Q1. Membrane processing includes which of the following methods?

1. Ultrafiltration
2. Reverse osmosis
3. Microfiltration
4. All of the above

ANSWER: 4. All of the above

• Explanation: Membrane processing is used in the dairy industry for non-thermal processing to maintain the majority of the nutrients and is primarily employed in the production of health and functional meals by concentrating and fractionating different components. Membrane processing includes Ultrafiltration, reverse osmosis, microfiltration, and electrodialysis.

READ MORE – FOOD TECHNOLOGY (22/08/2021)

Q2. ________ membrane module contains one or more membrane envelopes, each of which contains two layers of membrane separated by a porous permeate conductive material.

1. Spiral wound
2. Hollow fiber
3. Tubular module
4. Plate and frame design

ANSWER: 1. Spiral wound

• Explanation – Each membrane envelope in a spiral wound is made up of two layers of membrane separated by a porous permeate conductive substance. The permeate channel spacer allows permeating to flow freely through the membrane. To produce the membrane envelope, the two layers of the membrane with the permeate channel spacer between them are sealed with adhesive at two edges and one end. A perforated permeate collection tube is linked and sealed to the open end of the envelope.

READ MORE – FOOD TECHNOLOGY (12-09-2021)

Q3. __________ is termed as decline in flux.

1. Rejection
2. Fouling
3. Retentate
4. Permeate

ANSWER – 2. Fouling

• Explanation: When all operating parameters such as pressure, flow rate, temperature, and feed concentrations are kept constant, fouling is defined as a decrease in flux. It can be avoided by pretreatment of the feed, maintaining a minimum axial velocity, increasing the dynamic pressure of the flow, and maintaining a pH far away from the isoelectric point for proteinaceous feed.

READ MORE – FOOD TECHNOLOGY (02/08/2021)

Q4. _______ is the oldest membrane technology, having been used several decades before the first industrial use of reverse osmosis.

1. Microfiltration
2. Ultrafiltration
3. Flux
4. Concentration polarization

ANSWER: 1. Microfiltration

• Explanation: Microfiltration is the oldest membrane technique, having been utilized for decades before reverse osmosis became widely used in industry. MF is a pressure-driven system that uses far lower pressures than other systems, including Reverse Osmosis. In reality, the distinction between UF and MF is arbitrary, and there is no distinction based on pure theory.

READ MORE – FOOD TECHNOLOGY (22/07/2021)

Q5. The rediffusion of concentrated solids back into the feed is governed by __________.

1. Poiseuille’s law
2. Reverse osmosis
3. Fick’s law
4. Water flux

ANSWER – 3. Fick’s law

• Explanation – Concentration Polarization is described as an increase in solids concentration in the direction of the membrane as a result of permeate extraction across the membrane. Fick’s law governs the redistribution of concentrated materials back into the feed. The diffusion of molecules is described by this law.

• DAB (dcA / dz) – JAB

READ MORE – FOOD TECHNOLGY (21-09-2021)