FoodBowl #8

Invert sugar can be produced by hydrolysis of sucrose. The sugars produce from this process are:

• Glucose and galactose

• Glucose and glucose

• Glucose and fructose

• Fructose and galactose

Answer explanation

Invert sugar is produced by the hydrolysis of sucrose, a disaccharide made up of glucose and fructose. When sucrose is hydrolysed, it breaks down into its component monosaccharides, forming glucose and fructose. Therefore, the sugars produced from the hydrolysis of sucrose are glucose and fructose.

Oligofructose is added into milk powder and cultured milk to _________.

• give energy

• assist in the synthesis of growth hormones

• prevent tooth decay

• promote the growth of Bifidobacterium in the large intestine of the consumer

Answer explanation

Oligofructose is a type of dietary fiber that belongs to the group of fructooligosaccharides (FOS). It is not digested or absorbed in the small intestine, but it undergoes fermentation by beneficial bacteria in the large intestine, particularly Bifidobacterium. This fermentation process leads to the production of short-chain fatty acids and helps promote the growth of Bifidobacterium, which is considered a beneficial probiotic.

Adding oligofructose to milk powder and cultured milk aims to enhance the growth of Bifidobacterium in the large intestine of the consumer, which can contribute to improved gut health and overall well-being.

The industry that utilizes the most fructose syrup is the ___________.

• confectionery industry

• beverage industry

• baking industry

• snack food industry

Answer explanation

The beverage industry utilises the most fructose syrup. Fructose syrup, also known as high-fructose corn syrup (HFCS), is a commonly used sweetener in producing various beverages such as soft drinks, fruit juices, energy drinks, and flavoured waters. HFCS is preferred in the beverage industry due to its high sweetness level, stability, and affordability. It is often used as a substitute for sucrose (table sugar) to enhance the sweetness of beverages and provide desirable taste characteristics.

The glycosidic bond between the glucose units in cellulose is _______.

• 1 – 3

• 1 – 4

• 1 – 5

• 1 – 6

Answer explanation

The glycosidic bond between the glucose units in cellulose is a 1 - 4 glycosidic bond. Cellulose is a polysaccharide consisting of long chains of glucose molecules linked together through β-1,4-glycosidic bonds. This means the hydroxyl group on carbon 1 of one glucose molecule is linked to the hydroxyl group on carbon 4 of the adjacent glucose molecule, forming a linear chain. This type of linkage is crucial for cellulose's structural integrity and strength, which is a major component of plant cell walls.

Which of the following starch has the highest stability to retrogradation and syneresis?

• Rice

• Waxy corn

• Wheat

• Tapioca

Answer explanation

Among the options given, waxy corn starch has the highest stability to retrogradation and syneresis. Waxy corn starch is derived from a specific type of corn that contains a high proportion of amylopectin and a very low level of amylose. Amylopectin is a highly branched form of starch that has a lower tendency to retrograde compared to amylose, which is a linear form of starch.

Retrogradation refers to the process in which starch molecules reassociate and rearrange after gelatinization and cooling, leading to the formation of a firm and often undesirable texture. Syneresis, on the other hand, is the expulsion of water from a gel or starch-containing food, resulting in the separation of liquid.

Due to the high amylopectin content, waxy corn starch exhibits a reduced tendency to retrograde and form firm textures. It also demonstrates lower syneresis, making it more stable and suitable for applications where texture stability is important, such as in certain processed foods and food products.

The preservative effect of heat processing on food is due to the _________.

• destruction of vitamins

• denaturation of protein

• reduction in oxidative changes

• depolymerisation of starch

Answer explanation

Food is heated up or cooked. Heat is used to inactivate organisms or enzymes of spoilage significance in foods. Microorganisms are killed by heat because the application of heat coagulates the food proteins and inactivates the microbial enzymes and thus results in the death of microorganisms

In sterilising food, the time needed to destroy 90% of microorganisms is referred to as _________.

• z value

• F_o value

• L value

• D_T value

Answer explanation

The D_T value stands for "Decimal Reduction Time" and represents the time required to achieve a 1-log (or 90%) reduction in the microbial population. It is commonly used in microbial reduction calculations and is particularly relevant in thermal processing and sterilisation.

The D_T value helps determine the heat resistance of microorganisms and assess the effectiveness of a given heat treatment. It is crucial in establishing the thermal processing parameters necessary to achieve the desired microbial reduction and ensure the safety and quality of sterilised food products.

The followings are the effects of freezing and frozen storage to food, except ____________.

• cause lethality to microorganisms

• lower the rate of biochemical changes

• results in inactivation of enzymes

• cause damage to cells

Answer explanation

Freezing and frozen storage have various effects on food, but causing lethality to microorganisms is not one of them. Freezing can slow down the growth and metabolism of microorganisms, but it does not typically result in complete microbial destruction or sterilization.

The correct statement would be that freezing and frozen storage do not cause lethality to microorganisms. The other options are accurate effects of freezing and frozen storage on food:

b) Lower the rate of biochemical changes: Freezing slows down the rate of biochemical reactions in food, including enzymatic reactions and other chemical reactions that can lead to spoilage or degradation. This helps to maintain the quality and freshness of the food over an extended period.

c) Results in inactivation of enzymes: Freezing can inactivate enzymes present in food, reducing their activity and slowing down enzymatic processes. Enzyme activity is often significantly reduced at low temperatures, helping to preserve the nutritional value and sensory qualities of the food.

d) Cause damage to cells: Freezing can cause damage to the cellular structure of food. Ice crystals can form during freezing, leading to the rupture of cell membranes and potential changes in texture and quality. However, these effects can be minimized through proper freezing techniques and rapid freezing to reduce the formation of large ice crystals.

Overall, freezing and frozen storage are effective methods for preserving food by slowing down biochemical reactions, inactivating enzymes, and maintaining the integrity of cellular structure. However, they do not typically cause complete lethality to microorganisms.

Which of the following additive is added to bakery products such as bread to inhibit spoilage?

• Calcium carbonate

• Calcium propionate

• Potassium benzoate

• Potassium nitrate

Answer explanation

Calcium propionate is commonly added to bakery products such as bread to inhibit spoilage. It is a food additive that acts as a preservative by inhibiting the growth of molds and certain bacteria, thus extending the shelf life of baked goods.

Calcium propionate works by inhibiting the growth of various microorganisms, including fungi and bacteria, that can cause spoilage in bakery products. It helps prevent the development of mold, particularly in moist environments, and can also inhibit the growth of bacteria that contribute to spoilage.

a) Calcium carbonate is a mineral commonly used as a dietary supplement or food ingredient to provide calcium, but it does not possess significant antimicrobial properties to inhibit spoilage.

c) Potassium benzoate is a food preservative that is effective against yeasts, bacteria, and molds. However, it is more commonly used in acidic food and beverage products, such as carbonated drinks and fruit juices, rather than bakery products.

d) Potassium nitrate is primarily used as a food preservative in cured meats, such as bacon or ham, to prevent bacterial growth and enhance the preservation of the product. It is not typically added to bakery products for spoilage inhibition.

Which of the following is not categorised as a food conditioner under the Malaysian Food Regulations 1985?

• Modified starches

• Colouring substances

• Anti-caking agents

• Acidity regulators