In the UK, food temperatures are constantly checked, whether in production, storage or in display cabinets. In addition to monitoring the temperature of food, pH and salt content are also important.
pH in Food
Together with temperature, pH is one of the most important indicators of food quality and safety. The pH of raw materials such as mile and meat are measure to ensure quality standards have been properly met, while pH is also used to determine shelf life. For example, if the pH value of processed food is held below 4.5pH, then growth of pathogens such as clostridium botulinum are inhibited.
Typical pH values for Food Products:-
Bread A pH value of 4.0 to 5.8pH is recommended for baked break in order to prolong its shelf life. Batter has to be acidified to a pH of 4.1 or less to ensure that pathogens are not multiplied.
Meat pH of carcasses constitutes an important initial test to determine the condition of the animal prior to slaughter and can reveal stress experienced by the animal prior to slaughter. Typical pH value is between 5.4 and 7.0 which can also provide an indication of whether fresh meat has been properly stored as well as presence of lactic acid. During aging, the pH value will drop by more than 1 pH unit, furthermore by simply checking the pH, carcasses can be divided into tenderness groups.
Drinks Even small changes in the pH value of Natural Spring Water can provide an early warning of possible fouling of the natural strata. In Beer pH plays a crucial role. For example, the pH value of crushed malt is around 5.8pH, whereas it's ideal value for protein decomposition is around 5.5pH. In Wine the pH ranges from between 2.8 to 3.8pH with the pH value influencing various states of the process, including fermentation and conservation. With the pH exceeding 3.5pH certain bacteria can attack the wine.
Processed Food A pH value of around 4.5pH is the simplest way to ensure the stability of the product and prolong the shelf life.
Milk and Dairy Products In Milk, a pH value of around 6.8 is expected and any variance is an indication that the milk might be contaminated with impurities or can be signs of an infection within the herd. Pathogen growth in soft and fresh cheeses is slowed down considerably by ensuring that the pH stays in the 4.1 to 5.3pH region. Controlling the pH in butter production is vital:- cream is cooled after pasteurisation at a very strict pH value of between 6.70 and 6.85pH to generate sweet tasking butter.
Salt Testing
Salt content in food is becoming a more and more important parameter to be measured as it is recognized that a reduced salt intake is better for our health. The UK Food Standards Agency has developed a model to look at the effects of reducing the average salt content of different food groups, in particular in processed food which account for about 75% of the salt in our diets.
In 2002 the independent Scientific Advisory Committee on Nutrition (SACN) published a report that found increasing evidence for the link between high levels of salt in the diet and high blood pressure.
Evidence shows that the people with high blood pressure are three times more likely to develop heart disease and risk of a stroke. In England alone, high blood pressure contributes to more than 170,000 deaths a year.
The daily adult salt target set by the Food Standards Agency is 6 grams a day, but in fact the current UK average is around 9.5 grams a day.
