Foods can be characterized based on their mechanical properties particularly in terms of stress. What type of mechanical stress is most prevalent in fluids and viscous materials?
Shear Stress or Shear
Stress can act on food at different mechanical situations. What type of stress present in foods or AB materials if it has a varying effect?
Dynamic Stress or Dynamic
It is the term for the change in size or shape of a material in response to the applied force with a dimensionless ratio.
Strain
The ratio between the average normal stress (or pressure change) of a particular food sample over dilatation (or volume change/original volume) is termed as
Modulus or Bulk Modulus
Viscous occurs instantly with the application of stress and it is permanent. The rate of strain is proportional to the stress. The other term for viscous is
Flow Deformation
Shear stress and shear rate have two subscripts: z represents the direction of force and y represents the direction of normal to the surface on which the force is acting. A negative sign is introduced into the equation because the velocity gradient is negative. Themicroscopic form of this equation:
Newton’s Law of Viscosity
This mechanical property of food materials corresponds to a failure in the microstructure of the sample.
Bioyield Point
The unit of measure for viscosity is
Pa - Pascals
Texture Profile Analysis (TPA) compresses a bite-sized piece of food twice to simulate the chewing action of the teeth. Compression is usually set to ___% of the original length of the sample. What is the usual size of the sample?
1 cubic m.
We need a driving force to overcome resistance to transfer a property. The rate of a transfer process is given as _
Rate of a Tranfer Process= Driving Force/ Resistance
There are three modes of heat transfer: conduction, convection, and radiation. Under steady-state conditions, the rate of heat flow through a food material is defined by what law?
Fourier’s Law or Fourier’s Law of Heat Conduction
It is a wide group of analysis techniques used in science and technology to widely evaluate the properties of a material, component, or system without damage:
Non-destructive Techniques
A solid AB material may be comprised of free electrons and atoms bound to a periodic arrangement called a _:
lattice
A type of optical property measurement of foods that takes into account some physical structural features of the samples based on a specific wavelength of light:
Spectroscopic-based Techniques or Spectroscopy
What is the other term for “non-destructive” quality evaluation method?
Non-invasive
It is one of the first quality determinants of fresh fruits and vegetables judged by the buyer at the wholesaler, retailer, or consumer. The price and subsequent purchases may be more related to texture and flavor.
Visual Appearance
The sugar index in terms of soluble solids content (SSC) of any food material with juice content can be determined using a _:
Refractometer or Hand-held Refractometer
The unit of measure of SSC is _:
Brix or %Brix
It is a term which denotes a degree of excellence or a high standard or state:
Quality
The mechanical properties of food mainly result from the following factors, except for _:
a. Physical State
b. Structure
c. Pressure
d. Color
Color
True or False: Solid foods are mechanically characterized by compression tests or impact tests.
True
attract initial and continued purchases by consumers.
b.) Quality can be viewed from either a product or a consumer orientation.
c.) A consumer orientation views the product through the sensory perspective of the
consumer at the points of purchase and consumption
d.) Consumers often buy the first time based on appearance, but repeat purchases are
driven by expected quality factors determined by flavor compounds and texture
e.) Consumers may try a new product if attracted by its appearance and they are likely to
repurchase an item if it fails to deliver on the promise of that appearance.
Answer E
E
The following are four (4) major attributes that impart distinctive quality of a certain food
product upon evaluation, except for
a. Color and appearance
b. Flavor (taste and aroma)
c. Texture
d. Size and Shape
e Nutritional and Functional Values
Answer: D
