Flashcards in Food Chemistry Deck (259)
Would a more hydrophilic substance have a higher or lower HLB than a hydrophobic substance?
Within what range of its pK is a buffering agent is effective?
Plus or minus 1 pH unit
Why do triglycerides normally soften slowly and don't have sharp melting points?
Triglycerides can contain up to three different fatty acids and each fatty acid will have a different melting point.
Why do seed proteins like soy protein have a high isoelectric point?
Most of the glutamic and aspartic acid residues are amidated
Which sugar alcohol has the same sweetness as sucrose?
Which of the following solution would exhibit the lowest aw? Which the highest? a) 1 M NaCl b) 1 M glycerol c) 1 M glucose d) 1 M sucrose e) 1 M CaCl2
Lowest – 1 M sucrose, Highest – 1 M CaCl2
Which of the following gums should not be included in a formulation of a product, which does not require heating? Locust bean gum, Guar gum, Xanthan gum, or Gum Arabic
locust bean gum
Which of the following are emulsifying salts for use in processing cheese? sodium tartrate, sodium chloride, potassium chloride, all of the above
sodium tartrate (a)
Which is more viscous: high DE or low DE corn syrup?
Which has a higher melting point: oleic or palmitic?
Which fatty acid would be expected to have the highest iodine value- linoleic, oleic, or linolenic?
Linolenic (18:3 - has more unsaturation) (oleic has 1 double bond, linoleic has 2 double bonds)
Which amino acids may form dehydroalanine?
Cysteine, cystine, serine, P-serine
Where is banana oil obtained from?
Trick question? No oil in bananas?
Where does isoamylase and pullinase attack on a starch molecule?
Breaks the alpha-1,6 bond between 2 glucose molecules
When hydrogen peroxide is added, a positive catalase test shows the formation of what?
When alpha-amylase attacks starch, what products are formed?
Alpha-amylase hydrolyzes alpha 1,4 glycosidic bonds producing glucose, maltose, and dextrins
What vitamin is a 6-carbon compound with a structure very similar to glucose?
Vitamin C (ascorbic acid)
What type of secondary protein structure is most prevalent in β-lactoglobulin?
What type of pectin will form gels if the pH is below 3.6?
High methoxyl pectin
What type of pectin interacts with divalent cations to form gels?
Low methoxyl pectin
What type of gum as three main fractions based upon increasing sulfate ester content, known as kappa, iota, and lambda?
What two sugars comprise lactose?
Glucose and galactose
What term is given to strongly hydrophillic macromolecular materials that dissolve or disperse in water producing a thickening or viscosifying effect?
What term describes the spontaneous loss of fluid from a food gel?
What term describes the ability of a fat to exist in multiple crystal forms?
What results from the hydrolysis of a specific Phe105-Met106 bond in kappa casein?
Destabilization of the casein micelles (cheese curd formation)
What protein is responsible for transferring iron from the intestine to the blood stream?
What non-nutritive protein is a major component of connective tissue?
What molecule is a polymer of α-D-galacturonic acid that is produced commercially by extraction of citrus fruits and apples and is used to make jelly?