Why Tunnel Pasteurize new and emerging beverages?
Food Safety in beer was once focused on undesired foreign materials and debris found in individual beverages cans and bottles. While still important, Food Safety in beverages today is mostly microbiological because breweries have moved far beyond producing only traditional beers.
We all know of examples of production and beverage sales environments where products are made, sold very quickly and in a tight geography…premises such as brewpubs and local neighborhood breweries which can offer a promise of freshness and competent storage of product between production and sale/consumption. But for any volume, sales must extend further, and quality must be assured for longer timeframes and across varying real-world conditions.
Approximately 70% of beer spoilage cases result from contamination by lactic-acid bacteria, which produce flavors considered to be undesirable in most beer styles. The remaining spoilage cases are caused by a range of wild yeasts, as well as aerobic and anaerobic bacteria, that are present in the brewery environment and can carry-over to the beer if rigorous hygiene is not maintained.
Harmful pathogens are not able to grow in beer due to several microbiological ‘hurdles’ such as alcohol, low pH, low nutrient content and the presence of growth inhibitors such as isomerized hop acids.
In continued evolution within breweries and beverage plants of all sizes, beverages are coming from breweries these days that would not have been twenty years ago. We see the emergence and growth in popularity of novel alcoholic beverages that may contain added sugar, flavorings and colorings. We see alcoholic beverages based on extremely low malt- inclusion rates, the product being fermented ‘sugar brews’. Breweries today produce beers mixed with fruit juices, and natural sodas, and low alcohol, sweetened beverages appealing to non-traditional beer drinkers. We’re also seeing novel cannabis-isolate containing hybrid beverages, These new drinks offer fewer naturally-inherent microbiological hurdles for spoilage organisms.
Due to novel ingredients previously not involved in production, beverages need to address concerns over germination of spores, and the growth of pathogens and other spoilers not routinely encountered in the brewing industry. The pasteurization parameters to destroy the vegetative cells and spores of Bacillus spp. are higher than what is normally accepted as adequate for milk pasteurizing…. 170 deg F at ten minutes hold.
The most common spoilage organism of tomato juice, B. coagulens produces lactic acid in package if not destroyed. In pineapple nectar, Byssochlamys nivea is a thermal resistant filamentous fungi (mould) with mycotoxin-producing potential that needs high sterilizing temperatures equivalent to tomato juice. Not every alternative product requires as aggressive a pasteurizing regime, of course. There are some new products, such as cold-brew coffees, that actually should go through much higher retort temperatures because the individual coffee beans, when dropped on the ground can make contact with botulism. Basic beer pasteurization does help cold-brew coffees and other novel beverages in an essential way:
Coffee with residual sugar is prone to refermentation or spoilage and can easily become a problem. Canned and fermenting coffee creates alcohol and carbon dioxide. That CO2 will continue to build and the can will explode or, in the case of a bottle, the cap/crown might pop off.
As a matter of fact, any beverage that is sweet or semi-sweet, has residual sugar…which is prone to refermentation in the closed package. The challenge for a retort temperature approach is readily seen in low acid products like banana and kiwi puree. Often, to inactivate spores and natural enzymes, a temperature much be reached that changes the color of the product being pasteurized. For example, a standard retort thermal treatment of these purees is at 130-135°C (266-275 F); due to this temperature the puree color changes to pink for banana and to brown for kiwi at 90-95°C (194-203 F).
The only potential alternative to applying a retort regime is heavy pasteurization, storage and shipping of finished goods at refrigerated temperatures, and possible use of the common preservatives used by soft drinks manufacturers: potassium sorbate and sodium benzoate, in the event that the beverage is alcohol-free and non-acidic in nature. However, using preservatives is contrary to the “Clean-label” movement that seeks to eliminate preservatives, artificial flavors and coloring in food and beverage products.
At one point in American brewing history, many breweries were making malt-based coolers, sometimes referred to as alcopops and later as FMBs. Some of the beverages used a natural dairy-based clouding agent (“Cloud”) or non-dairy based to make milky Pina Colada flavored drinks. The palette of available natural clouding agents today is much broader.
Non-alcoholic plant-based beverages might be made up of about 90% water, sugar, flavoring …but plants parts have constituted the main raw materials in these beverages…and source of microbiological concern. Soybeans are used for the production of soymilk, rhizome of ginger plants for ginger beer, sorghum or other grains, sweet potato extracts, water extracts of flowers (such as roses or hibiscus) and leaves (especially tea leaves). Soymilk contains 26.25% protein, 22.24% oil, 21.55% total solids, 4.55% Ash, 24.4% carbohydrate .
Ginger powder has 5.21% ether extract, 61.21% carbohydrate, 8.89% protein. 8.47% ash and 1.70% crude fiber. Common microbial challenges for soymilk would be Pseudomonas spp., and for ginger beer, Lactobacillius, Leuconostoc, Bacillus, Staphylococcus, Candida and Saccharomyces. These species can be addressed in a tunnel pasteurizer.
So what other kinds of beverages benefit from tunnel pasteurization? Novel beverages including natural and botanical soft drinks, flavored malt beverages, novel alcoholic beverages which may or may not be carbonated, fruit-inclusive drinks, alcoholic spritzers based on neutral alcoholic bases brewed in breweries, canned cocktails, innovative hybrid beverages.
The process of pasteurization guarantees stability of the packaged product without refrigeration. In a PRO Engineering design, it is carried out in extensively proven-design pasteurization tunnels with various heating, retention, and cooling zones, in which heat transfer occurs through a water film formed by aspersion on the package. The process is dimensioned in “Pasteurization Units” (PU), in which 1 PU is equivalent to 1 minute at 60 ºC,
Raising the pasteurization temperature to 68 ºC will yield 14 PU if held for 1 minute, and a temperature of 77 ºC and holding 1 minute realizes 268 PU. By changing the hot water spray setpoints and dwell time within the pasteurizer zones, a PRO Engineering pasteurizer can be designed, built and tuned to deliver 5 to 2500 PUs, depending on what the product in the individual package would require. PRO offers a batch-pasteurizer small footprint system for startups and exploratory projects, and all scales of continuous flow-through tunnel pasteurizers that can accommodate different packaged product volumes and packages (bottles or cans). Instrumentation such as a traveling tunnel PU monitor can be run through the pasteurizer to document adherence to target pasteurization parameters.
In the brave new world of alternative adult beverages, with alcohol or without, a batch- or tunnel- pasteurizer engineered for purpose by PRO and sized so as to meet line speed requirements for throughput represents how quality is robustly assured once the products leave the production facility.
Authored by Jaime Jurado
(Master Brewers Association of the Americas)
Sponsored by Ed Michalski, CEO PRO Engineering and Manufacturing, Inc
PRO and Manufacturing, Inc has been providing equipment and engineering services to the beverage industry for 42 years. Contact Ed Michalski, CEO at: (414) 362-1500, [email protected]
PRO Engineering and Manufacturing was established in 1977 by Ed and Dave Michalski as a steel fabrication shop. For more than 40 years, PRO Engineering and Manufacturing, Inc. has been delivering solutions for beverage product shelf stability and consumption safety. As leading innovators in post-fill pasteurization, our skilled team offers the best in high-quality pasteurization equipment.
Phone: 414-362-1500 | Email: [email protected]