6-Off-Flavors and Taints in Foods Flashcards

1
Q

How Sensory evaluators differentiate off-flavor testing

A
  • Improved sensitivity descriptors or scale of intensity

- experience, ability to describe, or sensitivity to the stimulus

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2
Q

Methods to distinguish off-flavors

A
  1. when source is known - use panelist sensitive to flavor defect
  2. 30 people use triangle test
  3. Using discrimination test and do it rapidly
  4. Get as much information as possible and combine with hedonic test
  5. Using Level of significance (Statistical Method)
  6. Don’t ignore minority opinion
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2
Q

Sources of Food Taints

A
  • Airborne
  • Waterborne
  • Disinfectants, Pesticides, and Detergents
  • Packaging
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3
Q

How airborne taints goes into the food

A
  • Production
  • Manufacturing
  • Storage
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4
Q

Barny/Cowy off-flavors are formed due to _______

A

Poor Ventilation

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5
Q

Challenge of Airborne sources taints are

A
  • Difficult to identify
  • May occur randomly
  • Chemicals occur at low threshold and difficult to isolate and identify
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6
Q

Chloroanisole cause _____ off-flavor and Chlorophenol cause _____ off-flavor

A

Musty ; Medicinal taints

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7
Q

2 Sources of Waterborne Taints

A
  • Environment

- Major ingredients in food processing

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8
Q

Biological and Chemical factors that cause waterborne taints

A
  • Bacteria and Algae
  • Kerosene
  • Iodine
  • Geosmin
  • Isoborneol
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9
Q

Cause of Disinfectants, Pesticides, Detergents taints in foods is

A
  • Negligence by end-user

- Error in manufacturing part during cleaning

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10
Q

Risk of contamination can increase along with ________

A

Storage time

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11
Q

2 genetic type that cause off-flavors

A

Swine and Ovine

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12
Q

The differences between swine and ovine off-flavors

A
Swine
- Severe impacts to industries- persisting problem
- onion sweaty manure - like notes
- 92% female can detect
- Prevent by vaccination or breeding
Ovine
- actual flavor of mature ovine animal
- Mutton or Sweaty notes
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13
Q

at which level (ppb) bromophenol become desirable flavor

A

low level ( 3ppb )

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14
Q

Higher bromophenol compounds cause _______-like taints

A

Iodine

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15
Q

Off-flavors that is caused by chemical changes

A
  • Lipid Oxidation
  • Non-enzymatic Browning
  • Photo-induced off-flavors
  • Enzymatic flavor Changes
16
Q

Characteristic of lipid oxidation off-flavors are

A
  • Stale
  • Cardboard
  • Tallowy
  • Metalic
  • Painty
  • Fishy
17
Q

6 factors of lipid oxidation that cause off-flavors are

A
  • Length of the C-chain
  • Presence of the trace metals ( Co2+, Fe2+, and Cu2+ )
  • Level of Water activity
  • Temperature
  • Light exposure
  • Presence of antioxidants
18
Q

Light cause _______ and _______ which results off-flavors

A
  • Protein degradation

- Lipid Oxidation

19
Q

How to prevent photo-induced off flavors

A
  • Packaging with light impermeable bottles/ cans

- Pre-processing of hops - reduction to make saturated isohumulones

19
Q

Enzymatic Flavor Changes common cause

A
  • Lipoxygenase
  • Lipase
  • Protease
20
Q

Lipoxygenase involved in _________ of unsaturated fatty acid

A

autooxidation

21
Q

Lipoxygenase mechanism that cause off-flavors

A

Tissue damage - decompartmentalization - exposure

22
Q

Method to prevent lipoxygenase deteroriation

A

Blanching ( high temperature inactivate the enzyme )

23
Q

Milk lipase perferentially cleave _______ from Traicylglycerol

A

Butyric Acid

24
Q

Prevention of Microbial off-flavors

A
  • Heating
  • Irradiation
  • Addition of chemical preservative
  • Addition of antimicrobial agent
25
Q

3 main cause of microbial off-flavors

A
  • Fermentation goes wrong
  • Microbial enzyme
  • growth of microbes in food
26
Q

How microbes cause off-flavors in fresh fish

A

Trimethylamine oxide goes into trimethylamine due to bacterial enzymes

27
Q

Microbes that cause “earthy” taints

A

Molds and Actinomycetes

28
Q

Hypopichia burtanii cause _____-like smell due to ________ content

A

Plastic ; Cinnamon

29
Q

Malty-notes off flavors are cause by __________ bacteria

A

Lactobacillus maltaromicus

29
Q

Malty-notes off flavors are cause by __________ bacteria

A

Lactobacillus maltaromicus