Ingredients in soft drinks and fruit juices

2.1 Water as an ingredient

2.1.1 How much does water quality affect soft drinks?

Water is the principal component in all soft drinks and reconstituted fruit juices and it can have a fundamental effect on the quality of the end product. If water used in the manufacturing process is supplied by a reputable utility supplier and is fit for drinking as such, its quality is likely to be acceptable for use in beverage manufacture with minimal treatment solely for the purpose of removing chlorine and any other flavour taints. However, many soft drink plants have their own private water supply and the water from such sources may or may not be of suitable quality. In the United Kingdom, water from a private supply that is used in a food manufacturing process is subject to the constraints of the Private Water Supplies Regulations (those for Scotland were published in 2006; those for England will be published in 2009) to ensure that certain key quality criteria are met. Further information about appropriate treatments and quality specifications appear in subsequent answers.

The key factors that particularly need to be considered in relation to water to be used in soft drinks, assuming the water meets the quality requirements of the EU Water Directive for Drinking Water (98/83/EC), are as follows.

• Chlorine should always be removed as it sometimes reacts with other flavour or fruit constituents in a way that allows the development of a 'disinfectant' taste due to the formation of complex chlorophenols.

• Hardness The level of water hardness will affect the acidity of a soft drink or fruit juice and, in extreme situations, can create a buffering effect that will alter the pH of the product and possibly its microbiological stability and taste.

• Nitrate levels may be an important factor if the product is to be provided for babies or young children.

• Calcium levels, particularly in products containing high percentages of fruit components, may be important depending on the quality of the fruit constituent. If the pectin content of the fruit material has been degraded (see below), free calcium can react to form stable gels that create an unsightly and unpleasant end product.

• Iron and other metal ions can catalyse reactions that can create flavour and colour defects, particularly in products that are fortified with vitamins or other miscellaneous additives.

• Sunlight The use of water that has been subjected to prolonged exposure to sunlight (e.g. in an open reservoir in the summer) when algal blooms have occurred can lead to the formation of white floc in the end product. Such flocs are created by polysaccharides that occur as algal breakdown products.

2.1.2 Should water treatment be installed in a soft drink or fruit juice processing plant?

As a general guideline, water used in products should at least meet the quality standards of the EU Drinking Water Directive. Even then it will almost always be desirable to subject all process water to filtration or percolation through active carbon to remove chlorine and any other flavour taints. Other treatments may be considered desirable if there are particular constituents in the water that need to be removed or reduced (e.g. calcium).

When identical branded products are to be produced in more than one location or country, it is often the case that the brand owner will insist on water treatment to ensure product consistency wherever it is produced. In such situations the water quality required and the corresponding treatment needed will be specified by the brand owner.

Where water supplies do not conform to the EU Drinking Water Directive standard, it will be necessary to evaluate the quality and decide on an appropriate treatment. The usual range of treatments, where employed, will often incorporate removal of unstable iron (e.g. by oxidation and flocculation), removal of sediments by sand filtration, softening by ion exchange, and sterilisation by addition of chlorine gas and its subsequent removal by filtration through active carbon. Immediately before use water is usually exposed to ultraviolet (UV) light.

2.1.3 Is there an ideal specification for water to be used in soft drinks?

It is evident from previous answers that water to be used for soft drinks or for reconstituting fruit juice concentrates must be fit for human consumption and preferably meet all the guide values of the EU Drinking Water Directive. However, within the permitted range of individual constituents the variation is still large.

The ideal specification for a soft drink can probably be determined by reference to its microbiological quality, hardness, and freedom from toxic substances. Thus a water would, ideally, be free from all microbiological contaminants but especially coliforms as evidence of faecal contamination, Cryptosporidium and Giardia. It would also be free from toxic substances such as heavy metals, hydrocarbons, pesticides, herbicides, dioxins, etc. (‘free from’ in this context would usually mean not being detectable at an agreed limit). The water would also be low in content of metals such as iron, zinc and copper, low in calcium, sodium and potassium contents, and have a total solids content of less than 100 ppm. Freedom from dissolved oxygen is also desirable.

2.1.4 How frequently should water testing take place?

Depending on the nature of the water source, it may be possible to avoid any expense of testing. If water is supplied by a utility that has a statutory obligation to maintain water quality, informal arrangements may sometimes be made for the utility to take regular water samples from the soft drinks plant as part of their network sampling programme.

Water that is supplied as part of a private supply must be tested on a regular basis to meet the obligations set out in statute (the Private Water Supplies Regulations). Probably the most important test is to assess the microbiological quality, as the physico-chemical parameters are often reasonably stable. The testing parameters and frequency of testing required are set out in the above regulations. Testing of sources of ‘Natural Mineral Water’ and ‘Spring Water’ is a key part of the assessment and formal approval process, and testing of a wide range of parameters is an essential part of maintaining the reserved status.

Irrespective of the testing required by regulations, individual manufacturers may wish to set in place their own testing programme as part of a normal quality assurance scheme. This may be a condition of maintaining a franchise for internationally branded products.

2.1.5 Can I use natural mineral water or spring water to make a soft drink or reconstituted fruit juice, and can I bring these waters in by tanker?

The use of natural mineral water or spring water as an ingredient in soft drinks or reconstituted fruit juices is permitted. This can present a useful marketing opportunity, as the nature of the ingredient can be referred to in the list of ingredients (in the case of soft drinks).

The status of a natural mineral water (as water) requires that it is ‘bottled at source’ and thus precludes the use of a mobile tanker if the reserved description is to be maintained. There is no regulation preventing the use of a tanker to import natural mineral water to a plant but the reserved description may not then be used. Spring water may also be used as an ingredient in the manufacture of soft drinks.

It should be borne in mind that although there may be a marketing advantage in using natural mineral water or spring water, the physico-chemical characteristics may not be ideal for the manufacture of soft drinks or the reconstitution of fruit juice concentrates.

2.1.6 Is a ‘flavoured’ water a soft drink or a water?

The legal description that is probably correct for a flavoured water is either ‘x flavour soft drink’ or ‘x flavour low calorie soft drink’. The only permitted additive in water that allows the definition of water to be maintained is carbon dioxide. The addition of flavourings, sweeteners, colourings, citric acid or other permitted acids removes the product from what may legally be sold as water. In all situations where there is any doubt over the legal status or correct description of a product, appropriate legal advice should be sought and the product label sent for approval to the local authority trading standards department in the UK or to the competent authority in other countries.

2.2 Fruit components as ingredients

2.2.1 What types of fruit components are readily available and what are the differences between juices, comminutes, fruit purées and fruit extracts?

Fruit juices are...