9

Question 1

Why is something coloured?

cone and rods

Answer 1

• light from the sun, light bulbs, fluorescent bulbs) contains all visible wavelengths (why it is white)
• when white light (i.e. visible energy) interacts with an object a portion of this energy is absorbed with the remainder reflected or transmitted (passed through)  this is what we see
• an example: a carrot absorbed B and G and reflects
  yellow/orange/red

cones: colour
rods: light and dark

Question 2

Colouring Agents)

Functions:
7

Answer 2

• to restore the original appearance of the product/ingredient (correcting for food color changes during processing, packaging, distribution or storage) -> heat, light, chemical oxidation, enzyme reactions- some can lighten or darken or change colours completely
• to ensure product/ingredient colour uniformity (correct for natural colour variations and intensities)
• To intensify or introduce colour (association of flavor with colour)- purple= grape
• To protect flavors and light-sensitive vitamins (A and E) from photodegradation-> colourant absorbs wavelenght
• to give food an attractive appearance
• to help preserve product identity or
  Character ex. Ketchup, coke, mustard
• To serve as a visual indication of product quality

Question 3

Synthetic Food Colours

FD&C:

Answer 3

FD&C: food, drug and cosmetic designation
-> regulated; approved; safety; purity; consistency (2004 vs 2017 colour you buy will be the same- uniformity)
Acidic functional groups, conjugated, comprised of atoms with lone pairs  water solubility (12-20 g/100ml and colour [due to conjugation])

Question 4

Synthetic Food Colours

Two Types

Answer 4

a) dyes : - water soluble (powders (example jello)-and liquids)
- jones pop has high colorant content (99+%) high tinctoral strenghs

b) lakes : - chemically bound/strongly adsorbed on a carrier (e.g. aluminum hydrate: Al[OH]3) chemical compound being carried by an emulsifier
- lake is either oil soluble or via dispersion (chocolate milk)
- low colourant content (10-40%) so need to use more to get same effect (icings are hydrophobic)

Question 5

examples:
blue number 1
red number40

Answer 5

a) FD&C Blue No. 1 (bright greenish-blue): beverages, bakery goods, condiments, confections and dairy products
b) FD&C Red No. 40 (yellow-red): beverages, cereals, condiments, confections, dairy products, gelatins and puddings
- > rice krispies, cheerios, goldfish/rits crackers, Tylenol, mouth =wash, toothpaste, soaps, etc.

Question 6

Colourants (Colouring Agents)

FD&C Red No. 40: NOEL/NOAEL, ADI and EDI relationship

points to remeber when determining if the level is safe

Answer 6

• LD50 (mice and rats): 10 g/kg bwt
  
  • NOEL/NOAEL: 631 mg/kg bwt day
  • ADI of 7.0 mg/kg bwt day
  • 50 kg person: 50 kg x 7 mg/kg bwt day = 350 mg/day
  • EDI as a % of ADI: 17.91 (USA)/350 x 100% = ~5% only 5% of ADI

Points to remember: 1) assumption of maximum permitted levels (overestimation); (2) only 5% of ADI; (3) only 3% of noel/ noael; and (4) noel/noael safety factor of 100

Question 7

H) Colourants (Colouring Agents)

Toxicity

Answer 7

all have undergone extensive safety evaluation testing (>100 published studies)  no cmta (+ no reproductive disorders or negative growth implications)

- 1973: linking of behavioural disorders in children (hyperactivity/	learning disorders) with synthetic food colourant intake 	(“Feingold hypothesis”)  37 studies have shown no scientific 	linkage
- 2007 UK study (Southampton Study) again linked synthetic 	food colourants (6 tested) and hyperactivity in their study group 	of 3 and 8/9 year old children - the European Food Safety Authority assessed the results of 	the study and concluded:” the study provided only limited evidence that the additives had a small effect on the activity and attention of some children
- the FDA concluded (based on independent scientific 	assessment):” that no link was substantiated between the color additives (employed in the study) and behavioral effect”
- 2010 (EU): required warning labels on foods that contain any of 	the 6 colourants used in the UK study (3 of these are not 	approved for food use in the USA/Canada: quinoline yellow, 	ponceau 4R, and azorubine)-> Fd&c Red No. 40, Yellow No. 5 and Yellow No.6

Question 8

canda vs usa colour labeling

Answer 8

Canada

- in 2010 Health Canada requested input from consumers, food 	manufacturers and industry on possible amendments to the 	labelling of food colourants 
- the International Association of Color Manufacturers: supported the adoption of USA regulations (i.e. colourant names listed)	
- no change in product labelling in Canada to date
- ‘colour’ is what is labelled on the packaging

Question 9

the advantages of synthetic colourants

Answer 9

• extensively tested for safety/lack of toxicity
  
  • highly concentrated and pure (only need to use a little bit of it)
  • certified (consistency is maintained) (colour has to be the same)
  • wide range of colours can be produced (has the primary colours)
  • colours produced are acid, light and processing stable
  • application to a wide range of product formulations (can be an issue as they can be hydrophobic)
  • uniform final product colour
  • reproducible product colour
  • cost (cost efficient for the food industry

Question 10

GHB and GBL (-hydroxybutyric acid and -butyrolactone)

Answer 10

GHB and GBL (-hydroxybutyric acid and -butyrolactone) detection in drinks (date rape drugs)

- nervous system depressants, odourless/colourless, takes effect within 15-30 minutes and the effect can last 3-6 hours 
- a fluorescent sensor (GHB/GBL-orange) has been developed (March, 2014) that reacts with GHB or GBL to turn the drink orange