Published: 2018-08-21

ASSESSMENT OF REGENERATION AND Agrobacterium tumefaciens- MEDIATED TRANSFORMATION IN SOME SOYBEAN CULTIVARS

Phong V. Nguyen, Linh B. Tun, & Tú L. Phan
Electronic version: 21 Aug 2018 | DOI: hcmuaf.jsi.2018.001
Abstract | PDF (260.1K)

Abstract

Soybean [Glycine max (L.) Merr.] is a major source for food and animal feed and globally vegetable oil production. Significant efforts have been made in soybean breeding through conventional approaches but are limited by its self-pollination ability. Commercially available cultivars were used to produce transgenic soybeans. Their regenerative capacity and some relevant factors for successful genetic transformation were identified. The regeneration of the soybean cultivars was evaluated through shoot and root formation, shoots elongation, and adaption of plantlets in acclimatization period. While shoot-regeneration was well in HLDN29, DT22, DT84, and MTD176 cultivars, rooting capacity of investigated cultivars was the same. In vitro plantlets were well acclimatized under nursery conditions. Agrobacterium tumefaciens – mediated transformation showed that lipoic acid was efficient in reducing browning or necrosis of cotyledonary nodes during bacterial co-cultivation. Selective medium containing 10 mg.L-1 hygromycin was appropriate for screening of putative transformed shoots. Of the five shoots regenerated on selective media, two individuals were proved to be transformed by PCR analysis of hygromycin resistance gene (hptII).

DEVELOPMENT OF A PROCEDURE FOR PROCESSING OF AN INSTANT RED RICE PRODUCT

Thien T. Le, & Huong K. Dao
Electronic version: 21 Aug 2018 | DOI: hcmuaf.jsi.2018.003
Abstract | PDF (260.1K)

Abstract

Red rice which has not been undergone polishing contains many health-beneficial components in the bran such as vitamin B group, dietary fiber, minerals, as well as essential polyunsaturated fatty acids. Red rice is often used for people who are on diet, and want to reduce blood sugar and energy intake. Preparation red rice at home is time-consuming since it needs submersion and long-time cooking. The objective of this study is to estabilish a procedure for processing of a convenient instant red rice product to meet increasing demand of consumers. The red rice has been cooked and dried and it needs rehydration (reconstitution) before serving. Several treatments applied before and during drying of the cooked rice were compared to obtain a product characterized by (1) a short reconstitution time, and (2) acceptable sensory quality.

CHANGES OF SUPPLEMENTED ENCAPSULATED POLYPHENOLS DURING PROCESSING YOGHURT

Trang T. M. Ha, & Thien T. Le
Electronic version: 21 Aug 2018 | DOI: hcmuaf.jsi.2018.002
Abstract | PDF (260.1K)

Abstract

Polyphenols (PP) are natural antioxidants in plant materials. These components possess many health beneficial properties. In this study, a polyphenolic extract from mango kernel was encapsulated using coacervation method. The capsules were then added to yogurt making. The changes of PP during pasteurization, fermentation, and storage of the yogurt were evaluated. The results of the study showed that the pasteurization stage caused the highest reduction in concentrations of PP in the capsules. Concentrations of PP in the milk (not including the capsules) had a tendency of slight increase, which might indicate some release of PP from the capsules. Total PP (in the capsule and in the milk) reduced significantly after pasteurization. Pasteurization at 85oC (reduced about 35 % of PP in the capsules) was better than at 90oC in preservation of PP. Fermentation to reach pH of 4.6 at 43oC reduced further 20% of PP, whereas, at 37oC it reduced about 5%. Storage of the yogurt for a month did not significantly reduce PPs both at chilling as well as freezing condition. It was observed that the sensitive polyphenol species had been destroyed during previous pasteurization and fermentation. Sensorial evaluation did not find significant difference in scores of PP supplemented yogurt and control yogurt. In conclusion, supplement of encapsulated PP may give some good image for yogurt, however, these components are destroyed significantly during processing, especially during the heat treatment.

The awareness and willingness to pay of consumers for imported fruits with food safety certification

Quy D. Mai, Tung T. Dang, & Phuong M. Dang
Electronic version: 21 Aug 2018 | DOI: hcmuaf.jsi.2018.004
Abstract | PDF (260.1K)

Abstract

This study investigates the awareness and the willingness to pay of consumers for imported fruits with food safety certification on pesticide residues and hazardous preservatives through the survey of 407 consumers that were randomly selected in HCM City. Results from the survey revealed that the consumers are very concerned about the current situation of the unsafe fruit markets. They are also not satisfied with their own safety measures when consuming fruits. Estimates from the double-bounded Contingent Valuation Method (CVM) showed that on the average, the consumers are willing to pay an additional amount of 28.25 thousand VND/kg for imported fruits guaranteed with food safety. This relatively high level of WTP indicates that food safety policy for imported fruits can be implemented in practice with the financial fund obtained from the price differences between imported fruits with and without food safety guarantee.

RISK ASSESSMENT OF PESTICIDE BY ENVIRONMENTAL IMPACT QUOTIENT IN RICE CROP CULTIVATION AT THOAI SON DISTRICT, AN GIANG PROVINCE

Tuan Q. Le, & Diem T. B. Pham
Electronic version: 21 Aug 2018 | DOI: hcmuaf.jsi.2018.006
Abstract | PDF (260.1K)

Abstract

Environmental Impact Quotient (EIQ) is used to measure and access the risk of pesticide. Research was conducted in three communes Phu Hoa, Phu Thuan, and Vinh Khanh, Thoai Son district, An Giang province. The surveying and analyzing results indicated that EIQs have been at high level which was possible to affect on human health and environment. Pesticide kinds, amounts and times, as well as farmer’s habit induced the EIQ resulting in high risk in agricultural production activities. Relying to EIQ for pesticide, we can access the environmental problem and risk levels derived from pesticide. As a result, there are timely warnings sent to farmers who quickly reduce and control pesticide utilization for sustainable development in agriculture.

THE EFFECT OF CLIMATE CHANGE ON RUNOFF AND SEDIMENT IN SREPOK WATERSHED - CENTRAL HIGHLAND OF VIETNAM

Quyen T. N. Nguyen, , Long T. Bui, Loi K. Nguyen, & Liem D. Nguyen
Electronic version: 21 Aug 2018 | DOI: hcmuaf.jsi.2018.005
Abstract | PDF (260.1K)

Abstract

According to the IPCC’s fourth report, Vietnam is one of the five countries most affected by climate change. The aims of the study were to assess the impact of climate change on water and soil resources in Srepok watershed by using SWAT model based on three climate change scenarios that have been downscaling from the IPCC CMIP5 program. The results show that climate change scenarios strongly affect the flow at Giang Son station with efficiently effect on season changes in RCP 2.6 scenario, significantly effect ondry season, lightly increase runoff from January to August and decrease from September to November in RCP 8.5 scenario. The remaining three stations showed that, dry flow decrease and flood flow increas in RCP 2.6 and RCP 8.5 scenarios, RCP 4.5 scenario shows a prolonged runoff decline in May and Jun make the dry season tend to be longer in the watershed. For sedimentation, climate change scenarios showed an upward trend in rainy season and decrease in dry months, especially in the lowest months of the year (March and April) in low and high scenarios. The average scenario, the rule is similar in the rainy season but differenttrend in the dry season when the downtrend occurs onNovember, December and May next year.

THE EFFECTS OF NUTRIENT SOLUTIONS AND SHADING METHODS ON GROWTH AND YIELD OF WATER DROPWORT (Oenanthe javanica (Blume) DC.) IN HYDROPONIC SYSTEM

Tam T. M. Pham, Hoang T. Nguyen, Trang T. N. Nguyen, & Thuan T. Q. Nguyen
Electronic version: 21 Aug 2018 | DOI: hcmuaf.jvn.2018.001
Abstract | PDF (260.1K)

Abstract

Water dropwort, an aquatic plant grown and used widely in Vietnam, is mainly grown deeply in the water. Suitable liquid nutrient solutions and shading measures are influential factors to the growth, productivity and quality of water dropwort. A two factorialexperiment was arranged in complete randomized design (CRD) with three replications. Factor A was four nutrient solutions (Faulkner, Watercress, Hoagland and Arnon, andNPK (20-20-15) 2‰) and factor B was shading method (shading with one black net, reducing 70% sunshine (20,595 Lux - 25,365 Lux) and with two black nets, reducing 85% sunshine (10,396 Lux - 12,542 Lux). The research results showed that different nutrient solutions and shading methods were significantly influenced to the growth and quality of hydroponic water dropwort. Water dropwort planted in watercress nutritious solution combined reducing 70% sunshine resulted in the hight plant height (51.8cm), high number of leaves/plant (4.6 leaves), and high plant weight (5.7 g). As a result high commercial yield of weter dropwort (2,409 kg/1,000 m2) and the highest water dropwort dry matter content (13.2%) were obtained from this treatment. Water dropwort grown in watercress nutritious solution and shading of 70% produceed stem stiffness (2.4 N.cm-2),the stem brightness (L=55,3) and nitrate content (1,301 mg.kg-1fresh matter). Water dropwort grown in Faulkner solution, Watercress-growing nutrient solution, and Hoagland and Arnon solution in poly-greenhouse gave similar plant weight and yield.