Food packaging is an integral component of the food industry, serving to pro tect, preserve, and present products in a way that ensures quality and safety from production through consumption. This handbook, designed specifically for students and professionals in food technology and packaging science, pro vides a comprehensive and practical approach to understanding and conduct ing essential experiments in food packaging. This collection of experiments aims to bridge theoretical concepts with hands on experience, allowing learners to explore various aspects of packaging mate rials, techniques, and properties. From evaluating packaging material strength and permeability to understanding shelf-life and safety protocols, each exper iment in this handbook has been meticulously selected and crafted to foster a solid foundation in food packaging principles. Structured to encourage critical thinking and skill development, this handbook guides users through each step of the experimental process, offering insights into best practices, potential challenges, and industry-relevant applications. We hope that this resource serves as a valuable tool in preparing future pro fessionals to meet the evolving demands of the food packaging sector with confidence and expertise.

Objective After performing this experiment, you will be able to learn Sampling methods and procedures of packaging material. Introduction The objective of sampling of a packaging material is to obtain a representative sample of a whole lot for the required testing and/or grading. It is expected that the test results and grading will reflect the average quality of the PM from which the sample was taken. Principle The sample techniques and processes outlined in this publication are grounded upon scientific principles. Since the validity of any later test result depends on the quality of the sampling and the information given with the sample, the sampler is essential to the process of selecting lots for testing and/or grading. Every PM in the population being sampled has an equal chance of being selected, according to the random sampling principle. Usually, the sample size that is tested is very small in relation to the size of the lot that it represents. The sample must be taken carefully and in a way that gives assurance that it is genuinely representative of the lot. Similarly, in order to reduce the composite sample, all necessary.

Objective After performing this experiment, you will be able to learn: Water vapour transmission rate of packaging material Introduction Moisture Vapor Transmission Rate (MVTR), also known as Water Vapor Transmission Rate (WVTR), measures the rate at which water vapor passes through a material. MVTR is crucial in various industries where moisture control is vital. For example, moisture-sensitive foods and pharmaceuticals are packaged using materials with controlled MVTR to ensure quality, safety, and shelf life. In the textile industry, MVTR serves as a measure of breathability, enhancing comfort for outdoor clothing. In the building materials industry, managing moisture barrier properties in architectural components helps maintain appropriate moisture levels in the internal spaces of buildings. Various techniques are used to measure MVTR, ranging from gravimetric methods that assess moisture gain or loss by mass to advanced instrumental techniques capable of measuring extremely low transmission rates. It's important to note that special care must be taken when measuring porous substances like fabrics, as some techniques may not be suitable.

Objective After performing this experiment, you will be able to learn Sorting of samples by sink-floatation technique. Introduction Sink float is the simplest and cheapest method among all the wet sorting techniques in which polymers are separated based on their density. This technique is extremely fast, environment friendly and cost effective process for sorting of plastics. Since, the separations are done based on density, so any factor which may change the density of the pure polymer like blending, composite formation of multilayer structures etc. will not be separated well using this method. Moreover, if any two polymers are very close in density, they cannot be separated easily. That is why PVC and PET which are very close in their density can not be separated using sink floatation method. Initially the plastic waste is added to the container containing water and the system is gently stirred to evenly wet the surface of plastic and remove any air trapped on the surface. Since the density of polyolefins is near/close to each other but lighter than water, they all float in water whereas the heavier plastics sink. This technique is primarily used to separate polyolefins from other plastics. Now to further segregate the polyolefinic fraction, this method is extended by adding the polyolefin mixture to another container containing water and alcohol. As dropwise more and more alcohol are added to the water, the density of the medium will decrease and the polyolefins start separating. For separating the heavier fraction of the polymer, the mixture of polymers is added to water. To this water, dropwise salt water is added and stirred. Salt water increases the density of the medium slowly and at one point, the polymers which were sinking in water, will start floating depending on their density.

Objective After performing this experiment, you will be able to learn Sorting of given samples by selective dissolution technique. Introduction Sorting process is the process of separating the mingled and mixed plastic before the recycling process.  Selective Dissolution Technique (SDP) Recycling of plastic has become the major focus nowadays. Sorting of plastic materials is the major step towards recycling. One of the sorting techniques is selective dissolution although it has not found major usage in industry for various drawbacks. This technique uses the solubility parameter of different polymers for segregation purpose. Each polymer owing to its chemical structure has different solubility parameters. Hence, the solvents for each and every polymer are different. This difference in solubility in different solvents is used here for separating them from one another. Recycling of plastic has become the major focus nowadays. Sorting of plastic materials is the major step towards recycling. One of the sorting techniques is selective dissolution although it has not found major usage in industry for various drawbacks. This technique uses the solubility parameter of different polymers for segregation purpose. Each polymer owing to its chemical structure has different solubility parameters. Hence, the solvents for each and every polymer are different. This difference in solubility in different solvents is used here for separating them from one another.

Objective After performing this experiment you will be able to: To determine the peel strength of a given samples. Introduction Packaging is a key element to quality branding for an organisation, ensuring that the product labels are securely attached to products. Adhesion bond strength of a film to a surface can be quantified in terms of peel strength, bonding strength, and shear strength. Many protective covers are used as required for various applications. In most of such applications plastics films are used as the first preference of the manufacturers. In applications like, protective LCD screens and other scratch-prone surfaces very low peel force films are used. The force required to remove the protective films or the label is very important for both the consumer and the manufacturer. For example, for protective film application, the film must be easy to remove, yet the bond must be strong enough to remain intact for product security. Whereas, in a typical adhesive application, like laminated cups, the bond between the surfaces should be strong enough to withstand various environmental impact.

Objective After performing this experiment you will be able to learn: The stress-strain curve of the polymeric sample (polystyrene) and calculate the tensile strength, % elongation before break, young’s modulus. Principle Tensile Test (ASTM D638) Tensile strength is a measurement of ability of plastic material to withstand forces that tend to pull it apart. It is the amount of stress at the break point. This test also helps to determine the extent the material stretches before breaking known as elongation at break. Percentage elongation is defined as the amount of linear deformation of the sample before breakage. It is measured as strain value at the break point. Yield Point: It is the point at which an increase in strain occurs on stress-strain curve without the increase in stress. (point C) Yield Strength: The stress at which a specified limiting deviation from the proportionality of stress-strain curve is observed for a material is known as Yeild strength.

Objective After performing this experiment you will be able to learn: To determine the tensile properties of polymeric sample. Principle ASTM D638 covers the tensile properties of both reinforced and unreinforced plastics in the form of dumbbell-shaped molded plastic test specimens. Yield strength is measured as the highest stress where a film, when deformed, will resume its original dimensions when the force is removed. The yield stress is expressed as force per unit area (engineering stress) and is calculated as per Equation (1) and the elongation at yield as per equation (2).

Objective After performing this experiment you will be able to learn: To determine the tear resistance of polymeric film. Introduction Tear resistance testing is often used in the plastic film, paper and textile industries. Tear resistance is measured as a sample's ability to resist tearing. Tear strength is the maximum london the sample divided by the thickness of the material. Typically used for testing of plastic film, plastic sheets and other rubber products. Tear strength is calculated by force (in Newtons) divided by thickness (in millimeters, centimeters, inches, etc.): Tear strength = F/t A tear is generally uneven and usually unplanned. In cases like a packaged chips, already tear cuts are made following a perforated line so that the effort of tearing is less and the action will most likely produce a straight line. The speed at which a tear resistance test is conducted can affect the test significantly. Tear transmission resistance is common for acceptance testing with materials such as paper and rubber. Tear resistance in textiles involves the load required to spread a single "rip-tongue" type of tear or the type of tear where the material is initially cut.

Objective After performing this experiment you will be able to learn: The impact properties of polymeric film. Introduction Dart impact test is performed on plastic films and laminates to determine the effect of free falling dart on plastic films. The energy created by the falling dart causes the film to fail under some specified conditions. The test is widely performed by the manufacturers in plastic industries and paper & packaging industries to assess the durability and strength of the plastic films and other related products. Dart impact strength is dependent on film thickness as the test is sensitive to orientation of the chains in the film. The tackiness of the film (slip additives) and the condition of the dart surface also influence the values determined by this test. As dart impact is not tested in any specific film direction, it is sensitive to chain orientation in both directions. Best impact strength are usually obtained when the orientation is balanced in the Machine Direction and Cross Direction. Principle The test method is according to ASTM D1709

Objective After performing this experiment you will be able to learn: The procedure to analysethe Compatibility of Food Packaging Materials Using Shelf- Life. Introduction When testing a food product for shelf-life and stability, the packaging is a major factor to be considered. It is necessary to carry out stability testing in the packaging intended for marketing due to interactions that may occur between the package, the product and the environment. Testing is also important for establishing the correct specifications for procurement and quality control of incoming materials. The standards of packaging materials play a significant role in establishing optimum packaging specification. Properties of packaging materials like plastic and paper are affected by variables like temperature and humidity. Sensitivity of the packaging material to heat, light and moisture is due to their chemical nature. Compatibility of the packaging is as significant as development of the packaging systems or selecting packaging materials for food products.

Objective After performing this experiment you will be able to learn: How to  determine the caliper/GSM of paperboard. Introduction Thickness is calculated as the perpendicular distance between the two principle surfaces of paper or paperboard as measured under specified conditions. The GSM of paper may be defined as the thickness of a paper that is measured in a roundabout way. GSM stands for Gms per Square Metre - and is used to check the quality of the paper to be measured. It is a very simple to perform test but tells a lot about the basic properties of the material which are very important to decide the quality of the material. Also, the quality of the material is measured with its GSM value. The heavier a paperboard is, the better the quality. Principle Packaging materials are chosen by estimating the GSM of the sample material. High Grammage defines the strength of the paper. In certain applications high Grammage is desired, where the paper will be subjected to load and harsh working conditions.

Objective After performing this experiment you will be able to: Calculate the Burst strength of the given paper and Board. Introduction Bursting strength is defined as the measure of resistance to rupture in various materials. A test specimen is held between two circular clamps and subjected to an increasing pressure from a rubber diaphragm. The rubber diaphragm keeps on expanding with the help of a controlled pneumatic pressure until the test specimen ruptures. The pressure required to rupture the specimen at the time of reading is known as bursting strength. Principle The bursting strength of paper, paper board, including linerboard and corrugated board, is a combined measure of properties of the sheet, like tensile strength and elongation. In general, bursting strength is dependent on the type, proportion, preparation and amount of fibres present in the sheet and their formation, internal sizing, and to some degree, the surface treatment. Since bursting strength is an empirical property, this test serves to define “standard grades” in commercial activity in combination with basis weight.  

Objective After performing this experiment you will be able to learn: The water absorption of packaging material by Cobb method. Introduction The water absorptive capacity, or Cobb value, is defined as the mass of water absorbed in a specific time by 1 square meter of paper, board, or corrugated f iberboard under a head of 1 cm of water. To determine this value, conditioned test pieces are weighed before and after being exposed to water under specified conditions. The excess water is removed using blotting paper and a brass roller of defined dimensions and weight. The test piece is weighed immediately before and after exposure to water for a specified duration on one surface. The increase in mass due to water absorption is expressed in grams per square meter (g/m²). The Cobb value defines the water absorbency of paper as the amount of water absorbed by one side of a unit area of paper or board placed horizontally under a 1 cm water head within a given time. Principle This method, developed by Cobb, measures the amount of water absorbed by paper, paperboard, or corrugated fiberboard over a specified period under standardized conditions. It is applicable to paper or board that is not fully penetrated by water during the selected absorption time.

Objective After performing this experiment you will be able to learn : The Scuff Resistance of the Printed Sample. Introduction Scuff resistance or abrasion resistance is a desirable and sometimes critical property of printed materials. Abrasion damage can occur during shipment, storage, handling, and end use. The result is a significant decrease in product appearance and legibility of product information. A printed substrate's level of abrasion damage is influenced by numerous factors, including time, temperature, humidity, and shipping circumstances. This procedure offers a means of comparing printed materials' resistance to scuffs in a lab setting. The relative scuff resistance of printed inks, coatings, laminates, and substrates can also be assessed using this technique. This procedure can be changed to assess how a product—food, drink, powdered detergent, etc.—affects scuff resistance, which might happen when something spills or leaks while being transported. Labels, folding cartons, corrugated boxes, circulars, inserts, and other packaging materials with applied graphics on a flat substrate can all use this technique.

Objective After performing this experiment you will be able to learn: Gas / Vacuum packaging of foods and study their shelf life studies. Introduction Vacuum packaging is a food preservation technique that removes air from the package before sealing. This method involves manually or automatically placing items in a plastic film package, extracting the air, and sealing the package. The primary goal of vacuum packaging is to remove oxygen from the container to extend the shelf life of foods and, in the case of flexible packages, to reduce the volume of the contents and package. Shrink films are sometimes used to create a tight fit around the contents. Vacuum packaging is commonly used to store dry foods like cereals, nuts, cured meats, cheese, and coffee for extended periods. For short-term storage, vacuum packaging can also be used for fresh foods, such as vegetables and liquids, as it inhibits bacterial growth.

Objective After performing this experiment you will be able to learn: Special quality assurance needs, good manufacturing practices, HACCP, validation protocols, etc. Introduction Packaging is a very important element in product quality maintenance that is why quality of packaging has great influence and its quality assurance is necessary. Physical flow in the supply chain may deteriorate some packaging features, so their monitoring and proper conditions of storage, transport and suitable protection are important. The quality of packaging is essential; it is an important element of product quality and supply chain effectiveness. Packaging is influenced by quality of raw materials, proper conduct of the production, storage, transport and distribution processes in a company. That is why a lot of companies implement quality assurance or management systems. In regards to packaging risk categories there are different requirements.

Objective After performing this experiment you will be able to: Perform the cut out test for the given sample of food product. Principle The cut-out test is conducted to evaluate the overall quality of canned food. This test involves examining the condition of the food contents, the external and internal state of the can, and other characteristics of the product through various organoleptic, physical, and chemical assessments. Materials and Equipment 1. Canned food: 4?6 nos. Cans 2. Tone tester 3. Physical balance 4. Vacuum gauge 5. Can opener 6. Brix refractometer 7. Scale 8. pH paper near neutral ranges.

Objective After performing this experiment you will be able to learn: The effect of can close temperature on the resultant vacuum produced. Principle The unfilled volume of the hermetic (air-tight) food container usually referred to as the headspace, is a most important part of the container –contents system. In the majority of canned foods, the headspace consists of air and water vapor. Whereas a canned food would keep for a long time i.e. minimum two years of shelf life, stable, only if a certain degree of vacuum is created inside the can. The degree to which air has been extracted from a hermetic food container is measured by the pressure inside, which is referred to as vacuum. A vacuum of -101 kPa would mean that all of the gas has been expelled from the container; a vacuum of zero would mean that the pressure in the headspace is equal to atmospheric pressure. The difference between the pressure within the container and the air pressure is measured by a vacuum gauge.

Objective After performing this experiment you will be able to learn: Thermal Shock Resistance in Glass. Principle Thermal shock occurs when different parts of an object expand at different rates due to a thermal gradient. This differential expansion creates stress or strain within the material. If this stress exceeds the material's strength, it can lead to the formation of cracks. If these cracks are not stopped from propagating, they can cause the material to fail structurally. Thermal shock is quantified by the temperature difference between the heated temperature T1 and the cold water bath temperature T2 to which the object is subsequently exposed, which can reveal any cracks or damage. Purpose of Thermal Shock Test Glass items often experience significant temperature changes during normal use, and the thermal shock test is designed to ensure their resistance to such conditions. For example, moving a casserole dish from a hot oven to a cool countertop might be enough to cause it to break. This test evaluates the quality, durability, and strength of glass packaging materials used for both solid and liquid food products.

Objective After performing this experiment you will be able to learn  Determination of porosity of tin plate. Introduction Porosity in tinplate refers to the presence of tiny holes or pores in the tin coating on steel sheets used for making tin cans. These pores can expose the underlying steel to the contents of the can, potentially leading to corrosion and contamination of the food product. Ensuring minimal porosity is crucial for maintaining the integrity and safety of food packaging. Tinplate is produced by coating a thin layer of tin onto a steel sheet. This can be done through hot dipping or electroplating. The goal is to create a uniform and continuous tin layer that acts as a protective barrier against corrosion. During the coating process, imperfections such as pores or pinholes can form in the tin layer. These imperfections can occur due to variations in the coating thickness, impurities in the tin, or mechanical damage during handling and processing.When a tinplate can with porosity is filled with food, the contents can come into direct contact with the exposed steel through the pores.The acidic or basic nature of certain food products can accelerate the corrosion of the exposed steel, leading to the formation of rust.This corrosion can compromise the structural integrity of the can and potentially contaminate the food with rust particles or harmful by-products of the corrosion process. The primary function of the tin coating is to act as a physical barrier that prevents the food from contacting the steel. A continuous and defect-free tin layer ensures effective protection.Tin also provides cathodic protection to the steel. In the presence of an electrolyte (e.g., acidic food), tin acts as the sacrificial anode, corroding preferentially to the steel. However, this mechanism is only effective if the tin layer is relatively thick and the porosity is minimal.

Objective After performing this experiment you will be able to learn: Identification of paper and paperboard. Introduction Paper can be broadly classified into two categories: coarse papers, which are normally made of unbleached Kraft softwood pulp and used for packing, and f ine papers, which are usually composed of bleached pulp and used for writing paper, bond, ledger, book, and cover sheets. The main types of packaging papers are: Kraft paper Usually produced on a Fourdrinier machine, kraft paper is gritty and incredibly strong. It is then either machine-glazed on a Yankee dryer or machine-finished on a calendar. Sometimes it isn't calendared so that the rough surface will keep the bags from slipping over one another when they're stacked on pallets.

Objective After performing this experiment you will be able to learn: How to do edible packaging of food sample. Introduction Edible Packaging – An edible film or coating is simply defined as a thin continuous layer of edible material formed on, placed on, or between the foods or food components. The package is an integral part of the food, which can be eaten as a part of the whole food product. Edible packaging can be done in two types: Edible coating: Edible coating are applied and formed directly on food (e.g. by spraying, immersion, and fluidization) via a coating solution. This will be a part of the food and must not provoke unwanted change (organoleptic, physical, and chemical).

Objective After performing this experiment you will be able to learn: Physical tests of packaging material. I. Determination of Machine Direction  Introduction Machine-made paper has two directions and two sides: Directions a) Machine Direction: The direction in which the paper or board aligns with the flow of material on the paper machine. b) Cross Direction: The direction perpendicular to the machine direction

Objective After performing this experiment you will be able to learn: Moisture content of packaging material. Introduction The moisture content of paper is a critical parameter that significantly affects its other properties, such as printing quality and absorbency. Maintaining an optimal moisture level is essential for ensuring the functionality and durability of the paper. For instance, double-faced corrugated boards tend to break or crack during bending operations if they are too dry. Procedure • Weigh the conditioned specimen and place it in a drying oven, maintained at a temperature of 103°C ± 2°C, to expel moisture. Continue heating until a constant weight is achieved. • If the moisture content of the paper is to be determined "as received," the sample should not be conditioned.

Objective After performing this experiment you will be able to learn: Mildew resistance packaging material. Introduction Studying the mildew resistance of paper involves evaluating how well the paper can resist fungal growth under specific conditions. Mildew, a type of mold, can degrade paper quality, causing discoloration, weakening, and unpleasant odors. Here’s a detailed procedure to assess the mildew resistance of paper: Materials Needed Paper samples (different types, if comparison is required), Sterile petri dishes, Sterile distilled water Fungal spore suspension (commonly Aspergillus niger or similar mildew spores), Nutrient medium (e.g., potato dextrose agar or a similar agar that promotes fungal growth), Incubator, Sterile tweezers and scissors, Forceps, Micropipette or dropper, Humidity chamber (can be a sealed container with a saturated salt solution to maintain high humidity), Control samples (untreated paper).

Objective After performing this experiment you will be able to learn: pH value of packaging material. Introduction As mentioned earlier, these tests are performed to assess the suitability of the board for printing, corrosion protection, food packaging etc. The presence of acid in paper or paper possessing an acidic reaction is a property of specific importance. Not only may the presence of acid effect the aging properties of paper, but it also may act upon materials that come into contact with the paper. In addition, the sizing of paper, wet strength treatment, and dye and fillers retention, usually depend upon the addition of alum or other acidic materials to the beater furnish. Hence many appers are acidic to various degrees at the time of manufacture. pH is a measure of hydrogen ion present which depends both upon the amount of acidic material and upon its degree of ionization. Hence, pH does not measure the amount of acid present. Since it is the 'activity or ‘intensity’ of acid that is usually of most interest, the pH value is the more common test.