Categories
Chilled and frozen foods

Quality and consumer acceptability

SR PR Duran, HP Foods Ltd

Introduction

Quality is a necessary characteristic of a product that determines whether a consumer chooses a product or not. Due to the many troubles that hit the food market in the UK and continental Europe (E. coli, cattle spongy encephalopathy (“mad cow disease”), problems with genetically modified foods, the presence of dioxins in animal feed in Belgium), consumers have become more aware and therefore more “picky” when choosing products.

The concept of quality includes many aspects - from safety (harmlessness) to nutritional value, from organoleptic characteristics to the level of service. Consumers evaluate these characteristics as a whole and, based on their own criteria, decide which product to buy. Safety (harmlessness) of a product is a mandatory requirement, but it is always not enough to sell a product. Consumers need a product that has attractive organoleptic properties, and at a price that consumers find acceptable. The product must meet the needs of consumers in terms of providing services (for example, convenience and ease of opening the package) and better meet the growing dietary requirements (the presence of vitamins and functional additives, low calorie, low salt content). In general, quality is a combination of product characteristics that satisfy customer needs.

From this definition of quality, it follows that consumers will buy the cooled product again if they are satisfied with its organoleptic properties - in other words, if the product is pleasant to eat. Our senses are very sensitive and complex, which allows us to explore the world around us. For example, our sense of smell, although not as sensitive as that of some animal species, can recognize hundreds of different odors. In the second and third sections of this chapter, we will try to give a general idea of ​​how we determine the quality of cooled products using our senses. It will also be shown as an expert group. specially trained to identify and describe the organoleptic properties that can give product developers and quality managers the opportunity to develop the best products. The definition of quality with the help of trained people will give you the answer to the question of what exactly characterized the cooled product, but this is only one side of the question.

In the face of growing market competition, food manufacturers realized the need to find out from their real and potential consumers what they like and what they don’t, using preference tests. This is the second side of the question, and the section on consumer acceptability for the product provides an exhaustive list of tests used to understand the taste (preference) picture. In the last section, we will consider a combination of these two arrays of information, subjective and objective, to develop technical requirements based on the wishes of consumers and their expectations.

What determines the organoleptic quality of the product?

The organoleptic quality of the product is made up of its appearance, smell, texture, taste, and aftertaste.

Appearance

The appearance of the product is the first thing that the consumer evaluates when determining the quality of the cooled product. To assess its quality, you can use many characteristics of appearance - size, shape, distribution of pieces, surface texture, color and brightness, and all this - the determining factors for assessing the freshness and the expected quality in general. The dullness or brightness of the surface of red meat (lamb, beef) in combination with the intensity of the red color is used by consumers to assess the freshness of meat products in supermarkets. In turn, to improve their appearance in shop windows, supermarkets often use special lighting, and in some cases - spraying a thin layer of water on meat.

Appearance can be divided into two components: optical and visible structure. Optical appearance is mainly associated with parameters such as color, gloss and translucency. The visible structure refers to the texture of the product, including particle size, smoothness and surface texture. Color is probably the first and main characteristic that the consumer will use to judge the quality of the cooled product, since the deterioration of the product is often associated with a color change [23]. Color is also associated with psychological perception; red is associated with power, orange and yellow - with excitement and gaiety. Therefore, the food industry spends significant resources on the creation of properties that attract the eye of the buyer. In particular, artificially bred salmon is specially fed with carotenoids in order to give its meat a pinkish-orange color, which is further enhanced by smoking and is considered a sign of quality and freshness in the consumer’s mind.

 The smell, the type and intensity

The smell of the cooled product is a good indicator of freshness and quality. It is detected when volatile components inhale into the nasal cavity and come into contact with the olfactory system. Our olfactory system is less developed than vision, and with 5 million receptors, only 10 LLC smells are detected, while vision with more than 100 million receptors determines millions of shades of color [21]. Nevertheless, the sense of smell is highly effective in determining damage, foreign odors or tastes and is often more sensitive and more accurate than many complex instruments. When cutting a piece of meat or fish, the level of freshness of the product can be assessed by smell. [15] showed a strong relationship between the determination of volatile substances with an unpleasant odor by a group of experts and the deterioration of chilled fish during the storage period.

Taste

Taste is a necessary organoleptic component used to measure the quality of chilled foods. If the taste is undesirable or does not meet expectations, the product will be rejected. Taste is defined as the sum of sensations perceived in the mouth, in the back of the throat and in the nose along the nasopharyngeal (retronasal) route [23]. The concept of cousa (flavor) includes:

 primary tastes (salty, sweet, sour and bitter) caused by soluble substances;

 sensations (such as an astringent property, astringency, etc...);

 sensations of heat or cooling effect;

 sense of smell due to volatile substances.

Quality criteria related to taste / aroma are based on the appearance of the expected taste / aroma and its intensity.

Texture

The texture can be defined as the organoleptic perception of the physical structure of the food product. When working with the product and its preparation, textural properties for determining the overall quality can be assessed visually and by touch. Overripe hard cheese will be dry in appearance, and in the mouth it will give a feeling of dryness and roughness / roughness. Cheese makers use the accepted methods of determining textural characteristics as one of the components of the quality of cheese.

Determining how the texture of the organoleptic quality of the product is quite difficult; in reviews [2,6] describes the texture and classification. There are three different textural characteristics:

 mechanical properties associated with the reaction of the product to pressure - hardness, density, cohesive (binding) ability or suitability for long-term chewing - measured by the muscles of the hands, fingers, lips, tongue and jaws;

 the geometric properties associated with the placement of the physical components of the product - the size, shape, fiber, the presence of particles or lumps;

 Surface properties associated with the content in the product moisture and fat as well as their intensity discharge during mastication.

The essential component of the pleasure received from a meat product is the quality of its texture, and consumers are well aware of what softness is, suitability for long-term chewing or meat stiffness. As shown in [18], the texture of fresh fish and its storage conditions affect the quality of the texture of fresh fish. For dough-based products, such as pies with different fillings or pizzas, texture is a criterion that affects, and therefore, predicts the quality of the product best. In particular, confectionery tend to absorb moisture from other components and soak in moisture before the formation of any side flavor.

Methods of sensory evaluation

From the foregoing in the previous section it is clear that any measurement of the quality of chilled products requires the use of people. Organoleptic evaluation is a scientific discipline involved in measuring, studying and interpreting the perceptions of food properties through sight, smell, taste, touch and hearing [13].

Organoleptic evaluation is made by a small group of people (usually from 8 to 30 people) who have received some training in the field of objective testing, or a large group of consumers expressing their opinion about the product or a number of products without any prior preparation. The last option is called subjective testing. Purpose and hypotheses, defined in any project summary, determine the choice of the type of assessment to be performed, the type of expert group, as well as the overall organization of the test and experiment. The parameters to be considered are defined in detail in [5].

Objective testing is performed by qualified, specially trained specialists and can be used to identify and describe the differences between cooled products. This group of people (expert committee) may consist of company employees or special invited experts. After the initial selection, in which they determine the absence of any perceptual disorders (anosmia (smell disturbance) or agevzii (loss of taste sensitivity) in commission members), commission members participate in a progressively more complex and extensive program of learning to recognize, describe and evaluate any subtle differences between the test products. Many organoleptic assessment professionals have published training programs (both for general expert training [14] and for more specific and accurate sensory training [6]). Tests used to characterize the properties of food by experts on sensory evaluation can be differentiating or descriptive.

differentiating tests

Such tests are used if it is necessary to determine whether there are any differences between two or more products. Sometimes it may be necessary to change the supplier of one or another ingredient to reduce costs or for reasons of quality improvement, and then the purpose of the examination is to confirm that this does not affect the taste and aroma, texture or appearance of the product. At the same time, it is more profitable to turn to a highly qualified expert commission in the relevant field for an assessment of possible differences than to interview consumers. Such tests are very sensitive to any organoleptic abnormalities, as they use direct comparison. The most common differentiating test is the “triangle” criterion, when experts are given three samples in a predetermined order, with one of the samples different from the other two, and experts are asked to define an extra sample [4]. For example, a ham manufacturer may need to evaluate the effectiveness of packaging with a controlled gaseous medium compared to an existing system without changing the overall organoleptic properties over time. The sensitivity of the test allows you to make large capital investments with a high degree of confidence.

When comparing more than two products, ranking tests or tests with multiple comparisons are used. Usually the ranking test is used when the control sample cannot be used or is not required, and experts are asked to rank the products in order of intensity of a certain organoleptic property. The test with multiple comparisons is used when the control sample is used as a kind of reference point, and experts are asked to evaluate the intensity of the difference, if it exists.

Sometimes, the assessment of the perception of certain compounds and / or chemicals may require other tests that are important in assessing tastes or identifying materials that are difficult to evaluate. Threshold tests are used to determine at what concentration this compound can be organoleptically determined. Using the dilution method, the minimum amount of compound that can be determined in the product is recognized. In [12], this method was used to estimate the sharpness level of red pepper.

The descriptive (descriptive) tests

These tests are used to determine the organoleptic characteristics of the cooled product and their measurement. Panel members are selected based on their ability to describe and distinguish between samples. Experts are presented with product variants and asked to describe them. After the time allotted for the adoption and definition of agreed terms and scales, the commission presented the samples one by one and asked to give their assessment. One such descriptive method, called quantitative descriptive analysis, is described in [27]. The results are analyzed using univariate and multivariate analyzes. Dispersion Analysis [22] is used to measure differences between samples for each of the characteristics. The factor analysis of the main component is the method used to reduce the number of dimensional or organoleptic indicators to a manageable amount (usually two or three dimensions). Progress Analysis is mainly used to evaluate the performance and effectiveness of experts [1]. To summarize the results often use graphs or diagrams that present the results in a concise and clear form. The so-called “cobweb-like” graphics (see fig. 12.1) provide an overview of the sensory differences in the overall shape of the graphic for each product, giving a kind of “fingerprints” for individual products.

In recent years, other organoleptic methods have appeared to assess the quality of products using organoleptic evaluation. In particular, the method of recording time and intensity takes into account the dependence of organoleptic properties on time [9]. This method is particularly interesting for the evaluation of spicy foods or for the initial evaluation of taste (for example, sweets in artificially sweetened beverages) [19].

In fig. 12.1 in the form of a "spider" graph shows the differences of four samples of chilled smoked salmon in organoleptic terms. For each characteristic, the samples showed greater intensity away from the center. In particular, salmon D had a brighter orange color, and sample F had the least wet surface. Sample I was the least salted and smoked product.The differences in the organoleptic profile in four different samples of chilled smoked salmon

Fig. 12.1. The differences in the organoleptic profile in four different samples of chilled smoked salmon

Using a trained team of experts to measure the organoleptic properties

flavor

The presence of extraneous tastes in the product is the main threat for producers and consumers, since they can indicate danger and lead to high costs. A spoiled product that has got to the consumer can create difficulties for a manufacturer or retailer, leading to problems that are much more serious than simply having a complaint - direct costs (production losses, the need for funds for cleaning the enterprise, costs due to the disruption of established commercial relations with suppliers, manufacturers and trade), lawsuits and even the closure of the enterprise. Because of the presence of foreign tastes, other significant financial consequences may arise - for example, the loss of consumers and the damage to the prestige of the brand, manifested through a decrease in sales and a decrease in market share. Tastes are caused by the presence in the product of certain chemicals (usually volatile organic compounds) in very low concentrations, which makes the taste unacceptable to the consumer. External taste is an unpleasant smell or taste that a food product acquires from external sources, and internal foreign taste or smell is an unpleasant taste (smell) that a product acquires due to internal changes due to the activity of enzymes or microorganisms. There are an infinite number of sources of external and internal tastes, which makes it extremely difficult for manufacturers and retailers to fight them. Raw materials, packaging materials, working environment (for example, flooring, paint, detergents used), microbiological spoilage are all known sources of flavors. The source of contamination of the product can be water in which chlorophenols or chloroanisole are present. It is their presence that explains the largest number of known cases of the appearance of internal foreign tastes. Estimating and determining the taste and its source requires sensory evaluation of the product along with the use of some complex methods — for example, gas chromatography and mass spectrometry. Their combination was used in [10] to assess the external tastes in commercial and artificial breeding Atlantic salmon. It was found that the main difference was observed between river and sea salmon, and not between commercial and farmed salmon. Commercial salmon caught in the river showed enhanced sallow shades of taste and smell, with 2-methylisobornol and geosmin being the main components determining them.

Sensory quality monitoring

During the production of quality products to be refrigerated constant, and different methods are used to ensure product quality stability. Common to these methods is that one or more parameters measured with respect to the agreed quality characteristics. For example, the levels can be measured by pH,

the content of salt or sugar to ensure the absence of changes in the final composition of the product, however, these measurements, although important in themselves, do not allow to determine the taste or texture quality. Therefore, to ensure the preservation of a number of specified quality parameters, an organoleptic assessment is used. Regular monitoring of organoleptic quality includes setting a standard for a product that reflects the requirements of the consumer, which, in turn, is reflected in the main organoleptic characteristics. Then determine an acceptable range for each parameter, taking into account the commercial risks associated with consumer addiction. To assess the organoleptic quality, a commission is formed that learns to recognize products that are in each organoleptic parameter or within an acceptable range, or outside it. It is necessary that the employees of the company in the commission strive to achieve the proper quality, and in each assessment, to ensure accuracy and reliability, several experts should be involved. Standard procedures are established, which may include a “good-not-good” quality assessment, evaluation according to the requirements of SSZHNUMX for frozen and preserved foods [4], sample testing or a more accurate, but lengthy descriptive analysis.

As an example of evaluating the quality of cooled apple pie, below is a list of requirements, including acceptance ranges (Table 12.1) and a quality monitoring card for taste (Figure 12.2). Members of the expert committee are asked to individually evaluate each sample for each parameter, using an 10-grade scale, from “none” to “very strong”. The agreed or average estimate (the so-called “fast”) is then entered into a comparative table showing the unacceptable range for each parameter (the shaded areas in the table 12.1). The appearance of one or more skoros outside the unshaded area indicates that the product does not meet the quality criteria and additional research is required to confirm the obtained data. In fig. 12.2 shows a tendency to change the intensity of taste, characteristic of chilled apple pie over six months of production. For each evaluated batch of the product, the presence of shortages beyond the two permissible limits is already considered unacceptable. The intensity of taste varies significantly during a specified production period, and a special study should be organized to understand the causes of this variability and how to eliminate it.

Table 12.1. Table for comparing the characteristics of the taste and texture of chilled apple pie

Taste 0 1 2 3 4 5 6 7 8 9
The intensity of apple flavor Х Х Х Х Х Х х
Sweetness Х Х Х Х Х Х х
Sour taste Х Х Х Х Х Х х
Feeling fat test Х Х Х Х Х Х х
Side flavors Х Х Х Х х Х Х Х х
Texture
Myakish Х Х Х Х Х Х Х Х х
Friability apples Х Х Х Х Х Х Х х
Fat sensation in the mouth х Х х Х х х х х х

Quality monitoring for six months to assess the intensity of the taste of chilled apple pie

Fig. 12.2. Quality monitoring for six months to assess the intensity of the taste of chilled apple pie

Determination of shelf life

The shelf life of refrigerated products can be defined as the period between production and consumption, during which the product is in acceptable condition for safety and quality.

During storage, the cooled product undergoes changes due to chemical, microbiological and physical reactions. It was shown that for the determination of these changes, the most sensitive method for many products was precisely the organoleptic evaluation. Methods similar to those described above can be applied to sensory evaluation and shelf life of the product during storage. [8] showed that to measure the expiration of the shelf life of natural milk, organoleptic analysis using the descriptive method is more sensitive than traditional analytical methods.

Determination of the eligibility of the product for the consumer

Undoubtedly, the taste of the product is an important criterion for the acceptability of the product to the consumer. A good marketing and advertising campaign for a new refrigerated product may convince the consumer to purchase the product for the first time, but if this product does not have the expected parameters, the consumer will not buy it again. Although taste certainly plays an important role in product selection, it is not the only essential element. Attitudes, consumer confidence, food awareness, brand and product image, packaging convenience, price, and other sociocultural aspects (such as religious or educational) are all important criteria that a marketer must take into account. Although expert review boards for organoleptic evaluation are useful for understanding the organoleptic properties of a chilled product, when it comes to user acceptance and storage properties, tests should be conducted involving consumers.

Tests on the place of use for the selection (screening)

Such tests are used by many food-processing companies to evaluate the organoleptic properties of their products, including comparing products under development with competitors. These tests are very useful for taking several samples before full-scale production to reduce costs and optimize timing. To be sure of the result, the number of expert staff should not be less than the minimum allowed (it is recommended to use at least 50 people). The main negative point in the assessment of this type is the knowledge that employees have acquired, working in contact with the product, and the fact that their choice is inevitably affected by addiction. Researchers should minimize these addictions by hiding recognizable signs if possible.

Tests at home

These tests suggest that consumers are asked to rate one or more products at home. The advantage of such tests is that the evaluation is performed in a normal household environment, and therefore it is more likely that they reflect real behavior and product preferences. The advantage is also to receive information from the whole family, and not one person. The disadvantage is the lack of control over the responses - in particular, different consumers can use different methods and technologies for preparing products, which makes direct comparison difficult. In addition, when evaluating two or more products, the methods of heat treatment of different products may differ, as well as the time interval between preparation and consumption.

When conducting a home test, samples can be delivered home or taken from some center. After a certain period of time, the researcher talks with consumers by phone or in person. In this case, questions may be asked regarding the inclinations of each family member to a particular product, such as preparing and serving a dish, their expectations and the likelihood of purchase.

Tests carried out

When testing with consumer participation is necessary to observe closer or the number of products exceeds two or three, it is preferable to conduct a test in the active business parts of the city. Interviewers stop potential participants and ask specific questions to ensure that they meet the agreed criteria (given sample quotas) and in their desire to participate. Food enterprises often prefer just such testing, since it is cheaper to conduct it than tests at home. To measure attitudes towards the product, sensation scales are commonly used (so-called “hedonic scales”). Consumers are asked about their attitude to each product, as well as about the preferred sample as a whole.

The choice of products and the attitude towards them

All the methods described above use hedonic scales, which mainly reflect preferences regarding one or the other. If it is necessary to determine the reasons for choosing certain products, it is important to include other components in the study, in particular, cognitive and target components. To explain what determines the choice of product, many researchers have tried to include several factors. When consumers want to treat themselves to a piece of high-quality meat, they are probably more inclined to go to the local butcher and choose, often after discussion and advice, a quality steak from the sirloin.

Impressions from the buying process and the context in which it is performed become components of the buying decision process and product selection. In [17], it was studied how the name and information on the packaging can influence the choice of an orange juice in the face of economic constraints. The author observed a difference between hedonistic responses under the conditions of a “blind” choice with various given economic constraints and information. Other researchers have determined the effects on the selection of nutritional and health information [16]. Contextual analysis was explored in [26] to determine how, when, where, and who consumes certain products.

Qualitative research methods

Qualitative methods are used when the goal is to understand behavior and attitudes, rather than preferences (choices), although sometimes a combination of the two is considered. Two types of qualitative methods are focus groups and interviews. When testing with a focus group, a group of 8-10 consumers is gathered and asked to take part in discussions on a specific topic. To manage such a group, a moderator (moderator) is used, who leads the discussion to obtain relevant information using special clarification methods. In particular, to obtain maximum useful information, it is useful to use open and probing questions. To guide the discussion to issues of greatest interest, the moderator works according to a carefully prepared survey plan.

In recent studies, the focus group method was used to determine how successful the new bacon concept will be on the market. The basis of the survey plan was reactions to the idea, product, and various packaging formats. The main aspects that would attract the attention of the consumer to this new concept were convenience and usefulness to health. The question was not whether bacon was good, but rather what method of cooking was used — for example, relatively frying (“in a fried form, everyone is harmful”). In addition, bacon was particularly attractive for housewives, which can be heated in a microwave oven, thereby preserving its organoleptic characteristics, that is, the crunching ability (“I spend half of Life in the kitchen and I believe that the microwave is very good”).

When more sensitive issues are investigated or when interaction in a group is undesirable or unnecessary, individual interviews are used. At the same time, various methods of obtaining (extracting) information, often similar to those used for focus groups, are used. One of the methods that is used in the conditions of an interview is the method of “stable grids”. The studied objects are organized in groups of three, such that each object appears at least once and one object is transferred to the next trio. Two of these three objects are similar in the sense of the criterion determined by the researcher, and differ from the last object. Each interviewee is asked to describe how one of the objects differs from the other two. For assessing the level of difference or similarity for each consumer and for each parameter, sometimes [11] scaling is used.

Trends and Conclusions

A better understanding of the needs and expectations of the consumer is a necessary aspect of attracting and creating a new habit. In this chapter, we sought to show that for a complete understanding of consumer behavior, both organoleptic evaluations of the product and its evaluations by consumers are necessary. According to researchers and food companies, as has recently become clear, the use of an integrated approach to product quality and the development of new products lead to sustainable market success. In the food industry, product characterization based on consumer opinion is increasingly becoming a fashion trend. After many years of determining the characteristics of products, based on the requirements of production, food enterprises realized that consumer complaints are growing, and their “loyalty” to the product is not. The possibilities for consumers to contribute to the development of the quality characteristics of products are described in [20], where the organoleptic characteristics (determined by a professional expert committee) and the range of acceptability determined by the consumer are related. The study used canned grapefruit, and it was shown that any physical defects that were perceived as having a negative effect on texture and taste were the main obstacle to the acceptability of quality. On the other hand, the negative effect that uneven edges and broken lobules had on the perception of the product turned out to be less than previously thought. [2] proposed a global quality measurement tool based on user requirements — the Chamber of Quality, where consumer needs are transformed into measurable organoleptic characteristics using the example of frozen pears. This approach can be applied to chilled products.

Among food producers, it uses consumer participation at an early stage of product development, which reduces time and cost, often associated with a failure in the market for a product rejected by the consumer at a glance. It is estimated that in the UK 90% of new products appearing on the market each year are withdrawn from retail after half a year on the shelves.

In recent years, a lot of potential has been demonstrated by promising new methods — in particular, mapping preferences used to link organoleptic data and product acceptability to consumers, which have been equally useful for both marketing groups and product development groups [24]. This method allows researchers to more accurately determine the parameters of the optimal product according to organoleptic parameters determined by consumers.

The main risks associated with food products (especially beef and genetically modified foods) have had a strong negative effect on food acceptability. Consumers made their voices heard, and this led to the development of important strategic decisions by governments. Food manufacturers have realized the importance of understanding consumer behavior and identifying the mechanisms by which they select products and determine their acceptability. A very relevant topic for food manufacturers and retailers is respect for uniformity of measurements. A combination of quality assurance and strict control systems is being introduced in ever-growing highly developed international markets (see chapter 15).

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