modelling legume soaking and cooking processes to control...
TRANSCRIPT
Modelling Legume Soaking and Cooking Processes to Control
Their Nutritional Value: Case of Chickpea
Pan African Grain Legumes and World Cowpea Conference, Livingstone, Zambia, 28 February - 4 March 2016 1
A. Briffaz, C. Mestres, N. Achir & P. Bohuon
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I/ Introduction / objective
• Tyson chickpea cultivar (« desi » type):
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Overall physicochemical composition (g.100g−1)
Starch 36.8
Protein 23.5
Fibre 24.9
Moisture 9.1
Fat 4.9
Vitamins
Folic acid (µg.100g−1) 149.7
Niacin (B3) (mg.100g−1) 1.8
Oligosaccharides (g.100g−1)
Stachyose 1.6
Raffinose 0.6
Verbascose Not detected
I.1/ Overall chickpea nutritional composition
I.2/ Introduction & Objective of the study
• Several levers that build food quality all through value chain:
• Lever here: Soaking-cooking process • Aim: Control the nutritional value of chickpea during
soaking-cooking using a modelling approach
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LEGUME CULTIVAR
DOMESTIC OR INDUSTRIAL
TRANSFORMATION
CONSUMERS
PRE-HARVEST
Genetics
Bio-agro-climatic conditions /
stresses
Processing variables
Nutrition Organoleptic
Easy to prepare Energy friendly
+ Technical & socio-
economic constraints =>
“Multi-criteria”
modelling approach
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II/ Chickpea traditional soaking-cooking process
II.1/ Physicochemical phenomena involved in chickpea grain during processing
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Water transport
Deformation (swelling)
Starch gelatinization =f(T°C, Water Content)
Vitamins B9 (transport & thermal degradation)
MECHANISTIC AND GENERIC APPROACH THAT CAN BE ADAPTED
TO ANY LEGUMES
Heat transfer
II.2/ Domestic and industrial issues
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Rinsing or not
Soaking – Long time
(≥12h)
- Ambient T°C => sanitary risks - Loss of nutrients in soaking water
Cooking: - Long time (≥1h) - Thermal degradation of micronutrients
III/ Modelling of chickpea soaking-cooking process
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III.1/ Model input parameters: cultivar & process
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III/ Comparison between
predicted profiles and texture
• Folate content • α-galactosides
…
• Starch gelatinization
• Protein denaturation
• Size (8.4mm)
• Water, protein, starch contents
• Time • Temperature • WC ratio
Soaking-cooking variables
Physico-chemical
composition
(Anti) Nutritional
composition
Thermal properties
III.2/ Model adjustment & validation
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0
20
40
60
80
100
120
0 4 8 12 16 20
fola
te re
tent
ion
(%)
Time (h)
Experimental
Model
Temperature (°C)
00.20.40.60.8
11.21.41.6
0 1 2 3 4 5 6
Wat
er co
nten
t (db
)
Time (h)
30°C
60°C
90°C
POLARIZED LIGHT MICROSCOPY ON COOKED (80°C) COWPEA CROSS SECTIONS (40µm):
Comparison of the gelatinization front thickness (mm) for t=60min and t=210min:
4mm
EXPERIMENTAL MODEL
4mm
EXPERIMENTAL MODEL
TRANSPORT
THERMAL
DEGRADATION
III.3.1/ Example of a cooking simulation (100°C/100min): water uptake
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III.3.2/ Example of a cooking simulation (100°C/100min): starch gelatinization
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III.3.3/ Example of a cooking simulation (100°C/100min): vitamin losses
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IV/ Identification of nutritionally optimal soaking-cooking scenarios
using the model
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IV.1/ Combined effect of soaking time (30°C) and cooking time (100°C)
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020406080
100120
0 5 10 15Wat
er te
mpe
ratu
re (°
C)
Time (h) Longest treatment
60%
Compromise to find with degree of cooking…
68min
SOAKING
COOKING
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Thank you for your
attention
[email protected] For further information:
UMR QualiSud Food Process Engineering Research Unit, Montpellier, France
Questions?