Various characteristics of food packages are nowadays good, including their safety aspects. However, a novel problem has arisen: how to open the package easily. This is a challenge not only to consumers with reduced hand function, but it is common for all of us to face every now and then difficulties in opening packages. Especially adult consumers with reduced hand function, such as rheumatic or elderly people, or children are familiar with this issue. But what makes it easy to open a package, and what are the most critical factors for consumers in opening packages?
Nordic project ‘Scientific background for the basis of an international standard for easy-toopen packages’ (EASYOPENPACK) was aimed to answer these questions. The study was funded by NICe (Nordic Innovation Centre) (June 2006 -l June 2008). The participants of the project were the research institutes (Danish Technological Institute, SIK The Swedish Institute for Food and Biotechnology, SP Technical Research Institute of Sweden and VTT Technical Research Centre of Finland), representatives from companies (Stora Enso Oyj, Tetra Pak Packaging Solutions AB and Nolato Cerbo AB), and associations (Finnish Rheumatism Association, Pakkausteknologia – PTR ry, Spenshult Reumatikersjukhus, Reumatikerförbundet, Den Norske Emballasjeforening and Emballage og Transports Medlemskreds).
The aims of the Easyopenpack project were:
- To screen physical qualifications and capabilities of consumers to open packages easily
- To search critical aspects in opening of different types of food packages
- To identify the most relevant method(s), which has (have) the necessary qualifications for providing the basis for the final test method
- To inform, interest and involve Nordic companies in product development work
- To collect scientific background information for the CEN (European Committee for Standardization) work for developing the test method.
When the capability of handling packages is concerned from a consumer point of view, there are several factors possibly influencing on the easiness to open packages. These are reduction in hand strength, in sensibility/sensitivity, in dexterity and in power grip, left or right-handed, co-ordination difficulties, shaking, pain, medical treatment visual capability, cognition and personality. Different movements and capabilities are required from consumers to fend from the opening process and handle successfully the packages. Forbidden physical paths are key pinch grip, use of power and twisting or rotation of wrist. Avoided physical paths are pulling, lifting and pushing by using power, whereas allowed is pulling with straight wrist, lifting and pushing with straight wrist and pressing.
A wide variety of different types of opening mechanisms of food packages exist. Eight commonly used food packages were selected for the experiments, and these eight packages represented very well the distribution among different types of food packages with various opening mechanisms.
The most critical attributes for evaluating the easiness to packages turned out to be:
- visibility and clarity of the opening mechanism,
- keeping the grip from the opening mechanism,
- tightness and breakage of the opening mechanism,
- strength needed to open the package,
- need to use both hands in opening,
- rigidity and slipperiness of the packaging material,
- keeping the grip from the package,
- breakage of the package while opening, and
- degree of product staying inside the package after opening.
The mechanical test proved to be rather quick, easy and cheap to implement. It is also easily repeatable but does not imitate human action. Mechanical test measures only one dimension (strength), and necessitates specific equipment. By sensory assessment, a whole view of easiness to open packages can be formed. Sensory test imitates human action, and is easily repeatable. However, it is also rather time-consuming, expensive, and requires a well-trained panel. By a consumer study actual target groups can be imitated if recruitment criteria are well defined. Consumer test is culture-/ target group-dependent. It is also rather timeconsuming, expensive, not easy to implement, and difficult to repeat if the procedure is not controlled. The recruitment of the test group is crucial, and usually a big test group (n~100) is needed. Simple and specific phrasing of the questions is critical for getting reliable results, and standardised and specified test design is essential.
Mechanical test is not recommended alone for a test due to the very narrow view of measuring easiness to open packages. Sensory and consumer tests could be usable. However, in sensory test the descriptive attributes mentioned in chapter 5.2 must always be checked prior the assessments. In addition, correct criteria (questions to be related to the critical sensory attributes) must be determined for the consumer test, and the consumer panel must be big and representative enough. The possibility to drastic bias exist, if the procedures to perform the tests are not well and extremely detailed defined.