Unit 2 - Lesson 3 - Molasses Flashcards
1
Q
What is the genus of sugar cane?
A
Saccharum
2
Q
How tall can sugar cane stems grow?
A
As high as four metres
3
Q
What factors influence the selection of sugar cane varieties?
A
Climate and harvesting practices
4
Q
How is sugar cane usually planted?
A
From stem cuttings
5
Q
What factors affect the growing season and ripening of sugar cane?
A
Geographical location, soil condition, and water supply
6
Q
What is the typical useful life of a sugar cane plant?
A
Between five and seven years
7
Q
What is ratooning?
A
A practice used to extend the useful life of the plant by harvesting and leaving roots and part of the stem
8
Q
How long is a sugar cane crop typically grown before harvesting?
A
10-12 months
9
Q
Where is most sugar found in the sugar cane?
A
In the lower part of the sugar cane
10
Q
What is the maximum sugar concentration in sugar cane?
A
As high as 24% sucrose by weight
11
Q
What is the common sugar concentration found in sugar cane?
A
About 15-18% sucrose by weight
12
Q
How much sugar can 100 tons of sugar cane produce?
A
10-11 tons of sugar and 3 tons of molasses
13
Q
Why are sugar canes set on fire before harvesting?
A
To remove leaves and weeds, and to kill snakes
14
Q
What happens to the canes after harvesting?
A
They re-sprout from the rootstock
15
Q
What are the main products processed from sugar canes?
A
Cane sugar, molasses, and bagasse
16
Q
What is the primary purpose of processing sugar cane?
A
To produce crystallised cane sugar
17
Q
What does the rate of sugar loss from harvested cane depend on?
A
environmental conditions and the variety of sugar cane
18
Q
What is the first step in milling sugar cane?
A
Shredding and milling to extract sugar cane juice
19
Q
What material is removed after extracting sugar cane juice?
A
Bagasse
20
Q
What is added during the clarification of sugar cane juice and why?
A
Lime (calcium hydroxide) to precipitate insoluble plant debris
21
Q
What does heating the juice in the milling process do?
A
Starts chemical reactions to precipitate solid material and reduce viscosity to speed up settling of solids
22
Q
What is the purpose of the evaporator in the sugar milling process?
A
To increase sugar concentration and separate sugar crystals and molasses
23
Q
What is separated using a centrifuge in the milling process?
A
Solid sugar crystals from liquid molasses
24
Q
What is bagasse?
A
The fibrous material remaining after sugar cane is shredded and milled
25
What does bagasse contain?
1-2% residual sugars
26
What are some uses for bagasse?
* Burned to produce steam
* Used as animal feed
* Used to produce pulp, paper, and cardboard
27
True or False: The molasses is returned to the evaporator several times to extract more sugar.
True
28
What is the sugar content range in freshly extracted sugar cane juice?
18-24% sugar
29
What is the pH range of sugar cane juice?
5.0-5.5
30
What is the main sugar found in sugar cane juice?
sucrose
31
What microflora is typically found in freshly milled sugar cane juice?
wild yeast and bacteria
32
What is spontaneous fermentation?
Fermentation of sugars in the juice by wild yeast and bacteria
33
Why is sugar cane juice generally used immediately after milling?
To prevent spontaneous fermentation which can reduce alcohol yields
34
Name two spirits produced from sugar cane juice.
* Rhum Agricole
* Cachaça
35
What are three reasons sugar cane juice is suitable for distillers?
* Ferments rapidly
* No need for treatment before fermentation
* No additional nutrients needed in fermentation
36
What happens to sugar refining when world sugar prices are high?
More sugar is recovered, producing less molasses
37
What is high test molasses?
Concentrated sugar cane juice with no sugar removed, containing up to 80% sugar by weight
## Footnote
Good for rum fermentations
38
What is the sugar content range in molasses?
50% to 65% sugar
39
What is the difference between sulphured and un-sulphured molasses?
* Sulphured: Made from young green sugar canes, treated with sulphur dioxide
* Un-sulphured: Made from mature sugar canes, no treatment needed
40
What is the purpose of sulphur dioxide treatment?
to keep the green sugar canes fresh and prevent bacterial growth
## Footnote
also lightens the colour of the molasses and sugar
41
What is Grade A molasses and its characteristics?
* light molasses
* contains about 65% sucrose (highest sugar content of molasses grades)
* produced in the first crystallisation stage
## Footnote
highest sugar content because very little sugar has been extracted from the juice at this point
42
What characterizes Grade B molasses?
* contains 60% sucrose
* produced at the second boiling and crystalization stage
## Footnote
more sugar has been extracted, giving this molasses a slightly bitter taste
43
What is Grade C molasses and its characteristics?
* blackstrap molasses
* contains approx 50% sucrose
* contains mainly sucrose, with some glucose and fructose
* dark color
## Footnote
most commonly used molasses in distilling
44
What is the typical composition of molasses?
* 15-25% water
* 75-85% solids
45
What is the composition of molasses solids?
* sugars
* proteins
* carbohydrates
* acids
* salts
* vitamins
46
What factors affect the composition and quality of molasses?
* Quality of the sugar cane
* Climatic conditions
* Harvesting and processing methods
* Soil condition
47
What are three characteristics of molasses that make it suitable for rum distillers?
* Cheap source of fermentable sugar
* Contains nutrients for yeast growth
* Stable and easy to transport
* Can be stored for months to years
48
What is the percentage by weight of sucrose in blackstrap molasses?
35%
49
What is the combined percentage by weight of glucose and fructose in blackstrap molasses?
15%
50
What percentage by weight is attributed to water in blackstrap molasses?
20%
51
What is the percentage by weight of plant materials in blackstrap molasses?
20%
52
What percentage by weight do inorganic salts (ash) constitute in blackstrap molasses?
10%
53
Fill in the blank: Blackstrap Molasses contains _______ of water.
20%
54
True or False: Inorganic salts make up 15% of blackstrap molasses by weight.
False
55
What are the fermentable sugars found in molasses?
Sucrose, glucose, and fructose
## Footnote
These sugars typically make up 50% of the molasses.
56
What types of compounds make up the plant materials in molasses?
Complex mix of vitamins and mineral salts including nitrogen-containing compounds
57
Which vitamins are important for yeast growth and fermentation in molasses?
* Biotin
* Pantothenate
* Thiamine
58
What does the ash content in molasses indicate?
The ash indicates the inorganic salts, calcium, and sludge content
59
Why is the ash content important to distillers?
High levels of ash can cause fouling and calcium sulphate formation (as scale) in pipework and distillation equipment
60
What is the maximum ash content by weight that can be found in molasses?
15% by weight
61
What does specific gravity indicate in molasses?
Specific gravity indicates the total solids content.
62
What percentage of the solids content in molasses is dissolved sugar?
50%
## Footnote
sucrose, glucose, frucrose
63
What percentage of non-sugar material is present in molasses?
30%
## Footnote
inorganic salts, plant material
64
How is specific gravity of molasses measured?
hydrometer or refractometer
65
Can specific gravity give an exact sugar content reading and why?
No because of non-sugar molasses content
66
What is the standard temperature for Brix hydrometer readings?
20˚C
67
What is the significance of laboratory analysis for sugar content in molasses?
It is essential for finding the exact sugar concentration.
68
What instrument measures the refractive index of a molasses sample?
Refractometer.
69
How does the Total Sugar as Invert (TSAI) report molasses sugar content?
* one test measures sucrose
* one test measures fructose and glucose (reducing sugars)
* amount of sucrose converted to its equivalent amount of reducing sugars
* amounts are added together
70
How does the Total Sugar as Sucrose (TSAS) report molasses sugar content?
* molasses tested the same way as for TSAI
* amount of reducing sugars converted to its equivalent amount of sucrose
* amounts added together
71
What defines a reducing sugar?
A sugar that can donate electrons, such as glucose and fructose
## Footnote
These sugars contain an aldehyde group.
72
How do sugar producers measure sucrose and reducing sugars?
* Sucrose using a polarimeter
* Reducing sugars using titration with Fehling’s solution
73
What types of volatile acids are found in molasses?
* Acetic acid
* Formic acid
74
Why is volatile acidity an important parameter to consider?
volatile acids are poisonous to yeast and can negatively affect the speed and efficiency of fermentation
75
What is the ideal limit for volatile acidity in molasses?
< 2500 mg/L
76
What prevents micro-organisms from growing in raw, undiluted molasses?
The osmotic pressure is too high, and there is not enough water available for growth or fermentation.
77
Define osmosis.
Osmosis is when a solvent (water) passes from a dilute solution to a more concentrated one via a semi-permeable membrane.
78
What happens to the microbe's cell in high osmotic pressure conditions?
Water flows out into the more concentrated molasses, killing the cell.
79
What two types of bacteria can be found in molasses due to poor hygiene practices?
* Leuconostoc mesenteroides
* Zymomonas mobilis
80
Is molasses a sterile product?
No, molasses is not a sterile product and contains micro-organisms.
81
What effect does Leuconostoc mesenteroides have on sugar yield?
It converts sucrose into a non-fermentable dextran, causing loss of yield.
82
What does Zymomonas mobilis produce that can affect distilled spirits?
Unwanted flavour compounds.
83
What is indicated when diluted molasses becomes 'ropy'?
Both Leuconostoc mesenteroides and Zymomonas mobilis produce slime made of dextrins.
84
From what sources can molasses be produced?
* Sugar beets
* Sweet sorghum
* Sugar palm
* Citrus peel
85
What is sugar beet also known as?
Beta Vulgaris.
86
How long does it take for sugar beet to complete its biological cycle?
Two years.
87
What percentage of dry mass does sugar beet contain as sucrose?
15-20%.
88
What percentage of sugar beet molasess sugar is sucrose?
about 50%
89
How is sugar extracted from sugar beets?
The beets are finely sliced and soaked in clean water.
90
How does sugar beet juice compare to sugar cane juice?
Sugar beet juice contains more sugar and is purer but has a lower yield per hectare.
91
What is citrus molasses a by-product of?
The citrus fruit industries.
92
What is sweet sorghum syrup used for?
Production of fuel ethanol, neutral spirits, and baijiu.
93
What is sugar palm molasses derived from?
The concentrated product of the juice or sap from sugar date/sugar palm.
94
Sugar palm molasses contains what percentage of sugar?
about 45%
95
What spirits are made from sugar palm molasses?
* Arrack
* Lambanog
96
True or False: Sugar beets can be stored without loss of sugar potential after being harvested.
True.
