Unit 14: Product Development and Evaluation PDF

UNIT 14: PRODUCT DEVELOPMENT AND EVALUATION Structure 14.1 Introduction 14.2 Need for the Product Development 14.2.1 Influencing Factors 14.2.2 Consumer Oriented Product Development 14.3 How to Develop a New Product 14.3.1 Statistical Experimental Methods 14.3.2 M...

UNIT 14: PRODUCT DEVELOPMENT AND EVALUATION Structure 14.1 Introduction 14.2 Need for the Product Development 14.2.1 Influencing Factors 14.2.2 Consumer Oriented Product Development 14.3 How to Develop a New Product 14.3.1 Statistical Experimental Methods 14.3.2 Modelling for Process and Recipe 14.4 Sensory Evaluation 14.4.1 Acceptance Tests 14.4.2 Sensory Evaluation during Product Life Cycle 14.5 New Products and Ingredients 14.5.1 Functional Foods 14.6 Shelf life 14.6.1 Major Modes of Food Deterioration 14.6.2 Evaluation of the Food Quality 14.6.3 Procedures for Determination and Monitoring of Shelf life 14.7 Let Us Sum Up 14.8 Glossary 14.9 Answer to Check Your Progress Exercises 14.1 INTRODUCTION In India processed food is gaining importance as “commercial commodity”. It becomes more evident when we see the wide range of packaged food products available in the market. Increase in popularity of processed foods can be traced to several causative factors: growing urbanization, changes in lifestyle, increasing number of nuclear families, working women and the purchasing power. Food industry in India is broadening its product range in response to emergence of wider clientele range. The industry has to cope with the competition from the multinational companies who are launching new products at regular intervals. In such a situation, the food manufacturers have to be watchful not only about maintaining and improving the quality of their products in the market but also about developing new products. These new products shall have advantages such as offering convenience, better nutritive value, health benefit, superior sensory quality and 1 cost effectiveness. Developmental work in food industry is a continuous process beset with challenges. This unit will cover important areas of product development and evaluation. Objectives After studying this unit you will be able to: explain why is it necessary to develop new products describe what are the factors responsible for development of new products appreciate the role of sensory evaluation at different stages of product development assess consumer acceptability describe what are functional foods discuss the ingredients providing health benefits and their use in specialty foods and determine shelf life studies 14.2 NEED FOR PRODUCT DEVELOPMENT In the present market scenario of processed foods we observe that sales profile of established brand names undergo unpredictable fluctuations. In a few instances, the once popular product may lose its premium position in the market. Therefore, the manufacturer should evolve effective strategies to achieve and to retain a well secured place in the market. One such strategy is to introduce new products having better consumer appeal. So now in this context, let us first understand what we mean by product development? Product development is by definition a future-oriented practice. It is an effort to foresee the future needs of the market place and to translate this information into state-of-the-art products. 2 In order to develop a new product, the manufacturer should have the knowledge about all the factors influencing the development of new products. So then let us learn about these influencing factors. 14.2.1 Factors Influencing Product Development Product development is an innovative activity designed to meet the changing consumer demands. It is becoming increasingly important in the dynamics of marketing environment. Product developers should be familiar with marketing, financial implications and logistics of introducing a new product into the competitive market. Moreover, they have to know how to undertake product development work from the customer’s perspective. Products will have to be developed in response to a specific, clearly identified market opportunities. In addition to consumer demands, the driving forces behind new product development are peer competition, availability of new technology and alternate raw materials, and desire for novelty. Market fragmentation leads to developing different types of foods for various categories of consumers. As these are likely to intensify, the product life cycles are likely to shorten. Increase in the purchase power of sections of population, changing life styles, and increased emphasis on health and nutrition put pressure on processors to offer something new to the consumer. Science and technology in the food industry are increasingly defined by the demands and perception of the market place. To cope with such a situation the food industry has to resort to product development and innovation as a continuous activity. But, whatever may be the influencing force, remember it is always important to develop consumer oriented products. And how do we go about it? Read and find out. 14.2.2 Consumer Oriented Product Development It is important that new product development strategies are adjusted to identified needs in the market. This requires an appropriate methodology to translate consumers’ choice or expectations into identifiable quality characteristics. Once this concept is formed it will be possible to provide detailed guidance for product development. Consumer oriented approach consists of five steps: 1. Identify the opportunity for new product 3  2. Design of the new product 3. Market testing of the new product 4. Launching the product in identified markets and 5. Life – cycle management. Opportunity identification stage concerns the definition of the best market segment to introduce the new product, and the generation of new product ideas. At the product design phase the plan of action is : 1. To identify the key benefits the product is to provide to the consumer 2. Positioning of these benefits versus competitive products and 3. Development of the product and marketing strategy. Purchasing pattern of the consumer, what they consider important in their choice behaviour and what they consider short – comings in present product supply provide insight into some basic issues of product development. Consumer perception and preference have to be carefully studied while formulating a new product. Market testing may involve segmentation to identify relevant subgroups of consumers that are homogeneous in terms of preference and purchasing behaviour. If the new product is promising, as judged by the testing, it is ready for commercial sale. With our understanding of the concept of product development and the factors which influence it, let us now learn the process i.e. the methodology of product development. 14.3 HOW TO DEVELOP A NEW PRODUCT The process of developing a new product comprises three phases, namely formulation or recipe development, standardization of processing methods, and evaluation and testing of quality parameters of the final product. The critical issues here are: (i) to find out the optimised recipe, 4  (ii) to evolve effective processing conditions (iii) to ensure food products of high quality and (iv) to accurately predict marketability. It is well known that most of the food products contain a variety of ingredients and preparing the product involves several processing steps. So, while working on a new product one has to study whether the recipes and methods of processing can yield an acceptable product, or is there a need for modifying them to improve the quality and to meet the demands of the market. The three phases of product development, you learnt about earlier, are interrelated and any changes that are made in implementation of one phase, will affect other two phases. Therefore, the task of planning the work becomes complicated. The simplest methodology, therefore, in product development is adopting one – factor – at – a time method which is also known as trial and error method. It is a simple method in which if changes are to be made in the formulation, only one of the ingredients can be changed at time. For example flavourings, salt, and sugar are the ingredients used in the preparation of sweet and spicy varieties of fried snacks. These are considered as the variables which influence the product quality. Affect of flavourings is tested by varying its level while maintaining constant salt and sugar levels. The product with optimal quality is selected. The optimal salt and sugar levels are then determined in a similar way. The optimal levels of flavourings, salt and sugar are then combined in the preparation of the sweet and spicy fried snack which will have the overall optimum quality. The trial and error method has been in use for along time. But this optimization method has certain disadvantages: 1. It is laborious and time consuming 2. It does not provide information about variable interaction effects, and 3. Achieved optimum consists only one variable levels that are actually tested. This could lead an inexperienced product developer to unreliable or false optimal results. In the above example, the change in salt and / or flavourings levels would probably modify the optimal salt level. Because of these possibilities the “ overall optimum’ achieved might not be the true optimum. 5  Considering these drawbacks, more effective methods have been introduced in the field of new product development, which are highlighted now. 14.3.1 Statistical Experimental Methods Statistical experimental methods are used in product development. In order to adopt the statistical product design or experimental method, it is necessary to understand the basic concepts and terms. Important ones among these include: 1. Independent variables also known as factors are the parameters or characteristics, including ingredients and processing conditions, which have an effect on product quality. Independent variables can be varied. Amount or type of ingredients, temperature and time of processing and moisture content are examples of common factors in food production. 2. Dependent variables, or the responses are the important measurable food quality indices. These are influenced directly or indirectly by different factors. Some examples of responses are sensory quality, nutritional value, chemical composition, microbiological characteristics and shelf – life. 3. Test levels or levels are the quantity of factors selected to be tested in the experimental design. A combination of factor levels is chosen according the experimental design. 4. A model is a mathematical equation that describes the relationship between the response values and different factors quantitatively. It can predict optimized combination of factors to obtain products having required quality. While dealing with the experimental design method, different kinds of system problems are encountered. These are discussed next. A. Product process problem In food product design, there are two different kinds of system problems – process and mixture problems – that should be dealt with by different statistical experimental methodologies. In the process problem, all the independent variables are not related to each other but are orthogonal to each other. The change of one variable is not restricted by another 6 variable. Geometrically, the lines representing these variables meet at right angles. In bread making for example, the temperature of the baking oven can, in principle, be chosen without any influence on the setting of baking time. Of course, only suitable settings of oven temperature and baking time can lead to desired bread baking results. To solve a process problem, the statistical experimental designs used should contain no or few correlations between the independent variables, so that their natural or original properties of “independence” can be retained. These kinds of statistical experimental designs are usually factorial experimental designs or designs derived from it. B. Recipe problem Recipe is one of the most important factors leading to successful food products. A recipe usually includes several ingredients, which have different effects on specific food quality. To study these effects is the prerequisite for being able to choose the optimal recipes. Many food products are manufactured by mixing two or more ingredients. In bread and cake formulations, for example, flour, sugar, baking powder, shortening, and water are used. In this case, one or more properties of the food product generally depend only on the proportions of the ingredients present in the mixture and not on the amount of the mixture. One ingredient (an independent variable) cannot vary without changing at least one of the other ingredients in the mixture, because all the ingredients will be part of a constant sum of 100%. In other words, the variables or the ratios of different ingredients in the recipe are dependent on each other. These phenomena do not meet the orthogonality requirement of a conventional factorial design. Therefore, to study and model the effects that different ingredient components in a mixture have on the food product properties of interest, the factorial experimental design is no longer suitable unless it is modified. The effect of ingredient components (mixture variables) on food quality (response) are modeled differently from those effects based on the usual factorial experimental methodology. As described above, the distinguishing feature of a mixture problem is that the independent or controllable factors represent proportionate amounts of the mixture rather 7 than unrestrained amounts. These proportions are measured by volume, by weight, or by mole fraction. These are nonnegative numbers, and, if expressed as fractions of the mixture, they must add up to a unity, especially if the ingredients to be studied are the only ingredients comprising the mixture. So you realize, how the process and the recipe, are important in development process. How do we get about with them? Let’s get to know. 14.3.2 Modelling for process and recipe Generally, all problems that appear in food product design can be divided into mixture or process problems, with the latter having the dominant share. Sometimes a problem that seems to be a mixture problem is really a process problem and can only be solved with a corresponding factorial experimental method. As explained above, the difference between a process and a mixture study is quite distinct, and these studies need different statistical experimental techniques to deal with. In practice, it is not easy to distinguish a process problem with a mixture problem, when the food product design is only concerned with recipe or formulation development. To get a better understanding of the difference between them, a short description of performing a factorial experiment for solving a process problem and of running a mixture experiment is given: 1. A factorial experiment: It studies the effect of some independent variables on food quality indices (response) through varying two or more of these independent variables, such as temperature, time, pressure and pH value. A series of values or test levels of each factor is selected, and certain combinations of their levels are tested. 2. A mixture experiment: An experiment in which the food quality indices (response) are assumed to depend only on the relative proportions of the ingredient components present in the mixture and not on the amount of the mixture. In such an experiment, if the total amount of the mixture is held constant, the value of the response changes when changes are made in the relative proportions of the ingredients. 8  The development of bakery powder is described as a practical example that will help you in understanding the difference between a factorial and a mixture experiment. A premixed bakery powder for biscuit making consists of wheat flour F and three different chemical compounds A, B and C, which would be tested in the biscuit making according to a standard bakery experiment. The flour is used as a diluting medium, whereas A, B and C will be effective at different baking temperatures or baking phases. To develop an optimal baking powder formulation from F, A, B and C, the effect of various formulations are tested. Three different statistical experimental approaches are applied. Strategy 1 Wheat flour F 3940 g is, mixed with 60g of A, B and C, yielding a ratio of chemicals to flour of 3:197 in all formulations. All mixtures are produced in total amount of 4000 g. In all tests, the amount of flour F in the baking powder is fixed, and the amounts of the three chemicals A, B and C are varied as indicated in Table 13.1. Table 13.1: Mixture Experiment (Strategy 1) Chemicals Flour Chemicals Flour Total R (g) (g) (%) (%) atio of Chemical: F A B C Total F Total (g) A B C Total F (%) 40 10 10 60 3940 4000 1.00 0.25 0.25 1.5 98.5 100 3:197 30 15 15 60 3940 4000 0.75 0.375 0.375 1.5 98.5 100 3:197 30 20 10 60 3940 4000 0.75 0.50 0.25 1.5 98.5 100 3:197 20 20 20 60 3940 4000 0.50 0.50 0.50 1.5 98.5 100 3:197 Strategy 2 The wheat flour amount is fixed at 3940g, but that of the active ingredients is varied from 30 to 60 g with the ratio of A : B : C fixed at 3:2:1. The combinations to be tested are listed in the table 13.2. 9  Table 13.2: Mixture Experiment (Strategy 2) Chemicals (g) Flour Chemicals Flour Total Ratio of (g) (%) (%) Chemical: F A B C Total F Total (g) A B C Total F (%) 30 20 10 60 3940 4000 0.750 0.500 0.250 1.500 98.500 100 0.0152 25 16.7 8.3 50 3940 3990 0.627 0.418 0.209 1.254 98.746 100 0.0127 20 13.3 6.7 40 3940 3980 0.502 0.335 0.167 1.004 98.996 100 0.0101 15 10 5 30 3940 3970 0.378 0.252 0.126 0.756 99.244 100 0.0076 It is a single-factor experiment with four test levels of baking powder. Actually only the ratio of chemicals to flour are changed in the study. In this way the effect of changing the chemicals: flour ratio or of changing the amount of chemicals while holding the amount of flour constant can be measured. In this experimental design the effect of ratio of the chemicals to flour would be examined. Note that if the percentages of A, B and C are varied in addition as in the first experiment, this would then constitute a flour-component, mixture-amount experiment. Next look at the third strategy. Strategy 3 Two levels of wheat flour 3960g and 3940g and two levels of baking powder 60g and 40g are selected to be tested. In all trials the percentages of A, B and C are fixed at 3:2:1. The formulations are as in Table 13.3. This is obviously a factorial experiment in which we are interested in measuring how the biscuit quality will be influenced by changing the level of flour and chemicals. Table 13.3: Mixture Experiment (Strategy 3) 10  Chemicals Flour Chemicals Flour Total Ratio of (g) (g) (%) (%) Chemical: F A B C Total F Total (g) A B C Total F (%) 30 20 10 60 3940 4020 0.497 0.497 0.249 1.5 98.50 100 0.01523 30 20 10 60 3940 4000 0.500 0.500 0.250 1.5 98.50 100 0.01523 15 10 5 40 3960 4000 0.250 0.250 0.125 1.0 99.00 100 0.01010 15 10 5 40 3940 3980 0.254 0.254 0.127 1.0 99.00 100 0.01010 The example above gives a fair idea about how the factorial, mixture experiments are conducted for product development. With this we end the first section. Read the points to remember given herewith to recapitulated what you have learnt so far. Now attempt the check your progress exercises given herewith to judge for yourself how much you have grasped about the subject so far. Points to remember 1. Product development is an innovative activity designed to meet the identified needs in the market. 2. Consumer perception and preference have to be studied while formulating a new product. 3. Product development comprises formulation, standardization of processing method and evaluation and testing of final product. 4. The simplest methodology in product development is the trial and error method. 5. Statistical methods of product development are Factorial experiment and mixture experiment. Check your progress Exercise 1 1. Define product development --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- 2. List the factors influencing product development. --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- 3. What is trial and error method? 11  --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- 4. What are Independent and dependent variables? --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- 5. What are factorial experiment studies? --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- 6. What is a mixture experiment? --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- The next crucial aspect of product development is sensory evaluation i.e. to evaluate the product on the basis of appearance, acceptability on part of the consumer or on information based on food acceptance data. These aspects are discussed within the next sub-section entitled sensory evaluation. 14.4 SENSORY EVALUATION We begin our discussion on sensory evaluation by first understanding what we mean by sensory evaluation. Sensory evaluation is a scientific discipline used to evoke, measure, analyse and interpret reactions to those characteristics of foods and material as they are perceived by the senses of sight,smell, taste, touch and hearing. Next, why use sensory evaluation? Well, sensory evaluation is used to: evaluate a range of existing food products analyse a test kitchen sample for improvements gauge consumer response to a product check that the final product meets its original specifications 12 One may further wonder, why does the food industry need sensory assessment? Well, the food industry always try to : develop new products by modifying existing formulations enter new markets compete more effectively in existing market keep a high level of quality These compulsions, therefore, make sensory evaluation very essential. Food quality, or from the consumer view point, food acceptance is the most critical aspect of food. The collection of food acceptance data is a key component in studies on product development, quality control, food product acceptance in the market place and food service evaluation. How is this data collected? What are the different processes involved in the assessment of the product being developed? Usually, a sensory panel is constituted to conduct periodic quality assessment of the product, followed by consumer testing. Let’s learn about these processes. A. Sensory panel During the product development cycle it is necessary to conduct periodic quality assessment of the product being developed. This is done either with a consumer panel or a trained panel. Both kinds of panels are required as constituents of product development team. The trained panel is selected and trained in such a way that the panelists are capable of giving high reliability of judgments independent of psychological factors such as bias, motivation and individual experience. The expert is not viewed as representing the consumer. The role of the expert in product development is to determine flaws in the development process (too salty, poor texture etc), and possibly to attribute these flaws to specific processing steps, eg: burnt note attributable to overheating or higher processing temperature. This information is used by the developer to alter the formulation or to improve processing. As a result of experimentation and sensory evaluation an optimized product is developed. This is then submitted to a consumer to be maximally effective. 13 B. Consumer testing Consumer testing is the next crucial aspect in product development. Consumer testing can be done in three ways: 1. in-house laboratory testing 2. home testing and 3. institutional testing Let us discuss each of these next. 1. In-house laboratory acceptance testing represents the most controlled environment in which to conduct acceptance tests. Within the laboratory testing area, one can control a number of environmental variables (odour, light, temperature, humidity etc) and a number of stimulus variables (serving temperatures, portion size etc). In-house testing utilizes either laboratory personnel or consumers brought in for the tests. 2. In home testing, the selection and maintenance of a consumer panel is a key issue. The co-operation rate from consumer home panels is approximately 50 percent. It has been found that co-operation is best in households with: a) more than two members b) a younger housewife and c) more education. But home testing presents a practical problem, that is, the process of data collection is not done under the supervision of the investigator. Therefore, validity of the procedure and resulting data cannot be directly assessed. 3. The institutional food service setting, on the other hand, provides an excellent opportunity to collect food acceptance information. It is preferable to collect the food acceptance ratings from the consumers as they are eating, or just after they have completed eating. Collection of direct consumer acceptance ratings also provides the researcher with an opportunity to observe the food system in operation and to interact with consumers. Food acceptance data is collected by using feedback forms that are filled by the consumers. For their effective use the feed back forms should be brief and clear; it 14  should take only 1–2 min to fill out. Secondly, the format of questions should provide information which can be acted upon. Data collected on a number of food products showed that the card or form with different scales for different food attributes was most effective and useful. One example of a feed back form used in the consumer testing of low fat cake is given here. FEED BACK FORM After you have tested the Low Fat Cake, please rate it for each of the following characteristics by checking one box in each category. Temperature Flavour Portion Size Texture Too Hot Good Flavour Too Big Bad Texture Slightly Too Hot Slightly Good Flavour Slightly Too Big Slightly Bad Texture Just Right Neutral Flavour Just Right Neutral Texture Slightly Too Cold Slightly Bad Flavour Slightly Too Small Slightly Good Texture Too Cold Bad Flavour Too Small Good Texture Considering everything, how was the Low fat Cake Good Slightly Good Neutral Slightly Bad Bad COMMENTS You would have made note of the fact that food acceptance data is collected by the consumers by using feedback forms. There are a few acceptance tests normally carried out to evaluate product acceptability. What are these tests and how they are conducted? How is the sensory evaluation carried out during the product life cycle? These are some other crucial aspect we should know while on the topic of sensory evaluation. Read the next sub section and find out. 15 14.4.1 Acceptance tests What are Acceptance Tests? Acceptance tests are used to evaluate product acceptability or liking or to determine which of a series of products is the most acceptable or the most preferred. It should, however, be emphasized that acceptability and preference are not the same thing. For example, a person may prefer product A to product B, but actually find them both unacceptable. Information derived from acceptance testing will only be of value if it reflects the results that would be obtained in the population at large, and this is unlikely to be achieved unless a panel which represents the target population is recruited. Such consumer panels are usually quite large, and their use in product testing has tended to be the responsibility of the market researcher rather than the sensory analyst. However, there are common features in the test methodology and common products being studied, so it is appropriate for the sensory analyst to be aware of the existence and purpose of these acceptability tests, if only in the interests of the effective interdepartmental communication. In addition, the sensory analyst can sometimes apply acceptance tests in a limited way to obtain an indication about product acceptability and may be asked to pilot such “consumer guidance” tests during product development and before products are subjected to more detailed market research. There are three main methods of sample presentation that are used in acceptance tests – monadic, sequential monadic and paired presentation. 1. In monadic tests, samples are presented one at a time. 2. In sequential monadic tests, samples are presented in sequence, to be assessed one at a time. 3. In paired tests, samples are presented two at a time, generally with some form of direct comparison in mind. What are the Types of Acceptance Tests? There are two main aspects to acceptance testing: Measurement of Acceptability 16  Comparison of acceptability or preference These tests supply information about people’s likes and dislikes of a product. Note, these tests do not intend to evaluate specific characteristics, such as crunchiness or smoothness. A discussion on these tests follows: a. Hedonic Rating In this test the assessor is asked to record the extent of liking for a product, usually by selecting a category on a “hedonic” or liking scale that runs from “extreme like” to “extreme dislike”. A number of different scales have been developed and used. A very popular scale is the following nine – point hedonic scale: Like extremely Like very much Like moderately Like slightly Neither like nor dislike Dislike slightly Dislike moderately Dislike very much Dislike extremely The categories on this scale are equally spaced and it is quite common for the data to be analysed by assigning the values 1 to 9 to the categories on the scale, and then assuming that the intervals are equal. With this assumption, the data can be summarized by recording average liking “Scores”. b. Interval Scales An alternative approach is to rate liking on a proper interval scale or on a continuous line – scale, with only the ends of the scale being labeled “ extreme like” and “ Extreme dislike’. The distance of the mark along the scale or line can then be used as a genuine score. 17 c. Ratio scales It is also possible to record liking or acceptability using magnitude estimation scaling methods, but consumers may find it difficult to handle the concept of ratios without some initial practice, and may also feel uncomfortable with the arbitrary liking score that must be defined for the opening reference product. d. Paired Comparison (Preference) Test In this test the assessor is presented with two coded products and asked to indicate whether there is a preference between them. The test design should ensure that each sample is assessed equally often in first and second position. The panel size should be at least 50. If the panel is drawn from staff on site, care should be taken to exclude people who may have particular knowledge of the nature of the work or knowledge of the objectives for carrying out the work. Bear in mind that such a panel is unlikely to be representative of the target consumer population. At the simplest level the assessor is asked to state which sample is preferred and to offer reasons for preference. No – preference discussions are usually allowed and although, they are excluded from analysis, they are usually reported. This is a two – tailed test, as it is not known in advance which product is preferred, and both directions are of equal interest. The basic statistical analysis is by reference to two – tailed binomial tables, and the reasons for preference are tabulated. Comparative assessments of acceptability or preference can be undertaken using the paired (preference) method or by the ranking test. What Sort of Panel Is Required for Acceptance Tests? Consumer panels are the best group to use for evaluating the acceptability of a product or a range of products because they can be recruited to a quota that matches the profile of the target consumer population in terms of product usage, demographics etc. when using consumers for such tests, there are relevant codes of practice and guidelines to be followed. 18 An untrained panel of at least 50 people, possibly drawn from an “in-house” panel of company employees may on occasion be asked to evaluate the acceptability of a product or a range of products. However, this panel will not normally be representative of the target consumers, so should only be used to provide an initial indication of acceptability or as a “consumer guidance” study. As always this panel should be drawn from people who have no particular knowledge of the nature of the work. Under no circumstances should a trained panel be asked to evaluate the acceptability or preference of a product. Training encourages assessors to be diligent in focusing on objective measurement and generating information on the full range of product attributes. They can no longer be expected to behave as naïve consumers and provide simple subjective value judgments. After a detail discussion of sensory tests and evaluation let us learn about the role of sensory evaluation during the product life cycle. 14.4.2 Sensory evaluation during product life cycle The basic procedure for developing a new product, and supporting it while marketed, included distinct steps that are constant no matter what type of product is produced. Initial screening in product development roughly defines the final product. The objective during this phase of life cycle is to formulate and physically prepare a prototype that is close to the final product, yet knowing the product will go through extensive optimization. The different stages during product life cycle are summarized herewith: A. Product Optimization Sensory analysis during this phase of product development is critical and includes extensive evaluation with many kinds of tests, each playing a specific role in optimization of the new product. Trained descriptive panels are used to characterize the flavour profile and other characteristics compared to what is already in the market. Consumer panel are used to determine product acceptability and aid in defining the formula and product 19 specifications such as moisture, oil, salt, seasoning and oil flavour in fresh and aged products. Product testing by consumer panel can be conducted by the company developing the product or by an independent consumer evaluation agency. B. Scale up At this phase, sensory analysis consists of tests that compare the production samples with the optimized product. Depending on the resources available, either consumer panels or descriptive panels can qualify the production samples. Sensory specifications are also determined before the product is taken into full production. This is a time consuming-process, similar to establishment of analytical specifications. The first step consists of screening of samples that represent reasonable extremes in the manufacturing process and also represent different raw material samples. Descriptive analysis is then used to characterize the products in quantitative terms. Consumer data are used to determine which attributes are critical and to set acceptable limits around the optimum target. C. Production Sensory analysis does not stop after the product has been developed and is being produced routinely. However, it is critical that products continue to be analyzed to ensure the finished goods are consistently manufactured to design criteria and that the product profile does not “drift” over time. Typically, products and packages are inspected shortly after production in what is sometimes called a sample-cutting meeting. Persons involved in evaluating freshly made products must become familiar with how products with varying characteristics age during their expected shelf life. Traditional difference and / or variation testing should be conducted on a routine basis for quality assurance purposes. At this point, shelf-life testing should be conducted to ensure the product meets specifications till the end of its declared shelf life. 20 The entire discussion so far has been summed up in points to remember. Read them carefully. Next, answer the check your progress exercise to recapitulate what you have learnt so far. Points to remember 1. During product development cycle it is necessary to conduct periodic quality assessment by employing sensory evaluation methods. 2. A trained sensory panel helps in development of the formulation and improving / modifying processing steps. 3. Consumer acceptance data is vital for studying the product quality and to predict acceptance in the market. 4. Hedonic rating is a well known acceptance test. Usually a nine point hedonic scale is used. 5. In paired comparison test the assessor is asked to indicate whether there is a preference between two samples. 6. Sensory evaluation during product life cycle consists of initial screening, product optimization, evaluation of product prepared during scale of studies and during regular production. Check Your Progress Exercise 2 1. What is a trained sensory panel? -------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- 2. Name the three ways in which consumer testing can be done. --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- 3. Why are acceptance tests used? --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- 21 4. Give the nine point hedonic scale. --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- 5. What is paired comparison test? --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- 6. Mention the stages in product life cycle, at which sensory evaluation is used. --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------- So far we have learnt about the need for developing a product and the methodology of doing it. Now let us learn what are the ingredients that could be used in a product too make it a speciality product. 14.5 NEW PRODUCTS AND INGREDIENTS Present day needs as well as future trends in food product development are taken into consideration in selecting the ingredients. Increasingly the issue for the food industry becomes one of understanding the health benefits of food and diet and of targeting research towards elucidating the physiologically active components and their mechanisms of action. Many of these physiologically active compounds are found in well-known food sources, in addition to those less recognized. Soya, cereal bran, onion, garlic, many fruits and vegetables, are just a few among a wide variety of foods with potential health benefits. Research designed to understand and enhance these benefits is critically important. Clearly, such a targeted approach could lead to the development of “functional foods”. What are these functional foods? The next sub-section focuses on this aspect. 22 14.5.1 Functional Foods Traditionally, food products have been developed for taste, appearance and convenience for the consumer. With the increasing awareness of the role of diet in disease prevention there is an emergence of a new category of food products which provide health benefits. Generally, this type of foods, are called as functional foods. These foods provide nutrition as well as certain health benefits. A functional food is similar in appearance to conventional foods. It is consumed as part of a usual diet and has physiological benefits and / or reduces the risk of chronic disease. Functional food is also known as “ A food that has a component incorporated into it to give a specific medical or physiological benefit, other than a purely nutritional benefit”. In other words these are the food products having a defined and well established health claim. Health claim can relate to components of food or foods themselves. Three types of health claim are: 1. generic 2. commodity specific and 3. product specific. Generic health claims are those that relate a nutrient of a food product to a particular disease or condition. One example of health claim permitted in USA is as follows: “Diets low in saturated fat and cholesterol and rich in fruits, vegetables and grain products that contain some type of fibre, particularly soluble fibre, may reduce the risk of heart disease, a disease associated with many factors”. On the basis of this statement, new products containing one or more of the above ingredients could be developed. Commodity claim describes the claim for commodities or ingredients. Statements permitted in USA for oatmeal and oat bran reads: “Diets high in oat bran / oatmeal and low in saturated fat and cholesterol may reduce the risk of heart disease”. This highlights the health benefits of oat bran and meal. However, it does not indicate in the claim that the product on which the claim is placed is protective. 23 A product specific claim states that the product on which the claim is placed has a protective effect against a disease. For this type of claim, the product itself, rather than the ingredients or nutrients in it, have to be shown to have benefit. In all the above three types of claims, it is essential to provide scientific evidence in support of the beneficial effect of the commodity or ingredient or the product in the prevention or treatment of a condition. From the above information, we have a fair idea about how to plan development of a functional food. In order to do this, we must know about the special ingredients required for the formulations. A few such ingredients are described here. A. Oat products Oats fulfill admirably the description of a functional food, as one that, in addition to providing all normal attributes of a food – basic sustenance, pleasing taste and texture – also confers a specific health benefit. The outer layers of oats are similar to those of other cereals in being a good source of insoluble dietary fibre with the attendant capacity to improve colonic function and possibly reduce the risk of colon cancer. Many other functionally distinct components such as waxes, lignin, phytate, vitamins, minerals and phenolics concentrate in these layers. Some of these compounds are powerful antioxidants and may possess potent pharmacological properties. The Food and Drug Administration (FDA) of the USA has recently allowed a health claim for an association between consumption of diets high in oatmeal, oat bran, or oat flour and reduced risk of coronary heart disease. This represents the first health claim for a specific food under the Nutrition Labeling and Education Act (1990).The overall conclusion from the FDA review was that oats could indeed lower serum cholesterol levels, specifically low-density lipoprotein (LDL) cholesterol, without change in the high-density lipoprotein (HDL) fraction; on this basis a health claim for reduced heart disease risk was allowed. The FDA has allowed that the main active ingredient, in this respect, is the soluble fibre (1->3) (1->4)-β-D-glucan, or β-glucan. 24 B. Wheat bran The useful role of wheat bran in promoting regularity in colonic function and preventing constipation is generally accepted. In addition, growing research has focused its protective effect against colon and breast cancers. Amount of fibre in the diet has an effect on colonic function, the type of fibre and its digestibility or fermentability also play a significant role. Both soluble and insoluble fibres have value in promoting regularity in colonic function, as measured by stool weight and transit time, but they promote regularity via different mechanisms. Insoluble fibres, such as those from wheat bran, are resistant to fermentation by colonic bacteria and increase fecal bulk by retaining water. Among the different sources of dietary fibre as fecal bulking agents, wheat bran is probably the most studied and among the most effective. Wheat bran ranked among the highest in fecal bulking, exceeding fibres from fruit and vegetables, gums and mucilages, cellulose, oats, corn, legumes and pectin. From a food processing perspective, the range of particle size in commercially available wheat bran offers many functional benefits. While fiber particle size may affect its colonic effects, the range of particle size typically found in commercially available wheat bran (coarse bran > 1400 µm to very finely ground bran