Search: analysis of variance

This method is employed for determining the appropriate level of intensity for certain product attributes.

The sensory properties of a product can be identified and quantified by a tasting panel trained in descriptive testing using the profile method. The product profile is impartial and is used for product development as well as for monitoring changes in the product over time.

In consumer tests, the sensory acceptance for each individual product is determined using a scale with verbal anchor points.

A joint project in 2005 was organized by industry partners Hopsteiner, HVG and Johann Barth & Sohn along with the Central Marketing Organization of the German Agricultural Industries (CMA) and became known as the CMA scheme. This objective of this tasting scheme is to determine hop-related factors influencing the sensory analysis of beer.

First of all, the intensity and quality of the hop aroma and flavor are evaluated in their entirety according to a ten-point scale with 0 as unpleasant and 10 as very good/very pleasant. Then, the intensities of individual characteristics are also ranked on a ten-point scale, with 0 as imperceptible and 10 as very intense. For beer with a pronounced hop aroma, the following descriptors have become established in recent decades: fruity, floral, citrus, green-grassy and hop-spicy. These are available for specific training in the evaluation of hop oil fractions. Distinctive aromas detected by tasters can be described in the space provided. In order to characterize the overall impact of the hops, the bitterness is also evaluated sensorially. Both the intensity and the quality/harmony are evaluated on a ten-point scale, with 0 rated as completely lacking balance and 10 as very harmonious.

The mean values of the intensity of the hop aroma and flavor as well as the intensity of the bitterness are given on the score sheet (i.e., the sum of the scores divided by the number of tasters). The mean value of each aroma characteristic is reproduced as a spider diagram. The individual values should be checked for outliers prior to the calculating the mean. Since quality assessments are subjective by nature, the mean values can only be of limited value. However, they can be beneficial in determining whether any distinctive aroma or flavor characteristics were judged by the majority to be pleasant or unpleasant. The same applies to assessing the quality of the bitterness. 

One of the basic prerequisites for properly conducting sensory analysis is choosing an appropriate number of samples and presenting them to tasters in the relevant sequence.

In many cases, the extremely heterogeneous nature of non-alcoholic beverages as a group requires a comprehensive catalog of product-specific or category-specific attributes, in order to differentiate the effects of individual ingredients on the total sensory profile. With this as a consideration, the most important groups of raw materials used in the production of non-alcoholic beverages are listed below along with a short description of their general sensory features.

As mentioned previously, the individual categories of non-alcoholic beverages are characterized by different fruit contents. Correspondingly, a reduction in the influence of this ingredient on the overall sensory impression is to be expected as the fruit content is lowered. Thus, for products containing low amounts of juice such as fruit juice drinks, aromas are often used to round out the sensory profile in order to meet consumer expectations regarding flavor.

Since a preference for sweet foods has existed for thousands of years, naturally the use of sugar, sugar substitutes and artificial sweeteners also plays an important role in the production of non-alcoholic beverages. Fundamentally, a distinction among substances used for sweetening can be divided into the following groups:

• products as specified in regulations on types of sugars allowed for human nutrition (for example, in Germany, the "Verordnung über einige zur menschlichen Ernährung bestimmte Zuckerarten"), e.g., sucrose, dextrose)

• other carbohydrate (e.g., lactose, fructose)

• polyols (sugar alcohols)

• artificial sweeteners (e.g., saccharin, cyclamate, aspartame, stevia, etc.)

From a sensory standpoint, artificial sweeteners pose a special challenge. Along with the individual considerations to be taken into account regarding the different sweetening power compared to sucrose, artificial sweeteners can sometimes impart undesired flavors (e.g., bitter or metallic) which can be perceived sensorially. Furthermore, the sweetness profile, i.e., the perception of the sweetness sensation over time, is an important quality characteristic of an individual artificial sweetener or a mixture of sweeteners. Here, the goal is to avoid sweetness which lingers for an overly long time (compared to sucrose).

Depending on the product category, aroma can have a strong impact on the overall sensory profile of non-alcoholic beverages. When products with added aromas are tested sensorially, two primary goals should be followed: First, care should be taken to sufficiently characterize the corresponding type of aroma (e.g., differentiation of apple aromas into “green”, “yellow” and “red” aroma impressions). Second, more complex aromas (e.g., cola) should be specifically classified into discrete individual sensory perceptions which are important for an overall sensory description of the products, especially with regard to the clarification of consumer behavior.

For products made with the application of emulsions to create cloudiness or color, the relevant optical effect should be observed and evaluated with respect to color intensity and cloudiness.

The amount and characteristics of the carbon dioxide added to non-alcoholic beverages can have a decisive influence on how the product is perceived. Along with the actual and rather unspecific description of the perception of mouthfeel intensity as “tingling” or “prickling”, a balanced ratio of CO₂ bubbles with regard to size, distribution plays an essential role in consumer acceptance and therefore should be a part of an overall sensory description of the product.

Independent of these factors, the concentration of CO₂ influences the general perception the product by affecting the rate at which the aromas are liberated. This is the reason why the level of carbon dioxide must be the same when conducting sensory analysis sessions for comparison.

Many non-alcoholic beverages contain vitamins, in part from natural sources (i.e., from the fruit) and in part added to achieve technical goals or for nutritional purposes. Characteristic aroma notes can occur at higher vitamin dosages, which should also be included in the description, for example:

• ascorbic acid: sour

• β-carotene: earthy

• water-soluble vitamins: vitamin-like

Similarly, the use of preservatives can impart undesirable sensory impressions in the aroma as well as in the flavor and mouthfeel. This is often a reason for rejection of the product by consumers. A systematic, sensory comparison of two (otherwise identical) products, one containing the preservative and the other without, can provide valuable information regarding this type of additive.

The group referred to as “functional ingredients” (i.e., ingredients with a special enhanced functionality) encompasses several substances, which are associated with specific flavor impressions (e.g., the bitter flavor of hydrolyzed protein).

Quinine is a special member of this group (originally utilized for its fever-reducing effect), which is usually added to beverages to serve as a bitter component (e.g., in tonic water or in bitter lemon).

With this in mind, the descriptions, i.e., the compilation of a catalog of attributes to be used for the analysis of sensory profiles, should include the following categories:

• Appearance: color characteristics, intensity, cloudiness

• Aroma: specific characterization and individual classification of the perceived aroma notes

• Flavor: relevant basic flavors as well as specific characterization and individual classification of the perceived flavor notes

• Mouthfeel: sensation of the carbon dioxide/carbonation with regard to general intensity (“tingling mouthfeel”) as well as the size and number of CO₂ bubbles

• Aftertaste: only relevant for products with artificial sweeteners added (often in conjunction with a mouthfeel that is “lingering” and “mouthcoating” ) or unusually long lasting aroma impressions