hirschler

AIC 2010 Color and Food, Mar del Plata, Argentina, 12-15 October 2010

Whiteness, Yellowness and Browning in Food Colorimetry – a Critical Review Robert HIRSCHLER SENAI/CETIQT Colour Institute Rio de Janeiro, Brasil

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?

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)

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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 of surimi

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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!

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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-280 and -4 < Tw < +2

+

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Yellowness indices 1. CIE b* (or Hunter b) 2. YIE313 = 100 (CXX â&#x20AC;&#x201C; CZZ) / Y 3. WIFC = 142.86 b* / L*

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Yellowness indices 1. CIE b* (or Hunter b) 2. YIE313 = 100 (CXX â&#x20AC;&#x201C; CZZ) / Y 3. WIFC = 142.86 b* / L*

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Yellowness indices 1. CIE b* (or Hunter b) 2. YIE313 = 100 (CXX â&#x20AC;&#x201C; CZZ) / Y 3. YIFC = 142.86 b* / L* (Francis-Clydesdale?)

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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 / ?)

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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 / ?)

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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

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Case studies 他 ~ 300 articles in over 40 journals where some kind of WI, YI or BI occurs 他 Measurement conditions and detailed data obtained from the authors 他 8 case studies reported, 4 of which to be discussed

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Vargas et al. (2008)

Case study #1

Sensory characteristics of yoghurt “The addition of GM caused an increase in L*, h* and WI … the differences were only significant between the 0% and 100% formulations.”

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Arslan and Özcan (2010)

Case study #4

Drying of onion slices: effect of sun, oven and microwave drying on quality “Microwave oven drying revealed better colour AIC 2010 Mar del Plata values in the dried products”

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Taskaya et al. (2010)

Case study #5

Colour improvement in surimi “whiteness of restructured fish products … can be similar to AIC 2010 Mar del Plata the whiteness of surimi seafood”

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Taskaya et al. (2010)

Case study #5

Colour improvement in surimi “whiteness of restructured fish products … can be similar to AIC 2010 Mar del Plata the whiteness of surimi seafood”

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Sheehan et al. (2009)

Case study #6

Sensory characteristics of semi-hard cheeses â&#x20AC;&#x153;There was no significant effect of milk type on cheese AIC 2010 Mar del Plata whiteness (L* value)â&#x20AC;?

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Conclusions 1. 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. â&#x20AC;&#x153;Whiteâ&#x20AC;? 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 19

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. Mayoyes Alvarez 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.

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