Exploration of 21st century flameless

cooking

BPh70

Y.W.C.A. HIOE TJO YOENG COLLEGE

Exploration of 21st Exploration of 21st century flameless cookingcentury flameless cooking

廿一世紀之無火煮食研究廿一世紀之無火煮食研究

Flow1. Background2. Design of the Project3. Procedure4. Result5. Conclusion / Implication

What is gas

cooking? Flameless cooking?

Gas cooking means cooking that with

flames !

Flameless cooking means cooking that

without flames!

In the past…In the past…We used fossil fuels in an unrestrained way……

In the present…In the present…

In the future…In the future… Cooking will still be essential in our daily lives Flameless cooking can be carried out to reduce the fossil fuels used for cooking

The Percentage of Cooking Method that PeopleUsually Use

Town gas80%

Microwaveoven4%

LPG gas16%

Survey conducted by Y.W.C.A. Hioe Tjo Yoeng College

Design of our projectDesign of our project

Procedures of Procedures of ExperimentsExperiments

Preparations of food samplesPreparations of food samples

Egg custard

vitamin C solution

Liquidized tomato paste

Food Samples cooked by:

Electric cooker Microwave oven Solar cooker Town gas cooker

All the food samples ( egg custards, All the food samples ( egg custards, vitamin C dissolved solutions and vitamin C dissolved solutions and liquidized tomato paste) were cooked liquidized tomato paste) were cooked

by a by a CONSTANTCONSTANT amount of amount of energy, which is 211.2kJenergy, which is 211.2kJ

Take the initial and final temperatures of the cooked food

samples

Biuret testBiuret test Add sodium hydroxiAdd sodium hydroxi

de solution followed de solution followed by copper (II) sulphatby copper (II) sulphate e

The appearance of dThe appearance of deep purple colour ineep purple colour indicates the presence dicates the presence of proteinsof proteins

DCPIP testDCPIP test

Add the extract into Add the extract into a constant amount oa constant amount of DCPIP solution f DCPIP solution

Count the number of Count the number of drops of extract adddrops of extract added until the DCPIP soed until the DCPIP solution become decollution become decolorizedorized

Measure the thickness of coagulation of the egg custard

Measure the change in volumes

Results of the Results of the experimentsexperiments

Temperature rise of egg Temperature rise of egg custardcustard

Rise In Temperature

60

80

11

78

0

20

40

60

80

100

ElectricCooker

MicrowaveOven

Solar Cooker Town Gas

Cooker

Deg

ree C

els

ius

Unit : ºC

Cooking methodsCooking methods Condition of coagulationCondition of coagulation

Electric cookerElectric cooker The whole custard has The whole custard has

coagulatedcoagulated Microwave ovenMicrowave oven Coagulated part is Coagulated part is 2 cm2 cm

thickthick

Solar cookerSolar cooker NoNo custard has coagulated custard has coagulated

Town gas cookerTown gas cooker The whole custard has The whole custard has

coagulatedcoagulated and and

overcookedovercooked

microwave oven

electric cooker Distilled water

solar cooker

town gas Food sample: Custard

Nutrients retained (proteins)Nutrients retained (proteins)

Cooking Cooking methodsmethods

Results of Biuret Results of Biuret testtest

Relative Relative amount of amount of proteins proteins retainedretained

Electric cooker Electric cooker Deep purpleDeep purple HighHigh

Microwave Microwave oven oven

Deep purpleDeep purple HighHigh

Solar cooker Solar cooker Deep purpleDeep purple HighHigh

Town gas Town gas cookercooker

Lighter Lighter purplepurple

LowLow

Percentage Of Vitamin C In Food Sample Retained

49.0438.9

80.53

61.2

0102030405060708090

Electric Cooker Microwave Oven

Solar Cooker Town Gas

Types of Cooker

Perc

en

tag

e (

%)

of

Vit

am

in C

Vitamin C retainedVitamin C retained

Food samples: liquidized tomato pasteUnit : %

Amount of money for buying Amount of money for buying the cookerthe cooker

Unit : $

Price of the cooker

400

1500

50

2000

0500

10001500

20002500

ElectricCooker

MicrowaveOven

Solar Cooker Town Gas

Cooker

Pri

ce /

Dolla

rs (

$)

(approximately)

Conclusion and Conclusion and ImplicationsImplications

Factors to be consideredFactors to be considered

Nutrients retained

Cooking efficiency

Economical Price

Which one is the most preferable?

For nutrients retained:

SOLAR COOKER !!!!

For the highest cooking efficiency:

ELECTRIC COOKER !!!!For the most economical one:

FLAMELESS COOKING !!!!

ConclusionConclusion RankRankNameName Tem

peratureTem

perature

changechange

CoagulationCoagulation

Nutrie

nts re

tain

ed

Nutrie

nts re

tain

ed

(pro

tein

s)(p

rote

ins)

Nutrie

nts re

tain

ed (v

itam

in

Nutrie

nts re

tain

ed (v

itam

in

C)

C)

Cost

Cost

Electric Electric cookercooker

Microwave Microwave ovenoven

Solar cookerSolar cooker

Town gas Town gas cookercooker

Gas cooking is NOT better than

CONCLUSION

Why may FLAMELESS

COOKING take the place of

GAS COOKING?

Energy crisis

Price of fossil fuels Gas cooking becomes not so economical Flameless cooking is being improved and promoted

Is solar cooker really practical or

applicable?

Sunlight in Hong Kong is regional

In other countries with strong sunlight, a temperature as high as

96ºC

96ºC has been recorded Technology of solar cooker can be furt

her developed in the future

Exploration of 21st Exploration of 21st century flameless cookingcentury flameless cooking

廿一世紀之無火煮食研究廿一世紀之無火煮食研究

Data resources for solar cookerData resources for solar cooker1. Solar Cooker Country Report

http://solarcooking.org/docs.htm#country_reports

2. U.S. Department of Energy Efficiency and Renewable Energyhttp://www.eere.energy.gov/consumerinfo/factsheets/db5.html

3. Solar Cookers International http://solarcooking.org/newsletters/scrapr00.htm

4. Palmer Development Group http://www.ctech.ac.za/conf/due/SOURCE/Web/Sejake/Sejake.html

5. DSM http://www.dsm.com/en_US/html/about/about_us_home.htm

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