Life Cycle Inventory of different forms of Rice

by

Poritosh Roy, Tsutomu Ijiri, Daisuke Nei, Hiroshi Okadome, Nobutaka Nakamura, Yutaka Ishikawa and Takeo Shiina

Distribution Engineering Laboratory,National Food Research Institute, Tsukuba, Japan

Introduction

Rice is a staple food for nearly two-thirds of the world’s population.

However, rice consumption has been decreasing since 1960s, leads to develop different value added rice products to stabilize the rice consumption.

Fig. 2 Rice consumption trends in Japan (source: MAFF)

White rice, partially milled, brown rice, germinated brown rice, rice bread etc.

0

40000

80000

120000

160000

200000

Japa

nBan

glade

sh

China

India

Thaila

ndInd

ones

iaViet

Nam

Producing countries

Pro

duct

ion

(x10

00 t)

199520002005

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1985 1990 1995 2000 2002 2003

Consumption years

Per

cap

ita c

onsu

mpt

ion,

kg

Fig. 1 Rough rice production in major rice producing countries (source: FAO)

Population in 2005:Japan: 127.42 millions; Bangladesh: 146.7 millions (168 kg/person-year)

Table 1 Food components of riceRice variety Rice Milling

Type Degree, Energy, Protein, Thiamin Riboflavin Niacin, Dietary% kJ g (B1), mg (B2), mg mg fibers, g

1Brown rice 0 1456 10 0.41 0.04 6.3 3Japonica

1Partially milled 4-5 1473 9.5 0.3 0.03 3.5 1.41Partially milled 6-7 1485 9.4 0.24 0.03 1.7 0.91White rice 8-10 1485 9.2 0.08 0.02 12 0.52Germinated brown rice 0 1403 8.2 - - - 4.2

Indica3Milled parboiled rice 7-8 1544 - - - - -

1Upland rice; Food coposition table, 2000, Japan2Ohtsubo et al., 20053FAO

Food Components per 100 grams

Greenhouse gas emission has been increasing remarkably by a tremendous use of energy resulted global warming, is perhaps the most serious problem mankind faces today.

According to the Kyoto Protocol Japan has agreed to reduce its Greenhouse Gases (GHGs) emission 6% below the 1990 level by 2012.

Reducing its energy-derived CO2 emission to 1990 level is a prerequisite for achieving this target.

Agriculture and in particular rice production has been named as a significant contributor to greenhouse gas emission (primary and secondary).

This study attempts to evaluate the life cycle of rice (well milled, partially milled, brown rice, and parboiled milled rice) to determine if CO2emission can be reduced.

comparison of alternative produces, processes or services,

comparison of alternative life cycles for a certain product or service,

identification of parts where the greatest improvement can be made.

The purpose of an LCA can be:

Methodology

Milling: 8%Milling: 2% Milling: 5% Milling: 10%

Paddy Brown rice Germinated brown rice

Fig. 3 Photographs of paddy and different forms of rice

Fig. 4 Flow diagram of the life cycle of different forms of rice

The functional unit of this study is defined as the mass of the product i.e., 1 kg of rice (well milled or partially milled or brown or white or parboiled) consumed at households.

Cooking: Rice cooker

Cultivation

Harvesting Paddy Consumption Milling

Dehusking

Parboiling

Brown rice

Transportation/Packaging/Retail shop/Washing

CookingParboiled rice

Partially/well milled rice

Seedling

Dehusking

Dehusking Milling Waste

De-husking

Milling

Pre-steaming7-15 min

Soaking12-24 h

Steaming5-80 min

Drying14% mc

Parboiled Rice

Trad

ition

al p

arbo

iling

pro

cess

Fig.5 Flow diagram of the production process of parboiled rice

Fig. 6 Local parboiling devices

Capacity: 5-10 t/batch

FAO, 1997

Rice cooker

Earlier model

Latest model

Household energy ladder typical in south Asia (Smith et al., 1994)

Fuel wood collection by children and women

FAO, 1997

Fig. 7 Fuel wood collection, household energy ladder and cooking devices

Inventory analysis and data collection:Table 2 Data and the data sources for the inventory analysis

Tahara, 20050.011/kg-white riceWaste managementTahara, 20050.054/ kg-white riceTransportationTahara, 20050.008/kg-white ricePackagingNIAES, 20030.334/kg-brown riceProduction

SourcesCO2 emissionSystems

Energy consumption in milling processes were measured at laboratory and at a local farm.

Cooking processes were studied in the laboratory.The emission from the postharvest phases of parboiled rice was also collected from the literature (Roy et al., 2005).

Results and Discussion

Fig. 8 Energy consumption in the cooking processes

NH-PA10-HH: 1L (5.5 cup); NP-GA05-XA: 0.54L (3 cup)

White rice: 1.5Brown rice: 1.875

0.00.2

0.40.6

0.81.0

1.21.4

1.6

1-cup 2-cup 3-cup 5-cup

Ammount ofrice (180 ml/cup)

Ener

gy c

onsu

mpt

ion,

kW

h/kg Brown-NH-PA10 Brown-NP-GA05

White-NP-GA05

Fig. 9 Temperature and energy consumption patterns of different cooking processes (well and partially milled rice)

Cooking time, min

W e ll m ille d

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ture

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T -c o o k e rE ne rg y

Partia lly milled

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ture

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Ener

gy c

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kWT-room

T-cooker

E nergy

Fig. 10 Temperature and energy consumption patterns of different cooking processes (GBR and brown rice)

GBR

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0 20 40 60 80Cooking time, min

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ture

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Energy

Brown

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Cooking time, min

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T-roomT-cookerEnergy

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0 1 2 3 4 5 6 7 8Soaking time, h

Moi

stur

e co

nten

t, %

(w.b

.)

Brown Milled 10%Milled 8% Milled 5%Milled 2%

Fig. 11 Cooked rice

b. Partially milled

d. Parboiled ricec. Brown rice

a. white rice

Table 3 Energy consumption and quality indices of cooked rice

Type Water- Cooking Energy Cooked Hardness,of rice time, consumption, rice, Nrice ratio min kWh/kg MC%

Well milled 1.5 45.9 0.333 60.5 10.6Partially milled 2% 1.6 51.2 0.367 59.9 12.7Partially milled 5% 1.6 49.9 0.352 60.7 12.7Partially milled 8% 1.6 51.4 0.366 60.3 11.4GBR 1.5 64.2 0.404 65.1 10.9Brown rice 1.9 81.9 0.571 64.8 13.2Parboiled 2.5 48.6 0.433 67.9 13.9GBR: germinated brown rice

Fig. 12 LCI of different forms of rice

0.0

0.2

0.4

0.6

0.8

1.0

Milled Partially-milled 2%

Partially-milled 5%

Partially-milled 8%

Brown Parboiledmilled

Types of rice

CO

2 em

issi

on, k

g/kg

-ric

e

Production Parboiling

Milling Packaging

Transportation CookingWaste management

Fig. 13 LCI of different forms of rice (includes GBR)

0.0

0.2

0.4

0.6

0.8

1.0

Milled Partially-milled

2%

Partially-milled

5%

Partially-milled

8%

Brown Parboiledmilled

GBR

Types of rice

CO

2 em

issi

on, k

g/kg

-ric

e

Production ParboilingMilling PackagingTransportation GerminationCooking Waste management

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0.35

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Milled Partially-milled 2%

Partially-milled 5%

Partially-milled 8%

Brown Parboiledmilled

GBR

Types of rice

Em

issi

on, k

g/kg

-coo

ked

rice

Production ParboilingMilling PackagingTransportation GerminationCooking Waste management

Fig. 14 LCI of different forms of rice (based on the mass of cooked rice)

0

10

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30

40

50

60

Milled Partially-milled 2%

Partially-milled 5%

Partially-milled 8%

Brown Parboiledmilled

GBR

Types of rice

Em

issi

on, g

/MJ

of c

ooke

d ric

e

Production ParboilingMilling Packaging

Transportation GerminationCooking Waste management

Fig. 15 LCI of different forms of rice (based on the energy content of cooked rice)

Conclusions

The inventory was found to be increased gradually from partially milled rice to parboiled rice.

A change in rice production process and consumption pattern would reduce the energy consumption and environmental load from the rice life cycle.

However, taste of rice and its acceptability have to be considered for a method switching.

Motivation and awareness on environment and health are required for method switching.

The method switching would reduce environmental load from the rice industry and lead to reduce deforestation and global warming potential.