Fruit/Veg Processing

Question 1

cell wall of young plants are thin and composed mostly of ____ and held together by ___

Answer 1

cellulose; pectin

Question 2

with aging of plants, wall thickens and higher amount of ____ and ____

Answer 2

hemicellulose; lignins

Question 3

colours of fruits/veg due to these pigments in chloro/chromoplasts:

Answer 3

anthocyanins, carotenoids, chlorophylls

Question 4

fruits are good source of:

Answer 4

natural sugar, organic acid, flavour comps, bioactive phytochem, specific vit. and min.

Question 5

grapes and strawberries are examples of ____ fruits

Answer 5

non-climacteric (harvest fully ripened)

Question 6

apples and bananas are examples of ____ fruits

Answer 6

climacteric (harvest when immature)

Question 7

what is senescence?

Answer 7

phase associated with deterioration of fruits and veg caused by aging, tissue death, loss of quality (overripe/inedible)

Question 8

4 phases of postharvest changes in fruits/veg

Answer 8

growth, maturation, ripening, senescence

Question 9

plant hormone that plays key role in ripening/senescence

Answer 9

ethylene

Question 10

effect of ethylene on F+V?

Answer 10

break down chlorophyll, new pigments, acids break down, amylase degrade starch to sugar, break down pectin (soften), breakdown large organic cules to produce aroma/tastes

Question 11

climacteric fruits produce ___ level of ethylene when ripening, non-climacteric produce ____ ethylene during ripening

Answer 11

high; no

Question 12

ethylene is used as ___agent in citrus

Answer 12

de-greening

Question 13

what is metabolic process by which cells convert energy from one chem structure to another?

Answer 13

respiration

Question 14

in ______ little energy is reserved and there is excessive respiration, will eventually lead to metabolic collapse

Answer 14

leafy crops

Question 15

speed of post-harvest water loss depend on ______

Answer 15

external vapour pressure

Question 16

products with large SA to V ratio (leafy) will lose water quicker or slower than large spherical fruit?

Answer 16

quicker

Question 17

most important microorg cause post-harvest wastage of fresh produce are _____

Answer 17

fungi

Question 18

causes for quality deterioration for fresh produce?

Answer 18

fungal/bacteria growth, physiological disorders (mineral imbalance, innappropriate enviro, atm composition), phys injuries

Question 19

how to maintain quality of fresh produce?

Answer 19

precooling (room/forced air cooling, icing, hydro cooling), prestorage (surface coatings, irradiation), controlled atm storage, packaging

Question 20

coatings used in prestorage treatments?

Answer 20

carnuba/sugar cane wax, sugar esters, petroleum based (paraffin) wax

Question 21

purpose of polymeric films?

Answer 21

barrier to decay spread, affect mvmt resp gases, lower O2 and raise CO2, reduce resp and extend shelf life

Question 22

what is active modification?

Answer 22

pulling of slight vacuum in pack and then replacing atm w/ desired gas mix

Question 23

what is passive modification?

Answer 23

atm attained thru resp of products in pack