FISHERY TECHNOLOGY

1. METHODOLOGY

2. Sample Collection
Maize Grain Sample Collection
• Mature maize was collected at commercial maturity from a
commercial farm in the Amhara region, West Gojam zone in Adet
Wereda in Ethiopia
• The sample size of the collected maize amount was 90 kg, and the
sample taken for each run was 5kg

3. Material Collection for Roaster
Collection of Equipment Construction Material
and Construction of Roasting Drum-like Machine
• The construction materials used for making the roaster were
collected from the local market
• The equipment and machines used were found in Bahir dar university
institute of Technology and these types of equipment were roller
machines which were used to roll the metal sheet into a cylindrical
form, a grinder that was used to cut different parts as designed
dimensions, a welding machine, cutting machine

4. Collection of Construction Materials
• The collected material is categorized as food grade material, thermal
resistance material, good thermal insulating material, and strong and
capable the load and movement
• The materials used for construction collected from the local market
were: stainless sheet metal, metal rods, framing square tube metals
used for the construction of base frame structure, bolts, electrodes
used for welding different parts together, grinding disks used to cut
different metal parts as the desired object, fiberglass used to
insulating the whole roaster cover additional teff straw were used the
burning chamber, painting grise used as anti-rust, two bearing used
for free movement of the cylinder and connect to the burning
chamber frame

5. Collection of Construction Materials
• The materials used to construct the roaster were collected from the local
market, and these materials were categorized as food grade and resistant
to different conditions like high temperature, moisture, and strength for
heavy loads
Roasting Cylinder and Chamber Design
• Inner Roasting Drum-like cylinder roaster design Factors taken
into consideration for the design of the roasting cylinder were
according to the edibility of the end product, volumetric capacity,
thermal properties of the drum materials, and also durability
• Design requirement /assumption

6. Roasting Cylinder and Chamber Design
• Drum Dimension calculation
• Roaster Design Consideration and Sizing
Roaster Design Consideration and Sizing
• Dimension

7. Cylindrical holder
• The material used in the fabrication of the roasting machine was
stainless steel
• The following constructional operations were carried out on the
components before the machine was finally built: The marking and
cutting of components, drilling of components, machining of shafts,
welding of components, filling and smoothing, assembly of
components, and painting were done according to the procedures set
• The workshop tools and machines used included a scriber, a steel
ruler, a compass, a center punch, a treadle-operated guillotine for
cutting, and a welding machine for joining

8. Frame design
• The frame of this roaster is the skeleton of the whole machine since it
holds, carries, and connects all the cylinders, shells, and burning
chambers
• The frame has the following dimensions: 66, 66, and 100 cm in width,
height, and length, respectively
• 4 the frame dimension and structure system of the roaster

9. Heating /burning chamber design
• The internal body of the cylinder consists of length, radius, and width
with dimensions x1, x2, x3, and the two ends of the cylinder
• The heat generated from burning wood is transferred through
conducting corrugated metal sheet by conduction and hot air
convection means of the heat transfer and the conducted heat is
transferred to the roasting cylinder in both conventional and
conduction heat transfer means
• The burning chamber is designed to hold the wooden material and
distribute heat to the upper layer, or external surface, of the cylinder
under the jacketed, insulated shell

10. Components of the Machine Burning
Chamber
• The air heater
• The Air Inlet
• The firing Chamber’s
Components of the Machine Burning Chamber
Air Vents/chimney /smoke exhaust

11. Design and Fabrication of the upper shell
cover of the Roaster
• The upper cover of the roaster has dimensions of 33, and 100 cm in
radius and length, respectively, and this cover can be easily opened
and disassembled
• The shell cover was bent with a roller machine and welded by a
welding machine using electrodes
• The cover is designed according to the cylindrical roaster size, and the
size of this shell shown in Figure 3.4 has a 5 cm clearance from the
normal grain holding cylinder

12. Equipment Sizing and Capacity
• The amount of heat transferred to the roast grain/maize will be
calculated according to the formula bellow where Qu = energy
absorbed by grain/ maize, m = mass of maize kernels, c = specific heat
capacity of the maize, ∆T = change in temperature of maize, and t =
roasting time The capacity of roasting capacity test aims to find out
how many machines the actual capacity and level of fitness roaster
are listed in the user manual
• The roasting capacity can be formulated as in the Equation below:
Determination of power required to roast maize grain
• The thermal conductivity of a material, in general, varies with
temperature

13. Maize Grain Preparation
• The collected sample was dried by the sun until the moisture content
reached 13% or below
• Only healthy kernels that are uniform in size have been used for
roasting
• In this section, some details about the method, methodology,
equipment design, and other related activities discussed according to
the corresponding assigned procedures are written below

14. Maize Grain Preparation and Roasting
Roasting Experiment
Two methods of roasting and three levels of roasting time were selected
Each experiment was conducted with the same input or feed materials, and there
were trial experiments to adjust the roasting time that was used for systematic
random design
Conveyance Efficiency CE is also used to calculate the relationship, similar to the
formula used by Atere et al., to calculate the conveyance efficiency of water
removal for continuous roasting practice, but the roasting techniques may not be
used for "asharo kolo" since the process needs an intense roasting method for a
long time with a higher temperature

15. Roasting Experiment
• Two methods of roasting and three levels of roasting time were
selected
• Each experiment was conducted with the same input or feed
materials, and there were trial experiments to adjust the roasting
time that was used for systematic random design
• Conveyance Efficiency CE is also used to calculate the relationship,
similar to the formula used by Atere et al., to calculate the
conveyance efficiency of water removal for continuous roasting
practice, but the roasting techniques may not be used for "asharo
kolo" since the process needs an intense roasting method for a long
time with a higher temperature

16. Roasting Experiment
• The purpose of many roasting studies is to determine the optimal
temperature, rotation speed, and roasting time that produce a good
quality of roasted cereal and legumes and produces the taste and
color of peanuts favored to meet consumers’ expectations

17. 3.3.2 Sample Preparations for Roasting
• The raw maize grain was purchased from a local market from farmers
at Adet, which is known for maize production, and the place is around
Bahir Dar city
• The reason why the grain was purchased there was due to quality and
fresh samples because from the market merchants mixed weevil and
insect-damaged grain; hence, by eye inspection, we selected and
bought 80 kg of maize grain
• The clean and screened maize samples were first soaked in water for
up to four days to gain the optimum amount of moisture that
facilitates germination and weakens the kernel hardness and then
used as a medium to transfer heat throughout the kernels

18. Roasting
• About 6-10kg of Clean, soaked, and germinated maize was prepared
for each treatment and roasted according to the experimental design
setup
• The maize was roasted for 30 min,40min, and 50min, in both newly
designed jacketed manual rotate-able cylindrical drum-like roasters
and open pan/ roasters with equivalent power supply and roaster
thickness
• The power consumption is considered equivalent to one another
since the input mass is equal for each treatment

19. Sample Preparation for Analysis
Experimental Analysis and Activities cite
• The construction of the equipment will be done in Bahir Dar City or
Bahir Dar University Different quality attributes of rotary roasted corn
will be analyzed at Bahir Dar University Institute of Technology
• The roasted samples of grain under different experimental conditions
will collect and the following quality parameters will analyze in the
labs of BIT and others according to standard procedures
• The experiments will be replicated to reduce the experimental and
reliability of results

20. Experimental Design
• Maize kernels/barley will be subjected to pilot scale roasting
treatment for different time and temperature combinations using a
full factorial design with optimal time at 25min at 190oC ,but some
study shows barley roasted at 225oC according to the above base and
other past literature this study estimates the wooden fire burning
ranged between 100 and 250oC, but according to preliminary check,
the temperature has been determined
• The factorial experiment was conducted as a randomized design with
three replicates and the experimental design and method for this
study was two-way ANOVA with three levels of time as a factor and
others considered as constant with three replications

21. Experimental Design
• A complete randomized selection of the first level of time and the rest
systematic selection of interval approaches the level of roasting time
was selected after three trials of preliminary tests according to the
color and moisture content of roasted maize grain

22. Method of Analysis
Physicochemical Analysis
• After the roasting process was done except for the moisture content,
the protein, fiber, fat, ash, and CHO were analyzed by taking the
samples from well-packed roasted samples, whereas the moisture
was immediately done after cooling roasted maize grain
• Each proximate composition was done according to the methods
available and listed below details

23. Moisture Content
• The moisture content of the raw corn grain, roasted samples was
determined according to the Association of Official Analytical
Chemists 2000’ ; using the official method No. 925.10 by oven drying
method
• The 5g well-homogenized samples were weighed in a dry moisture
dish that dried in a hot air oven at 1050 for three hours and the
drying proceeded until a constant mass was obtained
• The moisture content of the sample was calculated from the
equation: Where, %MC = Percentage of moisture in the sample, Mi =
Weight of fresh sample and Mf = Weight of dry sample

24. Crude Protein Content
• The crude protein content of raw maize grain and roasted maize grain
samples were determined by the Kjeldahl method ; using the official
method No. 920
• Around 0.5g of the samples were weighed and put in a digestion flask
and then 1gm of catalyst mixture was added
• The flask has then been placed on a digestion burner for 4 hrs

25. Crude Fat Content
• The Crude fat of the raw corn, control roasted, and machine-roasted
samples was determined based on the Soxhlet extraction method ;
using the official method No. 920
• 250 ml quick-fit round bottom flasks were washed and dried in an
oven at 105˚C for 25 minutes and allowed to cool to room
temperature before it was weighed
• The fat obtained was expressed as a percentage of the initial weight
of the sample using the equation: Where: M1 = weight of the
extraction flask , M2 = weight of the extraction flask plus the dried
crude fat , and M = weight of the initial sample

26. Crude Fiber
• The crude fiber content of the corn and roasted corn was determined
by AOAC, ; using the official method No. 962
• About 200 ml of a 1.25% sulfuric acid solution was added to each
beaker and allowed to boil on a hot plate for 30 minutes by rotating
and stirring periodically
• The crude fiber was calculated from the equation: Where: M = the
initial weight of samples, M1 = the weight of the crucible with dried
residue , and M2 = the weight of the crucible with ash

27. Total Ash Content
• The ash content of the samples was determined by AOAC using the
official method 923
• Porcelain crucibles were treated in a muffle furnace for 30 minutes at
550 °C
• The crucible was cooled in desiccators for about 30 minutes at room
temperature and weighed

28. 6 Carbohydrate Content
• The total percentage of carbohydrates was determined by using the
difference method according to Onyeike
• This method involves adding the total values of crude protein content
, crude fat content , crude fiber content , moisture content , and ash
content of the sample and subtracting them from
• Total carbohydrates, including fiber, calculated from the equation are
Total CHO = 100 - ………

29. Gross Energy
• The total energy content of the roasted samples was determined
according to AOAC by multiplying the mean values of crude fat , total
carbohydrate , and crude protein by the Atwater factors 9, 4, and 4,
respectively, taking the sum of the products
• The total energy was calculated from the equation

30. Color Analysis
• The color values of the maize grains were expressed as ‘L’ , ‘a’ , ‘b’ ,
and ΔE A handhold chroma meter calibrated by a standard
whiteboard was used to measure the color
• The whiteness index values that combine lightness and yellow-blue
into a single term calculated as described by Hsu, Chen, Weng, and
Tseng as follows: calibrated by a standard whiteboard was used to
measure the color
• Yellowness is represented by a positive b* value and blueness by a
negative b* value

31. Total Phenolic Content
• The total phenolic content of samples was determined according to
the adapted Folin-Ciocalteu methods
• Other beverage product phenol also determined by Folin-Ciocalteu
methods
• The sample of roasted flour was homogenized with 10 mL of 60%
methanol containing 0.1% HCl and placed in a water bath for 2 hours
at 850 °C to eliminate vitamin C, as described by
• Folin Ciocalteu’s phenol reagent was stored at room temperature, and
the reagent was diluted with distilled water as required

32. Functional Properties
Bulk Density
• The bulk density of the sample was determined according to the
methods described by The raw and roasted maize samples were
transferred to a pre-weigh measuring cylinder and the new weight
was recorded
• The volume occupied by the flour in the measuring cylinder was also
recorded
• The bulk density was calculated from the equations

33. Water Absorption Index and Capacity
• The water absorption index of the raw and roasted maize samples
was determined according to the methods described by
• The sample was suspended in 30 ml of distilled water, cooked for 15
minutes in 90 °C water baths, then put in a tarred 50 ml centrifuge
tube and shaken for 30 minutes
• The sample was centrifuged for 10 minutes at 3000 rpm, and the
clear supernatant of the centrifugation was transferred into a pre-
dried and weighed glass beaker for estimation of the water solubility
index

34. Determination of Water absorption capacity
• Water absorption capacity is an indication of the amount of water
available for gelatinization
• It was determined according to the method used by Edema et al.
• Exactly 2.5 g of each roasted maize flour sample was added into 30 ml
distilled water in a weighed 50 ml centrifuge tube

35. Water Solubility Index
• The water solubility index determines the number of polysaccharides
released from the granule with the addition of excess water
• The water solubility index was determined by taking the sample and
filling a 100ml graduated cylinder up to the 10ml mark and adding up
to 50ml was attained and inverted for 2min and mixed well for 8
minutes after that the supernatant preserved from WAI
measurement, which was evaporated at 960C temperature overnight
• The WSI was calculated from the equation

36. Performance Test
• Before undertaking a performance test of the developed prototype, a
preliminary test was made to check whether the roaster is
functioning properly for the intended purpose
• The roaster had good functionality except for a few minor defects,
which were easily corrected since we were making trials after making
and assembling its components especially the power source and
rotating mechanisms and related parts
• the conducted roasting practice determines its performance in
different aspects the overall functionality of the roaster performance
and procedure of roasting the determination of moisture content was
done by taking samples at a random time interval

37. Statistical Analyses
• The analysis of variance and the descriptive statistics were done using
Minitab software, and statistical analyses were carried out using this
software on a two-way ANOVA general linear model was used to
perform a meaningful comparison and to determine whether
significant differences existed between the treatments
• An ANOVA with Schiff’s test was used to determine the source of the
significant differences in roasting time and roasting method
• This study is supposed to conduct two roasting methods with three
levels of time and three replications of the responses