hirschler
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Robert Hirschler (Brazil): Whiteness, yellowness and browning in food colorimetry – a critical reviewTRANSCRIPT
Whiteness, Yellowness and Browning in Food
Colorimetry – a Critical Review
Robert HIRSCHLERSENAI/CETIQT Colour Institute
Rio de Janeiro, Brasil
AIC 2010 Color and Food, Mar del Plata, Argentina, 12-15 October 2010
Whiteness, Yellowness and Browning in Food
Colorimetry – a Critical Review
Are these indices properly used?Are they used for the purpose they were meant to be used?
AIC 2010 Mar del Plata 3
Whiteness indices
1. CIE L* (or Hunter L)
2. WIJUDD = 100 – [(100 – L*)2 + (a*)2 + (b*)2]1/2
3. WIHUNTER = L – 3b (or L* – 3b*)
4. WICIE = Y + 800 (xn – x) + 1700 (yn – y)
AIC 2010 Mar del Plata 4
Whiteness indices
1. CIE L* (or Hunter L)
2. WIJUDD = 100 – [(100 – L*)2 + (a*)2 + (b*)2]1/2
3. WIHUNTER = L – 3b (or L* – 3b*)
4. WICIE = Y + 800 (xn – x) + 1700 (yn – y)
+National Fisheries Institute (1991)A manual of standard methods for measuring and specifying the properties ofsurimi
AIC 2010 Mar del Plata 5
Whiteness indices
1. CIE L* (or Hunter L)
2. WIJUDD = 100 – [(100 – L*)2 + (a*)2 + (b*)2]1/2
3. WIHUNTER = L – 3b (or L* – 3b*)+
4. WICIE = Y + 800 (xn – x) + 1700 (yn – y)
+ Use with caution!
AIC 2010 Mar del Plata 6
Whiteness indices
1. CIE L* (or Hunter L)
2. WIJUDD = 100 – [(100 – L*)2 + (a*)2 + (b*)2]1/2
3. WIHUNTER = L – 3b (or L* – 3b*)
4. WICIE = Y + 800 (xn – x) + 1700 (yn – y)+
+ Limits: 40 < W < 5Y-280and -4 < Tw < +2
AIC 2010 Mar del Plata 7
Yellowness indices
1. CIE b* (or Hunter b)
2. YIE313 = 100 (CXX – CZZ) / Y
3. WIFC = 142.86 b* / L*
AIC 2010 Mar del Plata 8
Yellowness indices
1. CIE b* (or Hunter b)
2. YIE313 = 100 (CXX – CZZ) / Y
3. WIFC = 142.86 b* / L*
AIC 2010 Mar del Plata 9
Yellowness indices
1. CIE b* (or Hunter b)
2. YIE313 = 100 (CXX – CZZ) / Y
3. YIFC = 142.86 b* / L* (Francis-Clydesdale?)
AIC 2010 Mar del Plata 10
Browning indices
1. BIABS = A420; A340; A400; R570/R650
2. BIL* = L*; 100 – L*; 100/L* (or Hunter L)
3. BIBUERA = 100 (xc – 0.31)/0.172 (C / 2o)
100 (xD65 – 0.32)/0.162 (D65 / ?)
AIC 2010 Mar del Plata 11
Browning indices
1. BIABS = A420; A340; A400; R570/R650
2. BIL* = L*; 100 – L*; 100/L* (or Hunter L)
3. BIBUERA = 100 (xc – 0.31)/0.172 (C / 2o)
100 (xD65 – 0.32)/0.162 (D65 / ?)
AIC 2010 Mar del Plata 12
Browning indices
1. BIABS = A420; A340; A400; R570/R650
2. BIL* = L*; 100 – L*; 100/L* (or Hunter L)
3. BIBUERA = 100 (xc – 0.31)/0.172 (C / 2o)
100 (xD65 – 0.32)/0.162 (D65 / 10o)+
+Elbert, Tolaba & Suárez ⇒ Bhattacharya
AIC 2010 Mar del Plata 13
Case studies
~ 300 articles in over 40 journals where some kind of WI, YI or BI occursMeasurement conditions and detailed data obtained from the authors 8 case studies reported, 4 of which to be discussed
AIC 2010 Mar del Plata 14
Case study #1
Sensory characteristics of yoghurt
Vargas et al. (2008)
“The addition of GM caused an increase in L*, h* and WI …the differences were only significant between the 0% and100% formulations.”
AIC 2010 Mar del Plata 15
Case study #4
Drying of onion slices: effect of sun, oven and microwave drying on quality
Arslan and Özcan (2010)
“Microwave oven drying revealed better colourvalues in the dried products”
AIC 2010 Mar del Plata 16
Case study #5
Colour improvement in surimi“whiteness of restructured fish products … can be similar to the whiteness of surimi seafood”
Taskaya et al. (2010)
AIC 2010 Mar del Plata 17
Case study #5
Colour improvement in surimi“whiteness of restructured fish products … can be similar to the whiteness of surimi seafood”
Taskaya et al. (2010)
AIC 2010 Mar del Plata 18
Case study #6
Sensory characteristics of semi-hard cheeses“There was no significant effect of milk type on cheese whiteness (L* value)”
Sheehan et al. (2009)
AIC 2010 Mar del Plata 19
Conclusions1. Measurement parameters (illuminant, observer, geometry
or even Hunter Lab or CIELAB) are very often not precisely (or not at all) given.
2. Colour parameters (L*; a*; b*; DE*, WI, YI, BI) are very often used in an arbitrary, inadequate manner.
3. “White” food products generally are not white enough for the WICIE to be used.
4. Using WIJUDD (or L*) instead of WIHUNTER or a YI or BI can often lead to erroneous conclusions.
5. The correlations among b*; YIFC, YIE313 and BIBUERA may be very strong or very weak depending on the sample sets.
6. There seems to be a crying need for more colour education in the proper application of colour measuring equipment in the food industry
AIC 2010 Mar del Plata 20
ACKNOWLEDGMENTS
The author would like to thank Dr. Ana Salvador Alcaraz, Ms. Derya Arslan, Dr. Yi-Zhong Cai, Dr. María Vargas Colás, Dr. Jacek Jaczynski, Dr. Diarmuid Sheehan, Dr. Ivan Švec and Dr. MayoyesAlvarez Torres, corresponding authors of the publications on which the case studies have been based, and to which they have kindly provided measurement details and additional data.