Sensory analysis used to develop a new process for mashed potatoes

Market demand for a high quality frozen mashed potato product has grown exponentially with the rapid growth of “ready to eat meals”.

Current industrial practice for the production of mashed potatoes involves energy intensive steps using water as the heat transfer medium to pre-cook and initiate starch gelatinization, a cooling step to retrograde the starch and a final cook followed by mashing.

To reduce production costs while maintaining or enhancing product quality, ABCO studied the best way to achieve this result using an adiabatic process.  In this process a minimal amount of steam is applied to the surface of the product and cooking continues as the product is held.  Using their extensive knowledge of existing Heat/Hold blanching technology, ABCO adapted this to process potatoes for the production of mashed potato.  The process is controlled by altering the Heat/Hold ratios, the number of Heat/Hold cycles and the total cook time.

ABCO worked in conjunction with Agri-Food Canada to compare the effect of heat transfer mediums (hot water v steam) on the sensory quality of mashed potatoes, resulting in the development of an energy efficient process to replace the conventional energy intensive three step process used in the production of fresh and frozen mashed potatoes. 
Approved results
A trained sensory panel was used to compare the results, which was supported by positive consumer trials.

The sensory analysis revealed that high quality mashed potatoes can be produced using an energy efficient, single step adiabatic process.  The steam processed mashed potatoes were significantly more uniform, brighter and lighter in colour than the water processed samples and the heat transfer medium had no significant effect on the final product adhesiveness or cohesiveness.  The steam processed product was perceived as significantly stronger in potato flavour and less bitter and stale.

The consumers preferred the steam processed samples over the water processed samples for flavour and texture.  Nearly all consumers commented that the appearance of the water process sample was greyer, blander and had gluey, gummy or pasty texture.

In traditional water and steam blanchers the product is held in the heating medium until the desired centre temperature of the product is achieved. The development of the steam Heat/Hold process allows for the surface of the product to be heated by steam and the heat to penetrate the product during the hold time. The study showed the feasibility of using an energy efficient potato processing system that produces a high quality product.  Further testing was conducted to determine the optimum number of Heat/Hold cycles, the optimal Heat/Hold ration and optimal cook time.  The sensory analysis guided the selection of the best processing conditions.

A range of experience in the Ready Meal Industry

Apart from offering an energy efficient process for production of quality mash potato, ABCO also offer a unique tray Blancher-Cooker-Cooler for the Ready Meal Industry in which many products can be prepared on the same day without cross contamination.  The ABCO unit uses pre-selected combinations of steam, hot water and chilled water to maximize the quality of each individual product.  Colour, texture and flavour retention is vastly improved which is critical to consumer acceptance in this quality sensitive market.

The machine is fully PLC controlled to facilitate quick and easy changeover in product processing and single or double lane machines are available to convey product through the machine in stainless steel trays.  Water immersion/steam, blanching with air/water refrigerated cooling options are also available


Further information covering the ABCO range of food processing equipment is available on request from the Walsall Engineering Group with comprehensive details on the ABCO website  www.abco.ca