Fruit and Vegetables

Question 1

Definition of fruit and vegetables

Answer 1

Fruit: fresh part of the plant
Vegetable: part of the plant served raw

Question 2

General properties of fruits & vegetables

Answer 2

Fruit: acidic and sugary, grouped into divisions depending on structure and composition
Vegetable: derived from various parts of plants, huge genetic diversity

Question 3

General composition of fruits & vegetables

Answer 3

Depends on various components

• high in water
• low in protein and fat
• good source of digestible and fermentable carbohydrates
• good source of vitamins and minerals

Question 4

Describe structure of a plant cell

Answer 4

Vacuole - composed of water and substances in it
Chloroplasts & Mitochondria - energy conversion through photosynthesis and cellular respiration
Leucoplasts - stores starch as an energy source
Nucleus - controls reproduction and protein synthesis

Question 5

Describe 4 plant tissues and their functions

Answer 5

Dermal tissue - layer of protective tissue
Vascular Tissue - used to transfer food and water
Supporting tissue - parenchyma, collenchyma & sclerenchyma
Storage tissue - parenchyma cell tissue making up most of the edible portion of F & V

Question 6

Understand turgor & texture

Answer 6

Tugor: rigidity of plant cells from being filled with water
Texture: affected when the plant tissue is damaged or killed by storage freezing or cooking

Question 7

Know about the other cell constituents affecting texture

Answer 7

Cellulose - major component of cell walls
Hemicellulose & Lignin - cells walls thicken as the plant ages
Pectin substances - glue in the cell to hold plant cells to one another
Starch - granules of starch molecules within cells swell upon heating causing the cell to swell and become firm and plump

Question 8

Understand the major groups of pigments in fruits and vegetables

Answer 8

• Chlorophylls - contain chloroplasts (green)
• Carotenoids - fat soluble & pre cursor for vitamin A (yellow - orange - red)
• Anthocyanins - belong to flavanoid group (purple, red and blue)
• Anthoxanthins - colour depends on pH (violet or blue).
  - includes Tannins (colourless but turn dark when reacted with metal ions)

Question 9

Function of Elaioplasts

Answer 9

Storage of lipids and oils

Question 10

Factors affecting F & V production

Answer 10

• soil
• watering and fertiliser requirements
• actual days available to grow and ripen

Question 11

What is harvesting?

Answer 11

Collecting F & V at the specific time of peak quality in terms of colour, texture & flavour, in order to market them. This can be done by hand or by machine (which affects the quality and quantity)

Question 12

Respiration and its influence on harvested F & V

Answer 12

• F and V continue to respire after harvest
• influences storage packing and refrigeration requirements
• can cause growth of mould or damaged produce

Question 13

Difference between ripeness and maturity of F & V

Answer 13

• Ripeness: the optimum or peak condition of flavour, colour & texture
• Maturity: the condition of a F/V when it is picked

Question 14

Explain climacteric & nonclimacteric with examples

Answer 14

Climacteric = fruits producing ethylene gas during ripening

Nonclimacteric = fruits don’t produce ethylene (- don’t ripen after harvesting) & are ethylene sensitive

Question 15

Changes to F & V post-harvest

Answer 15

Carbs - starch decreases quickly and sugar increases post harvesting
Pectins - contributes to softening of produce
Organic acids: decrease during storage and ripening (important for fruit)

Question 16

Post-harvest factors needing consideration during storage

Answer 16

• Temp reduction and maintenance reduces the metabolic activity of produce and spoilage microorganisms
• Use of natural or synthetic chemicals
• Modified atmosphere (humidity)

Question 17

Define senescence

Answer 17

Quality decline in stored respiring F & V after harvesting

eg. Strawberry going white, to red, to gross

Question 18

Describe the processing of fruits (canning, freezing, juicing)

Answer 18

Canning

• harvesting
• fruit sorted and washed by machine
• cans are filled with fruit, followed by addition of syrup or juice
• cans are sealed and cooked
• cans are cooled and sold to consumers

Frozen

• after initial preparations, bags are filled with fruit and syrup is then added
• packages seals and frozen

Fruit Juice 
- Extraction
- Clarification (clearing)
- Deaeration (removal of air)
- Pasteurisation/High-pressure processing (HPP)
 - Concentration
 - Essence add-back (flavours)
 - Canning or bottling
- Freezing
Juices can also be blended or cold pressed by a hydraulic press

Question 19

Describe the processing of vegetables (canning and freezing)

Answer 19

Canning

• veges are washed and mechanically peeled
• put into cans or jars
• brine is added
• cans are sealed and cooked
• cooled and sold to consumers

Frozen

• veges are washed, cut and blanched / pre cooked to ensure they keep their natural colour and flavour
• veges are frozen and then bagged