Proteins, sugars and fatty acids

Question 1

What can a ruminant diet contain?

Answer 1

Ruminant diet can contain natural plant polyesters (cutin), thus hydrolytic enzymes may be present

Question 2

Why are plastic digesting enzymes important?

Answer 2

Huge unexplored potential
Authors analysed ocean and soil metagenomes to assess the global potential of micro-organisms to degrade plastics

Question 3

Across the global microbiome what are the plastic degrading enzyme hits?

Answer 3

11,906 enzyme hits (ocean) and 18,119 (soil)
Potential to degrade up to 10 and 9 different plastic types was observed

Question 4

What is an application of proteins in the food industry?

Answer 4

Anti-freeze proteins (AFP)
Freezing point (FP) of marine fish body fluids: -0.7 degrees
AFPs change FP ca. -2.2 to -2.7 degrees, below ambient temp. -1.91 degrees

Question 5

What are the known modes of action of the AFP?

Answer 5

• Antifreeze- forces curvature, prevents larger formations
• Ice re crystallization inhibition- inhibits water movement
• Ice structuring- keeps channels open
• Ice adhesion

Question 6

What are the application of AFP?

Answer 6

Cryopreservation
Cryosurgery
Food preservation/texture
Transgenics

Question 7

What is an example of a fish protein?

Answer 7

Collagen/gelatin
Used extensively in food, cosmetic and biomedical industries

Question 8

How are collagen and gelatin structured?

Answer 8

Collagen- triple helix of 3 protein chains
Gelatin- Partially hydrolysed form of collagen

Fish collagen rich in amino acids glycine, alanine, valine and proline- widely sold as nutraceutical

Gelatin: gelling agent in food, medications, drug/vitamin capsules, photographic films and cosmetics

Question 9

What do carbohydrates contain?

Answer 9

Contain carbon, hydrogen and oxygen

Question 10

What are monosaccharides, disaccharides and polysaccharides?

Answer 10

Monosaccharides: simple sugars, 3 to 7 carbon atoms e.g glucose, fructose

Disaccharides: two monosaccharides linked via glycosidic linkage e.g. maltose

Polysaccharides: repeating units of simple sugars e.g. starch, glycogen

Question 11

What is important in the production of polysaccharides?

Answer 11

Marine macroalgae
Gelling properties, used as nutraceuticals
Can also provide pigments for use as cellular labels

Question 12

What are the major polysaccharide groups?

Answer 12

Agars: red algae
Aliginites: brown algae
Fucans: fucose containing, sulphated polysaccharide
Laminarins
Carrageenans: repeating galactose polymers

Question 13

What is agar used for?

Answer 13

Agar: widely used as gelling agent in food, microbiology, dentistry, molecular biology
Mixture of agarose and agaropecten
Agarose- repeating structure of galactose/anhydro alpha galactose
Agaropecten- contains sulphate groups which influence gelling properties

Retains liquid
Resistant to microbial hydrolysis

Question 14

What are Alginates?

Answer 14

Copolymer of mannuronic/guluronic acid, usually arranged in blocks
Soluble in water, forms gels at RT in presence of bivalent ions
Widely used in frozen foods, dressings, dentistry

Question 15

What are fucans/fucoidins?

Answer 15

Fucans: can be classified into
a. fucoidans
b. xylofucoglycuronans
c. glycorunogalactofucans

Sulphated polysaccharides

Question 16

What are laminarins

Answer 16

Laminarins: polysaccharide of glucose
Storage carbohydrate in brown algae

Question 17

What are the carrageenans?

Answer 17

A group of polysaccharides, which are repeating sequences if sulphated galactose and anhydro-beta-D-galactose

Question 18

How are the carrageenans divided?

Answer 18

Into 6 groups
Based on degree of sulphation, extraction methods and solubilities: kappa, iota, lambda, mu, nu, beta, and theta

Question 19

Why are the carrageenans valuable?

Answer 19

Valuable in the food industry because of their moisture binding and stabilizing properties
Widely used used to control consistency/texture of food, toothpaste, gel products and commonly used in milk products in particular
Obtained from several red algae
Potent inflammatory properties

Question 20

What polysaccharides are from crustaceans?

Answer 20

Chitin
Chitosan

Question 21

What are chitin and chitosan?

Answer 21

By products from bioprocessing plants
Accumulation of chitin increasing, slow degradation

Chitosan: derived from chitin by removal of alkyl groups

Question 22

What is the bioactivity of chitosan?

Answer 22

Chitosan/oligers reduce LDL-cholesterol
Anti cancer activity against lung cancer cells by stimulation of cytotoxic T lymphocytes
Wound healing- linked to release of cytokines

Chitin- anti-microbial and anti-oxidant properties

Question 23

What are lipids?

Answer 23

Highly polymorphic, contain principally carbon and hydrogen
Largely insoluble in water, inclusion of functional groups containing oxygen alters hydrophobicity

Question 24

What are omega 3-fatty acids?

Answer 24

Long chain, polyunsaturated fatty acids
Fatty acid: carboxylic attached to H-C chains
>1 double bond = unsaturated
Common sources- fish, shellfish
Importance:
- Membrane structure
- Signal transduction

Question 25

What is the nutraceutical market?

Answer 25

Term coined in 1989
Refers to raw foods, fortified foods or dietary supplements containing biologically active molecules, that provide health benefits beyond basic nutrition

Global market estimated at $250 billion in 2014
Fatty acids a major part of the market, but examples also include polysaccharides, proteins/peptides, phytochemicals, vitamins