Computer Based Experiments with Buckwheat in Food Processing ...

Proceedings ofthe 9th International Symposium on Buckwheat, Prague 2004

Computer Based Experiments with Buckwheat in Food Processing Vocational Education Andrej Sorgo!, Blanka Vombergar' I

Vocational College ofMaribor Food Processing School and Prva gimnazija Maribor, Slovenia Zivilska sola Maribor- Visja strokovna sola, Park mladih 12000Maribor 2Vocational College ofMariborFood Processing School, Slovenia ABSTRACT

Three computer based experiments with buckwheat were developed for use in post-secondary vocational education in food processing. The experiments examined germination of buckwheat, pH and the content of electrolytes and their diffusion into water. They should deepen our understanding of basic processes in the food processing industry and food preparation. Same experimental design could be used with other grains or transferred to other foods. Keywords: buckwheat, computer based experiments, vocational education, food processing. INTRODUCTION

The idea of introducing computer based experiments with buckwheat at our school arose when we realized the following: 1. Today computers and digital systems are used in industry, research, transport and at home as regulators, data-loggers, analytical tools, etc. Everyday school practice often does not reflect the importance of computers in real life. Many teachers understand the phrase "use a computer" as "use a computer for e-mail or Internet, for a database or as a sophisticated typewriter or calculator" (SORGO et al. 2002). However, we should try to teach our students about computers as a powerful tool for data sampling and data processing. 2. Demonstrations of processes and practical laboratory work can result in a better understanding of theoretical knowledge presented at lectures. The use of computers equipped with appropriate sensors can be a high way to enriching biological laboratory activities in a school (SORGO AND KOCIJANCIC 2003). 3. In last years the awareness of beneficial properties of buckwheat rose, and not last we can consider buckwheat and its products as Slovene national foods (KREFT 1995).

Bringing all three points together, we designed some computer based experiments with buckwheat and have more of them in plan .

MA TERIAL AND METHODS We used the computer data acquisition system CMCS3 developed in the ComLabSciTech pilot project, supported by the European Commission's Leonardo da Vinci programme (http://e-prolab.com), equipped with sensors produced by Vernier. Original software was written to support this interface. A mixture of buckwheat grains of unknown origin bought at a supermarket was used for our experiments. We used standard laboratory equipment and glassware from the school's science laboratory. All the experiments were developed in the laboratory for computerised experiments at Prva gimnazija Maribor and presented as a demonstration to students of the vocational college for food processing as part of the Biology and Food Processing Technology curriculum, and to secondary school students as part of compulsory electives.

730

Proceedings ofthe 9th International Symposium on Buckwheat, Prague 2004

EXAMPLE EXPERIMENTS

Germination of seeds at different temperatures It is well known that buckwheat needs warm soil to germinate. In a process of germination cells need oxygen for aerobic respiration. There is a correlation between the respiration rate and the consumption of oxygen. We can present this relation with measurements of oxygen concentration in a test bottle. An equal mass of wet buckwheat grains was put into two test bottles. The first test bottle was placed in a water bath with the temperature of approx. lOoC, while the second was kept at 35°C. The difference between oxygen consumption of the two samples was obvious already after few minutes. On the basis of results, students can make a conclusion why dry and cold atmosphere is obligatory for long term storage of seeds in storage houses. We can use any other seeds for the experiment and make various comparisons . Graph 1 Consumption of oxygen during germination of buckwheat at different temperatures (cold 10°C; warm 35°C) .....

----

:;t : i

"

..... ...._ .,---.. _---_. , ---- _.._.. -- --- -------,.--.---.--_.-, "'r-. __·-T·_·_·-l·· · ._.--''; -'_ '1'" T ; · r-·· ·.··r -_ r - i I ......'

--'-.,...

i

i i

i

-Y- -- -

I i

:

l

i

i

_ __ __ ._1

"

t l

--:-- 'fl· --

f

I

1·····-

..J. _ •• ._ .-1 ._ _

;.

I

.o"

~

-T, _ I

!

! !

-..!r- - - -.J ~ _ -- --J - - - ~

~t

~

f

,. . ,

I

.i •

R·

_ •• • • •· · · · · · _

., • • •• •• • • , • • •• ••• ••

~

•• , . _ • • _

• • _ , • ••

~

! '

1: " I ! I I

,

I

t-.,~

I ...l.."'.... - , ..~ . J. _. .~,..

I

I

,.....

;

-..- _ .

i

il :

,

-..+--~

!

I

i '

I i J., ........ __• ..t - ._. ,,'''' I ! ! j

i

~,,!!.!

i ,

1" " -....... 1

i I

.. •

r

,!

: " ""-J.

j

1

i

i i

i:

J _. [:::-~ ... ~ . .1 ......._...1._. •__ 1. _ _ "_

!, li !'

I .-" ....... """'i,....., . . _

I !

I

1!;

1 I

I

I'; - ·.·r

--t--'t·

I

I

~

·-f -" -- _.. -i--._---- -to- l~ l 11 I I 1 I"' : i ! I i i --'!,~.. ; i i

-I · ·~-..

1

l

t';

:

l.. . . .·~

I

-....--

: i

~ i F-·-'= -""-·""i""ii:::"i "~-";i"" ····';:;;; · " ··~······::':..:.;.:. t .- =.

.----.--:---

.. .

-.-........

.., - ~'

.....- _

I ' i _-_._-

~ ..'!

__._--;

Measurements of pH and conductivity We can use a computer equipped with pH and/or conductivity sensors for point measurements. There is a correlation between the concentration of electrolytes soluble in water and the conductivity of suspension. We put 10 gr. of each meal in 50 rol of distilled water and stirred the suspension with a magnetic stirrer for 5 minutes. Then we measured pH and conductivity.

731

Proceedings of the 9th International Symposium on Buckwheat, Prague 2004

pH

Flour Wheat T500 (white flour) Wheat - full grain flour Maize flour Rye T1250 (dark flour) Buckwheat 1 (flour) Buckwheat 2 (flour)

Conductivity (j.!S) 730 1356 512 1471 1385 1181

6,21 6,58 6,68 6,64 6,68 6,82

The difference between two types of wheat flour leads to the conclusion that a higher concentration of electrolytes is in outer parts of a grain . Some health issues about the importance of trace elements and possibly the location in the seeds could arise in a discussion after the experiment (BONAFACCIA et. al.2003).

Diffusion of electrolytes into water During food preparation water soluble ions diffuse from food into water, resulting in a loss of important electrolytes. Several factors like temperature, solubility of ions and the diameter of food particles have influence on this process. We milled buckwheat grains and put equal quantities of different fractions into distilled water. Our fractions were whole grains, broken grains, rough and fme flour. The conductivity of suspension was measured with conductivity probes for one hour. We can conclude from the results shown in the graph that the diffusion of ions in whole grains started after approx 20 minutes and is a very slow process . Contrary to the diffusion from whole grains, the diffusion from flour is a very fast process . Similar results can be expected with other types of grains. Students should conclude that only whole grains can be washed in water without loss of nutrients. They should transfer their fmdings about the importance of the ratio between surface and volume to other technological processes like cooling of meat. Graph 2 Diffusion of electrolytes from buckwheat into water measured as conductivity. Lower curve: whole grains, upper curve fine flour.

r-..· ·- · · · · .·.·.-·· ·-· ··. -· . ··.-· . ·.· . · - ~

--..- --

~

- ---

- ---

- - r - -r - - r - - r --T- - T- - T- - - - , - -

;,.-

f

!

t

I

I I

!

I I

---. --

I

I

- - r - -r - - r - - I - ~ Y~ ~ ~

i

~

J

; .~:f \

!

I !

I.U"",,~~~ 732

I

.

I

I

- - ~ -- ~-- ~ - -~- -~ - -

I

- L- - ~-- ~ -

I !_

.

~

1

I

I

!

I __ +~_~ __ ~ __

l__ ~ __ 1 !

I I I I ; I I I ' 1 - -~ -- ~ --~-- ~- -~- - ~--- -- ~-! I I I I I ! l I I I

;

,

I

!i

L---~~---J_ ~=_.;_:~_;~;:;~~:;~.;.~;;_=_±_: ::.:::t=:r~=t:J ~ .!!.~.~ ...J

. !!,",:::: -

IIlI ._..ll!li __..

. . .. . . . . . . . . . . .

.

.

m

_

Proceedings ofthe 9th International Symposium on Buckwheat, Prague 2004

CONCLUSIONS

Using computers equipped with the interface and appropriate sensors we were able to present to our students some basic principles in food processing technology and food preparation in a new fashion. This should hopefully result in a better understanding of processes in food processing, which is yet to be tested. Experiments can be easily adapted to other types of grain or be used to examine the differences between them. REFERENCES

BONAFACCIA G., MARROCHINI M., KREFT 1. (2003): Composition and technological properties of the flour and bran from common and tartary buckwheat. Food chemistry 80: 9 - 15. KREFT 1. (1995): Ajda. Ljubljana. SORGO A., DAKTARIUNAS A., BEITAS K., SAKALAUSKAS V. (2002): Computerised laboratory in science and technology teaching: the course on biological processes. In: Educational technology: International Conference on leT's in Education. [13.-16.11.2002, Badajoz (Spain)], (Ociedad de la informacion, 9). [Badajoz]: Junta de Extremadura. Consejeria de Education Cienca y Technologla. SORGO A., KOCIJANCrC S. (2003): Computer based experiments with carbon dioxide in biology lessons. In: Proceedings of the IASTED International conference on Computers and advanced technology in education, Including the lASTED international symposium on Web-based education, June 30July 2, Rhodes, Greece.

733