cyanocobalamin with the best stability ensured the accuracy of quantitation. Most of the impurities were removed by employing HLB SPE cartridges during the cleanup of sample extracts. Compared with the purification technology using immunoaffinity cartridges, the experimental costs were significantly reduced and the time of sample preparation was shortened. After the sample extracts were further purified and enriched through the first dimensional liquid chromatography by large volume injection, they were analyzed at 550 nm by the dual column switching method. The wavelength of 550 nm minimized the signal interferences from impurities and further improved the accuracy of results. In conclusion, the twodimensional liquid chromatography method with online column switching shows better sensitivity and reproducibility than the traditional liquid chromatography methods, and it is verified to be suitable for the determination of vitamin B12 in infant formulas.

Aflatoxins (AFT), whose basic structure is composed of difuran and coumarin, have 17 kinds of derivatives including B1, B2, G1, G2, M1, M2, etc. AFT M1 was firstly separated from milk. AFT M1 and AFT M2 were the derivatives of AFT B1 and AFT B2 through the animal metabolism. Especially, AFT B1 and AFT M1 have been defined as a category A and 2B carcinogen by the International Agency for Research on Cancer (IARC) from World Health Organization (WHO) in 1993, respectively. Moreover, AFT B1 and AFT M1 are regarded as strong carcinogens, the carcinogenic mechanism of which is achieved via affecting the pericellular membrane, inhibiting the synthesis of RNA and interfering the inductive style of specific enzymes. In December 2011, the General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China (AQSIQ) announced the selective examination results of 200 kinds of liquid milk products. The aflatoxin M1 in parts of milk products were over ranging the maximum residue limits (MRLs) of M1 in milk and milk products, of which the maximum superscalar were 140% exceeded. Moreover, the contents of aflatoxin M1 were found exceeded in milk powder again in July 2012. The method used now was to first heat the milk and milk products in water bath, then samples were cleanup and concentrated by immunoaffinity column after filtered or centrifuged. In this method, no clear sample solutions were obtained, when passing through the immunoaffinity column, sometimes the immunoaffinity column would be blocked, and the recovery would not in expectation. So a better method was needed for determinating the aflatoxin M1 in milk and milk products. The present study developed an improved analytical method for the fast determination of aflatoxin M1 in milk and milk products by ultraperformance liquid chromatography (UPLC) combined with large volume flow cell fluorescence detection (FLD). The milk sample was extracted by acetonitrile, and the ratio of the milk sample to acetonitrile was 1 to 2.5 in mass to volume. Then, the sample was extracted by vortex and ultrasound assisted liquidliquid extraction (ULLE), and was cleanedup and concentrated by aflatoxin M1 immunoaffinity column. The analyte was separated by UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μm), and was eluted with acetonitrilemethanol (50∶50) and pure water. The results showed that the limit of quantitation (LOQ) of aflatoxin M1 was 0.03 μg/kg, which was lower than the national criteria on determination of the minimum level of aflatoxin M1 in milk and milk products. Meanwhile, high correlation coefficient (R2>0.999) was obtained within linear range from 0.06 to 1.2 μg/kg, and reasonable recoveries (81.95%94.20%) were in different spike level. In addition, acetonitrile could effectively precipitate protein in milk during the pretreatment to obtain clear extraction which could rapidly pass through immunoaffinity column only by gravity. When using the large volume flow cell, the sensitivity was increased, which was three times than the standard flow cell. The results obtained from this method were similar to the classical method. In conclusion, this quantitative method has many advantages including simple pretreatment, rapid determination and high sensitivity, which can be applied to the determination and quantification of aflatoxin M1 in milk sample.

Sulforaphane (SFN) is an isothiocyanate (ITC) which exists as a precursor of glucosinolate (GS) in various cruciferous vegetables especially in broccoli. Sulforaphane has been regarded as a potential of anticancer agent derived from diet, mostly because of its powerful induction of phase Ⅱ enzymes, and it is also acted as an antagonist of injury factors including lipopolysaccharide (LPS) and homocysteine (HCY). The present study aims to explore whether broccoli extract, rich in sulforaphane, can protect the acute liver injury induced by ethanol in mice or not. The quantity of sulforaphane in broccoli extract was detected by high performance liquid chromatography (HPLC). Hematoxylineosin (HE) staining was used to determine the pathological changes in C57BL/6 mice model with the acute liver injury induced by ethanol. The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in serum of mice were measured using semiautomatic biochemical analyzer. The results showed that the quantity of sulforaphane in the broccoli extract was 1.26 mg/tablet. Liver masses in all sulforaphane treatment groups were obviously reduced which were presented as the sharply decreased ratio of liver mass/body mass. The seriously pathological evidence was observed in ethanol treatment group, while less changes were seen in the sulforaphane treatment groups. Sulforaphane could dramatically inhibit the activities of ALT, AST and ALP in serum of mice induced by ethanol, with more obvious suppression in the moderate (40 mg/kg) and highdose (80 mg/kg) groups, respectively. The result above indicates that the sulforaphane from broccoli extract tablets is able to protect the liver injury induced by ethanol.

Ethyl carbamate (EC) is a potential carcinogenic compound in most of fermented products. It widely exists in the fermented foods, especially alcohol beverages, such as grape wine, Japanese sake and Chinese yellow rice wine, etc. Thus, the search for effective methods to reduce EC level in final products must be carried on and considered. It has been reported that the optimal production methods for grape wine and high quality strains were capable of reducing the level of EC in grape wine product. Arginine is one of the major amino acids found in grape wine, which can be decomposed to the precursors of EC by yeast and malolactic fermentation bacteria. The degradation of arginine by lactic acid bacteria via the arginine deiminase (ADI) pathway has been reported. It involves three enzymes: ADI, ornithine transcarbamoylase (OTC) and carbamate kinase. The degradation of arginine metabolism produced ammonia, adenosine triphosphate, ornithine, carbamyl phosphate and some citrullines. Studies have shown that citrulline is a typical indicator of EC level in grape wine, and a correlation between citrulline production and ethyl carbamate formation by Lactobacillus hilgardii isolated from grape wines is reported. As generally acknowledged, urea is considered as the major precursor of EC production in grape wine fermentation which can be degraded by urease. In this study, different disposals were taken during the brewing process. The control group was designed without adding any inhibitor, whereas in the experimental groups, 0.001, 0.01, 0.2 mol/L Lornithine hydrochlorides were added, and 150, 750 U ureases per 1.5 kg solid at the eighth day were added as inhibitors, respectively. As a result, both the inhibitors acted well. The highest level of EC content in control group was 169 mg/L, while in the experimental groups with 0.01mol/L Lornithine hydrochloride and 150 U urease, the EC contents were 78.81 and 58.55 mg/L, respectively. Urea and citrulline both were the major substrates of EC production. Combining the data of EC formation and OTC activity, it can be concluded that the increase in intracellular OTC activity has an inhibition effect on EC formation in the processing of Chinese yellow rice wine. Nevertheless, the detailed regulatory mechanism still is under illustration for the processing in the future study.

Water milled Chinese New Year rice cake（NYRC） is a kind of delicious and nutritive Chinese traditional food. But the short shelf life of the NYRC restricts its industrialization development. The purpose of the study is to inhibit the growth of spoilage microorganisms effectively and to extend the shelf life of the vacuumpacked NYRC. There were four main steps: 1) the spoilage microorganisms were separated and characterized from vacuumpacked NYRC. 2) Six commonly used antibacterial agents were chosen against the spoilage microorganisms, and the minimum inhibitory concentrations (MIC) were determined. 3) The synergistic effects between glycerol monolaurate (GML) and other preservatives were measured. 4) In order to investigate application effect of chosen food preservatives, lab and factory testes were taken in NYRC product. The moisture, hardness and colour (L value) of the vacuumpacked NYRC were determined. The main results were as follows: 1) The spoilage microorganisms which led to corruption of vacuumpacked NYRC were two kinds of Bacillus. 2) Among the tested preservatives, GML had the lowest MIC which was 32 μg/mL. 3) There was synergistic effect of GML and sodium dehydroacetate, and the fractional inhibitory concentration index (FICI) was 0.531. The compound preservative made up of GML, citric acid and sodium dehydroacetate at the mass ratio of 1∶1∶1 was selected against the Bacillus. 4) Adding the selected compound preservative of 1.5g/kg could extend the shelf life from about 7 d to 20 d at 37 ℃. The compound preservative not only had no adverse effect on the moisture and color of NYRC, but also could reduce the hardness efficiently. In NYRC products, the compound preservative shows significantly better effect than the monomer GML. In addition, while prolonging the shelf life of the vacuumpacked NYRC, the compound preservative had no adverse effect on its quality.

It is well documented that the role of dietary composition in relation to the development of metabolic syndrome (MS) remains inconclusive. Several studies on the relationship between MS and energy intake have suggested that the macronutrient composition of the diet (proteins, fats, carbohydrates) may play an important contributing role to MS in adults. So, this study aims to investigate the possible relationship between MS and energy intake, percentage energy intake from macronutrients among urban populations in Ningxia, China. According to different economic levels from 2011 to 2012, 2 465 subjects (age: 1875 years) were selected using stratified cluster random sampling in Yinchuan, Wuzhong, Zhongwei, Guyuan, and Shizuishan in Ningxia, China. Dietary intake was assessed using 24h food records and a validated food frequency questionnaire. Body mass, height, waist circumference, blood pressure, triglyceride (TG), highdensity lipoprotein cholesterol (HDLC), and blood glucose were measured. Logistic regression models were adjusted for age, smoking, drinking, and physical activity factors. The results showed that there were 647 MS cases in all subjects. According to the diagnosis criteria of MS, the incidence of MS was 26.2% (men: 281 cases (25%); women: 366 cases (27.3%)), no significant difference in sex composition (P>0.05). As a way of lifestyle, there was no significant difference in smoking, drinking, exercise between MS group and control group (P>0.05); significant difference was found in tertian dietary intake of protein and fat energy percentage between MS group and control group (P<0.05). Compared with control group, body mass index, waist circumference, systolic pressure (SBP), diastolic pressure (DBP), fasting plasma glucose (FPG), cholesterol (TC), TG, and lowdensity lipoprotein cholesterol (LDLC) from MS group were significantly increased (P<0.05). After adjustment for age, gender, smoking, drinking and daily exercise levels, compared with the “normal” dietary pattern, Logistic multifactor analysis indicated that the subjects with the “high” protein energy intake to total energy intake had a higher odds ratio (OR) of high MS (OR: 1.417, 95% confidence interval (CI): 1.1241.787), and the subjects with the “high” fat energy intake to total energy intake had a higher OR of high MS (OR: 1.647, 95% CI: 1.2392.190), and the subjects with the “high” carbohydrate energy intake to total energy intake had a higher OR of high MS (OR: 1.810, 95% CI: 1.4032.330). In sum, the evidence of an association between macronutrient intake and MS is found. Obviously, the subjects with the “high” percentage of protein, fat, and carbohydrate energy intake to total energy intake excessive are the important risk factors of the MS in urban residents in Ningxia, China, so dietary intervention measures should be taken to prevent MS.

Protein adulteration and allergens are the two major food safety issues, and can pose health threats to consumers. One of the effective precautions is extensive test, which needs simple, rapid and lowcost test method. Present methods including sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDSPAGE), high performance liquid chromatography (HPLC) and liquid chromatographymass spectrometry (LCMS)/MS are not acceptable for consumers due to expensive instruments. Immunological technique is a rapid method for screening and is suitable for consumers to use. β-casein and β-conglycinin are not only the major proteins of milk and soybean, but also important food borne allergens. In this study, the monoclonal antibodies and polyclonal antibodies against β-casein and β-conglycinin were prepared and the enzymelinked immunosorbent assay (ELISA) kits were established for detecting adulteration and allergens. BALB/c mice were immunized four times with purified antigens adding adjuvant or not until the serum titer achieved 1∶1×105, and the mice spleen cells and myeloma cells SP2/0 were fused as the routine cellfusion technology. Positive cells were screened for 34 times with indirect ELISA by coating purified antigens, and were injected into mice peritoneal. The monoclonal antibodies were obtained after the purification of ascites. The polyclonal antibodies against β-casein and β-conglycinin were also prepared from rabbit serum immunized by antigens, respectively. The double antibody sandwich ELISA for β-casein and β-conglycinin were successfully established by optimized parameters. The results showed that the titers of purified monoclonal antibodies of β-casein and β-conglycinin were over 1∶1×107, and the polyclonal antibody titers of both were about 1∶2×105. The minimum detection limits of both ELISA kits were about 15 ng/mL, and no cross reaction were observed among the proteins of different species. In conclusion, the double antibody sandwich ELISA methods established for β-casein and β-conglycinin are sensitive and specific, and can afford a theoretical foundation for developing rapid, accurate and lowcost screening methods for the detection of adulteration and allergens.

Kinetics model for enzymatic hydrolysis can serve as the theoretical basis for process control, and it helps to develop efficient procedures of bioactive peptides preparation through protein hydrolysis. The enzymatic hydrolysates from eel protein were demonstrated to be effective in antioxidation and inhibition of αamylase in vitro, and could be exploited as resources of antidiabetic drugs and healthy food. So far, no data on the kinetics model for enzymatic hydrolysis of eel protein can be found. To elucidate the kinetic characteristics of enzymatic hydrolysis of eel protein, the hydrolysis of eel protein at 50 ℃, pH=7.2, with different initial concentrations of the eel protein ［S0］(0.25, 0.33, 0.50 g/mL) and different concentrations of the neutral protease ［E0］(3.33, 6.67, 10.00, 13.33 mg/mL) was preformed. The degree of hydrolysis (DH) of the eel protein was determined during a 240minute time course at varied time intervals. A kinetic model that took into account of enzyme inhibition by product or substrate was fit to the experimental data with nonlinear regression methods, and the parameters of the kinetic equation were estimated. The established kinetic equation was tested by comparing the predicted and actual DH values with paired ttest, when hydrolysis was conducted at 50 ℃, pH=7.2, and the initial concentrations of eel protein and neutral protease were 0.20 g/mL and 5.33 mg/mL, respectively. The results showed that the DH values increased rapidly within the first 30 minutes, after which the hydrolysis rate slowed down gradually. At 240 min, the DH values increased with the rise of the neutral protease concentrations, while decreased as the initial concentrations of the eel protein increased. The kinetic equation of eel protein hydrolysis was as follows: DH=1-(1+32.65［E0］/［S0］·t-0.1t)-0.061 9. The critical concentration of the neutral protease was 3.06×10-3［S0］, and the critical concentration of the eel protein was 326.50［E0］. During the 240 min hydrolysis, no significant difference was found between the actual and predicted by this kinetic equation DH values. In conclusion, both substrate inhibition and product inhibition existed during the eel protein hydrolysis catalyzed by neutral protease. There are critical concentrations for substrate and protease. The enzymatic hydrolysis will be impeded when the initial concentration of the eel protein is higher than the critical concentration, or the neutral protease concentration is lower than the critical concentration. The kinetic equation can fit the experimental data well, and can be used to predict the eel protein hydrolysis with neutral protease.

Phytosterols are natural bioactive compounds, usually including stigmasterol, sitosterol, campesterol, and rapeseed sterol. They have attracted growing attention owing to their beneficial effects. High performance liquid chromatography (HPLC) is the most frequently used method to quantify phytosterols. Although several detectors such as ELSD (evaporative light scattering detector) and UV (ultraviolet detector) are available for HPLC analysis, but UV detector is believed to be much more effective and always preferred in laboratories. In the recent literature available, the reverse phase column was mostly applied to determine phytosterols in HPLCUV system. However, the performance of normal phase column in phytosterol analysis has not been well studied and compared. In this study, the performances of both reverse phase and normal phase columns in HPLCUV system for phytosterol analysis were compared, and their respective advantages were illustrated. Both normal phase and reverse phase columns in HPLCUV were applied to detect phytosterols, respectively. The normal phase chromatographic conditions were as follows: using hypersil SiO2（4.6 mm×250 mm, 5 μm) as column and V(hexane)∶V(isopropanol)=99∶1 as mobile phase, column temperature of 35 ℃, flow rate of 1.0 mL/min, and detection wavelength of 205 nm. Reverse phase chromatographic conditions were as follows: using Merck RP18 (4.6 mm×250 mm, 5 μm) as column and pure methanol as mobile phase, column temperature of 35 ℃, flow rate of 1.0 mL/min, and detection wavelength of 205 nm. As a result, high sensitivity was observed for phytosterol detection using UV detector in both systems. It was revealed that the normal phase system could not separate individual phytosterol compounds, while the reverse phase system exhibited good separation capacity. In terms of retention time, the normal phase system needed much less time as compared with reverse one. In addition, phytosterols were much more soluble in the eluent of the normal phase system. It is concluded that the normal phase column is more suitable than reverse one for quantification of total phytosterols despite of lower separation ability. Furthermore, an efficient method for quantification of phytosterols employing the normal phase column and the benzoate internal standard is developed.