Lecture 11: Preservation Flashcards Preview

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Flashcards in Lecture 11: Preservation Deck (8):
1

What is the mechanism behind why nitrites act as a preservative in food products like bacon?

See slide 6; remember how nitrites react with Fe, and how this is significant both for preserving color and inactivating microorganisms.

2

What is the Code of Federal Regulations?

See the pre-class story from this lecture for a description.

3

How does the Code of Federal Regulations define a low acid food, and an acidic food?

See slide 4; I would recommend that you know the table on this slide.

4

Why are nitrates/nitrites more effective at killing microorganisms in acidic foods?

See slide 6 for a full description (has to do with the pKa)

5

What are two functions of ascorbate/isoascorbate in foods supplemented with nitrites?

1) favors the reduced form; 2) limits production of nitrosamines.

6

The most common food ingredient added, that allows food manufacturers to label "no nitrate/nitrite added", while actually increasing the level of these compounds, is _______

Celery salt

7

What is the mechanism of killing of sulfites?

Targets membranes, protein synthesis, DNA....is a general inhibitor

8

What enzyme do sulfites inhibit that reduces browning in fruits?

polyphenol oxidase