Published: 2019-08-30

Utilization of knife fish bone (Chitala chitala) as a material for fish protein and mineral powder production by enzyme hydrolysis

Thuy T. M. Le, & Truc T. Tran
Electronic version: 30 Aug 2019 | DOI: 10.52997/jad.5.04.2019
Abstract | PDF (260.1K)

Abstract

Utilization of knife fish bone as new materials to produce fish protein and mineral powder to increase the value of by-products is necessary. The objective of this study was to investigate effects of Tegalase enzyme concentration, heating time, and drying condition on the quality of hydrolyzed knife fish bone. The results showed that the sample hydrolyzed at 500C with the Tegalase enzyme concentration of 0.3% resulted in the highest peptide formation and amino acid content in protein solution (3602 peptide bonding and 16.4 g/L, respectively) as well as the highest mineral content (38.8%) in the bone sample. After hydrolysis, the sample was filtered to separate the bone and protein solution. The protein solution heated up to 90 - 1000C for 2 min showed the highest amino acid content (18.1 g/L). The moisture content, protein yield and recovery yield of the fish protein were 9.11%, 68.1%, and 2.19%, respectively when dried at 600C for 24 h. After hydrolysis, the bone was dried at the temperature of 600C for 3 h to get mineral powder with 11.4% moisture, 78.9% minerals and 21.9% calcium.

Effects of types and quantity of live food on growth performance and survival rate of cobia larvae (Rachycentron canadum)

Luong T. Lo, Nhan T. Dinh, Hoa T. B. Nguyen, Quyen T. T. Nguyen, Trang T. N. Pham, & Phu T. N. Nguyen
Electronic version: 30 Aug 2019 | DOI: 10.52997/jad.6.04.2019
Abstract | PDF (260.1K)

Abstract

The objective of the study was to evaluate effects of 3 different diets and 3 different live food stocking densities on cobia fingerling rear-ing in composite tanks system in the Ninh Thuan 1st grade Seafood Breeding Center from 6 - 25 days old. The experiment was per-formed as a 3 × 3 factorial design [live food types: 100% Copepoda (Cop), 100% Nauplius of Artemia (Art), and 50% Copepoda + 50% Artemia; live food stocking densities: 5 - 10 individuals/mL, 10 - 15 individuals/mL, and 15 - 20 individuals/mL]. Each treatment had 5 replicates.After the nursery phase, the results showed that environmental pa-rameters in all treatments were in normal ranges for cobia larvae growth. There was no difference in total length when cobia larvae were fed different feed densities (P < 0.05). The 100% Art live food and the live food density of 15 - 20 individuals/mL gave the high-est growth rate, whereas the 100% Cop live food and the live food density of 5 - 10 individuals/mL resulted in the lowest weight of larvae. There was no difference in weight gain when simultaneously changing the types and live food density (P < 0.05). The survival rate of cobia larvae was highest for the 100% Cop live food and the live food density of 15 - 20 individuals/mL and lowest for the 100% Art live food and the live food density of 5 - 10 individuals/mL. However, there was no difference in the survival rate of cobia larvae when simultaneously changing the types and live food density (P < 0.05).

Isolation and selection of microorganisms in cocoa fermentation

Phong X. Huynh, Thanh N. Nguyen, & Thuy H. T. P. Ho
Electronic version: 30 Aug 2019 | DOI: 10.52997/jad.7.04.2019
Abstract | PDF (260.1K)

Abstract

The objectives of this study were to investigate the change of microor-ganisms involved in cocoa (Theobroma cacao) fermentation and then to isolate, characterize and select the important microorganisms in cocoa fermentation. The results showed that microbial quantities continuously changed during cocoa fermentation and the highest quantity of domi-nant microorganisms at different stages of fermentation process as 8.03 log cfu/g of yeast, 6.34 log cfu/g of mold, 7.77 log cfu/g of lactic acid bacteria, 7.87 log cfu/g of acetic acid bacteria, 7.25 log cfu/g of Bacil-lus, and 10.93 log cfu/g of the total aerobic bacteria. There were nine yeast isolates belonging 5 genera of Saccharomyces, Kluyveromyces, Bret-tanomyces, Candida and Cystofilobasidium; 9 mould isolates belonging to 2 genera of Rhizopus and Aspergillus; 11 acetic acid bacteria iso-lates belonging to Acetobacter; and 13 spore-forming bacterial isolates belonging to Bacillus isolates. Three isolates of yeast (CY-1a, CY-1b, CY-2a) belonging to Kluyveromyces possessed the high fermentative ca-pacity and 4 Acetobacter isolates (CAAB-1d, CAAB-1a, CAAB-1e and CAAB-2d) produced high amounts of acetic acid.

Construction of artificial microRNA expression vectors for inhibition of Minc16281 gene in root-knot nematode Meloidogyne incognita

Phong V. Nguyen, Linh B. Tun, Loan T. N. Nguyen, & Thang B. Tran
Electronic version: 30 Aug 2019 | DOI: 10.52997/jad.8.04.2019
Abstract | PDF (260.1K)

Abstract

Effectors have been identified to play a very important role in the parasitism of plant-parasitic nematode. To cope with this type of pathogen, many approaches of silencing genes encoding for effectors have been studied and promise to be an effective tool to create plant varieties resistant to plant-parasitic nematodes. In this study, the Minc16281 gene encoding a pioneer effector with unknown function was determined and cloned from a Meloidogyne incognita population isolated from soybean field (ID: MH315945.1). The nucleotide sequence of this gene showed 97% identity to its homolog in GenBank (ID: JK287445.1) used as the control strain in our research. To generate host-induced gene silencing constructs which can potentially silence the expression of Minc16281 gene, two artificial microRNAs were syn-thesized based on the miR319 a structure of Arabidopsis thaliana and inserted into an expression vector in soybean. These microRNAs can be introduced into soybean to investigate the function of  MINC16281 on parasitism of root-knot nematode.

Chlorophyll extraction from Egyptian Luffa leaf

Cang H. Mai, Nguyen H. Nguyen, Giao T. Huynh, & y T. N. Le
Electronic version: 30 Aug 2019 | DOI: 10.52997/jad.12.04.2019
Abstract | PDF (260.1K)

Abstract

This study examined factors affecting on chlorophyll extraction from Egyptian Luffa leaf for using as food colorant. Optimal conditions for chlorophyll extraction were ethanol 96% for 97 minutes at 490C and extraction speed at 123 rpm. The quality of extracts was investigated for microorganisms, heavy metals andantioxidant activity by using the DPPH (2-2-diphenyl-1- DPPH ) method. The free radical scavenging activities of extract presented by the IC50 value was 261,7 μg/mL.

Optimization of drying the semi-dried lamb meat product (jerky)

Trinh A. Nguyen, Thao T. T. Nguyen, & Linh T. Le
Electronic version: 30 Aug 2019 | DOI: 10.52997/jad.11.04.2019
Abstract | PDF (260.1K)

Abstract

Convection drying was used to investigate the drying process of semi-dried lamb. The drying conditions were carried in combination of adding sorbitol and glycerin and salt. The results showed that the most appropriate drying conditions were at temperature of 560C, drying time of 210 min and wind speed of 0.24 m/s. The addition of sorbitol, glycerin, common salt in product was 4.37%, 1.93%, and 3.4%, respectively which were suitable for maintaining the aw of the product at 0.67 g.

Effect of coconut oil, milk powder on the viscosity and hardness of mixtures of cocoa powder and cocoa butter

Giang T. Tran, Bach T. Nguyen, & Uyen N. H. Truong
Electronic version: 30 Aug 2019 | DOI: 10.52997/jad.9.04.2019
Abstract | PDF (260.1K)

Abstract

The effects of changing in composition and adding of coconut oil and milk powder on physical states and rheological properties of cocoa powder/cocoa butter mixtures were investigated. The aim of this study is to keep the product quality at the right temperature and then consumer’s acceptance. The viscosity, hardness and the solidification temperature of cocoa powder/cocoa butter mixtures reduced when cocoa butter content increased or cocoa butter was replaced by coconut oil, or cocoa powder was replaced by milk powder. The viscosity (at 310C and 500C) significantly decreased in accordance with an increase in cocoa butter (from 40 to 50%), addition of coconut oils (from 10 to 20%) and replacement of cocoa powder by milk powder (from 5 to 10%) by weight. The cutting and breaking hardness of mixtures (at 100C and 200C) decreased sharply when the cocoa butter content was more than 50% of the mixture by weight. The solidification temperature of mixtures decreased from 240C to 200C when the coconut oil ratio increased from 20% to 40% of mixture weight.

Modification of Cellulose from water hyacinth (Eichhornia crassipes) for nanocomposite materials

Hien V. Nguyen, Thuy T. T. Lo, & Duy Q. Tran
Electronic version: 30 Aug 2019 | DOI: 10.52997/jad.4.04.2019
Abstract | PDF (260.1K)

Abstract

The effects of temperature, time, alkalinity and solid/liquid ratio on separation of lignin, hemicellulose to obtain cellulose from water hyacinth (Eichhornia crassipes) were investigated. Microcrystalline cellulose fibers were examined by microscope and infrared spectroscopy IR. The results showed that lignin and hemicellulose were removed by alkaline treatment. The obtained cellulose fibers were modified by esterification reaction with acetic anhydride in acetic acid, sulfuric acid with the aid of ultrasound. The cellulose acetate was investigated using transmission electron microscopy (TEM) and IR spectra. The synthesized nano fibers were in the diameter range of 50 - 100 nm from the TEM with even arrangement. The IR spectrum also showed that the –OH group was replaced by the –OCOCH3 group, thus, reducing the polarization and hygroscopic ability of cellulose, suitable for using as the reinforcing phase in biodegradable composite materials.

Production of sprouted garlic powder

Thanh T. Le, PHONG N. LE, Phuoc H. Le, Tri t. M. Le, & Trang T. T. Nguyen
Electronic version: 30 Aug 2019 | DOI: 10.52997/jad.10.04.2019
Abstract | PDF (260.1K)

Abstract

Sprouting garlic is considered as a high phytochemical product that ex-erts health benefit. This study aimed to develop spouting garlic powder from Phan Rang garlic. Three sprouting methods, including growing in the soil, water immersion under ambient temperature and incubating at 100C were investigated. The results showed that sprouting on the soil was the best method, characterizing sprouting garlicwith the sprouting length of 39.6 mm, total soluble solids of 17.10Bx, total acidity of 0.56%, moisture content 74.51%, and recovery rate 28.2%. The inhibitory ability against Colletotrichum gloeosporioides of fresh garlic sprouted in the soil had been evaluated. The results showed that the extract at the concen-tration of 5,5% was the most effective, indicated by completely inhibit-ing Colletotrichum gloeosporioides. To produce sprouted garlic powder, three drying methods, including heat-pump drying, air drying and freeze-drying, were examined. The freeze-drying method was the most appro-priate method to produce sprouted garlic powder with high nutritional value and the least changes of physicochemical properties. The pow-der obtained from this method showed a high inhibitory ability against Colletotrichum gloeosporioides (88% and 100% inhibition at 1.5 and 2%sprouted garlic, respectively)

Evaluation of stability and adapbility of heat-tolerant rice lines in Mekong delta

Lot V. Tran, Lang T. Nguyen, Phuoc T. Nguyen, & Buu C. Bui
Electronic version: 30 Aug 2019 | DOI: 10.52997/jad.1.04.2019
Abstract | PDF (260.1K)

Abstract

In two crop seasons of 2018, Winter-Spring and Summer-Autumn, in Long An, Can Tho, Hau Giang, An Giang and Tra Vinh provinces, an assessment of stability and adapability of heat-tolerant rice lines (HTL) was conducted. The experiment was performed as a randomized complete block design (RCBD) with 3 replicates. The quantity of fertilizers was equally applied for all treatments, including 100 kg N, 40 P2O5 and 30 kg K2O/ha. The results showed that HTL1, HTL2, HTL5, HTL7, and HTL8 were promising hybrid lines as they had short growth periods and high yields with good heat-tolerance. These rice lines were adapted well to both Winter-Spring and Summer-Autumn crops as indicated by the analysis of rice line and environment interaction.

Effects of different nitrogen fertilizer levels on yield, leave color, and content of bioactive compounds of Pouzolzia zeylanica L. Benn

Tuyen T. X. Vo, Tan D. Nguyen, & Thuy M. Nguyen
Electronic version: 30 Aug 2019 | DOI: 10.52997/jad.2.04.2019
Abstract | PDF (260.1K)

Abstract

The study was carried out to investigate the effect of 4 levels of nitrogen fertilizer (10, 15, 20 and 25 kg urea/1000 m2) applied on the color of leaves (chlorophyll index SPAD and the red-purple color by a* value in Hunter’ color system), yield and bioactive compounds content (anthocyanin, flavonoid, polyphenol and tannin) of Pouzolzia zeylanicaplant. The results showed that different nitrogen fertilizer levels had significant effects (P < = 0.05) on leave color, yield and content of bioactive compounds of this plant. At the level of 20 kg urea/1000 m2, the leaves had red-purple color and the obtained a* value was 8.06; the index of chlorophyll SPAD was 38.36; the yield was 1.64 ton/1000 m2, and the content of bioactive compounds was higher than other nitrogen fertilizer levels. The contents of anthocyanin, flavonoid, polyphenol and tannin were 0.296 mg CE/g dried material (DM), 5.03 mg QE/g DM, 15.54 mg GAE/g DM and 10.05 mg TAE/g DM, respectively.

Effects of lime and sawdust on arsenic reduction in corn planted on the inside of the dyke at Quoc Thai commune, An Phu district, An Giang province

Chinh T. Nguyen, & Chuong V. Nguyen
Electronic version: 30 Aug 2019 | DOI: 10.52997/jad.3.04.2019
Abstract | PDF (260.1K)

Abstract

Previous research has shown that soil and crops in Quoc Thai commune, An Phu district, An Giang province are severely contaminated with arsenic. The objectives of the experiment were (1) to evaluate effects of lime and sawdust on water pH and arsenic content in soil and 2) to determine effects of lime and sawdust on arsenic uptake by corn. The experiment was carried out in the field on the inside of the dyke with 4 treatments and 4 replications. The results showed that the treatment of lime combined with sawdust increased water pH and arsenic content in soil. The arsenic content in stems and leaves (95.3 mg/kg) and in seeds (6.33 mg/kg) of the maize was lower than that of the control by 31.9% and 49.4%, respectively. In brief, the use of lime in combination with sawdust to fertilize plants increased the water pH and arsenic content in the soil, while reducing the arsenic content in plants.