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Effects of Housing Systems on Cortisol Concentration of The Gilfs Raised in Group

Nguyen Thi Phuong Giang, Han Quang Hanh, Vu Tien Viet Dung, Pham Kim Dang, Vu Dinh Ton

Received: 14-11-2016 / Accepted: 05-01-2017
The study was conducted to determine the effects of two housing systems on cortisol concentration of gilts. A total of 20 gilts F1 (Landrace x Yorkshire) gilts with similar body weight and age were randomly allotted into four pens of two group-housing systems (two pens with outdoor yards and the other two without yards, 5 gilts per pen). Saliva cortisol concentration on the days 1, 3, 7, 15, 30, 50, and 80 and plasma cortisol concentration on the days 1, 3, 15, 30,and50 of the gilts after grouping wasere determined by ELISA test and ECLIA (Electrochemiluminescence Immunoassay) using COBAS system, respectively. Results showed that there were no significant differencesin saliva and plasma cortisol concentration of the gilts between the two housing systems (P > 0.05). However, in each housing system, saliva cortisol concentrations on the days of grouping were significantly different (P < 0.05). Cortisol concentration of the gilts in both two housing systems waserehighest on the 1stday after grouping (0.58 µg/ dL in the pens with yard and 0.59 µg/ dL in ones without yard),; they weregradually decreased on the 3rdday (0.48 µg/ dL and 0.46 µg/ dL)and; then theywaserelowest and stable on the following days. Similarly, in each housing system, plasma cortisol concentration taken in the days 1, 3, 15, 30 and 50 after grouping were wassignificantly different from each other (P < 0.05). Plasma cortisol concentration waserehighest in the 1stday after mixing (7.38 µg/ dL in the pens with outdoor yard and 7.17 µg/ dL in the indoor pens), followed by the 3rdday (5.35 µg/ dL and 5.19 µg/ dL), then they were gradually decreased and stable in the following days. A positive correlation between plasma and saliva cortisol concentration was found (withr = 0.73).
Land Accumulation and Concentration for Commodity-oriented Agricultural Development in Dak Nong Province

Nguyen Anh Duc, Nguyen Tuan Son

Received: 17-05-2021 / Accepted: 03-06-2021
The process of land accumulation and concentration has occurredin Dak Nong province. However, this process still reveals many limitations and has not met the needs of the province's commodity agriculture development.Based onassessing the current situationand analyzing factors affecting the process of land accumulation and concentration over time, thisstudyproposedsolutions to accelerate the process of land accumulation and concentration for commodity-oriented agricultural developmentin Dak Nongprovince. This study appliedthe participatory approachmethodto collect primary data, combinedboth qualitative and quantitative methodsin data analysis. Ourresults showedthat for the farm group, land accumulation took place in the form of buying and renting land from other farmers, while for the cooperatives, land concentration in the form of sharing land rights between farmers and entrepreneurs was dominant. The fluctuation of the land market and the resources of the actors involved in land accumulation and concentration were key factors influencingthe process of land accumulation and concentration.
Assessing the Situation of Agricultural Land Accumulation and Concentration in Hung Yen ProvinceDuring 2010-2021 Period

Truong Thu Loan, Nguyen Thi Hong Hanh, Ho Thi Lam Tra

Received: 02-07-2023 / Accepted: 04-08-2023
Land accumulation and concentration for development of commodity agriculture is an inevitable trend. The study aimed to assess the current situation and propose solutions to enhance accumulation and concentration of agricultural land in Hung Yen province. The methods used included secondary survey, primary survey, Likertscale and T-test. The area of Agricultural land in Hung Yen province is about 62.52% of the natural land area and tends to decrease with an average of 215,15 ha/year in 2010-2021 period. By 2021,Hung Yen province accumulated and concentrated 6.496,7 hectares of agricultural land (11.17%), with 3 main methods: (i) farm rental accounting for 48.96%, (ii) accumulated and concentrated but no change in land use rights, accounting for 32.97%; (iii) accumulated and concentrated based on the change in land use rights accounting for 19.07%. Land users assessed the accumulation and concentration of agricultural land in Hung Yen province with 2/12 criteria at a very good level and 10/12 criteria at a good level.The paper proposed solutions to increase the accumulation and concentration of agricultural land.
Land Accumulation and Concentration: Theoretical and Practical Fundamentals for Commodity Oriented Agricultural Development

Do Kim Chung

Received: 22-03-2018 / Accepted: 03-07-2018
During the last three decades,the agricultural policies, especially land policy,have been renovated and enabledimpressive development of Vietnam’sagriculture. However, agriculture sector is still unsustainable. One of the core causes of this situation is the slow process of land accumulation and concentration. This paper discusses concepts, viewpoints and modes of land accumulation and concentration. Based on the land accumulation and concentration facts during the last years, the paper proposes some recommendationstorenovate agricultural land policies for commodity oriented agricultural development.
Effect of Bioproduct of Purple Photosynthetic Bacteriaon Environmental Quality of Pond under Intensive Tilapia Farming

Do Thi Lien, Nguyen Thi Dieu Phuong, Nguyen Thi Bien Thuy, Do Thi To Uyen, Dinh Duy Khang

Received: 25-03-2014 / Accepted: 26-04-2014
The biological characteristics and classification of purple photosynthetic bacteria formulation consisting of three strains with high sulfide removal activity were studied. Of the three strains, two strains belong to species Rhodobacter sphaeroides denoted as QN71 and QN52 and the other to Rhodovulum sulfidophillum denoted as TH21. The use of purple photosynthetic bacteria formulation forclearly improved water quality of intensive tilapia farming pond environment. BOD3 concentration significantly reduced from 9.6-9.8 mg/l to 3.2-3.4 mg/l after 2.5 months, while BOD3 concentration gradually increased in the control. H2S concentration in water decreased from 0.03-0.04 mg/l down to 0 nilll and the concentration in sludge decreased from 5.4-6.67 mg/g to 3.5-4.5 mg/g. In two control ponds H2S concentration in water increased from 0.03 mg/l to 0.06 mg/l and in the sludge increased from 5.2 mg/g to 5.8 mg/g (DC1) and 6.4 mg/g (DC2). Using bioproducts of purple photosynthetic bacteria contribute to good effect to speed growth and development of intensive culture of tilapia.
Effects of Dietary Supplementation with Herbal Mixed Powder on GrowthPerformance, Gas Emission and Clostridium perfringensin Manure of Growing Pigs from 30-60kg

Vu Dinh Ton, Nguyen Thi Nga, Nguyen Van Duy, Nguyen Thi Trang, Hoang Minh Duc

Received: 25-07-2022 / Accepted: 07-03-2024
This study aimed to evaluate the effects of dietary supplementationwith herbalplants mixture on growth performance, gas emmission of NH3 and H2Sand Clostridium perfringens(C. perfingens) bacterium inmanure ofgrowingpigs from 30-60kg. Experimental pigs were divided into three groups, a control group without herbal plants mixture and two groups with two different levels of herbal plants mixture supplementation, 15 grams or 20 grams for one kg of feed. The supplementation with 15 grams and 20 grams herbalplants mixture improved the average daily gain by 11.67% and 13.45%, respectively, compared with the control.After 28 days of using feed with supplementation herbalplants mixture, the concentration of NH3emissions from pig manure in experimental group 1 (TD1)and experimental group 2 (TD2)has decreased by 51.58% and 49.47%, respectively, and the concentration of H2S in TD1 group and TD2 group has decreased by 13.92% and 51.03%, respectively, compared to the control group. The concentration of C. perfringensin the TD1groupand TD2groupdecreased by 23.17% and 27.35%, respectively, compared with the control group. The supplementationherbalplants mixture at 20 grams per kilogram of feed had better effect on reducing H2S emissions and the concentration of C.perfringensin pig manure than adding 15 grams of herbalplants mixture per kilogram of feed.
Effects of Dietary Supplementation with Herbal Mixed Powder on GrowthPerformance, Gas Emission and Clostridium perfringensin Manure of Growing Pigs from 30-60kg

Vu Dinh Ton, Nguyen Thi Nga, Nguyen Van Duy, Nguyen Thi Trang, Hoang Minh Duc

Received: 25-07-2022 / Accepted: 07-03-2024
This study aimed to evaluate the effects of dietary supplementationwith herbalplants mixture on growth performance, gas emmission of NH3 and H2Sand Clostridium perfringens(C. perfingens) bacterium inmanure ofgrowingpigs from 30-60kg. Experimental pigs were divided into three groups, a control group without herbal plants mixture and two groups with two different levels of herbal plants mixture supplementation, 15 grams or 20 grams for one kg of feed. The supplementation with 15 grams and 20 grams herbalplants mixture improved the average daily gain by 11.67% and 13.45%, respectively, compared with the control.After 28 days of using feed with supplementation herbalplants mixture, the concentration of NH3emissions from pig manure in experimental group 1 (TD1)and experimental group 2 (TD2)has decreased by 51.58% and 49.47%, respectively, and the concentration of H2S in TD1 group and TD2 group has decreased by 13.92% and 51.03%, respectively, compared to the control group. The concentration of C. perfringensin the TD1groupand TD2groupdecreased by 23.17% and 27.35%, respectively, compared with the control group. The supplementationherbalplants mixture at 20 grams per kilogram of feed had better effect on reducing H2S emissions and the concentration of C.perfringensin pig manure than adding 15 grams of herbalplants mixture per kilogram of feed.
Optimization of Culture Conditions for Biomass Production of Histamine Degrading Exiguobacterium profundumCH2.1 Strain

Nguyen Thi Hong, Pham Thi Diu, Nguyen Thi Phuong Anh, Tran Thi Thu Hang, Nguyen Thi Lam Doan, Nguyen Hoang Anh

Received: 24-10-2022 / Accepted: 27-01-2023
The aim of this study is to optimize the culture conditions of Exiguobacterium profundumCH2.1 degrading histamine in order to obtain maximum biomass. The effect of salt concentration, temperature and pH of the culture medium on the growth of E. profundumCH2.1 were determined by CFU method. The single-factor experiments showed that this strain grew well at concentration of salt from 5 to 10%; temperature 37C, and pH from 6 to 8. The JMP optimization software of Box-Behnken experimental design model indicated that temperature 36.7C, pH = 7 and 5% salt concentration appeared as optimal conditions of E. profundumCH2.1, and the cell biomass reached 7.95 log CFU/ml.After optimal condition test, the E. profundumCH2.1 had a log (CFU/ml) value of 8.01 at 3 day.
Effect of Concentration and Spray Drying Processing on the QualityofSoluble Green Tea-lotus LeafPowder

Hoang Thi Minh Nguyet, Nguyen Thi Luu, Dinh Thi Hien

Received: 12-07-2022 / Accepted: 15-08-2022
The study investigated the effect of concentration and spray drying temperature on the quality of soluble green tea-lotus leaf powder. The extract was obtained from the mixture of old tea leaves (cv PH1) and lotus leaves in a ratio of 88:12 by dry matter weight. To obtain the extract mentioned above, the mixture was soaked with water at a ratio of 1/10 at 95C for 15 minutes and stirred 3 times (1 min/time) at 90rpm. The extract was concentrated at temperatures of 50 ± 2C; 60 ± 2C; 70 ± 2Cand 80 ± 2C, and spray-dried at temperatures of 110 ± 2C; 115 ± 2C; 120 ± 2C; 125 ± 2C; 130 ± 2C. The results showed that the concentration and spray drying temperatures of 60 ± 2C and 110 ± 2C, respectively, were appropriateto obtain good sensory quality of soluble green tea-lotus leaf powder, and the products meet customers’ satisfaction. In addition, there were no microorganisms and heavy metal, indicating that the product meets hygiene and food safety quality requirements.
Effect of Salinity on Growth, Physiology andYield of Soybean[Glycine max(L.) Merr.]

Vu Ngoc Thang, Tran Anh Tuan, Le Thi Tuyet Cham, Vu Ngoc Lan, Pham Van Cuong

Received: 13-04-2018 / Accepted: 04-09-2018
Experiments were conducted to evaluate effects of salinity on germination, growth, physiology and yield of two soybean varieties DT84 and DT26. NaCl solution with 4 concentrations (0, 50, 100 and 150 mM) was used for treating soybean seeds in the germination experiment. In potted experiment, soybean plants were treated by adding different NaCl concentrations (0, 50 and 100 mM) to Hoagland solution from three weeks after germination to maturity stage. The results showed that the germination ratewas significantly reduced atNaCl concentration of 150 mMwith46.67%and 31.67% in DT84 and DT26,respectively.Increased salt concentration also decreasedroot and shoot length of seedlings, fresh weight of roots and shoots and high NaCl concentration (150 mM) significantlyinhibited seeding growth of both soybean varieties. In potted experiment, plant height, leaf area, dry matter, nodules, SPAD value, Fv/Fm ratio, yield and yield components decreased with increasing NaCl concentration, while the water saturation deficit and ion leakage increased. The individual yields of soybean under salinity stress at 50 and 100 mM NaCl reduced by 32.4% and 61.9% in DT84 variety and by 39.5% and 68.9% in DT26 variety, respectively. Evaluation of salinity susceptibility index (SSI) of two soybean varieties showed that DT84 variety was more salt tolerant than DT26 variety at both 50mM and100mM NaCl concentrations.
Antifungal Ability of Nanochitosan against Colletotrichum acutatumL2 in Post Harvest Tomato Fruit

Le Thanh Long, Nguyen Thi Nga, Nguyen Cao Cuong, Tran Ngoc Khiem, Nguyen Thi Thuy Tien

Received: 07-05-2015 / Accepted: 02-12-2015
This study examined the antifungal effect of nanochitosan on Colletotrichum acutatum L2 isolated from anthracnose infected tomato both in vitro and in vivo. The results demonstrated that nanochitosan inhibited the spore germination and the growth of C. acutatum L2. Inhibitory effect of 50% and 90% mycelial diameter and dry biomass was achieved at the nanochitosan concentration of 0.75 g/l and 1.53 g/l, 0.46 g/l and 1.1 g/l, respectively. Concentration of 1.6 g/l nanochitosan completely inhibited the growth of C. acutatum L2. In in vivo, nanochitosan could control the growth of C. acutatum L2 on tomato fruits. After 10 days, the nanochitosan concentration of 4 g/l inhibited 76% the development of lesion diameter and MIC50 was achieved at concentration of 1.14 g/l.
Bioaccumulation of Heavy Metalsin Carp (Cyprinus carpio) Cultured at Viet Nam NationalUniversity of Agriculture Fish Farm

Pham Kim Dang, Bui Thi Bich, Vu Duc Loi

Received: 24-12-2014 / Accepted: 18-04-2015
This study was conducted from January to August 2014 to evaluate the accumulation of heavy metals (Cu, Pb, Zn, Cd) in the carp cultured at the aquaculture experimental farm -Viet NamNational University of Agriculture. The accumulation of heavy metal in sediments, feed, water and in carp (muscle, liver, bowel, bearing) was determined by using atom absorption spectrometry (AAS) method. The results showed that in all samples, the highest concentration wasZn and the lowest concentration wass Cd.The average concentration of Cu, Pb, Zn, Cd in sediments, in water as lowerthan the limit specified by NTR 43: 2012/BTNMT, Standard PEL (1999) and by NTR 38: 2011/ BTNMT. For carp, metals concentrated in the liver, intestine, and gills but leastin muscle tissue. In the all of three samplings, the metal concentration in muscle, gill, intestine, liver, respectively was in the following order:Zn> Cu> Pb> Cd. In the organs of carp, the concentrationsof Cu, Zn, Pb, Cd,respectively,were in muscle (1.32 mg/kg; 30.96 mg/kg; 0.9 mg/kg; 0,01mg/kg); liver (2.36 mg/kg; 75.43 mg/kg; 0.08 mg/kg; 0.08 mg/kg); intestine(12.18 mg/kg; 137.33 mg/kg; 0.36 mg/kg; 0.03 mg/kg and in the gills (2.23 mg/kg; 140.92 mg/kg; 1.78 mg/kg; 0.09 mg/kg). Bioaccumulation factor (BSAF) of 4 metals in sediment and (BCF) in water for each the organs in the order Zn> Cu> Pb> Cd.Bioaccumulation factor (BCF) between metals in feed with the organs of carp was low (BCF <250).
Determination and Comparison of Pentosan Content from Several Cereal Grain in Vietnam

Nguyen Van Lam, Lai Thi Ngoc Ha, Nguyen Huong Thuy, Nguyen Thi Thu Hoai, Pham Thi Binh

Received: 29-05-2012 / Accepted: 28-07-2012
Pentosans are polysaccharides which exhibit both dietary fibre and prebiotic properties. Consumption of pentosan prevents the growth of colon cancer, promotes absorption of minerals and enhances immune system. In this study, the grain of 10 rice, 10 maize and 13 sorghum cultivars were selected to analyse pentosan concentration. The results showed that total and water-soluble pentosan content varied among these cereals, among these maize grains contain highest concentration. Wide variation in petosan concentration was also found within each grain group. Total and water-soluble pentosan content ranged from 0.54 to 1.65% and 0.01 to 0.02%, for rice cultivars; 0.54 to 2.33% and 0.01 to 0.03%, for sorghum cultivars; 2.81 to 4.1% and 002 to 0.1%, for maize cultivars, respectively.
Effect of Accotab on sucker controlcapacity, growth, devepopment and yield of waterpipe tobaco

Bui Thanh Tung, Hoang Minh Tan, Nguyen Dinh Vinh

Received: 19-06-2013 / Accepted: 26-08-2013
After cutting apical buds, the axilary buds The rapid emergence of suckers or axillary buds after topping significantly decreases the yield and quality of waterpipe tobaco material. The sucker removal by hand results in increased labor cost. Using Accotab for sucker control was carried out with variety Re Den in the Spring 2011 and 2012 at Tien Lang. Hai Phong.The experimentwas conducted with Accotab concentrations of 1; 1.2 and 1.5% in order to determine the most appropriate concentration for sucker control without affecting yield and quality of the products. Experimental results showed that treatment of Accotab decreased the number, length and weight of axilary buds, but increased the leaf size and productivity of waterpipe tobaco products. Accotab concentration of 1.2% was found most optimal; this concentration brought highest yield (1625 kg/ha) and highest economic efficiency (79.56 million/ha).
OPTIMIZATION OF FACTORS AFFECTING SYRUP PRODUCTION FROM "SIM" FRUIT (Rhodomyrtus tomentosa) FOR HIGH ANTHOCYANIN CONCENTRATION AND GOOD QUALITY

NguyenMinh Thuy, Nhan Minh Tri, Pham Thi Kim Quyen

Received: 11-11-2013 / Accepted: 24-02-2013
Rhodomyrtus tomentosaor Rose Myrtleis a wild plant native to Southeast Asia. Itsberry orfruit is sweet, edible and medicinallyused as a folk remedy for various diseases. The fruitcontains high concentration of anthocyanin,a natural polyphenol withpowerful antioxidantactivity. In this study, Sim fruitsharvested from Mang-Den, a highland area in Komtum, were pretreated withpectinase to maximize yield, transmittance (clarify) and anthocyanin in the filtrate. After taste adjustmentwith sugar and citric acid, the juice was pasteurized for preservation. The extraction by pectinase enzymes was optimized using response surface methodology. The results showed that the extraction condition with 0.1% pectinase at 40oC in 60 min wasoptimal for maximum yield of fruit juice (62.93%), clarity (T=38.3%) and amount of anthocyanin (68.52 mg/L). Pasteurizationwith PU858,3 = 9.18 minutes at 85oC for 4 minutes yielded syrup withgood safety and high anthocyanin concentration.
Effect of Colchicine Concentration and Duration of Treatment on Polyploidy Induction in Shallot (Allium cepaL., Aggregatum Group)

Tran Thi Minh Hang, Pham Thi Minh Phuong, Nguyen Thanh Tuan, Phan Thi Ngan

Received: 09-11-2015 / Accepted: 11-03-2016
Local shallot (Allium cepaL. ), Aggregatum group) variety grown inKinh Mon, Hai Duong was treated with colchicine in order to produce polyploid materials for high-quality shallot breeding in Viet Nam. The research was carried out at Faculty of Agronomy, Vietnam National University of Agriculture. The shallot bulbs were immersedincolchicine solution with different concentrations (0,2%; 0,4%; 0,6%; 0,8%; 1,0%; 1,2%; 1,4%; 1.6%; 1,8%; 2,0%)for oneto tendays. The results revealed that colchicine treatment at concentration 1,0% for 6 days was most suitable for inducing tetraploid shallot plants with survival rate of 80%. Thepercentage of tetraploids was20% in total treated bulbs. Treatment at higher concentration and longer duration increased the percentage of dead plants up to 100%. Thirty six tetraploid plants of shallot were produced.
Zooplankton Composition and its Relationship with Water Environment Parametersin the Aquaculture Area of Soc Trang Province

Nguyen Thi Kim Lien, Au Van Hoa, Tran Trung Giang, Vu Ngoc Ut, Huynh Truong Giang

Received: 18-03-2021 / Accepted: 10-01-2022
The objective of this study was to assess the effect of nutrient concentration on zooplankton distribution in the aquaculture area of Soc Trang province. A total of 4 sampling times was conducted from March to December 2019. At each sampling time, the nutrient parameters and qualitative and quantitative data of zooplankton were collected at 10 locations in the aquaculture zones. The results showed that species composition of zooplankton in the rainy season was higher than that in the dry season. The highest zooplankton abundance was recorded at stations in the tributary, in which protozoa was the most dominant class in most sampling stations. The contents of total suspended solids (TSS), total nitrogen (TN), phosphate (PO43-) and total phosphorus (TP) were not closely correlated with the composition of zooplankton. However, the nitrate (NO3-) concentration was positively correlated (P <0.05) with the component and abundance of Rotifera, Cladoceraand Copepoda. The results of the study could be the basic data source to support the management of surface water resources and the sustainable development of brackish aquaculture in Soc Trang province.
Optimization of Parameters in PolysaccharideExtraction and Bioactive Analysis from Myxopyrum smilacifolium(Wall.) Blume Roots

Luu Hong Son, Vu Thi Hanh, Nguyen Thi Tinh, Ta Thi Luong, Dinh Thi Kim Hoa, Ngo Xuan Binh

Received: 26-02-2021 / Accepted: 04-06-2021
It has been demonstrated that roots ofMyxopyrum smilacifolium(Wall.) contain many bioactive compounds including polysaccharides, saponin, flavonoids. This study aimed to determine the effects of the single-factor model on the amount of polysaccharide extracted from roots of Myxopyrum smilacifolium(Wall.) Blume), as a basis on a fractional factorial design at three levels through the Box–Behnken experimental design. Extracts obtained from optimized conditions were used for evaluation of their antibacterial, antioxidant, and anti-inflammatory ability. The results of the single-factor showed that the time of using ultrasound, the ethanol concentration, solvent/ material ratio, and extraction temperature were 60 seconds at 37 kHz, 80%, 15/1 (ml/g), and 80C for 90 min respectively. Under the optimized conditions by using the Box–Behnken experimental design, the results showed that the time of using ultrasound, the ethanol concentration, solvent/ material ratio, and extraction temperature were 64.67 seconds at 37 kHz, 81.56%, 15.33/1 (ml/g), and80C for 90 min respectively; and the total polysaccharide content was 16.1948 mg/g of the root. The extracts of total polysaccharides were able to inhibit Staphylococcus aureusK, Staphylococcus aureus, Shigella flexneri, Bacillus subtilis, Escherichia coli, Pseudomonas spp with antibacterial ring diameters as follow: 8.01; 18.06; 8.03; 6.84; 15.33; 9.39, and 10.13 mmrespectively. There was an IC50value of 168.94 ± 5.28 (µg/ml) when evaluating antioxidant activity. The anti-inflammatory ability was 28.31 ± 1.04; 33.76 ± 1.06; 50.04 ± 2.03 and 71.14 ± 2.81 (% BSA denaturation) corresponds to the extract concentration of 0.78125; 1.5625; 3.125 and 6.350 (μg/ml) respectively.
Effects of Postharvest Treatment by Propionic Acid in Combination with Wax Coating onQuality of Purple Passion Fruit (Passiflora edulisSims.)

Le Ha Hai, Nguyen Sang

Received: 05-04-2021 / Accepted: 04-06-2021
The research aimedto identify the concentration effects of propionic acid (AP) combined with a membrane coated with a mixture of beeswax and carnauba wax (MW) at a concentration of 8% on quality and storage time of postharvest purple passion fruit. After being washed and left to dry, the fruits were dipped in AP solution0.25; 0.35; and 0.45% for 10 minutes.After being left to dry again, the fruits were coated with 8% MW. After continuing to be left to dry, the fruits were placed in a foam tray put in carton boxes and stored at 5 ± 1°C, RH = 85 ± 2%. The untreated fruits and uncoated fruits were used as controls. The respiration rate, the percentage of weight loss, the total soluble solids (TSS) content, the total titrable acidity(TTA) and vitamin C content, the total microorganism population on the surface of the fruits and the percentage of fruits decay were analyzed and evaluated throughout the storage period. Research results showed that AP at a concentration of 0.45% combined with8% MW coating (CT3) is the best treatment for reducing the respiration rate, the total microorganism population on the surface of the fruits, the percentage of fruits decay and weight loss, slowly reduced TSS, TTA and vitamin C content. After 42 days in storage purple passion fruit treated by CT3 had the percentage of general loss including weight loss and decay is 11.9% in comparison with the control sample had the percentage of general loss is 96.2%.
Study on the Design of the Tube-Type Vacuum Honey Concentrator with Liquid Ring Partsand UltrasonicDevice Combination to Prevent the Crystallization

Dang Thanh Son, Tran Nhu Khuyen, Nguyen Thanh Hai

Received: 29-06-2020 / Accepted: 14-08-2020
The CD-1 tube-type vacuum honey concentrator with a liquid ring has been designed and manufactured based on the new principle, using the liquid ringand ultrasonic deviceto increase theevaporationabilityand crystallizationinhoneyto enhancing the quality of honey products during the condensed process.The single-case experiments have been appliedto determine the influence of concentration temperature, height of liquid ring, and time of broadcasting ultrasonic waves to the synthesis point of concentrated product quality, concentration and recrystallization time,and specific cost of electricity.The results of the experiments showedthatthe equivalent ofconcentration temperaturebetween35Cand53C, increasing the height of liquid ringfrom 380mm to 680mm and time of broadcasting ultrasonic waves from 15to 30 minwill bemore effective than increasing theconcentration temperature in terms of reducing quality due to heat effect, the concentration-time and specific cost of electricity.
Effect of Probiotics Addition on Vibrioand Growth of Postlarval White-leg Shrimp (Litopenaeus vannamei) in Biofloc Nursery

Huynh Thanh Toi, Nguyen Thi Hong Van, Pham Thi Tuyet Ngan

Received: 10-10-2018 / Accepted: 15-03-2019
This study was carried out to assess probiotics addition on Vibrioin culture medium and the growth performanceof poslarval white-leg shrimp (Litopenaeus vannamei) usingbiofloc technology. The postlarvae (0.007g/ind.in weightand0.90 cmin length) were nursed at 2postlarvae/lin 100 L tank containing 50 lof 30 ‰ seawater. Probiotics were daily added at 0.01 g/l(recommended concentration) and ½, 2 times, 3 times and 4 times reccomnended concentration compared to the control (without probiotics added). Results showed that after 20-day of culturethe ratio of Vibrio/total bacteria was lower in the probiotics addition treatment than the control. The individual length and weight of shrimps increased in all treatments when probitic added, especially the shrimps with three-times higher recommended concentration of probiotics significantly (P< 0.05) increasedin length and weight than that in the control treatment. The results of this study indicated that the ratio of Vibrio/total bacteria was reduced and shrimp growth performace improved when probiotics was combined withbiofloctechnology.
Evaluation of Effectivenessof Fecal Examination Techniques for Parasite Eggs and Oocystsin Dogs

Nguyen Thi Hoang Yen, Nguyen Than Thien, Dang Thi Phuong Thao, Nguyen Duyen Tung, Ha Quoc Viet

Received: 18-04-2019 / Accepted: 28-08-2019
The aim of this study was to evaluate the effectiveness of three fecal examination techniques: sugar floatation (SG: 1.27), saturated salt flotation (SG: 1.18) and formol-ether concentration, to determine the parasite eggs and oocysts in dogs. Examination of 270 dog fecal samples in some areas of Vinh Phuc, Thai Binh, Phu Tho and Thai Nguyen provinces, the result showed that the overall prevalence of gastrointestinal parasites in dogs is 75.18%. Twelve kinds of parasites were detected, consisting of one intestinal fluke (Heterophyids), six roundworms (Toxocara canis, Toxascaris leonina, Trichuris vulpis, Capillariasp., Strongyloides canisand hookworm), four tapeworms (Dipyllidium caninum, Diphyllobothrium latum, Spirometrasp., and Taeniasp.) and one coccidia (Cystoisosporasp.). Hookworm (58.81%) is the most prevalent in dogs, following by and Toxocara canis(31.11%). Sugar floatation technique showed the most effective for detection of roundworm eggs and coccidia oocysts, following by saturated salt floatation technique. Formol-Ether concentration one has more effective for detection of tapeworm egss and larva-containing roundworm eggs compared to the other techniques, but it cannot detect coccidia oocysts. In conclusions, the result of study showed that the choice of which fecal examination technique depending on the purpose of each study.
Effect of Chitosan Concentrationson the Quality and Shelf Life ofThach That PersimmonFruits

Nguyen Thi Hanh

Received: 24-05-2024 / Accepted: 18-01-2019 / Published: 31-05-2024
The objective of this study was to identìythe most suitable chitosan concentration for postharvest storage of Thach That persimmon (Diospyros kakiThunb.)fruits.Thepersimmonfruitswere firstly exposed toethylene, then treated with different chitosan concentrations of 1%; 1.5%; 2.0% and 2.5%, and finallystored under cold temperature (6-80C). Results showed that chitosan treatment considerably reduced the quality degradation of persimmons during the storage period. Chitosan concentration of 2.0% yieldedlowestweight loss, slowest change infruit color and firmness. Other biochemical parameters such as total acidity, tannin content reduced most slowly while the total sugar content increased most slowly in all samples. Using chitosan concentration of2.0%,Thach Thatpersimmonfruitscan be stored for25 days under cold temperature with good quality.
DOI: https://doi.org/10.1234/cka6zm46
Assessment of Soil Properties and Contamination Soil in Nhue River Basin in DuyTien District, Ha Nam Province

Phan Quoc Hung, Tran Thi Hong Thom

Received: 09-08-2016 / Accepted: 25-11-2016
The aims of the present study were to assess soil properties and soil contamination level in Nhue river basin. Forty soil samples and twelf water samples were taken. Results showed that soil pH varied from acidic to light acidic (4.3 - 6.0). Soil organic matter (SOM), total nitrogen, total phosphate and total potasium ranged from moderate to high (SOM: 1.50 - 2.50%; N: 0.08 - 0.20%; P2O5: 0.01 - 0.14%; K2O: 1.48 - 1.80%). The quantity and composition of microorganisms were diffrent between paddy soil and others. Total anaerobic bacteria were highest in paddy soil (8.2x106 CFU.g-1), 2.2 times of vegetable soil. Total fungi were variable with soil pH except actinomycetes. Analysis of irrigation water showed that 50% samples had pH exceeding the limit justified by QCVN 08:2008/BTNMT. TSS was high and very close to the limit. Some water samples showed that heavy metals (Pb, Cd, Cu, Zn ) were around concentration threshhold. Farmland in the study area showed sign of heavy metal contamintion. Concentration of copper in two soil samples (DTS02 and DTS03) in Bach Thuong commune was exceeding the limit (55.28 mg.kg-1 and 55.03 mg.kg-1, respectively). Concentration of heavy metals in paddy soil was higher than that in vegetable soil.
Effect of Postharvest Treatment With1-Methylcyclopropene on the Quality and Storage Life of Green Onionin Atmospheric Condition

Vu Thi Kim Oanh, Vu Thi Hang

Received: 15-10-2015 / Accepted: 05-05-2016
The aim of this study is to identify the optimum mode of postharvest treatment with 1-methylcyclopropene (1-MCP) forgreen onion (Allium fistulosum) in order to remain quality and prolong storage life at ambient condition. The two factors, concentration of 1-MCP and time exposed to 1-MCP, were taken into account. Singer factor experiment on concentration of 1-MCP was carried out first (with 6 concentrations of 0; 100; 200; 300; 400; 500ppm) along with 8 hours exposed to the chemical. Then the singer factor experiment on time exposed to 1-MCP was conducted (with 5 levels of 2; 5; 8; 11; and 14hours) along with the best 1-MCP concentration selected from previous experiment. Analyzed parameters include yellowingrates, chlorophyll, vitaminC content and their changes during storage period. The best green onion was obtained from the treatment with 200ppmfor8 hours exposed to 1-MCP. Also, two factors experiment was made in order to see interactions between them and look for the most optimal modeof 1-MCP postharvest treatmentforgeen onion. The results showed that the treatment laid on 208,9 ppm 1-MCP for 7 hours 44 minutes gave highest quality green onion in atmospheric condition.

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