Quality has never been more crucial for beverage businesses. Customers and retailers gravitate toward products that they find to be straightforward and trustworthy. One minor incident can tarnish a company’s reputation and have a negative effect on profits. Accurate data is the foundation for incorporating consistent quality into the products and processes.
Beverage shelf life study offers valuable information for developing quality standards that will help define and protect stable and competitive beverage brands.
What is beverage shelf-life and why is it important?
The meaning of beverage shelf-life
According to the Institute of Food Science and Technology, shelf life is defined as “the period during which the drink substance can stay safe; be certain to maintain its desired sensory, chemical, physical, microbiological, and functional characteristics; and, where applicable, comply with any label declaration of nutrition data when processed under the recommended conditions.”
In a nutshell, beverage shelf-life is a consumer’s guide to the number of time drinks can be stored until it begins to deteriorate, given all specified storage requirements are met.
The shelf-life of a product starts when it is prepared or manufactured. Common definitions of the various shelf-life concepts:
- Primary shelf life: the time elapsed between the manufacture and packaging of a drink and the point at which the drink first becomes unacceptable under defined environmental conditions.
- Secondary shelf life: the period after a beverage product’s packaging has been opened during which it retains an acceptable quality standard.
- Required shelf life: the minimum amount of storage time that a beverage must have to be profitable on the market.
- Maximum shelf life: the most extended amount of time that a food product will last if the best possible packaging solution is used.
- Display shelf life: the amount of time that products can be stored under specified or expected store display conditions.
The importance of beverage shelf-life
Beverage shelf-life aims to help consumers make safe and informed use of drinks. The shelf-life of beverages should only be considered valid if the product is purchased intact and undamaged.
Consumers should always follow manufacturers’ instructions on storage, particularly temperature and product use after opening. It is also recommended that consumers consider beverage shelf-life information when purchasing to avoid unnecessary waste.
What is a beverage shelf-life study?
A beverage shelf life study is a scientific process that determines how long a beverage can follow specific requirements in terms of microbiology, taste, appearance, nutrient levels, and aroma.
Under analysis, several tests get conducted on the given products to examine how they change with time and other environmental factors.
They concentrate on various aspects of the drink, such as its materials, packaging, manufacturing, and storage conditions. As a result, the influence of each of these variables on the product is observed.
The shelf life study report is determined by the specific type and quantity of these variables. If any of these things change in type or quantity, the shelf life study must be repeated.
Some of the benefits for beverage manufacturers that leverage a shelf life study:
- Enhancing product quality and reducing time to market
- Ensure product effectiveness during the product’s shelf life
- Ensuring that the formula’s combined ingredients remain stable over time
- Verifying the consistency of your formula with the packaging you’ve chosen
- Ensuring that your formula does not degrade in a way that jeopardizes the safety and purity of your product
- Investigating methods to extend product shelf life
- Specifying the storage conditions needed for your beverage to retain its quality over time
6 factors affecting beverage shelf life
1. Initial quality
For perishable ingredients, the initial microbial load will influence beverage shelf life. Using input materials that have already started to deteriorate (e.g., old oil) or overprocessing can change taste, texture, or loss of nutrients (e.g., vitamin C).
Packaging interactions include permeability of gases and water vapor into or out of the package, migration of package components into the drink, scalping of drink aromas into the package, and light penetration through the package.
These interactions alter the composition, quality, and physical properties of the drink and the package. For example, milk is susceptible to vitamin degradation and off-taste due to light-induced oxidation, so light protection is required.
So choosing a packaging that is suitable for your drink will affect your beverage shelf life but usually, you do this with a packaging supplier. So it depends on how do you select your supplier, the more long-standing experience they are in the industry the better.
But that is not the only thing you need to keep your mind when choosing a partner, a lot more to come already contained in this article right here: Top 20 great beverage packaging suppliers that you should know to enhance your beverage business.
3. Transportation and storage conditions
Relative humidity and variable temperatures in the supply chain (including the retail environment) will affect the shelf life of beverages. For example, higher-than-optimal temperature storage of refrigerated beverages will hasten microbial development. Higher temperature exposure also accelerates oxidation reactions, reducing product shelf life.
4. Product formulation
The addition of preservatives or antioxidants to the drink will help extend its shelf life. Changes in formulation, such as changing the type of acid, removing nitrates from beverages, and reducing salt added, can all affect the product’s shelf life.
5. Processing methods
Thermal processing reduces (e.g., pasteurization) or eliminates (e.g., sterilization) bacteria while also extending beverage shelf life. Other gentle processing methods, such as high-pressure processing, can also be used to minimize initial microbial levels.
6. Consumer handling
The transfer of a beverage from the store to the home after purchase will increase temperature exposure. Consumer refrigerators can also have storage temperatures that are higher than optimum. The shelf-life date assigned by the beverage manufacturer is no longer valid once the package is opened.
5 methods of beverage shelf-life testing
1. Direct method
These are real-time experiments that include storing the product in conditions close to those it would encounter and monitoring its evolution at frequent intervals. The main benefit of this method is that it generates a very reliable estimate of the amount of time it takes for a product to deteriorate.
However, they are tests that typically take a long time and do not consider the fact that a product’s storage conditions are not always consistent over time.
2. Challenge test
This method entails introducing pathogens or microorganisms into food during processing, distribution, and storage to expose the product to the real-life conditions it will face. The main drawback of this form of test is that only the effects of the tested parameters are examined.
The fact that the product might be exposed to several variables simultaneously is not addressed. Furthermore, they are studies that are very complicated and difficult to put into practice.
3. Predictive microbiology
This method studies the various microbial responses of foods to varying environmental conditions to predict the microorganisms’ behavior in the product. This form of analysis, often used when designing a new product, considers a product’s potential changing conditions. However, its main drawback is that it implies greater complexity for the manufacturer and that the results conform to a simulation, which may or may not be accurate.
4. Accelerate test
In these tests, elements like temperature, oxygen pressure, and moisture content are all changed to speed up the spoilage reactions. These predictions allow us to forecast the behavior of drinks under specific conditions and estimate how they will evolve under particular storage conditions.
Accelerated tests allow for incorporating changing environmental factors and concentration changes of the ingredients that make them up. These studies are highly versatile, fast, and low-cost for the manufacturer, allowing for the comparison of various scenarios. Since it is not an exact condition that would normally occur on the shelf in reality, there is some margin of flaws in the collected results.
5. Sensory test
Sensory testing is a scientific discipline that involves eliciting, measuring, analyzing, and interpreting reactions to the properties of drinks and other materials as perceived by the senses of sight, smell, taste, touch, and hearing.
It entails determining people’s attitudes about the same product with different manufacturing dates to decide whether or not they will consume it. This approach attempts to create a connection between the product’s shelf life and its perceived quality. While it is not a reliable method for estimating shelf life, it is essential to use it in conjunction with other methods to determine a product’s best by date.
How to conduct a beverage shelf-life study (with 9 steps)
Step 1: Review Formula and Storage Conditions
To ensure that your shelf life analysis is correct, your beverage should be manufactured in a manner that represents normal production. These may be samples from a pilot facility or a full-scale production run.
Benchtop samples may or may not indicate an actual production run (due to scale-up error). Ingredients, product form and claims, packaging, temperature exposure and handling, and expected usage after opening all affect beverage shelf life.
Step 2: Define testing factors for quality and safety
The required organoleptic quality and food safety requirements must be outlined after evaluating the formula and storage conditions. Any legal claims, such as nutritional content, must also be taken into account when testing for nutrients that can degrade over time. Consumer and legal requirements will determine a beverage’s testing program, and it should use accredited testing methods.
Step 3: Select test methods
Next, you determine what methods you want to proceed with. You should do this in a two-fold manner: one is through methods that use microbiological and chemical evaluations to evaluate both the safety and quality of the product and the other is through sensory method.
Microbiological analyses are performed to assess the growth and change of spoilage species over time and the level that a foodborne pathogen will reach if it becomes present in the beverage (typically through a challenge study, which is the worst-case scenario). Chemical analyses can detect changes in quality over time, such as pH, headspace, free fatty acids, and so on.
For sensory evaluation, you will decide your important product characteristics (a specific color, a specific smell, a specific taste, etc.) and evaluate how they react over the stated shelf life. Even if you decide that your product is microbiologically and chemically safe, you still want to consider these quality characteristics when determining shelf life because they will influence your consumer response.
Step 4: Set storage condition
Choose variables such as temperature, relative humidity, and lighting. The storage conditions of a product may be ideal, typical or average, or worst-case scenario. The variables may also be set or fluctuating to simulate real-life product exposure during distribution, storage and retail.
Step 5: Set target endpoint and testing frequency
For products with a short shelf life, evaluation can be performed daily or every two days. For moderate shelf life (three weeks) and long shelf life (one year), testing can be done at the initial point, endpoint, two to three occasions in between, and one point beyond the endpoint.
Step 6: Determine appropriate test and control samples
Set the shelf-life study’s ingredients, operation, and packaging. To eliminate variance, test samples should be from the same batch, and enough samples should be processed for duplicate or triplicate testing. If the product deteriorates over time, use freshly produced or chill or freeze samples to ensure reduced degradation.
Step 7: Perform shelf-life study
Store the samples under conditions outlined in the study and test them at the selected intervals.
Step 8: Analyze results and set shelf-life
Manufacturers must set their endpoint based on microbiological, chemical, or sensory requirements in the absence of guidelines (legal or voluntary). Typically, the shelf-life date is assigned as the last day of an acceptable sensory score or analytical results. The preliminary shelf-life date can be conservative and based on the worst-case manufacturing and storage scenario.
A shelf-life analysis should go beyond the actual expiry date to ensure that your beverage is safe after that date. If you make changes to your formula or manufacturing processes, you will need to re-validate your shelf-life testing.
Step 9: Monitor and confirm shelf-life
Once the beverage has been introduced into the market, sample at the distribution and retail levels and adjust the shelf-life date accordingly.
5 ways to extend beverage shelf life
Fruit juices contain vitamins, minerals, and fiber that help sustain a healthy lifestyle. However, some of the nutrients in fruits (carotenoids, phenolic compounds) are heat sensitive, so thermal treatments of fruit juices may lower the nutritional value and alter the taste. Essential oils derived from plants have antimicrobial properties, but their intense flavors can also affect the end product’s taste.
Researchers at the University of British Columbia investigate the use of natural acids from other fruits combined with essential oils as a natural preservative to solve these issues.
Current application: Watermelon juice
Applicability: Fruit juices
- Ingredients are all-natural, derived from fruits or other plants
- No thermal process is required, so there is no loss of nutrients from the final product
- Using apple/lemon juice blend masks the unpleasant taste of essential oils
- Appearance of the final product is altered due to the additives
- Adding a higher percentage of essential oils makes the final product unpalatable to consumers
- Approach still needs to be investigated for products other than watermelon juice
Combining natural acids from low-pH fruits and essential oil constituents could be a potentially effective way to extend the shelf life of fruit juices, non-thermally and organically.
Kancor has developed a natural antioxidant solution derived from rosemary called OxiKan CL. OxiKan CL is an entirely colorless, odorless and flavorless liquid extract that does not alter the organoleptic profile of the food matrix. It extends the shelf life of the food products by fighting lipid rancidity without imparting any aroma or color.
The company claims that OxiKan CL is an ideal natural antioxidant solution for sensitive food products such as popcorn, beverages, spreads, and dressings.
Current application: Potato chips, foods processed at high temperature
Applicability: Beverages, specialty fats, Omega-3 fortified products
- The absence of unwanted molecules such as chlorophyll, carotenoids, and xanthophylls makes OxiKan CL superior to other natural antioxidants
- It is most suitable for applications that are sensitive to the aroma, flavor, Omega 3 fortified products, and beverages
- Free from irradiation, non-GMO, halal and kosher certified
- Although OxiKan Cl is free of allergens, it is not allowed for use in infant food at the moment
New beverage treatment methods
Pulsed electric field (PEF) is a popular nonthermal food preservation technology that works by delivering short (in the order of microseconds) high-voltage electric pulses to beverages flowing between the two electrodes of the treatment chamber. A strong electric field is required to destroy the cell walls of microbes, causing cell death.
Microchips allow the two electrodes to be very close together, so even low voltages can produce high electric field strength, making it less expensive to run than traditional PEF instruments.
Current application: Blueberry juice
Applicability: Fruit juice
- Visual, odor and taste characteristics of the final product did not significantly change
- No significant losses of nutritional content of final product because treatment is nonthermal
- Lower voltage is needed compared to traditional pulsed electric field technologies
- Further research is needed to show that a viable high flow microfluidic system suitable for industrial applications is possible
- Effect on other fruit juices, or other beverages in general, has not been investigated
- The efficacy on high viscosity fluids remains a highly likely limitation
#4. eBeam technology
eBeam technology is a type of ionizing radiation. An accelerator generates electrons with very high velocity and energy. These energetic electrons can penetrate food particles and cause numerous double-stranded breaks in the DNA, rendering microbial pathogens ineffective. The electrons can further split water molecules and generate short-lived free radicals, which add to the inactivation of the microorganisms.
Current application: Apple juice
Applicability: Fruit and vegetable juice
- eBeam technology eliminates the usage of methyl bromide for the sterilization of food products
- The commercial dose of eBeam applied to the food product is dependent on the target pathogens and is tunable, with no effect on the quality of the food product
- Mangoes treated with eBeam technology remain ripe for longer
- The technology is a cost-effective solution
- Commercial applications of the technology have been slow
- Some consumers are resistant to the idea of using irradiated food products
- Currently, the process is labor-intensive, and therefore, the next step would be to test automation in the handling of the food products
- Possible health concerns could emerge due to the use of dosages at off-limits
- A thorough risk-based assessment of the dosage needed to sterilize the food products is required
Ultrasound inactivates microorganisms in two ways: mechanically, through the generation of shear force that ruptures cell walls, and chemically, through the formation of free radicals that also attack cell membranes to cause cell death.
Combining ultrasound and thermal treatments (thermosonication) has proven to be an effective method for eliminating microorganisms. Researchers are looking into adding the antimicrobial peptide nisin to this method to see if it can prolong the shelf life of apple juice.
Current application: Apple juice
Applicability: Fruit and vegetable juice
- The combination of methods (thermal, sonication, and nisin) was effective on a broader range of microbes than any one method alone
- Treatment conditions were mild, and time required was relatively short (52°C, 30 min)
- Nutritional and visual values of the final product were not significantly altered
- This treatment has also been shown to work on products like carrot juice
- Thermosonication has been shown to be more effective for acidic beverages (apple juice), so this may not apply to all types of beverages
- The effect of this treatment on the taste of the product has not been studied
10 drinks with long shelf-life
Most alcoholic drinks have a long shelf life, and any spirit with more than 20% alcohol content has almost no expiration date.
- Vodka: Indefinite, but it will lose it taste after 10 years
- Whiskey/ Bourbon: Indefinite if unopened, 6 – 24 months opened
- Rum: Indefinite if unopened, starts to lose flavor when opened
- Cognac: Indefinite, but will lose flavor after 10 years
- Tequila: Indefinite if unopened
- Fine wine: 10–20 years if stored properly in a wine cellar
Non-alcoholic beverages have a much shorter shelf life, usually from 6 to 12 months if they meet the required storage conditions and only last for a few days if opened. Thus, some drinks have a longer shelf-life than others.
- Energy drink: 18 – 36 month if unopened
- Iced tea: 18 – 24 month if unopened
- Sparkling water: 12 – 18 month in unopened
- Coconut water: 9 – 12 month if unopened
It’s essential to understand the mode of product deterioration to establish the beverage shelf life. Product formulation, process conditions, and storage conditions are crucial factors for product shelf life. Careful consideration of experimental design and test parameters is vital for accurate shelf-life evaluation.
The shelf life of commercial beverages should be monitored and adjusted as required. Following these considerations will help ensure a safe, quality food product that meets customers’ expectations.