Definition and Types of Food Quality Assessment

According to Law no. 18 of 2012 concerning Food, states that food quality is a value determined on the basis of food safety, nutritional content, and trade standards for food, food and beverage ingredients. Food quality assessment is an assessment of the quality of foodstuffs that have undergone processing or cooking. The purpose of food quality assessment is to obtain a quality standard that is fit for consumption.
Food quality is a set of characteristics or factors in a food product that distinguishes the level of satisfaction / aseptability of the product for buyers / consumers. Food quality is multidimensional and has many aspects. These aspects of food quality include nutritional aspects (calories, protein, fat, minerals, vitamins, etc.) as well as taste aspects (sensory, delicious, attractive, fresh) aspects of business (quality standards, quality criteria); as well as health aspects (physical and spiritual). Consumer satisfaction is related to quality.
However, other organoleptic characteristics such as smell, aroma, taste, and color also determine the profile of food products. Fulfillment of product specifications and functions in the relevant food product is carried out according to aesthetic (color, taste, smell and clarity), chemical (minerals, heavy metals and chemicals in foodstuffs) and microbiology standards (not containing Eschericia coli bacteria and pathogens) . Quality must be designed and shaped into the product (Kadarisman, 1996).
Subjectively, the assessment of food quality is determined by the process that consumers go through to be able to dig up information on the product. This process starts from the initial formation of needs to the post-purchase quality assessment of the product. Considerations made by consumers can also be influenced by certain factors, such as internal factors (gender, age, education level, and type of work) and external factors (information obtained from the environment).

2. Methods of Food Quality Assessment

Consists of two, namely objective and subjective assessments.
A. Objective (physical, biological, chemical, microorganism)
The method of quality testing using tools is known as the method of quality testing objectively, including:
1) Physical test
Product quality is measured objectively based on the physical things that appear from a product. The method of quality assessment by means of tools can be used to reveal hidden characteristics or characteristics of food quality. Generally, the results of measuring the quality characteristics by sensory test have a high correlation value with the results of measuring the quality characteristics by means of a tool. The physical test measurement method is used to test the color, volume, texture, viscosity or viscosity and consistency, tenderness and plasticity as well as specific gravity.
Advantages :
  • Has high relevance to product quality
  • This method is quite easy and fast to do, the results of measurements and observations are also quickly obtained
  • Can help business analysis to increase production or marketing
  • The limitations due to some sensory characteristics cannot be described.
  • The objective of the tool / instrument must be always calibrated to ensure the accuracy of using simple tools and the accuracy of the results of the tools.
  • There can also be miscommunication between managers and panelists.
Physical testing can be done using tools or instruments such as:
  • Spectrophotometer.
  • Planimeter.
  • Texturometer.
  • Penetrometer & Hydrometer.
  • Lactometer.
  • Alcoholmeter.
  • Saccharometer. 
2) Chemical test
The chemical test measurement method is a test in which the quality of the product is measured objectively based on the chemical content contained in a product. The chemical test measurement method is divided into two groups, namely proximate analysis, namely water content and ash content, and qualitative / quantitative analysis, namely protein, fat, carbohydrate, fatty acid, reducing sugar content and amino acid content.
  • Very objective, have standardized procedures.
  • The results can be trusted (high reliability).
  • Can determine the quality of food from the chemical nutrients contained in it.
  • Expensive.
  • Complex.
  • Demand expertise and knowledge in the field of chemical analysis.
  • Requires precision and care in the process, because it involves chemical reagents.In the chemical test method using several methods including:
Gravimetry is an analytical method based on weight measurement, which involves: the formation, isolation and weight measurement of a sediment. Gravimetric analysis is a method of quantitative analysis by weighing. The initial stage of gravimetric analysis is the separation of the components you want to know from other components contained in a sample and then deposition is carried out.
Measurement in the gravimetric method is by weighing, the number of components being analyzed is determined from the relationship between the weight of the sample to be analyzed, the relative atomic mass, the relative molecular mass and the weight of the precipitate the reaction results. Gravimetric analysis can be carried out by means of precipitation, evaporation and electrolysis.
Volumetry is a volumetric analysis which is a part of quantitative chemical analysis, in which the determination of the substance is carried out by measuring the volume of the solution or the weight of the substance whose concentration is known, which is needed to react quantitatively with the solution of the substance needed earlier.
In volumetry, the determination is carried out by means of titration, namely, a process in which the standard solution (in the form of a solution that has a known concentration) is added gradually from a burette to a specified or titrated solution until they react until they are complete and reach the equivalent amount of solution. standard is equal to zero, the equivalent of the solution being titrated and this titration point is called the equivalence point or end point of the titration.
To determine the perfection of the reaction between the standard solution and the solution being titrated, a chemical known as an indicator is used, which can help determine when the addition of the titrant must be stopped. When the reaction between the drained solution and the standard solution has been complete, the indicator should provide a clear visual change in the solution (for example, in the presence of a change in color or the formation of a precipitate). The point at which the indicator gives a change is called the end point of the titration and at that time the titration must be stopped.
In volumetry, there are 2 types of standard solutions, namely the primary standard and the secondary standard.
a) Primary standard
Namely a solution in which the levels can be known directly, because it is obtained from the results of weighing. In general, it can be expressed in terms of N (mol. Equivalent / L) or M (mol / L). Examples of primary standard solutions are: NaCl, oxalic acid, sodium oxalate.
b) Secondary Standard
Namely solutions in which the concentration is determined by means of freezing, by primary standard solutions or by appropriate gravimetric methods. Example: NaOH (standardized with oxalic acid primer).
The requirements for a raw material are:
  • Its chemical composition is known with certainty
  • Must be pure and easy to purify
  • Can be dried and is not hygroscopic
  • Stable, both in a pure state, and in solution
  • Can be dissolved in a suitable solvent and can react sthokiometry with the solution to be standardized or with the substance to be determined.
  • The equivalent weight is large, so that the effect of weighing errors can be minimized. 
Spectrophotometry is an analytical method based on measuring the absorption of monochromatic light by a row of colored solutions at a specific wavelength using a prism monochromator or diffraction grid and a vacuum phototube detector or a vacuum photon tube. Spectrophotometry can be considered as an extension of a visual examination with a more in-depth study of energy absorption. The radiation absorption by a sample is measured at various wavelengths and streamed by a percam to produce a specific spectrum that is unique to different components (Saputra 2009).
Chromatography is a molecular separation technique based on differences in movement patterns between the mobile phase and the stationary phase to separate the components (in the form of molecules) that are in solution. The dissolved molecules in the mobile phase will pass through the column which is the stationary phase. Molecules that have a strong bond with the column will tend to move more slowly than molecules with a weak bond. With this, various types of molecules can be separated based on the movement of the column. After the components elute from the column, they can be analyzed using a detector or can be collected for further analysis. The basic principle of chromatography is a separation based on a two-phase differential distribution between the stationary phase and the mobile phase. This movement of the mobile phase results in a differential migration of components in the sample.
3) Microbiological test
Microbiological test measurement methods to measure the number of bacteria, mold, yeast and protozoa, for example: total microbial test (Total Plate Count / TPC). The microbiological test is an important test, because in addition to being able to predict the shelf life of a food, it can also be used as an indicator of food sanitation or an indicator of food safety. Microbiological testing includes qualitative tests to determine the quality and durability of a food, quantitative test for pathogenic bacteria to determine its safety level, and test for indicator bacteria to determine the level of food sanitation (Fardiaz, 1993).
In microbiological tests, product quality is measured objectively based on the presence of microorganisms in a product. This test plays a major role in determining food sanitation hygiene but also has several drawbacks, namely the risk of contamination of the testers and it takes a long time because microbes must be incubated.
Various kinds of microbiological tests can be carried out on foodstuffs, including quantitative microbial tests to determine the resistance of a food, qualitative tests for pathogenic bacteria to determine the level of safety and indicator tests to determine the level of food sanitation. The tests carried out on each foodstuff are different depending on various factors, such as the type and composition of foodstuffs, methods of packaging and storage and consumption, consumer groups and various other factors (Dirjen POM., 1979).
The MPN method is usually used to calculate the number of microbes in a liquid sample, although it can also be used for solid samples by first making a 1:10 suspension from the sample (Fardiaz, 1993).
The MPN method uses a liquid medium in a test tube, where the calculation is carried out based on the number of positive tubes that are overgrown by microorganisms after incubation at a certain temperature and time. Positive tube observations can be seen by observing the emergence of turbidity or the formation of gas in a small tube (Durham tube) that is placed in an upside down position, namely for gas-forming microorganisms.
In the MPN method, the dilution must be done higher than the dilution in a matter of plates, so that some tubes containing the liquid medium that are inoculated with the diluted solution contain one cell, some other tubes contain more than one cell or other tubes do not contain cells. Thus after incubation, it is expected that growth will occur in some tubes which are stated as positive tubes, while others are negative. Pros: Plays a big role in knowing food sanitation hygiene. Disadvantages: Risk of contamination of testers and takes a long time because microbes must be incubated
4) Types of Microbiological Tests
TPC (Total Plate Count) analysis. This analysis is a quantitative analysis, which is to calculate the number of growing colonies. The media used was Nutrient Agar Broth (TLV). The samples tested included empty containers, rinsing water, air quality, and finished products. Raw water (BT), empty bottles, empty gallon bottles, empty cups, rinsing water, bottle risers, rinser gallons, recycle water, and finished products. The method used is direct pouring method. Meanwhile, the cap gallon, cap screw, and lid use the swab test method. In the analysis of air quality, it does not use the pouring method or the swab test method, but a method by placing the existing media on the petridish and placing it in the filling room with the open petridish.
For samples in the form of bottled and gallon finished products, they must be allowed to stand for 2 days prior to analysis, with the aim of removing ozone. If there is still ozone, microbes cannot grow. For Raw Water (BT) samples and finished products, daily TPC analysis was carried out. Likewise for empty containers, rinsing water, and air quality. As for the weekly TPC analysis (product after 5 days) which is carried out only on finished products, because the peak of microbes will grow rapidly after 5 days. The incubation period for this analysis was 24 hours.
Coliform analysis (E. coli)
Coliform analysis is a quantitative analysis with an indication that if the analysis result is positive, it is marked with a red heart spot on the media and negative if there is no liver red spot. The media used was Violet Red Blue (VRB), the method used was the filtration method with the samples tested were raw water, finished products and rinsing water. This analysis is carried out every day while for room quality E. Coli analysis is carried out once a week without the filtration method but the media is open. The purpose of the E. Coli analysis is to determine the presence or absence of E. Coli in water. Where the E. Coli bacteria causes diarrhea. The incubation period is 24 hours.
Pseudomonas aeroginosa (PA) analysis
The analysis is a quantitative analysis, if positive then it is indicated by bluish-green colonies on the membrane, negative if marked by color on the membrane. The medium used was Cetrimite Agar Base (CAB). The method used is the filtration method with the samples being tested are bottles, gallons, cups. This analysis is carried out once a week. The incubation period for this analysis is 24 hours.
Salmonella analysis
Salmonella analysis is a quantitative analysis, if the results of the analysis are positive, it is marked with black spots that resemble fish eyes on the membrane. The media used is Bismuth Sulfite Agar (BSA). The method used is a filtration method with a sample point of the product so whether or not Salmonella bacteria can interfere with the digestive tract. The incubation period for this analysis is 3x24 hours.
Yeast and Mold (YM) Analysis
YM analysis is a quantitative analysis by counting the number of growing colonies. The media used is Potato Dextro Agar (PDA). The method used is the filtration method with the samples tested are finished products (bottles, cups and gallons) and empty containers (empty bottles, empty gallon bottles and empty cups), while the gallon cap, cap srew, and lid from the filling room are done with swab test method.
For indoor air quality by leaving the media open in the room. The incubation period for this analysis was 2 × 24 hours. Strengths: can strengthen the results of the subjective (organoleptic) quality assessment, the results of the assessment are more definite. Weaknesses: requires laboratory equipment that is suitable for each test, the price of the equipment is relatively expensive, takes longer, and requires experts. 
b. Subjective (Organoleptic Test)
1) Definition of Organoleptic Test
Sensory Assessment, also called Organoleptic Assessment or Sensory Assessment, is the most ancient way of assessment. Sensory assessment becomes a field of science after assessment procedures are standardized, rationalized, linked to objective assessments, data analysis becomes more systematic, as well as statistical methods are used in analysis and decision making.
Organoleptic assessment is very widely used to assess quality in the food industry. Sometimes these assessments can yield very careful assessment results. In some respects the sense of judgment exceeds the precision of even the most sensitive instrument.
The sensory assessment by means of the organoleptic test includes:
  • Assessing the texture of an ingredient is one element of food quality that can be felt by the touch of the fingertips, tongue, mouth or teeth.
  • Appearance factors which include color and brightness can be assessed through the sense of sight.
  • Flavor is a stimulus that can be felt by the senses of smell and taste together. Flavor assessment is directly related to human senses, so it is one quality element that can only be measured subjectively.
  • Sound is the result of observations with the sense of hearing that will distinguish between crispness (by breaking the sample), sluggishness, and so on.
Strengths: being able to describe certain properties that cannot be replaced by means of measurement using machines, instruments or other equipment and are widely liked because they can be carried out quickly and directly. Weaknesses: bias can occur, panelist errors, testing errors, subjectivity, weakness in controlling variables, and incomplete information.
2) Purpose of Organoleptic Test
The purpose of holding the organoleptic test is directly related to taste. Everyone in each region has a certain taste tendency so that the products to be marketed must be adjusted to the tastes of the local community. In addition, it is also adjusted to the target consumer, whether children or adults. The objectives of the organoleptic test are to:
  1. Product development and market expansion.
  2. Quality control of raw materials, products and commodities.
  3. Product improvements.
  4. Comparing own products with competitors' products.
  5. Evaluation of the use of new materials, formulations and equipment.
3) Types of Panelists
In assessing the quality of a commodity, the panel acts as an instrument or tool. This tool consists of a person or group called a panel whose task is to assess the nature or quality of food based on subjective impressions. People who are members of the panel are called panelists.
In organoleptic assessment, there are several kinds of panels. The use of these panels may differ depending on their purpose. There are 6 types of panels that are commonly used, namely: individual panels, limited panels, trained panels, moderately trained panels, untrained panels, and consumer panels. The differences between the six panels are based on their “expertise” in conducting organoleptic assessments.
a) Individual panel (individual expert)
An individual panel is a highly skilled person with a very high specific sensitivity that is acquired through talent or intense training. The individual panels are very familiar with the properties, roles and processing methods of the materials to be assessed and have very good mastery of organoleptic analysis methods. The advantages of using this panelist are high sensitivity, avoidable bias, efficient assessment and not fatigue quickly. Individual panels are usually used to detect slight deviations and identify their causes. The decision is entirely up to one person.
b) Limited panel (small expert panel)
The limited panel consists of 3-5 people who have high sensitivity so that bias is avoided. These panelists are familiar with the factors in organoleptic assessment and know how to process and the effect of raw materials on the final result. Decisions are taken in discussion among its members.
c) A trained panel
The trained panel consists of 15-25 people who have quite good sensitivity. To become trained needs to be preceded by selection and training. This panelist can assess several stimuli so that they are not too specific. The decision is taken after the data is analyzed together.
d) Untrained panels
A moderately trained panel consisting of 15-25 people previously trained to identify certain characteristics moderately trained panels can be selected from a limited circle by testing the data first. Meanwhile, highly distorted data may not be used in the decision. 
e) Untrained panel
The untrained panel consists of 25 lay people who can be selected based on ethnicity, social level and education. Untrained panels are only allowed to judge simple organoleptic tools such as preference traits, but should not be used in that case untrained panels are usually adults with the same composition as female panelists.
f) Consumer panel (consumer panel)
The consumer panel consists of 30 to 100 people depending on the marketing target of the commodity. This panel has a very general nature and can be determined based on individuals or certain groups.
In organoleptic assessment, a panelist needs senses that are useful in assessing the sensory properties of a product, namely:
Vision associated with luster color, viscosity, size and shape, volume density and specific gravity, length and width and diameter and shape of the material.
  • The sense of touch as it relates to structure, texture and consistency. Structure is a characteristic of the constituent components, texture is a pressure sensation that can be observed by mouth or finger touch, and consistency is thick, thin and smooth.
  • The sense of smell, smell can also be used as an indicator of damage to the product, for example, there is a bad smell which indicates the product has been damaged.
  • Sense of taste, in terms of taste sensitivity, sweetness can be easily felt on the tip of the tongue, salty taste on the tip and edges of the tongue, sour taste on the edge of the tongue and a bitter taste on the back of the tongue.
4) Laboratory Requirements
An organoleptic assessment laboratory is a laboratory that uses humans as measuring devices based on their driving ability. This laboratory needs certain requirements in order to obtain an honest and pure psychological reaction without the influence of other factors.
Important Elements in an Organoleptic Assessment Laboratory.
  1. Atmosphere: includes cleanliness, serenity, fun, neatness, order, and aesthetic presentation.
  2. Room: includes a sample preparation room / kitchen, a tasting room, a waiting room for the panelists and a meeting room for the panelists.
  3. Equipment and Facilities: includes sample preparation tools, sample presentation tools, and communication tools (light systems, input formats, instruction formats, stationery).
Organoleptic Assessment Laboratory Requirements
To ensure a calm atmosphere like the above, special requirements in the laboratory are needed.
  • Isolation: to be calm, the laboratory must be separated from other rooms or other activities, provide a relaxed atmosphere in the waiting room, and each member needs a separate tasting booth.
  • Soundproof: the tasting booth must be soundproof, the laboratory must be built away from the crowd.
  • Odor Level: the assessment room must be free of foreign odors from outside (free of smell of perfume / panelist cigarettes), away from sewage and processing rooms.
  • Temperature and Humidity: the room temperature should be kept at room temperature (20-25 ° C) and the humidity is adjusted to about 60%.
  • 'Light: the light in the room is not too strong and not too dim.
Taster Booth
The taster booth is located in the tasting room, this room is a partition with a length of 60-80 cm and a width of 50-60 cm. The taster booth is an isolated one and enough to seat one panelist. This is so that each panelist can make an individual assessment.
Each tasting booth is equipped with:
  1. Window (to enter the tested sample).
  2. Table (to write / record impressions, place to put samples, glass of mouthwash).
  3. Round chairs.
  4. Water pipe faucets, waste water reservoir.
Sample Preparation Kitchen
The sample preparation kitchen should be separate but not too far from the tasting room. Odors from the kitchen should not contaminate the tasting room. The busyness of preparing samples should not be seen or heard by the panelists in the tasting room.
Below is a drawing of a floor plan of the test laboratory, preparation room and tasting booth. 

Floor plan of the test laboratory
Floor plan of the test Laboratory

preparation room kithcen
Preparation Room/Kithcen

taster room food quality assessment
The taster room food quality assessment

Food quality assessment is an assessment of the quality of foodstuffs that have undergone processing or cooking. The purpose of food quality assessment is to obtain a quality standard that is fit for consumption. Food Quality Assessment consists of two ways, namely objective assessment (physical, biological, chemical, microorganism) and subjective (organoleptic: color, volume, texture, viscosity, tenderness, specific gravity).

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