Báo cáo khoa học nông nghiệp " Investigation of rice kernel cracking and its control in the field and during post-harvest processes in the Mekong Delta of Vietnam " docx

These include i research in the field ii experimental work on drying iii extension and training to farmers, service providers and extension workers, and iv Training of Nong Lam Universit

Ministry of Agriculture & Rural Development

Project Progress Report

FIRST SIX-MONTHLY REPORT

No of Milestone (MS) 2

Investigation of rice kernel cracking and its control in the field and during

post-harvest processes in the Mekong Delta of Vietnam

026/VIE05

September 2006

NONG LAM UNIVERSITY

Table of Contents

5.1 Implementation Highlights _ 20 5.2 Smallholder Benefits 21 5.3 Capacity Building 23 5.4 Publicity 23 5.5 Project Management 23

6.1 Environment 23 6.2 Gender and Social Issues 24

7.1 Issues and Constraints 24 7.2 Options _ 7.3 Sustainability

1 Institute Information

and its control in the field and during post-harvest processes in the Mekong Delta of Vietnam

Professor Shu Fukai

Contact Officer(s)

In Australia: Team Leader

Organisation: The University of

Queensland

Email:b.bhandari@uq.edu.au

In Australia: Administrative contact

Position: Research support officer Fax: +61 7 33658383

Organisation: The University of

Queensland

Email: k.johnston@research.uq.edu.au

In Vietnam

Position: Head, Department

of Chemical Engineering

Organisation: Nong Lam

University

Email:tv@hcmuaf.edu.vn

2 Project Abstract

Since the project commencement date of April 2006, three cooperatives were selected for installation of driers and reapers in order to provide small holder farmers the technical knowledge to practice optimum harvesting, and drying methods and conditions Systematic data collection was undertaken to quantify the amount of cracked rice in the field due to early or delayed harvesting practices Experiments were also conducted to characterise a newly installed drier in one of the cooperatives Extensive literature review and preliminary experiments were conducted at the University of Queensland to apply molecular relaxation concept into rice cracking A systematic survey on milling losses was undertaken to obtain actual data A workshop was held in Can Tho for the extension workers in order to provide them information about the project and to share each others experience on the knowledge on the rice cracking This project also assisted to continue a collaborative working culture among various research teams across faculties in the Nong Lam University and also between the University, Government organisations, farmers cooperative and farmers Training of one NLU staff member in Australia and visits of project leader to rice research institutes in Thailand and Philippines will take place in October 2006

3 Executive Summary

There are four main project objectives that will be implemented phase wise during the course of the project duration These include (i) research in the field (ii) experimental work on drying (iii) extension and training to farmers, service providers and extension workers, and (iv) Training of Nong Lam University personnel engaged in the project During the past 5 months (April-Aug 2006) three farmers cooperatives were identified in three different provinces (Can Tho, Kieng Giang and Long An) to implement various activities Each of these cooperatives was installed with one reaper/combined harvester or

a flat bed-dryer (8 ton capacity) Data collection on post-harvest losses (in more than two provinces), harvesting time experiment (two cooperatives and one seed centre) and a drying experiment were undertaken in various provinces and also at the Nong Lam University One MPhil student from Nong Lam University undertook preliminary work

on the application of glass relaxation concept to improve the mechanical property of rice One day seminar/workshop was organisedinCan Thofor extension workers and scientist from post-harvest institutions to highlight the project objectives and also to obtain input from the extension workers on grain losses in relation to harvesting, drying and milling practices in Mekong Delta

4 Introduction & Background

4.1 Project objectives

The specific objectives of this project are:

1 To identify and generate information for the appropriate harvesting method (manual

or mechanical) of rice to reduce grain cracking and losses

2 To improve the performance of current driers and optimise the drying method to minimise the broken portion on the basis of fundamental structural relaxation concept, particularly in a high temperature compact-drying system

3 To make the farmers, service providers, millers and extension workers aware of various factors responsible for harvesting and milling losses and degradation of rice quality

4 To increase the research and teaching capability of institution and staff members on rice quality and related products

4.2 Expected project outputs

The expected outputs during the last 5 months period were:

• Selection of cooperatives for undertaking experiments and as a centre for demonstration to farmers

• Experiments to identify optimum harvesting methods to reduce grain loss

• Production of demonstration materials

• Experiments for optimum drying conditions identified for high temperature compact dryers

• New process intervention introduced to validate molecular relaxation concept

• Reports/publications

• 39 extension workers are trained with new information

• Production of 6-monthly report

4.3 Approach and Methodology

The approach and methodology were adopted from the original project proposal In this project, the smallholder farmers are the major target for extension work through the pilot farmers’ cooperatives particularly for Objectives 1 and 3 Three farmers cooperatives were identified in three different provinces (Can Tho, Kieng Giang and Long An) (Figures 1,2) As for Objective 2, the analysis of the problem will be analysed at micro or molecular level using a glass-rubber transition and molecular relaxation concepts This new approach and understanding is expected to assist in developing high capacity dryers which will use high drying temperature As for Objective 4, strong research collaboration will be fostered at NLU to capture the expertise from various departments and faculties; research staff members will be trained in Australia and a visit will be organised for project leader

Figure 1: Location of three cooperatives (in Can Tho, Kien Giang and Long An provinces) in Mekong Delta

Figure 2: Visit of Tan-Phat A farmers cooperative in Kieng Giang province by Australian and

Vietnamese project personnel (8-ton flat bed drier is installed in this cooperative)

4.3.1 Implementation Methodologies

This project consisted of four main activities to achieve the goals as highlighted in the objectives:

Objective 1 activities: Conducting experiments to relate harvesting time and methods on cracking

fraction of rice and losses for different varieties and seasons

The objective of this experiment is to determine the effect of harvesting time on kernel cracking and optimize harvesting period of some rice varieties in Summer-Spring season in the MRD

Harvesting time field experiments were conducted on two most cultivated varieties of Tan Thoi 1 (Can Tho) and Tan Phat (Kien Giang) cooperatives, and in seed centre of An Giang province Optimum harvesting time for each variety was determined based on analysis of experimental data According to local survey results, the two most cultivated rice varieties OM 2718 and OM 1490, An Giang 24 and Jasmine were chosen in Can Tho, Kien Giang and An Giang provinces, respectively Using a randomised block design, the rice was harvested 6 days prior and 6 days post-maturity stages in 2 days intervals The number of rice kernels with cracks and chalkiness were measured for both brown and milled rice The full analyse of the results will be presented in the yearly report

Harvesting method (manual and harvester) comparison on the post-harvest losses was also undertaken in Can Tho and Long An provinces Cracking behaviour of the grain due

to threshing was also investigated in Can Tho and Kien Giang provinces Data of the actual harvesting losses due to current harvesting practice by farmers were collected in Can Tho and Kien Giang provinces Experimental design and data will be presented in the next report

Objective 2 activities: This comprised of the following activities:

Optimization of the drying method based on glass relaxation phenomenon

An eight-ton capacity flat bed drier was installed in Tan Phat A cooperative located in

addition to the dryer installed in a cooperative, another one-ton lab scale flat bed dryer

wo mobile lab scale dryers were also built to dry the samples collected in the field

high temperature compact drier with a tempering system is being designed at Nong

igure 3: The 8-ton dryer installed at Tan-Phat cooperative, Kien Giang province

er operating at reversible air flow mode)

Tan-Hiep District of Kieng Giang Province At first, we intended to contract the construction of the dryer with additional features to a local dryer manufacturer, but no contractor was willing to do it to meet our need So, the research team decided to build

an air-reversible SRA-8 design from NLU with slight modifications The installation of the dryer was completed in mid-July 2006 (Figure 3), just in time for the wet-season harvest, and for experimental purpose This time the purpose of the experiment was to evaluate the performance and throughput of the dryer at different drying regimes The full results and interpretations of this and forthcoming work will be submitted in the next report It is to note that this information will be provided to farmers and extension workers during the training and seminar sessions

In

is being constructed at NLU which will be used to undertake experiments under controlled condition (Figure 4)

T

(Figure 5) These dryers were used in the field to dry the rice samples collected during the harvesting time trials

A

Lam University It will be built in the next six months

F

(second figure shows dry

-A

Figure 4: A one-ton drier being constructed at NLU for laboratory experiments

at controlled conditio s

ve terature survey and preliminary experiments to characterise the cracking behaviour of

cal

on Test (Figure 6)

text

The re etnamese counterpart by providing recent literatures lated to rice drying and cracking behaviour At the moment her work is limited to a few

Figure 5: Mobile Lab scale cabinet dryer to dry the rice samples n

A Vietnamese student (Mrs Tuyen-Thuc Truong) working at UQ undertook extensi li

Australian varieties of rice The preliminary study included the followings:

• Analysis of physical properties and total amylose content of selected rice

varieties;

• Determination of glass-rubber transition temperature by Thermal Mechani

Compressi

• Effects of tempering on mechanical strength of rice (by texture analyser using

rig depicted in Figure 7)

searcher also assisted Vi

re

Australian rice varieties She will be visiting Vietnam early next year to work on Vietnamese rice varieties

0.5 mm

1 mm

Objective 3 activities: This comprises of following sub-activities:

i Demonstrations to the farmers and provincial pilot cooperatives on the benefit of

mechanical drying against sun drying and the economic value of the correct harvesting time and method

As indicated above each of the identified cooperatives was installed with one reaper/combined harvester or a flat bed-dryer (8-ton capacity) The demonstration materials are being prepared at present The demonstration and training activity for the farmers were not done during this period but will begin in the next 3 months

ii Study the performance of milling plants and solutions to improve the milling efficiency

We have commenced to collect the data of milling losses in two provinces The milling loss data were collected directly from three milling plants in each province (Kien Giang and Tien Giang) Since the work is being continued, the full report will be presented next year The available data will also be incorporated into the training manual

Objective 4 activities: Training the staff members to improve the R &D and teaching capability in

rice science and technology

There was no activity during this period, but one research worker from Nong Lam University will

be visiting University of Queensland from October The project coordinator Dr Vinh Truong is also visiting Thailand and Philippines in the first week of October

5 Progress to Date

5.1 Implementation Highlights

The brief highlights of the project executed in the past 5 months are described below

2.0 mm 2.5 mm 3.0 mm 3.5 mm 4.0 mm

90 mm

9 mm

99 mm

Figure 6: Texture analyser attached with a

UQ rig to measure the glass-rubber

transition of rice kernel (this device will be

duplicated in NLU next year)

Figure 7: UQ Rig to measure mechanical strength of individual kernel of rice (same device will be used at NLU)

5.1.1 Influence of harvesting time on rice cracking

Experiments conducted on two common rice varieties indicated that the rice cracking is obviously influenced by the variety and time of harvesting Harvesting the rice a few days prior to maturity will not have much effect on rice cracking, but delayed harvesting will result in significant rice cracking (up to 24% of total brown rice) Few representative results obtained from two varieties are presented as below in Figure 8 A full analysis of the data will be undertaken and will be presented in the next report As planned, this information will be included in the training document for farmers

5.1.2 Drying of paddy using a reversible flat bed dryer

Some preliminary experiments on the 8-ton capacity dryer were conducted to characterise this dryer The work also quantified the energy consumption during the process per

kilogram of a paddy dried Some highlights of this initial work are as follow:

- The effect of air reversal is very apparent in reducing the final moisture differential which can influence head rice yield during milling

- Air reversal also decreased the drying time

- The drying temperature in the dryer was stable and can be kept within ± 2 oC

- The husk and diesel consumptions per kg of rice dried were 33.45 kg and 1.77 litres, respectively at a drying temperature of 43oC The drying time for paddy was

approximately 12 hrs to bring the moisture down from 26 to 15% (wet basis)

However, the drying time decreased to 8 hrs by using two stage drying (50oC for 1 hr followed by drying at 43oC)

These remarks are preliminary and need to be supplemented by data on milling analysis, which is being undertaken and will be reported at a later stage All these information will

be used in the extension work

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