Use new system to analyze dairy product properties.

Scientists at Food Science Australia and Newport Scientific have jointly developed a miniature processing system for dairy products. Research led to the development of an instrument that is helping dairy food manufacturers reduce the costly problems caused by fluctuations in the consistency of milk supply.

The rapid visco analyzer (RVA) is commercially available through Newport Scientific (http://www.newport.com.au). It is already widely used to evaluate the reheat and formulated properties of starches in a wide range of grains. At Food Science Australia, researchers have projects in progress aimed at developing and testing the usefulness of the RVA for the process simulation of dairy products or other fermented and baked foods whose processing involves controlled heating, cooling and mixing steps. Development and testing of process simulations for new products can be undertaken at Food Science Australia, by arrangement with food companies.

Product quality control is a particular challenge for the Australian dairy industry because farming practices cause variation in milk composition over the season. This also may be the case elsewhere. These variations can adversely affect the properties and quality of consumer dairy products, such as yogurt, cream cheese and ice cream.

Researchers can program the RVA to replicate the processing conditions of dairy products. Each processing step can be controlled, and the viscosity of the product measured throughout the processing cycle, allowing manufacturers to make corrections to the process or composition of the mixture. This allows companies systematically to investigate a real food system, with the added advantage that this investigation can now be done on a much more economical and convenient scale.

In its operation as a miniature process simulator or batch reactor, the RVA is fully programmable with respect to heating, cooling and mixing. It provides progressive monitoring of the temperature, paddle rotation rate and viscosity of samples. With this capability, it can be used to simulate many food-manufacturing processes, particularly for dairy products such as recombined products, yogurt, cream cheese and ice cream. As such, the RVA is a very useful tool for product development and can be used to troubleshoot batch-wise variability in product quality caused by a variation in ingredients or processing conditions.

The RVA is also useful for efficiently modeling the effects of ingredients, substitute ingredients and processing conditions to improve cost efficiency of the product manufacturing process. There are many ways in which the RVA can be used as a tool to circumvent large-scale processing mistakes and associated waste. In the low-profit-margin food industry, this approach to quality control can translate into significant cost savings.

The RVA can make 10 g to 20 g of products and process multiple batches a day, whereas larger-sized pilot processing plants can only produce one or two batches per day and may require thousands of liters per batch. The size of the RVA will allow dairy product manufacturers to use the instrument within the processing facility to do regular checks on the properties of their product and make adjustments to the full-scale process if necessary.

Food Science Australia researchers are interested in demonstrating the usefulness of the RVA for simulating food processes. Newport Scientific is also interested in expanding the operating specs of the instrument with respect to temperature, pressure and mixing dynamics in order to increase its adaptability. The system is able to simulate processing of a wide range of medium- to high-moisture foods, including baked and fermented products.

Further information. Louise Bennett, Process and Supply Chain Innovation, Food Science Australia, Graham Road, P.O. Box 20, Highett, Victoria 3190, Australia; phone: [phone]; fax: [phone]; email: [e-mail].