Technical Challenges (3) Flashcards
(41 cards)
what does “dietary fibers” include?
polymeric CHOS: cellulose, hemicellulose, pectin, gum
what are characteristics that fibers affect?
- color and flavor
- oil and H2O retention
- colloidal emulsion stability (improves)
- texture and gel formation
- other viscometric properties (eg. thickening and mouthfeel)
what are functions of cellulose in food formulations?
- stabilize foams and emulsions
- stabilize pectin and starch gels under heating
- modify textures
- improve adhesion
- replace fat and oil
- control ice crystal growth
what does cellulose not affect?
flavor
color
microbial contamination
describe the function of native cellulose powders in food pdts
- does not soften on hydration and heating
- may impart rough mouthfeel
describe benefits of using native cellulose in food pdts
- abundant
- cost effective
- inert and insoluble
- no caloric value
describe the production of colloidal MMC
- fibrous cellulose material is hydrolyzed to remove the paracrystalline region to form MCC
- add hydrocolloids (substance that forms gel in water) and CMC (carboxyl methyl cellulose) to form colloidal MMC
what is MMC
microcrystalline cellulose
describe the functional properties of MCC
- foam stabilizer
- emulsion stabilier
- heat stability w/ minimal loss of viscosity
- textural modifier (shortens texture or adds body)
- suspension aid of particulates
- replace fats and oils in emulsions
- controls ice crystal growth
- prevents aggregation of protein and other solids
- opacifier and whitening
what properties of starch is improved with the addition of MCC?
- improvement of heat and shear stability
- less starch thickener needed
what is CMC
carboxymethylcellulose
how is CMC chemically formed?
cellulose + alkali + chloroacetic acid = CMC
what requirement is needed for CMC to be water soluble?
degree of substitution of 0.45 or higher
in CMC, higher degree of polymerization = ____ (higher/lower) viscosity
higher
what differs chemically between different CMC?
- degrees of polymerization
- degrees of substitution
- uniformity of carboxyl methyl groups
describe solubility of CMC
soluble in cold water
- gives clear solutions w/ neutral flavor
what is the primary property of CMC?
what is it commonly used for?
- viscosity production
- used as a thickener and stabilizer
what are functional properties of CMC
- soluble in cold water
- increases viscosity
- stabilizer (b/d of anionic nature)
- improves water retention and water binding
- improves moistness and prolongs shelf life
- good film forming properties
what is HPMC
hydroxypropyl methyl cellulose
what structural/chemical components is HPMC characterized by?
- monomeric chain length
- degree of substitution
- ratios of hydroxypropyl and methyl substitution
MC and HPMC are soluble in ___ water but not in ___ water
cold; hot
what are major functional properties of HPMC?
- high emulsion stability
- extremely soluble in water
- good water retention
- reversible thermal gelation
- good resistance in acidic medium
- good film forming properties
describe the unique reversible thermal gelation property of HPMC
viscosity initially decreases with rising temp but then increases until a gel is formed
processes are reversible
describe solubility of HPC
water soluble (up to 40C) and organic soluble