High Sugar Preservation

Question 1

Properties of sugar

Answer 1

Soluble
Hygroscopic
Fermentable

Question 2

Solubility of sugar

Answer 2

Hydrophilic

Fructose > glucose > sucrose

Question 3

Ability to absorb moisture from the environment

Answer 3

Hygroscopicity

Question 4

Hygroscopicity

Answer 4

Fructose > glucose > sucrose

Invert sugar, HFCS, honey, molasses > sucrose

Question 5

Fermentable

Answer 5

Able to form CO2 and alcohol

Question 6

What is the most fermentable sugar?

Answer 6

Glucose

Question 7

Two conditions needed for sugar preservation

Answer 7

1) 40-65% sugar conc., + acid, - O2
2) more than 70%, no need for acid

Question 8

Preservative action of sugar

Answer 8

Lowers Aw and increases osmotic potential
Addition of acids

Question 9

“No shelf-life” sugars

Answer 9

Honey
Heavy syrup
Molasses

Question 10

True or false. The higher the sugar content of food, the lower the Aw of the food

Answer 10

True

Question 11

Aw of foods and inhibiting microorganisms

Answer 11

Aw Food Microorganisms
1.00-0.95. 40% sucrose or 7% salt Some yeasts, gram negative rods, bacterial spores
0.95-0.91. 50% sucrose or 15% salt Most cocci, bacilli, lactobacilli, some molds
0.91-0.88. 65% sucrose or 15% salt. Most yeasts
0.80-0.75. 26% salt. Halophilic bacteria
0.65-0.60. Confectionary products. Osmophilic yeasts

Question 12

Sugar concentration provides use for…., but still…

This pertains to:

Answer 12

Visually undesirable fruits

Wholesome

Jams, jellies, and preserves

Question 13

Requirements for jelly formation

Answer 13

Sugar
Pectin
Acid (low pH)

Question 14

Jams

Answer 14

Made from ground or mashed fruits

Question 15

Preserves and examples

Answer 15

Made from whole fruits, halves or chunks

Halo-halo ingredients (kaong), canned blueberries

Question 16

Jelly

Answer 16

Made with sugar, pectin, and juice from fruit

Question 17

Needed conditions for jelly

Answer 17

Sugar: 60-65%
Pectin: 0.5-1%
pH: 3.1 - 3.4

Question 18

Conserves

Answer 18

Made with 2 or more fruits, often with dried fruits (raisins), nuts. Cooked with sugar.

Question 19

Marmalade

Answer 19

Made from chopped, sliced, and pureed citrus
Cooked with sugar
Suspended soft pieces of rind or cooked peel

Question 20

Butters

Answer 20

Pureed fruit cooked slowly with little sugar until all liquid evaporated and mixture becomes dark.

Question 21

High-sugar preservation utilizes….

Answer 21

Osmotic dehydration

Question 22

Mechanism of osmotic dehydration

Answer 22

Immersion of food in a hypertonic solution

Solute (sugar) enters the food, moisture is eluted from the food interior into the hypertonic solution

Question 23

During OD, how many % weight of fresh fruits and vegetables are reduced

Answer 23

50%

Question 24

OD process includes

Answer 24

OD process includes drying, leaching, and impregnation

Question 25

OD is usually followed by other drying methods

Answer 25

Air drying
Deep fat frying
Freeze drying

Question 26

Types of osmotic agents

Answer 26

Glucose
Glucose syrup
Glycerol
Sucrose
Sorbitol
Corn syrup
Fructo-oligosaccharides

Question 27

Reduces browning

Answer 27

Sugar solution

Question 28

How does sugar solution reduce browning?

Answer 28

Preventing O2 entrance
Retaining volatile compounds
Providing stability to pigments

Question 29

Disadvantages of sucrose

Answer 29

Crystallize upon drying
Sweetness hinders its application in vegetable processing

Question 30

Why is sucrose best for preservation?

Answer 30

Convenient, effective, good flavor