Whether sliced from a raw ingredient or cut from a sheeted dough, vegetable, fruit and high-protein chips need to some form of thermal processing to remove water and create a crisp texture. Thermal processing can address challenges these ingredients pose and improve production efficiencies and final product quality.
TNA’s vacuum frying technology uses low cooking temperatures to address some of the issues high sugar and starches bring to thermal processing. Chips made from parsnips, beets, carrots, apples, kiwifruit or mango — all of which are high in natural sugars and prone to acrylamide development and caramelization — can see a benefit from these low temperatures.
“Thanks to a much gentler process, the end product upholds the natural qualities of the raw material, including the nutritional value and color, without the need for additives or colorants,” said Arnaud Jansse, food technologist, TNA. “This is because the breaking down of important vitamins and minerals and natural coloring components is reduced. At the same time, the process gives enough control to prevent discoloring such as browning or caramelization.”
When frying meat chips, the challenge isn’t so much over-caramelization but chips frying and sticking together. Hold-down belts and multi-zone frying technology can address this, explained Doug Kozenski, sales manager, process prepared, Heat and Control.
“This prevents pieces from frying together and allows for bedding of the partially fried chips to create higher belt loadings and to minimize fryer lengths,” he said.
On the baked side, Ken Zvoncheck, director of process technology, Reading Bakery Systems, recommended convection ovens for baked chips. While direct-gas-fired ovens may work well for crackers, baked chips’ thinness and ability to retain water have required convection to draw that water out evenly and without burning the product.
“Convection is the most efficient way to pull moisture out of the product,” he said. “It’s like putting your clothes out to dry on a windy day versus a still day. When it’s windy, the clothes dry much faster. We’re able to control the velocity of the air in the convection ovens independently on the top and bottom in order to control color and bake. Generally, the greater the air speed, the faster that moisture is going to be pulled out of the product.”
Because the chips are so thin, the bake is relatively fast with many products being baked under one minute, so this efficiency is necessary.
Dryers provide an additional step for baked chips and the main thermal processing for meat-based chips. In the case of baked chips, dryers can help snack producers remove the last bit of excess moisture without burning the products.
“Trying to use conventional ovens by increasing bake times merely for additional drying impacts throughput and affects quality, typically over-browning, both of which can be resolved using radio frequency drying technology,” said Lisa Mitchell, marketing manager, Radio Frequency Co., Inc.
Triple-pass dryers can help with thin products like vegetable chips.
“These chips want to shingle on top of each other, so you can’t just put them in a single-pass dryer and expect that moisture to come out evenly,” Mr. Zvoncheck said.
A triple-pass dryer will tumble the chips multiple times from one belt to another, achieving even drying and color.
For meat chips, dryers provide the main source of thermal processing. Typically, this can be a lengthy process to achieve the very low-moisture levels these products require.
“To attain this level, a significant amount of time is necessary to drive moisture from the product,” Mr. Kozenski said. “The time varies depending on the raw product’s specific characteristics.”
Heat and Control developed a continuous roaster/dryer system to replace the static rack ovens traditionally used for this process. With a continuous system, meat chip producers can reduce their labor and improve product consistencies and produce these chips in bulk more efficiently. Product can be loaded into the system and discharged in a continuous stream. Heated air circulates and dries the meat chips as they tumble through the system.
Armed with innovative technologies and control throughout the process, snack producers can take on these innovative bases.