Food Quality

1
Food Quality

• Food Chemistry and factors influencing the foods
  we eat

2
Food Quality

• Introduction
• HOW DO YOU DEFINE QUALITY ???
• Most important aspect of quality is safety
• Price is usually a reflection of quality
• Beyond nutrition, we often eat for pleasure,
  enjoyment, and even eatertainment.

3
Overall Quality Factors

• General Quality Factors
• Microbial safety first concern
• Prevent product tampering
• Nutritional quality
• Fat, protein, carbs, alcohol, vitamins, minerals,
  fiber, phytochemicals, etc
• Storage stability
• How long will the product last?

4
Standards of Quality

• Quality standards
• FDA - mandatory (21 CFR)
• Minimum quality standards and standards of
  identity
• Ice cream, mayonnaise, margarine, catsup
• USDA - optional
• Subjective evaluation of quality
• Beef Prime, choice, select, cutter, canner

5
Quality Control

• Quality control (QC)
• Lots and lots of jobs in the food industry in QC
• Insure quality of finished product by inspecting
  at several important control points
  
• Raw materials
• In-line processing
• Final product
• Storage
• Chemical composition and understanding of
  chemical reactions and mechanisms are vital to QC

6
Quality Control

• Quality control
• Objective testing for quality
• Such testing varies among food products
• Quality control charts - plot quality testing
  over time
• Establish control limits

Red out of control Yellow use caution Green
average
7
Food Quality

• Consumers judge quality using their senses
• Sight
• color, shape, obvious defects, etc.
• Taste
• Sweet, sour, bitter, salty
• Texture
• crispiness, smoothness, crunchy

8
Appearance

• Size and shape
• Size is easily measured
• Weight
• Count (per box)
• Visual look
• Automated sorters
• Shape is more difficult to measure

9
Weights and Measures

• 1 bushel 8 gallons
• 1 peck ¼ bushel
• Apples (1 bushel) 42-48
• Blackberries (1 gallon) 5-6
• Blueberries (1 gallon) 6-8
• Grapes (1 bushel) 44-55
• Oranges (1 box) 90
• Grapefruit (1 box) 85

10
Appearance

• Color
• Very important
• Several ways to measure
• Instrumental
• Sensory panel
• In this classwe will cover
• Browning reactions
• Natural and Certified colors

11
Flavor

• Flavor Taste Aroma
• 4 tastes sweet, sour, bitter, salty
• A 5th taste? .....umami (taste sensation)
• Not all scientists are convinced that umami is a
  unique taste
• Some say the sensation caused by umami is simply
  a taste enhancer
• Numerous odors (volatile, aroma-active compounds)
• In this class, we will examine some basic
  chemical parameters influencing food flavor

12
Toxicology

• Are there chemicals in our foods that are
  harmful?
• What is the relationship between dose and a
  harmful response?
• What is our responsibility to the public in the
  food industry?

13
Phytochemistry

• There are both nutrient and non-nutrient
  compounds in our foods.
• Phyto plant
• So a plant-based diet offers a diversity of
  compounds that have no known use for sustaining
  life.
• So why are these compounds important?
• If some of these compounds are good for us,
  then why dont we say they are essential?

14
Food Additives

• What does GRAS mean?
• Microbial inhibitors
• Antioxidants
• Sequestrants and chelating agents
• Emulsifiers
• Stabilizers and thickeners
• Bleaching and maturing agents
• pH control agents
• Food colors
• Sweeteners
• Flavoring agents
• Nitrites

15
Food Fermentations

• Can you name some fermented foods?
• There are several types of fermentations, all are
  based on some basic chemical parameters.
• What is it about these foods that we like
  (besides the alcohol?)

16
BeveragesPepsiCo

• Sierra mist
• Lipton brisk
• Fruitworks
• Aquafina
• Mug root beer
• Slice
• Mirinda
• Frappuccino
• Liption iced tea

• Pepsi
• Pepsi one
• Diet Pepsi
• Wild cherry Pepsi
• Pepsi twist
• Mountain dew
• Mtn Dew-Code Red

• Pepsi
• Tropicana
• Frito-Lay
• Quaker Oats

17
Irradiation

• Spices, potatoes, onions, some fresh fruits and
  vegetables, pork, poultry, beef
• Non-food uses
• If irradiated, must have a seal

Radura Seal
18
An Over-View of Food Chemistry and its Influence
on Food Quality

• Think about FOOD QUALITY and FOOD CHEMISTRY
• On a full sheet of paper..
• Using what you know or have learned thus far,
  list 2 things that influence your personal
  perception of food quality.
• Then briefly describe what aspects of food
  chemistry influence this perception of quality.
• i.e. The smell of cooked carrots can be good or
  bad.
• The good aroma is a function of their
  temperature (hot or cold) and the presence of
  volatile terpenoids that I personally like. A
  bad aroma can result when carrots are
  over-cooked or canned, giving them a metallic
  taste.