The Food Manufacturing Brainstorm features industry
experts sharing their perspectives on issues critical to the
overall food industry marketplace. In this issue, we ask:
Which innovations in thermal food processing should manufacturers
be aware of and how can they benefit operations and product quality?
Ramesh Gunawardena, Manager of Technology & Process Development, JBT FoodTech
As we all know, different cooking processes are used to achieve different cooking results and, often
times, food products must be exposed to more than one cooking process to achieve the desired sensory attributes. In this regard, studies have shown that a condensation cooking zone that uses high humidity provides the most efficient heat transfer process to deliver energy to the surface of the food items.
However, there are two inherent limitations to cooking with high humidity. First, high humidity suppress-es color development. Secondly, the condensation heat transfer remains in effect only when the surface
temperature of the food items is below the dew point temperature of the surrounding environment.
Further, conditioning the oven atmosphere for any given application depends on the food item (
substrate) and the quality as defined by the processor. Here it must be understood that different species
behave differently when exposed to a given processing condition due to the meat structure, ingredients,
formulations and fat-to-lean content. Therefore, it is important for the processor to maintain the right
operating conditions and to use the proper technology for each product and process if the processor
wants to optimize for product quality and yield for greater profitability.
Key innovations that take advantage of the foregoing approach to processing food items combine
vertical annular airflow with dynamic airflow control (DAC). DAC means reversing the directionality of
this predominantly vertical airflow as the product is being carried on a variable-weave self-stacking belt
traversing upward on a helical path. Reversing the airflow in this way provides for an even top/bottom
surface color development, but more importantly extends the condensation zone to produce higher
product yields relative to conventional horizontal flow spiral ovens. Finally, this provides the most consistent product quality across the belt-width for lowest standard deviations of product temperatures at the
oven discharge, again extending the yield advantage. ◆
Errol Raghubeer, Ph.D., Vice-President, Microbiology & Food
Technology, Avure Technologies, Inc.
Consumers are demanding minimally processed foods with high nutritional value without preservatives. Thermal processing is widely used for the preservation of food and beverages but can
affect the organoleptic and nutritional properties of foods. High Pressure Pasteurization (HPP) is a
non-thermal process that is one of the fastest growing food technologies.
In HPP, packaged foods are subjected to pressures up to 6,000 bars (87,000 psi) in a vessel
containing water. These pressures inactivate pathogenic and spoilage microorganisms in foods
without affecting the nutrients, flavor and taste of the foods. The pressure is distributed evenly on
all sides of the package, allowing different sizes of products to see the same pressure at the same
time, unlike thermal treatment where there is a temperature differential based on product size and
differences in packages.
HPP is especially desirable for foods that are sensitive to heat such as guacamole, fresh juices
and high nutritional beverages, wet salads, sliced deli meats and several other food categories.
These products contain no chemical preservatives, meet food safety standards, and have an
extension of quality and shelf-life. Published results on sensorial analyses and consumer panels
have confirmed similarities of flavor and taste of HPP products to fresh. ◆