Celebrated author and TV personality Julia Child once joked: "Always remember: If you're alone in the kitchen and you drop the lamb, you can always just pick it up. Who's going to know?" Kitchen practices in relation to food health and safety, in truth, have been evolving. Microbial activities, including bacterial benefits and detriments, have been undergoing a huge amount of demystification. A number of practices and measures believed to be safe - even healthy - in the past have been proved otherwise. A few of these have been compiled by food microbiologist and Food Safety Information Council vice president Cathy Moir:

Fallacy #1: Cooked food can only be refrigerated once completely cooled.

According to Ms. Moir: "Micro-organisms can grow rapidly in food at 5C-60C. Temperature control is the simplest and most effective way of controlling the growth of bacteria. Perishable food should spend as little time as possible in the 5C-60C danger zone. If food is left in the danger zone, be aware it is potentially unsafe to eat."

Fallacy #2: Smell is a fool-proof measure for food expiry.

Bacteria can grow on food without causing the smell or appearance of food to change. Check for spoilage and expiry carefully before consumption to avoid food poisoning and contamination.

Fallacy #3: Covering food in oil allows food to last long in normal, room temperature.

Although there are practices - especially in the Mediterranean - where food is preserved by using oils such as olive oil, such practices must be done using special technique and requiring special safety conditions.  However, Ms. Moir cautions: "Adding oil will not necessarily kill bugs. The opposite is true for many products in oil if anaerobic micro-organisms, such as Clostridium botulinum (botulism), are present. Lack of oxygen provides perfect conditions for their growth.

"Outbreaks of botulism arising from consumption of vegetables in oil " including garlic, olives, mushrooms, beans and hot peppers " have mostly been attributed to products not being properly prepared."

Australian regulations, for example, require pH that is less than 4.6 for making vegetable oils as such a level of PH does not allow the growth of bacteria that cause food poisoning.

Fallacy #4: Defrosted meat or chicken cannot be frozen again.

Ms. Moir advices of two conditions that allow for meat or poultry to be frozen again even after it has been thawed.  The first is if these frozen food were thawed inside the refrigerator at a temperature of 5 degrees Celsius or below. The second is if the thawed meat or poultry were cooked and repacked for freezing. Cooked food should only be allowed a maximum of 30 minutes to cool before refrigeration or freezing.

Fallacy #5: Meat must be washed before cooking or when preparing for cooking.

Ms. Moir explains: "It is not a good idea to wash meats and poultry when preparing for cooking. Splashing water that might contain potentially hazardous bacteria around the kitchen can create more of a hazard if those bacteria are splashed on ready-to-eat foods or preparation surfaces."

"Wash fruits and vegetables before preparing and serving, especially if they're grown near or in the ground as they may carry dirt and micro-organisms.

"This applies particularly to foods that will be prepared and eaten without further cooking. Eating foods raw that traditionally have been eaten cooked or otherwise processed to kill pathogenic micro-organisms (potentially deadly to humans) might increase the risk of food poisoning."