Part IV General issues
Part IV General issues
21 Optimizing packaging T. Lyijynen, E. Hurme and R. Ahvenainen, VTT Biotechnology Finland 21.1 Introduction Package design has great significance for the success of foodstuffs nowadays Packages are clearly an integral part of the manufacturing and distribution processes. As clothes speak for their wearers, so too packages speak for the acked food product Packages are developed not only to make weekdays easier for the consumer, but also to make times of celebration more festive. Many food products would not be in shops and on dining tables, if they had not been packed. Nowadays packages face difficult challenges and roles. They have to create the ambience that hitherto was forged by personal service. Packages eplace the salesman In addition, packaging has many other functions and requirements which it has to fulfil more and more effectively and economically. These functions and requirements are changing all the time and their importance in ensuring the success of the product is growing. The aim is to make the optimal package that satisfies all functional requirements in addition to meeting environmental and cost demands as well as possible. The answer to these complex demands is orecision packaging VTT Precision Packaging Concept has been developed in the Technical Research Centre of Finland and it is a new and unique tool to optimize packaging for foodstuff Elsewhere optimization methods for transport packages have been developed, but not for primary packages, which are in direct contact with foodstuff. The VTT Precision Packaging Concept is based on the predetermined minimum shelf-life needed to allow the packed foodstuff to suit the market and the business strategy of the company. A longer shell-iieo reach the consumer's table from the factory. The shelf-life is naturally chosen
21.1 Introduction Package design has great significance for the success of foodstuffs nowadays. Packages are clearly an integral part of the manufacturing and distribution processes. As clothes speak for their wearers, so too packages speak for the packed food product. Packages are developed not only to make weekdays easier for the consumer, but also to make times of celebration more festive. Many food products would not be in shops and on dining tables, if they had not been packed. Nowadays packages face difficult challenges and roles. They have to create the ambience that hitherto was forged by personal service. Packages replace the salesman. In addition, packaging has many other functions and requirements which it has to fulfil more and more effectively and economically. These functions and requirements are changing all the time and their importance in ensuring the success of the product is growing. The aim is to make the optimal package that satisfies all functional requirements in addition to meeting environmental and cost demands as well as possible. The answer to these complex demands is precision packaging. VTT Precision Packaging Concept has been developed in the Technical Research Centre of Finland and it is a new and unique tool to optimize packaging for foodstuff. Elsewhere optimization methods for transport packages have been developed, but not for primary packages, which are in direct contact with foodstuff. The VTT Precision Packaging Concept is based on the predetermined minimum shelf-life needed to allow the packed foodstuff to reach the consumer’s table from the factory. The shelf-life is naturally chosen to suit the market and the business strategy of the company. A longer shelf-life is 21 Optimizing packaging T. Lyijynen, E. Hurme and R. Ahvenainen, VTT Biotechnology, Finland
442 Novel food packaging techniques needed for an export market than for a home market. Depending on the business strategy, the company can favour either short or long best-before times. It should be noted that the selling time of the product does not necessarily have any other connection to the real shelf-life but, naturally, the selling time is always shorter than the shelf-life. This chapter gives a description of the VTT Precision Packaging Concept for the optimization of food packages. At the end of the chapter, examples of optimization are given using different gas-packec foodstuffs 21.2 Issues in optimizing packaging The basic aim in the optimization of food packages is to create a tool for decision-making policy for launching new products. The packaging optimization concept should not only advantageously help food manufacturers, but also packaging material and packaging manufacturers to evaluate and compare the feasibility of their new and present products. In todays competitive market, packaging innovation can be a big advantage in efforts to persuade the consumer to buy a certain brand, and the packaging optimization concept may help to educe the economic support and time needed for package development. Several factors should be considered in the optimization process for packages, covering the performance in logistics, marketing properties, consumer convenience, costs, and environmental stresses(see Fig. 21. 1). The general goals in package optimization are the cost-effectiveness of the packaging process and environmental issues, e.g. source reduction of packaging materials. The importance of these factors is discussed below 21.2.1 Performance in logistics One of the most important tasks of a food package is to afford protection from environmental conditions, like oxygen, light and moisture. This is crucial for maintaining the quality and safety of most packaged foods. Therefore, it is essential that a package has sufficient mechanical strength to protect the packaged product from environmental stresses during distribution and storage Environmental issues, however, demand that packaging material consumption is kept to a minimum and that packaging materials be recoverable. This requires the food industry to use thinner materials that still have both sufficient mechanical strength and barrier properties. An optimized, downsized package may also reduce wholesaler and retailer costs On the other hand, in some cases it may also be favourable to use relatively thick, recyclable monomaterial layers (e.g. polyethylene)suitable for energy recovery. In other words, an optimized food package minimizes the waste in the overall packaged product New packaging solutions should also be technically feasible. That is, they ay not set any limitations on either packaging speeds or the quality of seals ackage dimensions need to be logistically congruent with the secondary
needed for an export market than for a home market. Depending on the business strategy, the company can favour either short or long best-before times. It should be noted that the selling time of the product does not necessarily have any other connection to the real shelf-life but, naturally, the selling time is always shorter than the shelf-life. This chapter gives a description of the VTT Precision Packaging Concept for the optimization of food packages. At the end of the chapter, examples of optimization are given using different gas-packed foodstuffs. 21.2 Issues in optimizing packaging The basic aim in the optimization of food packages is to create a tool for decision-making policy for launching new products. The packaging optimization concept should not only advantageously help food manufacturers, but also packaging material and packaging manufacturers to evaluate and compare the feasibility of their new and present products. In today’s competitive market, packaging innovation can be a big advantage in efforts to persuade the consumer to buy a certain brand, and the packaging optimization concept may help to reduce the economic support and time needed for package development. Several factors should be considered in the optimization process for packages, covering the performance in logistics, marketing properties, consumer convenience, costs, and environmental stresses (see Fig. 21.1). The general goals in package optimization are the cost-effectiveness of the packaging process and environmental issues, e.g. source reduction of packaging materials. The importance of these factors is discussed below. 21.2.1 Performance in logistics One of the most important tasks of a food package is to afford protection from environmental conditions, like oxygen, light and moisture. This is crucial for maintaining the quality and safety of most packaged foods. Therefore, it is essential that a package has sufficient mechanical strength to protect the packaged product from environmental stresses during distribution and storage. Environmental issues, however, demand that packaging material consumption is kept to a minimum and that packaging materials be recoverable. This requires the food industry to use thinner materials that still have both sufficient mechanical strength and barrier properties. An optimized, downsized package may also reduce wholesaler and retailer costs. On the other hand, in some cases it may also be favourable to use relatively thick, recyclable monomaterial layers (e.g. polyethylene) suitable for energy recovery. In other words, an optimized food package minimizes the waste in the overall packaged product. New packaging solutions should also be technically feasible. That is, they may not set any limitations on either packaging speeds or the quality of seals. Package dimensions need to be logistically congruent with the secondary 442 Novel food packaging techniques
Optimizing packaging 443 Alternative packaging Specified shelf-life and VTT Precision Packaging Concept Costs Convenience Fig 21.1 The VTT Precision Packaging Concept is a customized tool for optimization food packagin package and pallet. The ratio of packaged product to package volume should be 21.2.2 Marketing properties The marketing properties of a package should be fulfilled as well as necessary, not as well as possible. This means that, optimally and cost-effectively, only adequate investment is needed to fulfil the need for, e.g., package design in terms of packaging material consumption, decoration and information. Keeping up the brand image of a product should be taken into account when making packaging decisions. It is important that package designers, manufacturers and users can co-operate closely to achieve an optimum package 21.2. 3 Costs From a food manufacturer's point of view, especially, the costs of primary packaging materials as well as indirect packaging costs(storage, transportation energy consumption, and labour costs)should certainly be as low as possible. A cost-competitive package is, of course, a benefit for both the packaging and the food manufacturers. a packaging innovation requiring a minimum of investment and giving consumers products they like, at affordable prices, can be seen to be a very attractive goal. Such innovations could be, e. g, easy-open seals or thinner materials which consumers find more environmentally friendly 21.24 Consumer convenience Such properties of a package that make it convenient for the consumer include it being easy to handle, carry, store and dispose of/re-use, as well as its openability, resealability, and microwaveability
package and pallet. The ratio of packaged product to package volume should be as high as possible. 21.2.2 Marketing properties The marketing properties of a package should be fulfilled as well as necessary, not as well as possible. This means that, optimally and cost-effectively, only adequate investment is needed to fulfil the need for, e.g., package design in terms of packaging material consumption, decoration and information. Keeping up the brand image of a product should be taken into account when making packaging decisions. It is important that package designers, manufacturers and users can co-operate closely to achieve an optimum package. 21.2.3 Costs From a food manufacturer’s point of view, especially, the costs of primary packaging materials as well as indirect packaging costs (storage, transportation, energy consumption, and labour costs) should certainly be as low as possible. A cost-competitive package is, of course, a benefit for both the packaging and the food manufacturers. A packaging innovation requiring a minimum of investment and giving consumers products they like, at affordable prices, can be seen to be a very attractive goal. Such innovations could be, e.g., easy-open seals or thinner materials which consumers find more environmentally friendly. 21.2.4 Consumer convenience Such properties of a package that make it convenient for the consumer include it being easy to handle, carry, store and dispose of/re-use, as well as its openability, resealability, and microwaveability. Fig. 21.1 The VTT Precision Packaging Concept is a customized tool for optimization of food packaging. Optimizing packaging 443
444 Novel food packaging techniques 21.2.5 Environmental stresses nvironmental aspects should be taken into account as far as possible in the optimized package. The relevant issues include the need for low environmental stresses from the packaging material and packaging, the necessity of a low ratio of package weight to product weight, the need for as little of the package volume to be waste as possible, and the incineration possibilities of different packaging materials 21.3 The VTT Precision Packaging Concept The VTT Precision Packaging Concept includes several phases(see Fig. 21.2) The first task is to specify the required shelf-life for a foodstuff and determine the basic requirements for this food package, e.g. by using shelf-life prediction models. After that it is possible to choose different combinations of package types and to optimize the package. Optimization is performed in four steps: (i) scoring the tested package types, (ii) evaluating the importance of package characteristics, (iii)calculating the coefficients for each of the characteristics, and(iv) calculating the optimization result of each of the tested package types 21.3.1 Determination of basic requirements for packaging Precision packaging is based on a pre-determined minimum shelf-life needed to allow the packed foodstuff to reach the consumer's table from the factory. The shelf-life is naturally chosen to suit the market and the business strategy of the company. A longer shelf-life is needed for an export market than for a domestic Minimum required shelf-life for the food stuff Minimu oplimIzation scoring the selected, alternative packaging type calculating the coefficient for the characteristic OPTIMAL PACKAGE
21.2.5 Environmental stresses Environmental aspects should be taken into account as far as possible in the optimized package. The relevant issues include the need for low environmental stresses from the packaging material and packaging, the necessity of a low ratio of package weight to product weight, the need for as little of the package volume to be waste as possible, and the incineration possibilities of different packaging materials. 21.3 The VTT Precision Packaging Concept The VTT Precision Packaging Concept includes several phases (see Fig. 21.2). The first task is to specify the required shelf-life for a foodstuff and determine the basic requirements for this food package, e.g. by using shelf-life prediction models. After that it is possible to choose different combinations of package types and to optimize the package. Optimization is performed in four steps: (i) scoring the tested package types, (ii) evaluating the importance of package characteristics, (iii) calculating the coefficients for each of the characteristics, and (iv) calculating the optimization result of each of the tested package types. 21.3.1 Determination of basic requirements for packaging Precision packaging is based on a pre-determined minimum shelf-life needed to allow the packed foodstuff to reach the consumer’s table from the factory. The shelf-life is naturally chosen to suit the market and the business strategy of the company. A longer shelf-life is needed for an export market than for a domestic market. Fig. 21.2 A scheme for determining the optimal package. 444 Novel food packaging techniques
Optimizing packaging 445 The VTT Concept uses mathematical modelling to determine the minimum package requirements for the foodstuff. The modelling of the shelf-life of foodstuffs is performed in the following steps: (1) selecting factors and responses,(ii) selecting the experimental design method (screening or more extensive method),(iii) carrying out tests, (iv) analysing results,(v) making shelf-life predictions and(vi) determining the minimum package requirements The factors that might be relevant and might affect the quality deterioration of the foodstuff are chosen, for example, oxygen transmission rate of a packaging material, carbon dioxide concentration of a package, ge volume and storage conditions(temperature, illumination, etc. ) The parameters In shelf-life testing of food can include sensory and analyses and microbiological determinations. The minimum package requirements can also be based both on the information of the shelf-life tests and on the literature data 21.3. 2 Determining different package and storage combinations After the required packaging parameters for a foodstuff at certain storage conditions have been determined, it is possible to select the different alternatives of packages and packaging materials, packaging methods and package conditions all of which give equally acceptable food quality at the end of the required shelf-life of the product (e.g. vacuum or gas-flushed package wit specified packaging material and gas concentrations) 21.3.3 Scoring the selected alternative package type The selected, alternative package types giving the same minimum required shelf-life, are first scored by rating different characteristics of each package type. As an example, the following package attributes can be used in a Precision Packaging Concept mechanical strength of a package suitability with respect to packaging standards ratio of package weight to product weight volume of package waste ibility of incineration life cycle assessment of packages marketing properties of a package consumer convenience consumer attitude cost of packaging material indirect packaging cos All these characteristics are scored on a scale from I to 5, with I corresponding to poor and 5 to excellent quality. Fractional numbers are also allowed. The scoring is performed in co-operation with experts representing wholesalers, food manufacturers, packaging material manufacturers and independent specialists of ackaging technology and plastics industry
The VTT Concept uses mathematical modelling to determine the minimum package requirements for the foodstuff. The modelling of the shelf-life of foodstuffs is performed in the following steps: (i) selecting factors and responses, (ii) selecting the experimental design method (screening or more extensive method), (iii) carrying out tests, (iv) analysing results, (v) making shelf-life predictions and (vi) determining the minimum package requirements. The factors that might be relevant and might affect the quality deterioration of the foodstuff are chosen, for example, oxygen transmission rate of a packaging material, carbon dioxide concentration of a package, package volume and storage conditions (temperature, illumination, etc.). The quality parameters in shelf-life testing of food can include sensory and chemical analyses and microbiological determinations. The minimum package requirements can also be based both on the information of the shelf-life tests and on the literature data. 21.3.2 Determining different package and storage combinations After the required packaging parameters for a foodstuff at certain storage conditions have been determined, it is possible to select the different alternatives of packages and packaging materials, packaging methods and package conditions all of which give equally acceptable food quality at the end of the required shelf-life of the product (e.g. vacuum or gas-flushed package with specified packaging material and gas concentrations). 21.3.3 Scoring the selected alternative package types The selected, alternative package types giving the same minimum required shelf-life, are first scored by rating different characteristics of each package type. As an example, the following package attributes can be used in a Precision Packaging Concept: • mechanical strength of a package • suitability with respect to packaging standards • ratio of package weight to product weight • volume of package waste • possibility of incineration • life cycle assessment of packages • marketing properties of a package • consumer convenience • consumer attitudes • cost of packaging material • indirect packaging costs. All these characteristics are scored on a scale from 1 to 5, with 1 corresponding to poor and 5 to excellent quality. Fractional numbers are also allowed. The scoring is performed in co-operation with experts representing wholesalers, food manufacturers, packaging material manufacturers and independent specialists of packaging technology and plastics industry. Optimizing packaging 445
446 Novel food packaging techniques Mechanical strength of a package This is determined using a simulated transportation test. For example in the VTT ransportation test, a whole pallet positioned on a vibration table is subjected to a simulated road transportation of about 1000 km. As an example, during this 45- minute test run. the table is vibrated at a constant acceleration of 0.5 g. with the frequency of the table sweeping between 5 and 55 Hz. Since each package type resonates at its own specific frequency, every package tested is exposed to mor or less high accelerations during the test procedure. In general, the packages in the top layer of a pallet are exposed to the highest accelerations, which can be even more than 6 g. After the test, all the possible flaws, such as flexes, fractures, open seals and product disorientation originating from the transportation tests are recorded, and the test packages are scored as follows I point: if even one tested package in the pallet is leaking, the whole sample group is rejected Suitability with respect to packaging standard. This is evaluated by examining the volume occupied by the primary packages tested in a secondary package, which had the dimensions of the pallet area Scores between I and 5 are given on the following basis I point: relatively large empty space left in the secondary package 5 points: primary packages tight together, no empty space in the secondary tio of package weight to product weight score for this ratio(= Sm)is calculated using eqn I Sm=0.444.(1-m/m:100+5 where mp= weight of the empty package and m= weight of the packaged food Equation I was formulated on the following basis I point corresponds to an empty package weighing 10% of the weight of the packaged product, and 5 points correspond to an empty package weighing 1% of the weight of the packaged product ge waste This is scored from 1 to 5 on the following basis I point: a rigid package, e.g. tray, which cannot be scrunched and which would require a large space in a household waste basket 5 points: a package that is made of a thin flexible material, which can easily be put in a household waste basket without the need for stuffing or crunching
Mechanical strength of a package This is determined using a simulated transportation test. For example in the VTT transportation test, a whole pallet positioned on a vibration table is subjected to a simulated road transportation of about 1000 km. As an example, during this 45- minute test run, the table is vibrated at a constant acceleration of 0.5 g, with the frequency of the table sweeping between 5 and 55 Hz. Since each package type resonates at its own specific frequency, every package tested is exposed to more or less high accelerations during the test procedure. In general, the packages in the top layer of a pallet are exposed to the highest accelerations, which can be even more than 6 g. After the test, all the possible flaws, such as flexes, fractures, open seals and product disorientation originating from the transportation tests are recorded, and the test packages are scored as follows: • 1 point: if even one tested package in the pallet is leaking, the whole sample group is rejected. • 3 points: there are some minor dents or flexes. • 5 points: no package is affected by the vibration test. Suitability with respect to packaging standards This is evaluated by examining the volume occupied by the primary packages tested in a secondary package, which had the dimensions of the pallet area. Scores between 1 and 5 are given on the following basis: • 1 point: relatively large empty space left in the secondary package. • 5 points: primary packages tight together, no empty space in the secondary package. Ratio of package weight to product weight The score for this ratio ( Sm) is calculated using eqn 1 Sm 0:444 1 ÿ mp=mf 100 5 1 where mp weight of the empty package and mf weight of the packaged food. Equation 1 was formulated on the following basis: • 1 point corresponds to an empty package weighing 10% of the weight of the packaged product, and • 5 points correspond to an empty package weighing 1% of the weight of the packaged product. Volume of package waste This is scored from 1 to 5 on the following basis: • 1 point: a rigid package, e.g. tray, which cannot be scrunched and which would require a large space in a household waste basket. • 5 points: a package that is made of a thin flexible material, which can easily be put in a household waste basket without the need for stuffing or scrunching. 446 Novel food packaging techniques
Optimizing packaging 447 Suitability of the empty package for incineration This is evaluated as follows I point: cannot be incinerated under any conditions, e.g., metal can 2 points: can be incinerated in a plant specialized for problem waste 3 points: can be incinerated in a plant for municipal waste 4 points: can be incinerated in a power plant for fossil fuel resources 5 points: can be incinerated in the home Marketing properties of a package These are evaluated by awarding scores between I and 5 on the following basis I point: package design or packaging material does not meet the requirements of brand/company image and logistics, it has poor printability, insufficient space for labels and poor visibility on the shelf 5 points: excellent package design, proper packaging material, excellent printability, enough space for labels, excellent visibility of the packaged product on the shelf. Consumer convenience This is evaluated by awarding scores between I and 5 points as follows I point: package dimensions and sharp corners make it difficult to handle carry, store and dispose of, it is difficult to open without a tool and/or spillage of the product, it is not resealable, and is not suitable for microwave ovens 5 points: package is easy to handle, carry, store and dispose of/re-use, as well as being easy to open, and reseal, and is suitable for microwave ovens, if necessary These( Sc) are calculated using eqn 2 based on the annual production reports given by the food manufacturers and the corresponding cost information for the necessary primary packaging materials given by the different packaging material manufacturers. The cost of the packaging material is first scored by the food manufacturers. as follows I point represents a packaging material cost that is far too high compared to the total manufacturing cost of the product, whereas 5 points equals a very economical ratio of packaging material costs to the total manufacturing cost Sc=[4/(e1-c)-1·(cs-cx)+5 where cr and cs are the costs corresponding to 1 and 5 points, respectively awarded by the food manufacturer, and cx is the cost of the packaging material of the sample. For example, if the food manufacturers rate packaging materials costs of 0.03 t/package for a specified product as very economical whereas 0.13
Suitability of the empty package for incineration This is evaluated as follows: • 1 point: cannot be incinerated under any conditions, e.g., metal can. • 2 points: can be incinerated in a plant specialized for problem waste. • 3 points: can be incinerated in a plant for municipal waste. • 4 points: can be incinerated in a power plant for fossil fuel resources. • 5 points: can be incinerated in the home. Marketing properties of a package These are evaluated by awarding scores between 1 and 5 on the following basis: • 1 point: package design or packaging material does not meet the requirements of brand/company image and logistics, it has poor printability, insufficient space for labels and poor visibility on the shelf. • 5 points: excellent package design, proper packaging material, excellent printability, enough space for labels, excellent visibility of the packaged product on the shelf. Consumer convenience This is evaluated by awarding scores between 1 and 5 points as follows: • 1 point: package dimensions and sharp corners make it difficult to handle, carry, store and dispose of, it is difficult to open without a tool and/or spillage of the product, it is not resealable, and is not suitable for microwave ovens. • 5 points: package is easy to handle, carry, store and dispose of/re-use, as well as being easy to open, and reseal, and is suitable for microwave ovens, if necessary. Scored costs of packaging material These ( Sc) are calculated using eqn 2 based on the annual production reports given by the food manufacturers and the corresponding cost information for the necessary primary packaging materials given by the different packaging material manufacturers. The cost of the packaging material is first scored by the food manufacturers, as follows: • 1 point represents a packaging material cost that is far too high compared to the total manufacturing cost of the product, whereas • 5 points equals a very economical ratio of packaging material costs to the total manufacturing cost. Sc 4= c1 ÿ c5ÿ1 c5 ÿ cx 5 2 where c1 and c5 are the costs corresponding to 1 and 5 points, respectively, awarded by the food manufacturer, and cx is the cost of the packaging material of the sample. For example, if the food manufacturers rate packaging materials costs of 0.03=C/package for a specified product as very economical whereas 0.13 Optimizing packaging 447
448 Novel food packaging techniques e/package is far too expensive, 5 points would be awarded to 0.03 t/package, 3 points to 0.08 t/package and 1 point 0. 13 t/package Indirect packaging costs These are estimated by including storage, transportation, energy consumption and labour costs. The estimations are made qualitatively. That is, different package types(nlowpacks, form-fill-sealed-packs, preformed trays)are ranked against each other on a scale of 1 to 5 21.3. 4 Evaluating the importance of package characteristics After the characteristics of the selected, alternative packages have been scored, the importance of the characteristics is evaluated by the food and packaging material manufacturers, the wholesaler and independent packaging technology and plastics industry specialists. As an example, the importance of the characteristics evaluated by the food and packaging material manufacturers is presented in Fig. 21.3 21.3.5 Caleulating the coefficients The coefficients I for each of the characteristics are then calculated as follows (eqn 3) =0.4j+0.25·l+0.25i+0.1 Indirect packaging costs Cost of packaging Consumer convenience Marketing properties Possibility of Volume of package waste 口 Food manufacturers Suitability with standards manufacturers Mechanical strength Importance of the characteristics(%) Fig. 21.3 The importance of the various characteristics of packages evaluated by Finnish food manufacturers and packaging material manufacturers
=C/package is far too expensive, 5 points would be awarded to 0.03=C/package, 3 points to 0.08 =C/package and 1 point 0.13 =C/package. Indirect packaging costs These are estimated by including storage, transportation, energy consumption and labour costs. The estimations are made qualitatively. That is, different package types (flowpacks, form-fill-sealed-packs, preformed trays) are ranked against each other on a scale of 1 to 5. 21.3.4 Evaluating the importance of package characteristics After the characteristics of the selected, alternative packages have been scored, the importance of the characteristics is evaluated by the food and packaging material manufacturers, the wholesaler and independent packaging technology and plastics industry specialists. As an example, the importance of the characteristics evaluated by the food and packaging material manufacturers is presented in Fig. 21.3. 21.3.5 Calculating the coefficients The coefficients I for each of the characteristics are then calculated as follows (eqn 3): I 0:4 if 0:25 ip 0:25 iw 0:1 is 3 Fig. 21.3 The importance of the various characteristics of packages evaluated by Finnish food manufacturers and packaging material manufacturers. 448 Novel food packaging techniques
Optimizing packaging 449 where ir is the importance of a given package characteristic as evaluated by the food manufacturer of the product, ip is the mean rating for the importance of the package characteristic as evaluated by the packaging material manufacturers of the product, i is the importance of the package characteristic as evaluated by the wholesaler, and is is the mean importance of the package characteristic as evaluated by the independent specialist for the packaging technology and plastics industry. Since food manufacturers have a very significant role in the decision-making process in terms of package performance, applicability and functionality, the weighting of i with a coefficient of 0. 4 ensures that its influence on the coefficient I is the greatest. The significance of the influence of both the wholesaler and the packaging material manufacturers is rated as being quite important and so each of their importance scores is weighted with a coefficient value of 0. 25. The influence of the independent specialists is rated the lowest and the corresponding importance score is, therefore, weighted with a coefficient value of 0. 1. The coefficients used in eqn 3 were agreed between all the participants referred to above and VTT 21.3.6 Calculating the optimization result The score, s, given to each of the characteristics of the tested packages is multiplied by the corresponding coefficient, 1, given to these nine characteristics, where OR is the optimization result of a certain tested packag type(eqn 4) OR=s1·l1+s2·+s3·l3+..+s9·l9 It is also possible to ignore some characteristics, and calculate the optimization result with, for example, only seven characters. In fact, this is the case in the examples in the section 21. 4. That is, in an optimized package, the mechanical strength of a package and its suitability with respect to packaging standards ar considered as the essential requirements that all packages should fulfil before being launched. Therefore, these requirements can be ignored when calculating the optimization result. 21.4 Examples of food packaging optimization The following examples illustrate the using of the VTT Precision Packaging Concept. The foodstuff examples are gas-packed cheese slices, raw chicken legs roasted chicken balls and ham pizza 21.4.1 Gas-packed cheese slices Storage and packaging are particularly important factors for the shelf-life of cheese. There are some basic packaging requirements that are the same for all types of cheese: firstly, oxygen must be excluded to prevent mould growth and
where if is the importance of a given package characteristic as evaluated by the food manufacturer of the product, ip is the mean rating for the importance of the package characteristic as evaluated by the packaging material manufacturers of the product, iw is the importance of the package characteristic as evaluated by the wholesaler, and is is the mean importance of the package characteristic as evaluated by the independent specialist for the packaging technology and plastics industry. Since food manufacturers have a very significant role in the decision-making process in terms of package performance, applicability and functionality, the weighting of if with a coefficient of 0.4 ensures that its influence on the coefficient I is the greatest. The significance of the influence of both the wholesaler and the packaging material manufacturers is rated as being quite important and so each of their importance scores is weighted with a coefficient value of 0.25. The influence of the independent specialists is rated the lowest and the corresponding importance score is, therefore, weighted with a coefficient value of 0.1. The coefficients used in eqn 3 were agreed between all the participants referred to above and VTT. 21.3.6 Calculating the optimization result The score, s, given to each of the characteristics of the tested packages is multiplied by the corresponding coefficient, I, given to these nine characteristics, where OR is the optimization result of a certain tested package type (eqn 4): OR s1 I1 s2 I2 s3 I3 . . . s9 I9 4 It is also possible to ignore some characteristics, and calculate the optimization result with, for example, only seven characters. In fact, this is the case in the examples in the section 21.4. That is, in an optimized package, the mechanical strength of a package and its suitability with respect to packaging standards are considered as the essential requirements that all packages should fulfil before being launched. Therefore, these requirements can be ignored when calculating the optimization result. 21.4 Examples of food packaging optimization The following examples illustrate the using of the VTT Precision Packaging Concept. The foodstuff examples are gas-packed cheese slices, raw chicken legs, roasted chicken balls and ham pizza. 21.4.1 Gas-packed cheese slices Storage and packaging are particularly important factors for the shelf-life of cheese. There are some basic packaging requirements that are the same for all types of cheese: firstly, oxygen must be excluded to prevent mould growth and Optimizing packaging 449