30E-21 |
Evaluation of numerical algorithms for the instrumental measurement of bowl-life and changes in texture over time for RTE breakfast cereals |
C. M. GREGSON and T. C. Lee. Dept. of Food Science, CAFT & NJ-NSCORT, Rutgers University, 65 Dudley Road, New Brunswick, NJ 08901 Bowl-life is a sensory quality parameter used widely in the breakfast cereal industry to determine the length of time a product retains its crispness whilst immersed in milk. Instrumental texture measurements have a number of advantages over sensory techniques, including repeatability, objectivity and low cost. Over the past decade, a variety of numerical methods have been developed to determine the textural properties of crispy foods. The objective of this study was to evaluate a range of numerical techniques for the determination of bowl-life and changes in texture as a function of time in the bowl. A TA.XT2 texture analyser (Stable Micro Systems, UK) was fitted with an Ottawa Cell and blank watertight base plate. 30g of cornflakes were placed into the cell and immersed in milk. At a known time interval the milk was rapidly drained from the cell and compressed by a plunger at 5mm/s. Force, distance and time data were measured at an acquisition rate of 400 points per second. The data were analyzed using a variety of numerical techniques, including fractal analysis (Richardson plot), Fast Fourier Transform and linear distance. The results were plotted as a function of time. To complement these results, bowl-life was determined using a 15 member untrained sensory panel. The results show that linear distance was able to follow the change in texture and reduced linearly with the natural log of time (crispness=125*ln(t) + 893, R©÷=0.993, 3 s.f.). By comparing this data to sensory bowl-life assessment, a critical linear distance was found which could be used to determine bowl-life. This study has resulted in an instrumental method of measuring bowl-life, which is simple to use and has the additional advantage of being able to follow texture change as a function of time. As such, this method may be a valuable asset to the breakfast cereals industry.
Session 30E, Food Engineering: Rheology and texture
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