OPTIMIZATIONOFENZYMATIC HYDROLYSIS PROCESS FROM SHRIMP BY-PRODUCT FOR SHRIMP SAUCE PRODUCTION

Shrimp by-product from shrimp processing industry adapted to food safety was hydrolyzed by alcalase and flavourzyme and optimized by response surface methodology. Shrimp by- product was grounded and treated with fixed alcalase 0.2% (4.8AU/kg protein) andflavourzyme loadings (0.1-0.4%), pH (6.0-9.0), temperature (45-650C) and hydrolysis time (5-13h) in order to improve hydrolysis process in shrimp sauce production. At optimal conditions of pH of 7.5, temperature of 590C,flavourzymeloadings of 0.4% (100LAPU/g protein), alcalaseof 0.2%, and hydrolysis time of 8.2h, hydrolysis degree was 36.76% compared to control sample (hydrolysis by HCl 6N at 1000C for 24h). Shrimp hydrolysis solution was mixed with 25% of NaCl before fermentation. After 10 days of fermentation, shrimp sauce had total nitrogen of 13.2g/l, amino nitrogen of 9.625 g/l, NH3 of 2.13g/l. These properties and sensory quality were equivalent to control sample(2.5 months of fermentation by traditional process).

THE CHANGES OF PROTEIN STRUCTURE IN TILAPIA SURIMI DURING GELATION BY RAMAN SPECTROSCOPY

Structural changes, textural properties in Tilapia surimi myofibrillar protein during gelation were studied by Raman spectroscopy. The change in the amide I (1600-1700 cm-1) region indicated that the decrease in a-helices content accompanied by increase in ß-sheet and random coil after heating. The conformation of S-S bond was observed in the Raman spectrum near 500-600 cm-1 in the samples of 30-40 oC incubation temperature which produce textural profile with high gel strength. Intensity of the band near 758 cm-1 as well as a slight decrease in I853/I826 ratio when the heat increase 60-70 oC showed that the hydrophobic interaction was involved in the heat-induced gelation of surimi protein.

The Right to Education for Ethnic Minority Women and Girls in Vietnam

The right to education is a fundamental human right that has been widely recognized by the United Nations and in core international human rights instruments.  Over the years as an active and responsible member of the international community, Vietnam has always worked on amending its laws to fulfill international commitments that would create an equal legal environment for the enjoyment of fundamental rights, including the right to access education. However, given their unique characteristics, ethnic minority women and girls still face discrimination and dual inequalities in their living environment, including those arising from both their ethnicity and gender. Difficulties in accessing education have led to a low percentage of ethnic minority women working in professional and technical jobs; most do simple jobs with low incomes. Barriers to education or employment generally arise due to gender stereotypes and male chauvinism. With this in mind, this article will focus on the following matters to address and resolve issues related to the right to education for ethnic minority women and girls in Vietnam: (i) an analysis of the international legal framework and Vietnam’s law on topics of gender equality in education for ethnic minority women and girls; (ii) a discussion on the reality of adopting rights to education for ethnic minority women and girls in Vietnam; (iii) identification of barriers and challenges that ethnic minority women and girls face when pursuing their educational rights; and (iv) recommendations for Vietnam to ensure the right to education for ethnic minority women and girls in the future.   Keywords: Human rights, minority’s rights, the right to education, gender equality, women’s rights

The Factors of Consumer Intension of Using Mobile Payment in Vietnam

Purpose: Within the context of emerging mobile technologies, Mobile payment or M-payment has been introduced as the new trend for payment methods bringing more value and convenience to consumers. However, the development of M-payment services is still quite timid in some Southeast Asia countries including Vietnam. This is also the reason and motivation for the author to do this research.   Theoretical framework: The goal of this study is to spot some factors that affect the use behavior (UB) of M-payment consumers in five major metropolises that were most influential on the economy in Vietnam.   Design/methodology/approach: A quantitative questionnaire was used to measure the responses of participants and Partial Least Squares (PLS) method was employed to analyze the collection data as well as test all hypotheses.   Findings: The results indicated that SI has been the important factor leading to the BI to use M-payment followed by SV and SC issues and BI also had a strong influence on the UB of consumers. Since M-payment is still in the infancy stage and is one of the most exciting mobile applications for the next few years in Vietnam, the identification of important factors concerning M-payments.   Research, Practical & Social Implications: To investigate the factors affecting UB of Vietnamese M-payment consumers, the researcher proposed a research model which analyzes the impact of various variables extracted from system quality (ST), service quality (SV), security (SC), social influence (SI) on behavioral intention (BI) to use and BI on M-payment UB.   Originality/value: This study will assist merchants and software developers to design and improve the systems and services to ensure the full acceptance and continuous use of the systems. Finally, a set of suggestions for the subsequent research works also was listed at the end of this study

Antibacterial activity of Piper betle extracts on Helicobacter pylori and identification of potential compounds

Helicobacter pylori is one of the most common infectious bacteria in the world that causes gastric diseases leading to cancer. The increase of multiple antibiotic resistance rates of H. pylori have been reported worldwide. Thus, development of novel drugs is urgently required. Piper betle has many therapeutic values in traditional medicine. In this study, therefore, we investigated antibacterial activity of P. betle extracts and their fractions against a H. pylori strain isolated in Vietnam. The agar disk diffusion assay showed inhibition zone of ethyl acetate extract and methanol extract from P. betle leaf that of were 46 mm and 32 mm in diameter, respectively. After fractionation of the ethyl acetate extract through silica gel column chromatography, two peaks, PD2 and PD3, out of 12 fractions showed the strongest antibacterial activity. PD2 was sub-fractionated further by re-chromatography on the silica gel column, and subfraction TK12 gave best resolution on LC-MS analysis. Finally, 4 potential compounds, quercetrin, calodenin B, vitexin and plicatipyrone, were identified in TK12 fraction.

IDENTIFICATION AND CHARACTERIZATION OF A PURPLE NONSULFUR BACTERIUM ISOLATED FROM COASTAL AREA OF HAI PHONG FOR USING IN PRODUCTION OF UNSATURATED FATTY ACID (OMEGA 6, 7, 9)

Purple nonsulfur bacteria are a group that has so much biotechnological applications, particularly in producing of functional food rich with unsaturated fatty acids. A purple nonsulfur bacterium (named HPB.6) was chosen based on its strong growth, high lipid and synthesis of unsaturated fatty acid (omega 6,7,9). Studying on basic biological characteristics showed that the cells of HPB.6 were observed as ovoid-rod shape, none motility, Gram negative staining. The diameter of single bacterium was about 0.8-1.0 µm. The cells divide by binary fission and had bacteriochlorophyll a (Bchl a). This bacterium grew well on medium with carbon and nitrogen sources such as acetate, succinate, pyruvate, butyrate, glutamate, arginine, leucine, tyrosine, alanine, methionine, threonine, glutamine, yeast extract and NH4Cl. This selected strain grew well on medium with salt concentrations from 1.5 - 6.0% (optimum 3%), pH from 5.0 to 8.0 (optimum at pH 6.5) and could withstand Na2S at 4.0 - 5.2 mM. Based on morphological, physiological properties and 16S rRNA analysis received demonstrated that HPB.6 strain belongs to the species Rhodovulum sulfidophilum

NUTRIENT RECOVERY AND POLLUTANT REMOVAL FROM PIGGERY WASTEWATER BY SPIRULINA CULTIVATION

Spirulina is noticed for great applications on food supplements, animal feeds, pharmaceutical, cosmetics, biofuel, fertilizer, etc. Spirulina cultures in wastewaters could enhance the feasibility of commodities due to its ability to reduce the cost of biomass production and remove pollutants in wastewaters. This study investigates the effects of wastewater pretreatment using various aeration periods (i.e. from 3 to 7 days), the supplement of bicarbonate and N:P ratios on the growth of Spirulina sp. HH to produce protein-rich biomass. The work showed that Spirulina sp. had the ability to effectively remove ammonium, with the highest efficiencies up to 99.9 %. However, the high concentration of ammonium in wastewater, from 125 mg N/L upward, caused a decline in the growth rate of Spirulina. The growth and remediation potential of Spirulina sp. were in the best condition with the N:P ratio of the medium in the range of 19:1-22:1. This study suggested a procedure to cultivate Spirulina sp. in piggery wastewater and remove pollutants efficiently

Effects of imidacloprid and fenobucarb on the dynamics of the psyllid Diaphorina citri Kuwayama and on the incidence of Candidatus Liberibacter asiaticus

Introduction. The effects of imidacloprid and fenobucarb insecticides on the dynamics of the psyllid Diaphorina citri and on the incidence of Candidatus Liberibacter asiaticus ( Ca. L. a.), the putative causal agent of Huanglongbing disease (HLB), were studied in a field experiment. Materials and methods. The experimental design consisted of three independent 0.5-ha Citrus orchards planted with disease-free HLB-susceptible orange trees, located in a Citrus producing area seriously affected by HLB. Imidacloprid was applied monthly to the trunks in one orchard at a rate of 0.15 g a.i.·tree –1 ; fenobucarb was sprayed fortnightly in a second orchard at a rate of 250 g a.i.·ha –1. The 3rd orchard was managed as a control without insecticide applications. The total number of adult D. citri specimens and the percentages of trees harbouring psyllid eggs and 5th instar nymphs were monitored at fortnightly intervals in each orchard. Ca. L. a. incidence was assessed in each orchard by PCR at 5 months, 12 months and 24 months after planting. Results. Compared with the control, both the fenobucarb and imidacloprid treatments reduced adult psyllid populations by over 90% and reduced the frequency of trees harbouring eggs and 5th instar nymphs. Only imidacloprid treatments totally prevented development of a new generation of adults from eggs. Two years after planting, the prevalence of Ca. L. a. was 0.939, 0.745 and 0.239 in the control and in the orchards treated with fenobucarb and imidacloprid, respectively. Discussion and conclusion. The results indicated that, although both the insecticides used effectively reduced D.citri populations by killing adults and nymphs and by affecting or preventing psyllid reproduction in orchards, neither of the two insecticide treatments totally prevented transmission of Ca. L. asiaticus. However, due to its long-lasting effect and systemic activity, the imidacloprid treatment provided the best protection against infections, and delayed and slowed down the spread of the pathogen. Furthermore, it reduced the number of pesticide applications needed and left the way open for biological integrated pest management programmes. (Résumé d'auteur

Dry Eyes Status on Des Scale and Related Factors in Outpatients at Vietnam National Institute of Ophthalmology

BACKGROUND: Dry eye (DE) can effect on quality of life by pain, inability to perform certain activities that require prolonged attention (driving, reading,…) and productivity at work and finally effect to Q0L associated with DE. OSDI is scale questionnaire is created team to measure the quality of life related to ocular surface disease. AIM: To describe the dry eye disease according to OSDI scale and related factors of this disease. METHODS: A cross-sectional descriptive study was carried out on outpatients (≥ 16-year-old) who were examined and diagnosed with dry eyes at Vietnam National Institute Of Ophthalmology from April to July 2018. Data was collected using the OSDI questionnaire. RESULTS: The average age of participants was 44.6 years; 80.9% of patients were female; 39.9% were identified having mild dry eye. The related factors have been identified that associated with severe dry eye, including age OR = 1.03 (95%CI: 1.01-1.05, p = 0.005), binocular good vision OR = 0.11 (95%CI: 0.05-0.23; p < 0.0001), medical history OR = 17.09 (95%CI: 2.24-130.25; p < 0.0001), chronic conjunctivitis OR = 0.36 (95%CI: 0.14-0.91; p = 0.027), refractive errors OR = 0.14 (95%CI: 0.04-0.48; p < 0.0001), Sjogren's syndrome OR = 31.13 (95%CI: 7.08-136.76; p < 0.0001). CONCLUSION: Several related factors have been identified associated with severe dry eye, including: age, binocular good vision, medical history, chronic conjunctivitis, refractive errors, Sjogren's syndrome

Morphology and DNA marker for distinguishing Paphiopedilum hangianum and Paphiopedilum emersonii from Vietnam

Genus Paphiopedilum has species having lovely flowers which are incredibly attractive to everyone. Their ornamental and commercial value caused over-collection and illegal poaching and trade. Due to these reasons, nowadays, the Venus slipper orchids are facing to deplete in nature. Therefore, it is important to consider these species conservation. Mainly, it is necessary to prioritize the identification and phylogenetic analysis methods of the genus Paphiopedilum which includes many species with similar morphological characteristics. Consequently, it isn't easy to distinguish the identical species of this genus when the plants are young or not yet fully flowering. Therefore, this study aimed to distinguish two Paphiopedilum species, i.e. P. hangianum and P. emersonii, which have similar morphological characteristics, through comparative morphological analysis and differences in DNA barcoding sequences. To solve the problem associated with species identifications, a morphological comparison table was created with the four DNA sequence markers matK, rbcL, rpoC1 and trnH-psbA. The results of the morphological analysis showed that P. hangianum and P. emersonii are significantly different from each other in the flower's characteristics. While the difference in leaf morphology of both selected species is found very little, it is also distinguishable upon careful comparison. Moreover, the DNA barcoding indicator gave accurate and rapid distinctions between the two species, even when     the plants are young or without flowers. Furthermore, this DNA barcoding can establish an evolutionary relationship between the two selected species and the other species of the genus Paphiopedilum. The results of this study also suggested that the indicator trnH-psbA is a suitable marker for distinguishing these two species and can be applied for the phylogenetic analysis of the genus Paphiopedilum in Vietnam